JP7363379B2 - Control device and rotating electrical machine system - Google Patents

Description

The disclosure in this specification relates to a control device and a rotating electric machine system.

Patent Document 1 discloses a control device for a rotating electric machine. This control device detects the current flowing through the stator winding and compares it with an overcurrent threshold to suppress demagnetization of the permanent magnets included in the rotating electrical machine.

Japanese Patent Application Publication No. 2012-130087

In the configuration of the prior art, if the overcurrent threshold value is not set with a large margin, for example, there is a risk that demagnetization will occur. There is a problem that the usable current range is narrow.

One object of the disclosure is to provide a control device and a rotating electric machine system that can widen the range of current used while suppressing the occurrence of demagnetization.

One aspect disclosed here is
A rotating electric machine comprising a rotor (40) having a permanent magnet (42), and a stator (50) having a slotless structure having a stator winding (51) and having no slots formed by magnetic teeth. (10) A control device that controls
a temperature estimation unit (S8, S10, S11, S12, S20, S20A, S20B, S20C, S80) that acquires temperature information including at least the temperature of the stator winding and estimates the temperature of the permanent magnet based on the temperature information; ,
The overcurrent threshold for the current flowing through the stator winding is set according to the estimated temperature of the permanent magnet, the current flowing through the stator winding is acquired, and the current flowing through the stator winding is set based on the set overcurrent threshold. an overcurrent determination unit (S30, S40, S50) that determines whether or not there is an overcurrent;
A control unit (S51, S52, S53, S54, S60, S70) that controls the rotating electric machine based on the determination result of the overcurrent determination unit,
The temperature estimator stores the estimated temperature of the permanent magnet used for overcurrent determination as a previous value, and estimates the temperature of the permanent magnet based on the obtained stator winding temperature and the previous value.
The temperature estimation unit acquires, as temperature information, at least one of the temperature of the elements (66) constituting the inverter (100) and the temperature of the cooling water that cools the inverter, and calculates the temperature of the elements and the temperature of the cooling water. , Estimate the temperature of the permanent magnet based on the obtained stator winding temperature and the previous value,
Rotating electric machines are applied to moving objects,
Further comprising a startup determination unit (S9) that determines whether a startup switch of the mobile body has been switched from off to on,
When the starting switch is switched from off to on, the temperature estimating unit obtains the stop time from when the starting switch is turned off until it is turned on, and if the stopping time is shorter than a predetermined time, the temperature estimator obtains the stop time based on the previous value. The temperature of the permanent magnet is set, and when the stop time is longer than a predetermined time, the temperature of the permanent magnet is estimated based on the obtained stator winding temperature without using the previous value.
Another aspect disclosed herein is
A rotating electric machine comprising a rotor (40) having a permanent magnet (42), and a stator (50) having a slotless structure having a stator winding (51) and having no slots formed by magnetic teeth. (10) A control device that controls
a temperature estimation unit (S8, S10, S11, S12, S20, S20A, S20B, S20C, S80) that acquires temperature information including at least the temperature of the stator winding and estimates the temperature of the permanent magnet based on the temperature information; ,
The overcurrent threshold for the current flowing through the stator winding is set according to the estimated temperature of the permanent magnet, the current flowing through the stator winding is acquired, and the current flowing through the stator winding is set based on the set overcurrent threshold. an overcurrent determination unit (S30, S40, S50) that determines whether or not there is an overcurrent;
A control unit (S51, S52, S53, S54, S60, S70) that controls the rotating electric machine based on the determination result of the overcurrent determination unit,
When it is determined that an overcurrent is flowing, the control unit is configured to turn the stator winding so that the number of turns of the stator winding is larger than the first number of turns that is set when it is determined that no overcurrent is flowing. The number of turns of the stator winding is controlled so that the
When it is determined that no overcurrent is flowing, the control unit sets the number of turns of the stator winding to the first turn number when the torque command value for the rotating electrical machine is below the threshold value, and the torque command value is higher than the threshold value. Then, the number of turns of the stator winding is controlled so that the number of turns of the stator winding is greater than the first number of turns.

Another aspect disclosed herein is a rotating electric machine system, comprising:
A stator with a slotless structure that has a rotor (40) that has a permanent magnet (42) and is rotatably supported, and a stator winding (51), and has no slots formed by magnetic teeth ( 50); a rotating electric machine (10) comprising;
an inverter (100) that has switches (Sp, Sn) and switches energization and disconnection to the stator windings by turning on and off the switches;
a winding temperature sensor (151) that detects the temperature of the stator winding;
a current sensor (152) that detects the current flowing in the stator winding;
A control device (110) that controls driving of the switch,
The control device is
a temperature estimation unit (S8, S10, S11, S12, S20, S20A, S20B, S20C, S80) that acquires temperature information including at least the temperature of the stator winding and estimates the temperature of the permanent magnet based on the temperature information; ,
The overcurrent threshold for the current flowing through the stator winding is set according to the estimated temperature of the permanent magnet, the current flowing through the stator winding is acquired, and the current flowing through the stator winding is set based on the set overcurrent threshold. an overcurrent determination unit (S30, S40, S50) that determines whether or not there is an overcurrent;
A control unit (S51, S52, S53, S54, S60, S70) that controls the rotating electric machine based on the determination result of the overcurrent determination unit,
An inverter is composed of multiple elements,
It further includes a plurality of element temperature sensors (153) that individually detect the temperature of the elements.
the plurality of elements are arranged along the stator;
The temperature estimation unit estimates the temperature of the permanent magnet based on the temperature of the stator winding and the temperature of the plurality of elements.

According to the present disclosure , since the stator has a slotless structure, the temperature of the permanent magnet can be estimated with high accuracy based on temperature information including the temperature of the stator winding. Then, the overcurrent threshold can be set according to the estimated temperature of the permanent magnet. The overcurrent threshold can be made to correspond to a demagnetization limit that changes depending on the temperature of the permanent magnet. Since it is not necessary to provide an excessive margin, the usable current range can be widened while suppressing demagnetization.

The multiple aspects disclosed in this specification employ different technical means to achieve their respective objectives. The claims and the reference numerals in parentheses described in this section exemplarily indicate correspondence with parts of the embodiment described later, and are not intended to limit the technical scope. The objects, features, and advantages disclosed in this specification will become more apparent by reference to the subsequent detailed description and accompanying drawings.

FIG. A vertical cross-sectional view of a rotating electric machine. A sectional view taken along the line III-III in FIG. 2. FIG. 4 is an enlarged cross-sectional view of a part of FIG. 3; An exploded view of a rotating electric machine. Exploded view of the inverter unit. FIG. 3 is a torque diagram showing the relationship between ampere turns and torque density of a stator winding. FIG. 3 is a cross-sectional view of a rotor and a stator. FIG. 9 is an enlarged view of a part of FIG. 8; A cross-sectional view of the stator. A vertical cross-sectional view of the stator. A perspective view of a stator winding. FIG. 3 is a perspective view showing the configuration of a conducting wire. FIG. 2 is a schematic diagram showing the configuration of a wire. The figure which shows the form of each conducting wire in the nth layer. FIG. 3 is a side view showing conductive wires in the n-th layer and the n+1-th layer. FIG. 3 is a diagram showing the relationship between electrical angle and magnetic flux density for the magnet of the embodiment. FIG. 7 is a diagram showing the relationship between electrical angle and magnetic flux density for a comparative example magnet. Electrical circuit diagram of a control system for a rotating electric machine. FIG. 3 is a functional block diagram showing current feedback control processing by the control device. FIG. 3 is a functional block diagram showing torque feedback control processing by the control device. FIG. 7 is a cross-sectional view of a rotor and a stator in another example. FIG. 23 is an enlarged view of a part of FIG. 22. FIG. 3 is a diagram specifically showing the flow of magnetic flux in a magnet section. FIG. 7 is a sectional view of a stator in another example. FIG. 7 is a sectional view of a stator in another example. FIG. 7 is a sectional view of a stator in another example. FIG. 7 is a sectional view of a stator in another example. The side view which shows each conductor of an nth layer and an (n+1) layer in another example. FIG. 7 is a sectional view of a stator in another example. FIG. 1 is a diagram showing a rotating electrical machine system and a control device according to a first embodiment. 5 is a flowchart showing processing executed by the control device. The figure which shows the gap between a stator winding and a magnet part. FIG. 3 is a diagram showing the relationship between ampere turns and magnetic flux of a stator winding. FIG. 7 is a diagram showing the arrangement of winding temperature sensors in a rotating electric machine system according to a second embodiment. The figure which shows arrangement|positioning of the winding temperature sensor in another example. FIG. 7 is a diagram showing the arrangement of winding temperature sensors in a rotating electric machine system according to a third embodiment. FIG. 7 is a diagram showing a rotating electric machine system and a control device according to a fourth embodiment. FIG. 3 is a diagram showing the arrangement of a semiconductor module and an element temperature sensor. 5 is a flowchart showing processing executed by the control device. FIG. 7 is a diagram showing a rotating electrical machine system and a control device according to a fifth embodiment. 5 is a flowchart showing processing executed by the control device. The figure which shows the setting of the current value of estimated magnet temperature. FIG. 3 is a diagram showing changes over time in winding temperature and estimated magnet temperature. FIG. 7 is a diagram showing a winding structure of a rotating electrical machine in a rotating electrical machine system according to a sixth embodiment. The figure which shows the structure of a stator winding. 5 is a flowchart showing processing executed by the control device. Diagram showing series connection. Diagram showing parallel connections.

A plurality of embodiments will be described with reference to the drawings. In embodiments, functionally and/or structurally corresponding and/or related parts may be labeled with the same reference numerals. Descriptions of other embodiments can be referred to for corresponding and/or related parts.

(First embodiment)
The rotating electrical machine of this embodiment can be applied to a drive source for a moving body. The moving object is, for example, a vehicle such as an electric vehicle (EV), a hybrid vehicle (HV), or a fuel cell vehicle (FCV), a flying object such as a drone, a ship, a construction machine, or an agricultural machine. In this way, the rotating electric machine is used, for example, as a vehicle power source, that is, as a traveling drive source. In addition to mobile objects, rotating electric machines can be widely used for industrial purposes, household appliances, OA equipment, game machines, and the like. First, the basic configuration of the rotating electric machine will be explained.

<Basic configuration of rotating electrical machine>
FIG. 1 is a vertical cross-sectional perspective view of a rotating electrical machine 10. FIG. FIG. 2 is a longitudinal cross-sectional view of the rotating electrical machine 10 in a direction along the rotating shaft 11. As shown in FIG. FIG. 3 is a cross-sectional view of the rotating electric machine 10 in a direction perpendicular to the rotating shaft 11 (a cross-sectional view taken along the line III--III in FIG. 2). FIG. 4 is a cross-sectional view showing a part of FIG. 3 in an enlarged manner. FIG. 5 is an exploded view of the rotating electric machine 10. In FIG. 3, hatching indicating the cut plane is omitted except for the rotating shaft 11 for convenience of illustration. In the following description, the direction in which the rotating shaft 11 extends is referred to as the axial direction, the direction extending radially from the center of the rotating shaft 11 as the radial direction, and the direction extending circumferentially around the rotating shaft 11 as the circumferential direction.

The rotating electric machine 10 of this embodiment is a synchronous multiphase AC motor, and has an outer rotor structure, that is, an external rotation structure. The rotating electric machine 10 is roughly divided into a bearing section 20, a housing 30, a rotor 40, a stator 50, and an inverter unit 60. Each of these members is arranged coaxially with the rotating shaft 11, and is assembled in the axial direction in a predetermined order to configure the rotating electrical machine 10.

The bearing section 20 includes two bearings 21 and 22 that are spaced apart from each other in the axial direction, and a holding member 23 that holds the bearings 21 and 22. The bearings 21 and 22 are, for example, radial ball bearings, and each has an outer ring 25, an inner ring 26, and a plurality of balls 27 arranged between the outer ring 25 and the inner ring 26. The holding member 23 has a cylindrical shape, and bearings 21 and 22 are assembled inside the holding member 23 in the radial direction. The rotating shaft 11 and the rotor 40 are rotatably supported inside the bearings 21 and 22 in the radial direction.

The housing 30 has a cylindrical peripheral wall portion 31 and an end surface portion 32 provided at one of both ends of the peripheral wall portion 31 in the axial direction. Of both ends of the peripheral wall portion 31, the side opposite to the end surface portion 32 is an opening portion 33, and the housing 30 has a configuration in which the opposite side of the end surface portion 32 is completely opened by the opening portion 33. A circular hole 34 is formed in the center of the end face portion 32, and the bearing portion 20 is inserted into the hole 34 and fixed with a fixing device such as a screw or a rivet.

A rotor 40 and a stator 50 are housed within the housing 30, that is, an internal space defined by the peripheral wall portion 31 and the end surface portion 32. In this embodiment, the rotating electric machine 10 is of an outer rotor type, and a stator 50 is disposed inside the housing 30 in the radial direction of a rotor 40 having a cylindrical shape. The rotor 40 is cantilevered by the rotating shaft 11 on the end face portion 32 side in the axial direction.

The rotor 40 has a rotor body 41 formed in a hollow cylindrical shape and an annular magnet portion 42 provided inside the rotor body 41 in the radial direction. The rotor main body 41 has a substantially cup shape and functions as a magnet holding member. The rotor main body 41 includes a cylindrical magnet holding part 43, a fixed part 44 which is also cylindrical and has a smaller diameter than the magnet holding part 43, and an intermediate part that connects the magnet holding part 43 and the fixed part 44. It has a section 45. The magnet portion 42 is attached to the inner circumferential surface of the magnet holding portion 43 .

The rotating shaft 11 is inserted into the through hole 44a of the fixed part 44, and the fixed part 44 is fixed to the rotating shaft 11 in the inserted state. That is, the rotor main body 41 is fixed to the rotating shaft 11 by the fixing portion 44 . Note that the fixing portion 44 is preferably fixed to the rotating shaft 11 by spline coupling using unevenness, key coupling, welding, caulking, or the like. Thereby, the rotor 40 rotates together with the rotating shaft 11. The axis of rotation of the rotor 40 coincides with the axis of the rotating shaft 11.

The bearings 21 and 22 of the bearing portion 20 are assembled on the radially outer side of the fixed portion 44 . As described above, since the bearing portion 20 is fixed to the end surface portion 32 of the housing 30, the rotating shaft 11 and the rotor 40 are rotatably supported by the housing 30. Thereby, the rotor 40 is rotatable within the housing 30.

The rotor 40 is provided with a fixing portion 44 only on one side of both sides in the axial direction, so that the rotor 40 is supported on the rotating shaft 11 in a cantilevered manner. Here, the fixed part 44 of the rotor 40 is rotatably supported by the bearings 21 and 22 of the bearing part 20 at two different positions in the axial direction. That is, the rotor 40 is rotatably supported by two bearings 21 and 22 in the axial direction on one side of both axial ends of the rotor main body 41. Therefore, even if the rotor 40 is cantilever-supported by the rotating shaft 11, stable rotation of the rotor 40 is realized. In this case, the rotor 40 is supported by the bearings 21 and 22 at a position shifted to one side with respect to the axial center position of the rotor 40.

In addition, in the bearing section 20, the bearing 22 near the center of the rotor 40 (lower side in the figure) and the bearing 21 on the opposite side (upper side in the figure) have a gap between the outer ring 25, the inner ring 26, and the balls 27. The dimensions are different. For example, the bearing 22 has a larger gap size than the bearing 21. In this case, even if vibrations due to runout of the rotor 40 or imbalance due to component tolerances act on the bearing section 20 on the side near the center of the rotor 40, the effects of the runout and vibrations are well absorbed. Ru.

Specifically, by enlarging the play size (gap size) in the bearing 22 by preloading, vibrations generated in the cantilevered structure are absorbed by the play portion. The preload may be a fixed position preload, or may be applied by inserting a preload spring, a wave washer, etc. into a step on the axially outer side (upper side in the figure) of the bearing 22.

The intermediate portion 45 is configured to have an axial step between the radial center side and the outer side thereof. In the intermediate portion 45, the radially inner end and the outer end are located at different positions in the axial direction, so that the magnet holding portion 43 and the fixed portion 44 partially overlap in the axial direction. . In other words, the magnet holding portion 43 protrudes axially outward from the base end portion (the lower back end portion in the figure) of the fixing portion 44 . In this configuration, compared to the case where the intermediate portion 45 is provided in a flat plate shape without a step, it is possible to support the rotor 40 with respect to the rotating shaft 11 at a position near the center of gravity of the rotor 40, and the rotor 40 stable operation can be achieved.

Due to the configuration of the intermediate portion 45 described above, the rotor 40 has an annular bearing housing recess 46 that surrounds the fixed portion 44 in the radial direction and accommodates a portion of the bearing portion 20 at a position inward of the intermediate portion 45. is formed. Further, a coil accommodating recess 47 is formed to surround the bearing accommodating recess 46 in the radial direction and to accommodate a coil end portion 54 of a stator winding 51 of a stator 50, which will be described later. There is. The accommodation recesses 46 and 47 are arranged adjacent to each other inside and outside in the radial direction. That is, a portion of the bearing portion 20 and the coil end portion 54 of the stator winding 51 are arranged so as to overlap inside and outside in the radial direction. Thereby, the length dimension in the axial direction of the rotating electric machine 10 can be shortened.

By bending the coil end portion 54 inward or outward in the radial direction, the axial dimension of the coil end portion 54 can be reduced, and the stator axial length can be shortened. The direction in which the coil end portion 54 is bent is preferably determined in consideration of assembly with the rotor 40. Assuming that the stator 50 is assembled inside the rotor 40 in the radial direction, the coil end portion 54 may be bent radially inward on the insertion tip side with respect to the rotor 40. The bending direction on the opposite side may be arbitrary, but the outer diameter side with ample space is preferable in terms of manufacturing.

The magnet portion 42 includes a plurality of magnets arranged radially inside the magnet holding portion 43 so that magnetic poles alternate along the circumferential direction. Details of the magnet portion 42 will be described later.

The stator 50 is provided inside the rotor 40 in the radial direction. The stator 50 includes a stator winding 51 wound into a substantially cylindrical shape and a stator core 52 disposed radially inside the stator winding 51 . The stator winding 51 is arranged to face the annular magnet part 42 with a predetermined air gap in between. The stator winding 51 consists of a plurality of phase windings. Each phase winding is configured by a plurality of conductive wires arranged in the circumferential direction and connected to each other at a predetermined pitch. In this embodiment, three-phase windings of U-phase, V-phase, and W-phase and three-phase windings of X-phase, Y-phase, and Z-phase are used, and two sets of phase windings for these three phases are used. , the stator winding 51 is configured as a six-phase phase winding.

The stator core 52 is formed in an annular shape from laminated steel plates made of a soft magnetic material, and is assembled inside the stator winding 51 in the radial direction.

The stator winding 51 is a portion that overlaps the stator core 52 in the axial direction, and includes a coil side portion 53 that is radially outer of the stator core 52, and one end side and the other end of the stator core 52 in the axial direction. It has coil end portions 54 and 55 that respectively extend to the sides. The coil side portions 53 respectively face the stator core 52 and the magnet portion 42 of the rotor 40 in the radial direction. When the stator 50 is disposed inside the rotor 40 , the coil end portion 54 on the bearing portion 20 side (the upper side in the figure) of the coil end portions 54 and 55 on both sides in the axial direction is located on the rotor 40 . The coil accommodating recess 47 formed by the rotor body 41 accommodates the coil accommodating recess 47 . Details of the stator 50 will be described later.

The inverter unit 60 includes a unit base 61 fixed to the housing 30 with a fastener such as a bolt, and an electrical component 62 assembled to the unit base 61. The unit base 61 includes an end plate portion 63 fixed to the end of the housing 30 on the opening 33 side, and a casing portion 64 that is provided integrally with the end plate portion 63 and extends in the axial direction. The end plate portion 63 has a circular opening 65 at its center, and a casing portion 64 is formed to stand up from the periphery of the opening 65.

The stator 50 is assembled on the outer peripheral surface of the casing portion 64. That is, the outer diameter of the casing portion 64 is the same as the inner diameter of the stator core 52, or slightly smaller than the inner diameter of the stator core 52. By assembling the stator core 52 on the outside of the casing portion 64, the stator 50 and the unit base 61 are integrated. Furthermore, since the unit base 61 is fixed to the housing 30, the stator 50 is integrated with the housing 30 when the stator core 52 is assembled to the casing portion 64.

The radially inner side of the casing portion 64 is a housing space for housing the electrical component 62, and the electrical component 62 is arranged in the housing space so as to surround the rotating shaft 11. The casing part 64 has a role as an accommodation space forming part. The electrical component 62 includes a semiconductor module 66 that constitutes an inverter circuit, a control board 67, and a capacitor module 68.

Here, the configuration of the inverter unit 60 will be further described using FIG. 6, which is an exploded view of the inverter unit 60, in addition to FIGS. 1 to 5 above.

In the unit base 61, the casing part 64 has a cylindrical part 71 and an end surface part 72 provided at one of the axial ends of the cylindrical part 71 (the end on the bearing part 20 side). The opposite side of the end surface portion 72 is completely opened through the opening 65 of the end plate portion 63. A circular hole 73 is formed in the center of the end surface portion 72, and the rotating shaft 11 can be inserted into the hole 73.

The cylindrical part 71 of the casing part 64 serves as a partition part that partitions the rotor 40 and stator 50 arranged on the radially outer side of the casing part 64 from the electric component 62 arranged on the radially inner side thereof. The rotor 40, the stator 50, and the electric component 62 are respectively arranged so as to be lined up inside and outside in the radial direction with the cylindrical portion 71 in between.

The electrical component 62 is an electrical component that constitutes an inverter circuit, and has a power running function that rotates the rotor 40 by passing current through each phase winding of the stator winding 51 in a predetermined order, and a power running function that rotates the rotary shaft 11. Accordingly, it has a power generation function of inputting the three-phase alternating current flowing through the stator winding 51 and outputting it to the outside as generated power. The electrical component 62 may have only one of a power running function and a power generation function. The power generation function is, for example, a regeneration function that outputs regenerated power to the outside when the rotating electric machine 10 is used as a power source for a vehicle.

As a specific configuration of the electric component 62, a hollow cylindrical capacitor module 68 is provided around the rotating shaft 11, and a plurality of semiconductor modules 66 are arranged circumferentially on the outer peripheral surface of the capacitor module 68. They are placed side by side. The capacitor module 68 includes a plurality of smoothing capacitors 68a connected in parallel to each other. Specifically, the capacitor 68a is a laminated film capacitor formed by laminating a plurality of film capacitors, and has a trapezoidal cross section. The capacitor module 68 is configured by 12 capacitors 68a arranged in a ring shape.

In the manufacturing process of the capacitor 68a, for example, a long film of a predetermined width, which is formed by laminating a plurality of films, is used. A capacitor element is produced by cutting a long film into an isosceles trapezoid shape, with the film width direction set as the trapezoid height direction, and the upper and lower bases of the trapezoids alternating. Then, the capacitor 68a is manufactured by attaching electrodes and the like to the capacitor element.

The semiconductor module 66 includes semiconductor switching elements such as MOSFETs and IGBTs, and is formed into a substantially plate shape. In this embodiment, the rotating electric machine 10 includes two sets of three-phase windings, and an inverter circuit is provided for each of the three-phase windings. Electrical component 62 has a total of twelve semiconductor modules 66.

The semiconductor module 66 is placed between the cylindrical portion 71 of the casing portion 64 and the capacitor module 68. The outer peripheral surface of the semiconductor module 66 is in contact with the inner peripheral surface of the cylindrical portion 71, and the inner peripheral surface of the semiconductor module 66 is in contact with the outer peripheral surface of the capacitor module 68. In this case, the heat generated in the semiconductor module 66 is transmitted to the end plate part 63 via the casing part 64 and is emitted from the end plate part 63.

A spacer 69 may be disposed between the semiconductor module 66 and the cylindrical portion 71 in the radial direction. In the capacitor module 68, the cross-sectional shape of the cross section perpendicular to the axial direction is a regular dodecagon, while the cross-sectional shape of the inner circumferential surface of the cylindrical portion 71 is circular. Therefore, the spacer 69 has a flat inner circumferential surface. , the outer peripheral surface is a curved surface. The spacer 69 may be integrally provided so as to be continuous in an annular shape on the radially outer side of each semiconductor module 66. Note that it is also possible to make the cross-sectional shape of the inner circumferential surface of the cylindrical portion 71 the same dodecagon as the capacitor module 68. In this case, it is preferable that both the inner peripheral surface and the outer peripheral surface of the spacer 69 be flat surfaces.

In this embodiment, a cooling water passage 74 through which cooling water flows is formed in the cylindrical part 71 of the casing part 64, and the heat generated in the semiconductor module 66 is transferred to the cooling water flowing through the cooling water passage 74. is also released. In other words, the casing portion 64 is equipped with a water cooling mechanism. As shown in FIGS. 3 and 4, the cooling water passage 74 is formed in an annular shape so as to surround the electrical component 62 (semiconductor module 66 and capacitor module 68). The semiconductor module 66 is arranged along the inner peripheral surface of the cylindrical portion 71, and a cooling water passage 74 is provided at a position overlapping the semiconductor module 66 inside and outside in the radial direction.

The stator 50 is arranged on the outside of the cylindrical part 71, and the electric component 62 is arranged on the inside. Therefore, the heat of the stator 50 is transmitted to the cylindrical portion 71 from the outside, and the heat of the semiconductor module 66 is transmitted from the inside. In this case, it is possible to cool the stator 50 and the semiconductor module 66 at the same time, and the heat of the heat generating members in the rotating electric machine 10 can be efficiently dissipated.

The electrical component 62 includes, in the axial direction, an insulating sheet 75 provided on one end surface of the capacitor module 68, and a wiring module 76 provided on the other end surface. One of the axial end surfaces of the capacitor module 68 (the end surface on the bearing section 20 side) faces the end surface section 72 of the casing section 64 and is overlapped with the end surface section 72 with an insulating sheet 75 sandwiched therebetween. Further, a wiring module 76 is assembled to the other end surface (the end surface on the opening 65 side).

The wiring module 76 includes a main body 76a made of synthetic resin and shaped like a circular plate, and a plurality of bus bars 76b, 76c buried inside the main body 76a. 68 is electrically connected. Specifically, the semiconductor module 66 has a terminal 66a extending from its axial end surface, and the terminal 66a is connected to a bus bar 76b on the radially outer side of the main body portion 76a. The bus bar 76c extends on the radially outer side of the main body portion 76a on the side opposite to the capacitor module 68, and is connected to a wiring member 79 at its tip, as shown in FIG.

According to the configuration in which the insulating sheet 75 and the wiring module 76 are provided on both sides of the capacitor module 68 in the axial direction as described above, the heat dissipation path of the capacitor module 68 is provided from both end faces of the capacitor module 68 in the axial direction to the end face portion 72 and the wiring module 76. A path leading to the cylindrical portion 71 is formed. Thereby, heat can be radiated from the end face of the capacitor module 68 other than the outer peripheral face where the semiconductor module 66 is provided. In other words, heat can be radiated not only in the radial direction but also in the axial direction.

The capacitor module 68 has a hollow cylindrical shape, and the rotating shaft 11 is disposed on the inner circumference thereof with a predetermined gap. Therefore, the heat of the capacitor module 68 can also be released from the hollow part thereof. In this case, the rotation of the rotating shaft 11 generates a flow of air, thereby enhancing the cooling effect.

A disk-shaped control board 67 is attached to the wiring module 76 . The control board 67 has a printed circuit board (PCB) on which a predetermined wiring pattern is formed, and a control device 77 made of various ICs, a microcomputer, etc. is mounted on the printed circuit board. The control board 67 is fixed to the wiring module 76 with fixing devices such as screws. The control board 67 has an insertion hole 67a in its center, through which the rotating shaft 11 is inserted.

The control board 67 is provided on the opposite side of the capacitor module 68 among both sides of the wiring module 76 in the axial direction, and the bus bar 76c of the wiring module 76 extends from one side to the other side of both sides of the control board 67. There is. In such a configuration, the control board 67 is preferably provided with a notch to avoid interference with the bus bar 76c. For example, it is preferable that a part of the outer edge of the circular control board 67 is cut out.

In this way, the electrical component 62 is housed in the space surrounded by the casing part 64, and the housing 30, rotor 40, and stator 50 are arranged in layers on the outside thereof. According to this configuration, electromagnetic noise generated in the inverter circuit is suitably shielded. In the inverter circuit, switching control is performed in each semiconductor module 66 using PWM control using a predetermined carrier frequency, and electromagnetic noise may be generated due to the switching control. It can be suitably shielded by the housing 30, rotor 40, stator 50, etc. on the radially outer side.

A through hole 78 is formed in the vicinity of the end plate portion 63 in the cylindrical portion 71, through which a wiring member 79 for electrically connecting the stator 50 on the outside and the electric component 62 on the inside is inserted. As shown in FIG. 2, the wiring member 79 is connected to the end of the stator winding 51 and the bus bar 76c of the wiring module 76 by crimping, welding, or the like. The wiring member 79 is, for example, a bus bar, and it is desirable that the joint surface thereof be crushed flat. The through hole 78 may be provided at one or more locations, and in this embodiment, the through hole 78 is provided at two locations. The configuration in which the through holes 78 are provided at two locations allows the winding terminals extending from the two sets of three-phase windings to be easily connected using the wiring members 79, and is suitable for performing multiphase wiring. It becomes.

Inside the housing 30, as shown in FIG. 4, a rotor 40 and a stator 50 are provided in order from the outside in the radial direction, and an inverter unit 60 is provided inside the stator 50 in the radial direction. Here, if the radius of the inner circumferential surface of the housing 30 is d, the rotor 40 and the stator 50 are arranged radially outward from a distance of d×0.705 from the center of rotation. In this case, the area radially inward from the inner circumferential surface of the stator 50, that is, the inner circumferential surface of the stator core 52, is the first area X1, and the area between the inner circumferential surface of the stator 50 and the housing 30 is the first area X1. In the case of two regions X2, the cross-sectional area of the first region X1 is larger than the cross-sectional area of the second region X2. Moreover, the volume of the first region X1 is larger than the volume of the second region X2 when viewed in the range where the magnet portion 42 of the rotor 40 and the stator winding 51 overlap in the axial direction.

Note that when the rotor 40 and the stator 50 are magnetic circuit components, in the housing 30, the first region X1 that is radially inward from the inner circumferential surface of the magnetic circuit component is the inner circumference of the magnetic circuit component in the radial direction. The volume is larger than that of the second region X2 between the surface and the housing 30.

Next, the configurations of the rotor 40 and stator 50 will be explained in more detail.

In general, a stator in a rotating electric machine is known to have a stator core made of laminated steel plates, which has an annular shape, has multiple slots circumferentially, and stator windings are wound within the slots. ing. Specifically, the stator core has a plurality of teeth extending in the radial direction from the yoke portion at predetermined intervals, and slots are formed between the circumferentially adjacent teeth. For example, a plurality of layers of conductive wires are housed in the slots in the radial direction, and the stator windings are configured by the conductive wires.

However, in the stator structure described above, when the stator winding is energized, as the magnetomotive force of the stator winding increases, magnetic saturation occurs in the teeth of the stator core, which causes the rotating electric machine to It is possible that the torque density is limited. That is, it is considered that magnetic saturation occurs in the stator core when rotating magnetic flux generated by energization of the stator windings concentrates on the teeth.

Moreover, as a configuration of an IPM rotor in a rotating electric machine, a structure in which a permanent magnet is disposed on the d-axis and a rotor core is disposed on the q-axis is generally known. In such a case, by exciting the stator winding near the d-axis, excitation magnetic flux flows from the stator to the q-axis of the rotor according to Fleming's law. This is thought to cause a wide range of magnetic saturation in the q-axis core portion of the rotor.

FIG. 7 is a torque diagram showing the relationship between ampere turns [AT] showing the magnetomotive force of the stator winding and torque density [Nm/L]. The broken line indicates the characteristics of a general IPM rotor type rotating electric machine. As shown in Figure 7, in a typical rotating electric machine, increasing the magnetomotive force in the stator causes magnetic saturation in two places: the teeth between the slots and the q-axis core. The increase in torque will be limited. Thus, in the general rotating electric machine, the ampere-turn design value is limited by X1.

Therefore, in this embodiment, in order to eliminate the torque limitation caused by magnetic saturation, the rotating electrical machine 10 is provided with the configuration shown below. That is, as a first measure, a slotless structure is adopted in the stator 50 in order to eliminate the magnetic saturation that occurs in the teeth of the stator core, and a slotless structure is adopted in the stator 50 in order to eliminate the magnetic saturation that occurs in the q-axis core portion of the IPM rotor. , SPM rotor is adopted. According to the first idea, the above two portions where magnetic saturation occurs can be eliminated, but the torque in the low current range may be reduced (see the dashed line in FIG. 7). Therefore, as a second measure, in order to compensate for the decrease in torque by increasing the magnetic flux of the SPM rotor, we adopted a polar anisotropic structure in which the magnet magnetic path is lengthened and the magnetic force is increased in the magnet section 42 of the rotor 40. ing.

In addition, as a third measure, a flat conducting wire structure is adopted in which the radial thickness of the conducting wire is reduced in the coil side portion 53 of the stator winding 51 in order to recover from the decrease in torque. Here, due to the polar anisotropic structure described above, it is considered that a larger eddy current is generated in the opposing stator windings 51. However, according to the third device, the occurrence of radial eddy current in the stator winding 51 can be suppressed due to the flat conducting wire structure which is thin in the radial direction. As described above, according to each of the first to third configurations, as shown by the solid line in FIG. Concerns about possible large eddy current generation can also be alleviated.

Furthermore, as a fourth measure, a magnet portion 42 that utilizes a polar anisotropic structure and has a magnetic flux density distribution close to a sine wave is employed. According to this, it is possible to increase the torque by increasing the sinusoidal matching factor through pulse control, etc., which will be described later, and it is also possible to further suppress eddy current loss due to the gentle change in magnetic flux compared to a radial magnet.

Furthermore, as a fifth idea, the stator winding 51 has a strand conductor structure in which a plurality of strands are gathered together and twisted. According to this, the fundamental wave component is collected and a large current can flow, and the cross-sectional area of each strand can suppress the generation of eddy current caused in the circumferential direction, which occurs in a conductor that has a flat conductor structure and spreads in the circumferential direction. Since it becomes smaller, it can be suppressed more effectively than the third technique of making it thinner in the radial direction. Since the plurality of strands are twisted together, the magnetomotive force from the conductor can be offset by the eddy current against the magnetic flux generated according to the right-handed screw rule in the direction of current flow.

In this way, by further adding the fourth and fifth ideas, it is possible to increase torque while using a magnet with high magnetic force, which is the second idea, while suppressing eddy current loss caused by the high magnetic force. can be achieved.

Below, the slotless structure of the stator 50, the flat conductor structure of the stator winding 51, and the polar anisotropic structure of the magnet portion 42 will be individually explained.

First, the slotless structure and flat conductor structure will be explained. FIG. 8 is a cross-sectional view of the rotor 40 and stator 50, and FIG. 9 is an enlarged view of a part of the rotor 40 and stator 50 shown in FIG. FIG. 10 is a cross-sectional view showing a cross section of the stator 50, and FIG. 11 is a cross-sectional view showing a vertical cross section of the stator 50. Further, FIG. 12 is a perspective view of the stator winding 51. In addition, in FIG. 8 and FIG. 9, the magnetization direction of the magnet in the magnet part 42 is shown by the arrow.

As shown in FIGS. 8 to 11, the stator core 52 has a cylindrical shape in which a plurality of electromagnetic steel sheets are laminated in the axial direction and has a predetermined thickness in the radial direction. A wire 51 is to be assembled. The outer peripheral surface of the stator core 52 serves as a conductor installation portion. The outer circumferential surface of the stator core 52 has a curved shape with no irregularities, and a plurality of conducting wire groups 81 are arranged circumferentially on the outer circumferential surface.

Stator core 52 functions as a back yoke that becomes part of a magnetic circuit for rotating rotor 40. In this case, there is no tooth (that is, iron core) made of a soft magnetic material between each conductive wire group 81 adjacent in the circumferential direction, that is, a slotless structure. In this embodiment, the resin material of the sealing part 57 enters into the gap 56 of each conducting wire group 81 . In other words, in the state before the sealing portion 57 is sealed, the conductor wire groups 81 are arranged on the radially outer side of the stator core 52 at predetermined intervals in the circumferential direction with gaps 56 being inter-conductor regions. As a result, the stator 50 has a slotless structure.

Note that a configuration in which teeth are provided between each conductor group arranged in the circumferential direction means that the teeth have a predetermined thickness in the radial direction and a predetermined width in the circumferential direction. It can be said that this structure forms part of a magnetic circuit, that is, a magnet magnetic path. In this respect, a configuration in which teeth are not provided between each conducting wire group 81 as in the present embodiment can be said to be a configuration in which the above-described magnetic circuit is not formed.

As shown in FIGS. 10 and 11, the stator winding 51 is sealed by a sealing portion 57. As shown in FIGS. When viewed in the cross section of FIG. 10, the sealing portion 57 is provided between each conducting wire group 81, that is, by filling the gap 56 with a synthetic resin material. The structure is such that an insulating member is interposed between the two. That is, the sealing portion 57 functions as an insulating member in the gap 56. The sealing portion 57 is formed on the outside of the stator core 52 in the radial direction in a range that includes all the conductor groups 81, that is, in a range where the radial thickness dimension is larger than the radial thickness dimension of each conductor group 81. It is provided.

Furthermore, when viewed in the longitudinal section of FIG. 11, the sealing portion 57 is provided in a range that includes the turn portion 84 of the stator winding 51. A sealing portion 57 is provided on the radially inner side of the stator winding 51 in a range that includes at least a portion of the end surface of the stator core 52 . In this case, the stator winding 51 is substantially entirely sealed with resin except for the ends of the phase windings of each phase, that is, the connection terminals with the inverter circuit.

In a configuration in which the sealing portion 57 is provided in a range including the end face of the stator core 52, the sealing portion 57 can press the laminated steel plate of the stator core 52 inward in the axial direction. Thereby, the laminated state of each steel plate can be maintained using the sealing part 57. Note that in this embodiment, the inner circumferential surface of the stator core 52 is not sealed with resin, but instead, the entire stator core 52 including the inner circumferential surface of the stator core 52 is sealed with resin. It may also be a configuration.

When the rotating electric machine 10 is used as a vehicle power source, the sealing portion 57 is made of a highly heat-resistant fluororesin, epoxy resin, PPS resin, PEEK resin, LCP resin, silicone resin, PAI resin, PI resin, etc. It is preferable that it be configured. Further, considering the linear expansion coefficient from the viewpoint of suppressing cracking due to expansion differences, it is desirable that the material is the same as that of the outer coating of the conducting wire of the stator winding 51. That is, silicone resins whose coefficient of linear expansion is generally twice or more that of other resins are preferably excluded. In addition, for electric products such as electric vehicles that do not have an engine that uses combustion, PPO resin, phenol resin, and FRP resin, which have heat resistance of about 180° C., are also candidates. This is not the case in fields where the ambient temperature of the rotating electrical machine 10 can be considered to be less than 100°C.

The torque of the rotating electrical machine 10 is proportional to the magnitude of the magnetic flux. Here, when the stator core has teeth, the maximum amount of magnetic flux in the stator is limited depending on the saturation magnetic flux density in the teeth. On the other hand, when the stator core 52 does not have teeth as in this embodiment, the maximum amount of magnetic flux in the stator 50 is not limited. Therefore, this configuration is advantageous in increasing the current applied to the stator winding 51 to increase the torque of the rotating electrical machine 10.

Each conducting wire group 81 on the radially outer side of the stator core 52 is composed of a plurality of conducting wires 82 each having a flat rectangular cross section and arranged in the radial direction. Each conducting wire 82 is arranged in a direction such that "radial dimension<circumferential dimension" in the cross section. Thereby, each conducting wire group 81 is made thinner in the radial direction. In addition, the conductor region is made thinner in the radial direction, and the conductor region extends flatly to the region where the teeth were conventionally located, resulting in a flat conductor region structure. As a result, an increase in the amount of heat generated by the conductor, which is a concern due to a reduction in cross-sectional area due to thinning, is suppressed by flattening the conductor in the circumferential direction and increasing the cross-sectional area of the conductor. Note that even with a configuration in which a plurality of conductive wires are arranged in the circumferential direction and connected in parallel, the effect based on the same principle can be obtained, although the cross-sectional area of the conductor is reduced by the amount of the conductor coating.

Since there is no slot, in the stator winding 51 in this embodiment, the conductor area in one circumferential direction can be designed to be larger than the gap area. Note that in conventional rotating electric machines for vehicles, the number of conductor areas/gap areas in one circumferential direction of the stator winding is one or less. On the other hand, in this embodiment, each conducting wire group 81 is provided such that the conductor area is equal to or larger than the gap area. Here, as shown in FIG. 10, if the conductor area in the circumferential direction in which the conductor wires 82 (that is, straight portions 83 described later) are arranged is WA, and the area between the conductor wires between adjacent conductor wires 82 is WB, then the conductor wires The area WA is larger in the circumferential direction than the inter-conductor area WB.

The torque of the rotating electric machine 10 is approximately inversely proportional to the radial thickness of the conducting wire group 81. In this respect, by reducing the thickness of the conducting wire group 81 on the radially outer side of the stator core 52, the structure is advantageous in increasing the torque of the rotating electric machine 10. The reason for this is that the distance from the magnet portion 42 of the rotor 40 to the stator core 52, that is, the distance of the portion without iron, can be reduced to reduce magnetic resistance. According to this, the interlinkage magnetic flux of the stator core 52 caused by the permanent magnets can be increased, and the torque can be increased.

The conducting wire 82 is made of a coated conducting wire in which the surface of a conductor 82a is covered with an insulating coating 82b, and insulation is ensured between the conducting wires 82 that overlap each other in the radial direction and between the conducting wire 82 and the stator core 52. has been done. The thickness of the insulating coating 82b is, for example, 80 μm, which is thicker than the coating thickness (20 to 40 μm) of commonly used conducting wires. Thereby, the insulation between the conducting wire 82 and the stator core 52 can be ensured without interposing an insulating paper or the like between the two.

It should be noted that each phase winding constituted by the conducting wire 82 maintains insulation properties due to the insulating coating 82b, except for exposed portions for connection. The exposed portion is, for example, an input/output terminal portion or a neutral point portion in the case of a star-shaped connection. In the conducting wire group 81, radially adjacent conducting wires 82 are fixed to each other using resin bonding or self-bonding coated wire. This suppresses dielectric breakdown, vibration, and noise caused by the conductive wires 82 rubbing against each other.

In this embodiment, the conductor 82a is configured as an aggregate of a plurality of wires 86. Specifically, as shown in FIG. 13, the conductor 82a is formed into a twisted thread shape by twisting a plurality of wires 86. Further, as shown in FIG. 14, the wire 86 is configured as a composite body made by bundling thin fibrous conductive materials 87. For example, the wire 86 is a composite of CNT (carbon nanotube) fibers, and the CNT fibers include boron-containing fine fibers in which at least a portion of carbon is replaced with boron. As the carbon-based fine fibers, vapor grown carbon fibers (VGCF) and the like can be used in addition to CNT fibers, but it is preferable to use CNT fibers. Note that the surface of the wire 86 is covered with a polymeric insulating layer such as enamel.

Since the conductor 82a is formed by twisting a plurality of wires 86 together, the generation of eddy current in each wire 86 is suppressed, and the eddy current in the conductor 82a can be reduced. Further, since each strand 86 is twisted, there are parts in one strand 86 where the directions of magnetic field application are opposite to each other, so that the back electromotive force is canceled out. Therefore, it is possible to reduce eddy currents. In particular, by forming the wire 86 with the fibrous conductive material 87, it becomes possible to make the wire thinner and to significantly increase the number of twists, thereby making it possible to more appropriately reduce eddy currents.

As described above, the conductor wires 82 have a flat rectangular cross section and are arranged in plurality in the radial direction.For example, a plurality of wires 86 are gathered together in a twisted state, and in this state, a synthetic resin is applied. It is preferable to harden and mold it into a desired shape by means of methods such as the following.

Each conducting wire 82 is formed by bending so as to be arranged in a predetermined arrangement pattern in the circumferential direction, thereby forming a phase winding for each phase as the stator winding 51. As shown in FIG. 12, in the stator winding 51, a coil side portion 53 is formed by a straight portion 83 of each conductive wire 82 that extends linearly in the axial direction, and the coil side portion 53 is formed on both sides of the coil side portion 53 in the axial direction. Coil end portions 54 and 55 are formed by the protruding turn portions 84.

Each conducting wire 82 is configured as a series of wave-wound conducting wires by having straight portions 83 and turn portions 84 alternately repeated. The straight portions 83 are arranged at positions facing the magnet portion 42 in the radial direction. They are connected to each other by turn portions 84. The straight portion 83 is a magnet facing portion that faces the magnet portion 42 in the radial direction.

In this embodiment, the stator winding 51 is wound in an annular shape by distributed winding. In this case, in the coil side part 53, straight parts 83 are arranged in the circumferential direction at a pitch corresponding to one pole pair of the magnet part 42 for each phase, and in the coil end parts 54, 55, each straight part 83 for each phase are connected to each other by a turn portion 84 formed in a substantially V shape. The straight portions 83 that form a pair corresponding to one pole pair are configured such that the directions of current flow are opposite to each other. Furthermore, the combinations of the pair of straight portions 83 connected by the turn portions 84 are different between the one coil end portion 54 and the other coil end portion 55, and the connection at the coil end portions 54 and 55 is different. By repeating the windings in the circumferential direction, the stator winding 51 is formed into a substantially cylindrical shape.

More specifically, the stator winding 51 uses two pairs of conducting wires 82 for each phase to form a winding for each phase, and one of the three-phase windings (U phase, V phase, W phase) and the other three-phase winding (X phase, Y phase, Z phase) are provided in two layers, inside and outside in the radial direction. In this case, if the number of phases of the winding is S and the number of logarithms of the conducting wire 82 is m, then 2×S×m=2Sm conducting wire groups 81 are formed for each pole pair. In this embodiment, the number of phases S is 3, the number of logarithms m is 2, and since the rotating electric machine 10 has 8 pole pairs (16 poles), 2×3×2×8=96 conducting wire groups 81 are arranged in the circumferential direction. It is located in

In the stator winding 51 shown in FIG. 12, in the coil side part 53, straight parts 83 are arranged in two layers, radially inner and outer layers, overlapping each other, and in the coil end parts 54, 55, each straight line part 83 overlaps in the radially inner and outer layers. Turn portions 84 are configured to extend circumferentially from portion 83 in directions opposite to each other in the circumferential direction. That is, in each of the conductive wires 82 that are adjacent to each other in the radial direction, the directions of the turn portions 84 are opposite to each other except for the portion that becomes the coil end.

Here, the winding structure of the conducting wire 82 in the stator winding 51 will be specifically explained. In this embodiment, a plurality of conductive wires 82 formed by wave winding are provided in a plurality of layers (for example, two layers) inside and outside in the radial direction. FIG. 15 is a diagram showing the form of each conducting wire 82 in the n-th layer, in which (a) shows the shape of the conducting wire 82 seen from the side of the stator winding 51, and (b) shows the shape of the conducting wire 82 in the n-th layer. The shape of the conducting wire 82 seen from one side in the axial direction of the child winding 51 is shown. In addition, in FIG. 15, the positions where the conducting wire groups 81 are arranged are shown as D1, D2, D3, . . . , respectively. Further, for convenience of explanation, only three conductive wires 82 are shown, and they are referred to as a first conductive wire 82_A, a second conductive wire 82_B, and a third conductive wire 82_C.

In each of the conductive wires 82_A to 82_C, the straight portions 83 are arranged at the n-th layer position, that is, at the same position in the radial direction, and the straight portions 83 are spaced apart from each other by 6 positions (3×m pairs) in the circumferential direction. They are connected to each other by turn portions 84. In other words, in each of the conducting wires 82_A to 82_C, every fifth straight portion 83 is connected to each other by the turn portion 84 on the same pitch circle centered on the axis of the rotor 40. For example, in the first conducting wire 82_A, a pair of straight portions 83 are arranged at D1 and D7, respectively, and the pair of straight portions 83 are connected to each other by an inverted V-shaped turn portion 84. Further, the other conducting wires 82_B and 82_C are arranged in the same n-th layer with their circumferential positions shifted by one. In this case, since the conductive wires 82_A to 82_C are all arranged in the same layer, it is conceivable that the turn portions 84 interfere with each other. Therefore, in this embodiment, an interference avoidance part is formed in the turn part 84 of each of the conductive wires 82_A to 82_C by partially offset in the radial direction.

Specifically, the turn portion 84 of each of the conductive wires 82_A to 82_C has an inclined portion 84a which is a portion extending in the circumferential direction on the same pitch circle, and a portion extending from the inclined portion 84a in the radial direction inside the same pitch circle (Fig. 15(b), and has a top portion 84b, an inclined portion 84c, and a return portion 84d, which are portions that extend in the circumferential direction on another pitch circle. The top portion 84b, the inclined portion 84c, and the return portion 84d correspond to an interference avoidance portion. Note that the inclined portion 84c may be configured to shift outward in the radial direction with respect to the inclined portion 84a.

That is, the turn portion 84 of each of the conductive wires 82_A to 82_C has an inclined portion 84a on one side and an inclined portion 84c on the other side on both sides of the top portion 84b, which is the center position in the circumferential direction. The radial positions of the respective inclined portions 84a and 84c are different from each other. Note that the radial position of each inclined portion 84a, 84c is the position in the front-rear direction in FIG. 15(a), and the vertical position in FIG. 15(b). For example, the turn portion 84 of the first conducting wire 82_A extends along the circumferential direction starting from the D1 position of the n layer, bends in the radial direction (for example, radially inward) at the top portion 84b that is the center position in the circumferential direction, and then By bending in the circumferential direction again, it extends along the circumferential direction again, and by further bending in the radial direction (for example, outward in the radial direction) again at the return portion 84d, it reaches the end position D9 of the n layer. There is.

According to the above configuration, in the conductive wires 82_A to 82_C, one of the inclined portions 84a is arranged vertically in the order of the first conductive wire 82_A → the second conductive wire 82_B → the third conductive wire 82_C from the top, and the conductive wires 82_A to 82_C are arranged at the top part 84b. The top and bottom of the conductive wire 82_C are reversed, and the other inclined portions 84c are arranged vertically in the order of the third conductive wire 82_C, the second conductive wire 82_B, and the first conductive wire 82_A from the top. Therefore, the conductive wires 82_A to 82_C can be arranged in the circumferential direction without interfering with each other.

Here, in a configuration in which a plurality of conducting wires 82 are stacked radially to form a conducting wire group 81, a turn portion 84 connected to the radially inner linear portion 83 of each linear portion 83 of the plurality of layers and a radially outer It is preferable that the turn portions 84 connected to the straight portions 83 are arranged at a distance in the radial direction from each other. In addition, when the conductive wires 82 of multiple layers are bent to the same side in the radial direction near the end of the turn portion 84, that is, the boundary with the straight portion 83, the insulation may be deteriorated due to interference between the conductive wires 82 of the adjacent layers. It is advisable to ensure that no damage occurs.

For example, in D7 to D9 in FIG. 15, the conductive wires 82 that overlap in the radial direction are each bent in the radial direction at the return portion 84d of the turn portion 84. In this case, as shown in FIG. 16, the bending radius of the bending portion may be made different between the n-th layer conductor 82 and the n+1-th layer conductor 82. Specifically, the bending radius R1 of the conducting wire 82 on the radially inner side (nth layer) is made smaller than the bending radius R2 of the conducting wire 82 on the radially outer side (n+1th layer).

Further, it is preferable that the amount of shift in the radial direction is different between the conductive wire 82 of the nth layer and the conductive wire 82 of the (n+1)th layer. Specifically, the shift amount S1 of the conducting wire 82 on the radially inner side (nth layer) is made larger than the shift amount S2 of the conducting wire 82 on the radially outer side (n+1 layer).

With the above configuration, even if the conductive wires 82 overlapping in the radial direction are bent in the same direction, mutual interference between the conductive wires 82 can be suitably avoided. As a result, good insulation properties can be obtained.

Next, the structure of the magnet portion 42 in the rotor 40 will be explained. In this embodiment, the permanent magnet constituting the magnet portion 42 is assumed to have a residual magnetic flux density Br=1.0 [T] and a coercive force bHc=400 [kA/m] or more. Since 5,000 to 10,000 [AT] is applied due to phase-to-phase excitation, if a permanent magnet of 25 [mm] with one pole pair is used, bHc = 10,000 [A], which indicates that there is no demagnetization. Here, in this embodiment, since a permanent magnet whose axis of easy magnetization is controlled by orientation is used, the magnetic circuit length inside the magnet is different from the magnetic field of a linearly oriented magnet that generates 1.0 [T] or more. It can be made longer than the circuit length. In other words, in addition to being able to achieve the magnetic circuit length per pole pair with a smaller amount of magnets, it also maintains its reversible demagnetization range even when exposed to harsh high temperature conditions compared to designs using conventional linearly oriented magnets. I can do it. In addition, the inventors of the present application have discovered a configuration in which characteristics similar to those of polar anisotropic magnets can be obtained even when using conventional magnets.

As shown in FIGS. 8 and 9, the magnet part 42 has an annular shape and is provided inside the rotor main body 41, specifically, inside the magnet holding part 43 in the radial direction. The magnet section 42 has a first magnet 91 and a second magnet 92. The first magnet 91 and the second magnet 92 are each polar anisotropic magnets, and have different magnetic poles. The first magnets 91 and the second magnets 92 are arranged alternately in the circumferential direction. The first magnet 91 is a magnet that serves as a north pole in the rotor 40, and the second magnet 92 is a magnet that serves as a south pole in the rotor 40. The first magnet 91 and the second magnet 92 are permanent magnets made of rare earth magnets such as neodymium magnets.

In each of the magnets 91 and 92, the magnetization direction extends in an arc shape between the d-axis, which is the center of the magnetic pole, and the q-axis, which is the boundary between the magnetic poles. In each of the magnets 91 and 92, the magnetization direction is radial on the d-axis side, and the magnetization direction is circumferential on the q-axis side. In the magnet portion 42, magnetic flux flows in an arc shape between adjacent N and S poles by the magnets 91 and 92, so the magnet magnetic path is longer than, for example, a radial anisotropic magnet. Therefore, as shown in FIG. 17, the magnetic flux density distribution becomes close to a sine wave. As a result, unlike the magnetic flux density distribution of the radial anisotropic magnet shown as a comparative example in FIG. 18, the magnetic flux can be concentrated at the magnetic pole position, and the torque of the rotating electric machine 10 can be increased. Note that in FIGS. 17 and 18, the horizontal axis indicates electrical angle, and the vertical axis indicates magnetic flux density. Furthermore, in FIGS. 17 and 18, 90° on the horizontal axis indicates the d-axis (that is, the center of the magnetic pole), and 0° and 180° on the horizontal axis indicate the q-axis.

The sinusoidal matching rate of the magnetic flux density distribution may be set to a value of 40% or more, for example. In this way, the amount of magnetic flux in the central portion of the waveform can be reliably improved compared to the case of using radially oriented magnets or parallel oriented magnets with a sinusoidal matching rate of about 30%. Moreover, if the sine wave matching rate is set to 60% or more, the amount of magnetic flux in the central portion of the waveform can be reliably improved compared to a magnetic flux concentration arrangement called a Halbach arrangement.

In the comparative example shown in FIG. 18, the magnetic flux density changes sharply near the q-axis. The steeper the change in magnetic flux density, the more the eddy current generated in the stator winding 51 increases. In contrast, in this embodiment, the magnetic flux density distribution is close to a sine wave. Therefore, near the q-axis, the change in magnetic flux density is smaller than the change in magnetic flux density of the radial anisotropic magnet. This makes it possible to suppress the generation of eddy currents.

By the way, in the magnet portion 42, a magnetic flux is generated near the d-axis of each magnet 91, 92 (i.e., at the center of the magnetic pole) in a direction perpendicular to the magnetic pole surface, and the magnetic flux is shaped like a circle that moves away from the d-axis as the distance from the magnetic pole surface increases. form an arc. Further, the more the magnetic flux is perpendicular to the magnetic pole surface, the stronger the magnetic flux becomes. In this respect, in the rotating electric machine 10 of the present embodiment, each conducting wire group 81 is made thinner in the radial direction as described above, so that the center position of the conducting wire group 81 in the radial direction approaches the magnetic pole surface of the magnet part 42, so that it cannot be fixed. The child 50 can receive strong magnetic flux from the rotor 40 .

Further, the stator 50 is provided with a cylindrical stator core 52 on the radially inner side of the stator winding 51, that is, on the opposite side of the rotor 40 with the stator winding 51 in between. Therefore, the magnetic flux extending from the magnetic pole surface of each magnet 91, 92 is attracted to the stator core 52 and circulates using the stator core 52 as part of the magnetic path. In this case, the direction and path of the magnet magnetic flux can be optimized.

Next, the configuration of a control system that controls the rotating electric machine 10 will be explained. FIG. 19 is an electric circuit diagram of the control system of the rotating electrical machine 10, and FIG. 20 is a functional block diagram showing current feedback control processing by the control device 110. FIG. 21 is a functional block diagram showing torque feedback control processing by the control device 110.

In FIG. 19, two sets of three-phase windings 51a and 51b are shown as the stator winding 51. The three-phase winding 51a includes a U-phase winding, a V-phase winding, and a W-phase winding, and the three-phase winding 51b includes an X-phase winding, a Y-phase winding, and a Z-phase winding. A first inverter 101 and a second inverter 102 are provided for each three-phase winding 51a, 51b. The inverters 101 and 102 are constituted by full bridge circuits having upper and lower arms of the same number as the number of phases of the phase windings. The energizing current is adjusted in each phase winding.

A DC power supply 103 and a smoothing capacitor 104 are connected in parallel to each inverter 101, 102. The DC power supply 103 is constituted by, for example, a battery pack in which a plurality of single cells are connected in series. Note that the semiconductor module 66 shown in FIG. 1 and the like includes switches that constitute the inverters 101 and 102. The capacitor 104 corresponds to the capacitor module 68 shown in FIG. 1 and the like.

The control device 110 includes a microcomputer consisting of a CPU and various memories, and controls energization by turning on and off each switch in the inverters 101 and 102 based on various detection information in the rotating electric machine 10 and requests for power running drive and power generation. implement. The control device 110 corresponds to the control device 77 shown in FIG. The detection information of the rotating electrical machine 10 includes, for example, the rotation angle (electrical angle information) of the rotor 40 detected by an angle detector such as a resolver, the power supply voltage (inverter input voltage) detected by a voltage sensor, and a current sensor. Contains the energizing current of each phase detected by . Control device 110 generates and outputs operation signals for operating each switch of inverters 101 and 102. Note that the request for power generation is, for example, a request for regenerative drive when the rotating electrical machine 10 is used as a power source for a vehicle.

The first inverter 101 includes a series connection body of an upper arm switch Sp and a lower arm switch Sn in three phases consisting of a U phase, a V phase, and a W phase. The high potential side terminal of the upper arm switch Sp of each phase is connected to the positive terminal of the DC power supply 103, and the low potential side terminal of the lower arm switch Sn of each phase is connected to the negative terminal (ground) of the DC power supply 103. . One end of a U-phase winding, a V-phase winding, and a W-phase winding is connected to an intermediate connection point between the upper arm switch Sp and the lower arm switch Sn of each phase. These phase windings are connected in a star shape (Y connection), and the other ends of each phase winding are connected to each other at a neutral point.

The second inverter 102 has the same configuration as the first inverter 101, and includes a series connection body of an upper arm switch Sp and a lower arm switch Sn in three phases consisting of an X phase, a Y phase, and a Z phase. ing. The high potential side terminal of the upper arm switch Sp of each phase is connected to the positive terminal of the DC power supply 103, and the low potential side terminal of the lower arm switch Sn of each phase is connected to the negative terminal (ground) of the DC power supply 103. . One ends of an X-phase winding, a Y-phase winding, and a Z-phase winding are connected to intermediate connection points between the upper arm switch Sp and the lower arm switch Sn of each phase. These phase windings are connected in a star shape (Y connection), and the other ends of each phase winding are connected to each other at a neutral point.

FIG. 20 shows a current feedback control process that controls the U, V, and W phase currents, and a current feedback control process that controls the X, Y, and Z phase currents. First, control processing on the U, V, and W phase sides will be described.

In FIG. 20, the current command value setting unit 111 uses the torque-dq map to determine the power running torque command value or the power generation torque command value for the rotating electrical machine 10, and the electrical angular velocity ω obtained by time-differentiating the electrical angle θ. , the d-axis current command value and the q-axis current command value are set. Note that the current command value setting section 111 is provided in common on the U, V, and W phase sides and the X, Y, and Z phase sides. The power generation torque command value is, for example, a regenerative torque command value when the rotating electric machine 10 is used as a power source for a vehicle.

The dq conversion unit 112 converts current detected values (each phase current) by current sensors provided for each phase into d-axis current and q-axis current, which are components of an orthogonal two-dimensional rotating coordinate system with the field direction as the d-axis. Convert to .

The d-axis current feedback control unit 113 calculates a d-axis command voltage as a manipulated variable for feedback-controlling the d-axis current to the d-axis current command value. The q-axis current feedback control unit 114 calculates the q-axis command voltage as a manipulated variable for feedback-controlling the q-axis current to the q-axis current command value. In each of these feedback control units 113 and 114, a command voltage is calculated using a PI feedback method based on the deviation of the d-axis current and the q-axis current from the current command value.

The three-phase converter 115 converts the d-axis and q-axis command voltages into U-phase, V-phase, and W-phase command voltages. The above-mentioned units 111 to 115 are feedback control units that perform feedback control of the fundamental wave current based on the dq conversion theory, and the command voltages of the U-phase, V-phase, and W-phase are feedback control values.

The operation signal generation unit 116 generates an operation signal for the first inverter 101 based on the three-phase command voltage using a well-known triangular wave carrier comparison method. Specifically, the operation signal generation unit 116 controls the upper and lower arm switches in each phase by PWM control based on a magnitude comparison between a signal obtained by normalizing the three-phase command voltage with the power supply voltage and a carrier signal such as a triangular wave signal. Generates an operation signal (duty signal).

In addition, the X, Y, and Z phase sides have a similar configuration, and the dq converter 122 converts the current detection value (each phase current) by the current sensor provided for each phase by converting the field direction to d. The current is converted into a d-axis current and a q-axis current, which are components of an orthogonal two-dimensional rotating coordinate system with an axis.

The d-axis current feedback control section 123 calculates the d-axis command voltage, and the q-axis current feedback control section 124 calculates the q-axis command voltage. The three-phase converter 125 converts the d-axis and q-axis command voltages into X-phase, Y-phase, and Z-phase command voltages. The operation signal generation unit 126 then generates an operation signal for the second inverter 102 based on the three-phase command voltages. Specifically, the operation signal generation unit 126 controls the upper and lower arm switches in each phase by PWM control based on a magnitude comparison between a signal obtained by normalizing the three-phase command voltage with the power supply voltage and a carrier signal such as a triangular wave signal. Generates an operation signal (duty signal).

The driver 117 turns on and off the three-phase switches Sp and Sn in each inverter 101 and 102 based on the switch operation signals generated by the operation signal generation units 116 and 126, respectively.

Next, the torque feedback control process will be explained. This process is mainly used for the purpose of increasing the output of the rotating electric machine 10 and reducing losses under operating conditions where the output voltage of each inverter 101, 102 becomes large, such as in a high rotation region and a high output region. The control device 110 selects and executes either the torque feedback control process or the current feedback control process based on the operating conditions of the rotating electric machine 10.

FIG. 21 shows torque feedback control processing corresponding to the U, V, and W phases, and torque feedback control processing corresponding to the X, Y, and Z phases. Note that in FIG. 21, the same components as those in FIG. 20 are designated by the same reference numerals, and the description thereof will be omitted. First, control processing on the U, V, and W phase sides will be described.

The voltage amplitude calculation unit 127 determines a command value for the magnitude of the voltage vector based on a power running torque command value or a power generation torque command value for the rotating electric machine 10 and an electrical angular velocity ω obtained by time-differentiating the electrical angle θ. Calculate the voltage amplitude command.

The torque estimator 128a calculates estimated torque values corresponding to the U, V, and W phases based on the d-axis current and q-axis current converted by the dq converter 112. Note that the torque estimation unit 128a may calculate the voltage amplitude command based on map information in which the d-axis current, the q-axis current, and the voltage amplitude command are associated.

The torque feedback control unit 129a calculates a voltage phase command, which is a command value of the phase of the voltage vector, as a manipulated variable for feedback controlling the estimated torque value to the power running torque command value or the power generation torque command value. The torque feedback control unit 129a calculates a voltage phase command using a PI feedback method based on the deviation of the estimated torque value from the power running torque command value or the power generation torque command value.

The operation signal generation unit 130a generates an operation signal for the first inverter 101 based on the voltage amplitude command, the voltage phase command, and the electrical angle θ. Specifically, the operation signal generation unit 130a calculates three-phase command voltages based on a voltage amplitude command, a voltage phase command, and an electrical angle θ, and generates a signal in which the calculated three-phase command voltages are normalized by the power supply voltage. A switch operation signal for the upper and lower arms in each phase is generated by PWM control based on magnitude comparison between the signal and a carrier signal such as a triangular wave signal.

Incidentally, the operation signal generation unit 130a generates a signal based on pulse pattern information, voltage amplitude command, voltage phase command, and electrical angle θ, which is map information in which a voltage amplitude command, a voltage phase command, an electrical angle θ, and a switch operation signal are associated. The switch operation signal may also be generated.

Furthermore, the X, Y, and Z phase sides have a similar configuration, and the torque estimating unit 128b calculates the X, Y, and Calculate the estimated torque value corresponding to the Z phase.

The torque feedback control unit 129b calculates a voltage phase command as a manipulated variable for feedback controlling the estimated torque value to the power running torque command value or the power generation torque command value. The torque feedback control unit 129b calculates a voltage phase command using a PI feedback method based on the deviation of the estimated torque value from the powering torque command value or the power generation torque command value.

The operation signal generation unit 130b generates an operation signal for the second inverter 102 based on the voltage amplitude command, the voltage phase command, and the electrical angle θ. Specifically, the operation signal generation unit 130b calculates three-phase command voltages based on a voltage amplitude command, a voltage phase command, and an electrical angle θ, and generates a signal in which the calculated three-phase command voltages are normalized by the power supply voltage. A switch operation signal for the upper and lower arms in each phase is generated by PWM control based on magnitude comparison between the signal and a carrier signal such as a triangular wave signal. The driver 117 turns on and off the three-phase switches Sp and Sn in each inverter 101 and 102 based on the switch operation signals generated by the operation signal generation units 130a and 130b.

Incidentally, the operation signal generation unit 130b generates a signal based on the voltage amplitude command, voltage phase command, electrical angle θ, and pulse pattern information which is map information in which the switch operation signal is associated, the voltage amplitude command, the voltage phase command, and the electrical angle θ. The switch operation signal may also be generated.

According to the rotating electric machine 10 configured as described above, the following excellent effects can be obtained.

In the stator 50, teeth made of a soft magnetic material are not provided between circumferentially adjacent linear portions 83 of the stator winding 51, that is, between adjacent magnet facing portions. According to this configuration, compared to the case where teeth are provided between each straight part 83, by bringing each adjacent straight part 83 closer together, the conductor cross-sectional area can be increased, and the cross-sectional area of the stator winding 51 can be increased. It is possible to reduce heat generated due to energization. In a so-called slotless structure in which teeth are not provided between the straight sections 83, magnetic saturation can be eliminated by the absence of teeth between the straight sections 83, increasing the current flowing to the stator winding 51. becomes possible. In this case, it is possible to suitably deal with the fact that the amount of heat generated increases with the increase in the applied current. As described above, it is possible to optimize the heat dissipation performance of the stator 50.

The stator core 52 is assembled to the stator winding 51, and in the assembled state, teeth made of a soft magnetic material are not provided between straight portions 83 adjacent in the circumferential direction. In this case, the stator core 52 provided on the opposite side in the radial direction to the rotor 40 functions as a back yoke, so that even if there are no teeth between the straight portions 83, a proper magnetic circuit can be maintained. It becomes possible to form

The stator winding 51 is sealed with a sealing portion 57, and thereby an insulating member is provided between circumferentially adjacent linear portions 83 in the stator winding 51. Thereby, even if the linear portions 83 are arranged close to each other in the circumferential direction, good insulation can be ensured in the linear portions 83.

Since the conducting wire 82 in the stator winding 51 is made flat and the radial thickness in the straight portion 83 is made thin, the radial center position of the straight portion 83 can be brought closer to the magnet portion 42 of the rotor 40 . This makes it possible to suppress magnetic saturation in the stator 50 by employing a slotless structure, while increasing the magnetic flux density in the straight portion 83 of the stator winding 51 and increasing torque. Further, as described above, since it is possible to bring the straight portions 83 adjacent to each other in the circumferential direction close to each other, the conductor cross-sectional area can be ensured even if the conducting wire 82 is made flat.

Since each conducting wire 82 of the stator winding 51 is made of an aggregate of a plurality of wires 86, the current flow path in the conducting wire 82 can be made thinner. Thereby, even if an eddy current is generated when the magnetic field from the magnet part 42 interlinks with the conducting wire 82, the effect of suppressing the eddy current of the conducting wire 82 against the eddy current can be obtained. As a result, the eddy current flowing through the conducting wire 82 can be reduced.

Furthermore, since each conducting wire 82 is constructed by twisting the strands 86, there are parts in each strand 86 where the directions of magnetic field application are opposite to each other, and the back electromotive force caused by the interlinkage magnetic field cancels out. be done. As a result, the effect of reducing the eddy current flowing through the conducting wire 82 can be enhanced.

Since each strand 86 is made of the fibrous conductive material 87, the current flow path in the conducting wire 82 can be made thinner, and the number of twists of the current flow path can be increased. Thereby, the effect of reducing eddy currents can be enhanced. Note that the strands 86 are preferably made of at least carbon nanotube fibers.

In the stator 50 having a slotless structure, since teeth are not provided, the conductor area WA can be expanded in the circumferential direction compared to the inter-conductor area WB. Thereby, a configuration in which the conductor area WA is larger than the inter-conductor area WB in the circumferential direction can be suitably realized.

Since the turn portions 84 of the stator winding 51 are shifted in the radial direction and have interference avoidance portions that avoid interference with other turn portions 84, different turn portions 84 can be arranged apart from each other in the radial direction. I can do it. Thereby, it is possible to improve the heat dissipation performance in the turn portion 84 as well, and as a result, it is possible to further improve the heat dissipation performance in the stator 50.

As a configuration for avoiding mutual interference in the turn portions 84 of the respective conductive wires 82 on the same pitch circle of the stator 50, the turn portions 84 are formed by an inclined portion 84a (the third portion) which is a portion extending in the circumferential direction on the same pitch circle. 1 portion), a top portion 84b, a slope portion 84c, and a return portion 84d (corresponding to (equivalent to two parts). Thereby, mutual interference at the turn portion 84 can be appropriately avoided.

Among the straight parts 83 of the plurality of layers, the turn part 84 connected to the radially inner straight part 83 and the turn part 84 connected to the radially outer straight part 83 are set to have a diameter smaller than that of the straight parts 83. Since they are arranged apart in the direction, the heat dissipation performance in the turn portion 84 can be improved.

Since the bending radius of the bent portion in the turn portion 84 is made different between the turn portion 84 connected to the straight portion 83 on the radially inner side and the turn portion 84 connected to the straight portion 83 on the radially outer side, each turn The portions 84 can be suitably spaced apart.

In the turn part 84, the amount of radial shift from the straight part 83 at the bent part is determined by the turn part 84 connected to the straight part 83 on the radially inner side and the turn part 84 connected to the straight part 83 on the radially outer side. Since they are different from each other, the respective turn portions 84 can be appropriately spaced apart from each other.

Note that the polar anisotropic structure of the magnet portion 42 is not limited to the above example. In the example shown in FIGS. 22 and 23, the magnet section 42 is configured using a magnet arrangement called a Halbach arrangement. The magnet portion 42 includes a first magnet 131 whose magnetization direction (orientation of magnetic poles) is the radial direction, and a second magnet 132 whose magnetization direction (orientation of the magnetic poles) is the circumferential direction. First magnets 131 are arranged at predetermined intervals in the circumferential direction, and second magnets 132 are arranged at positions between adjacent first magnets 131 in the circumferential direction. The first magnet 131 and the second magnet 132 are permanent magnets made of rare earth magnets such as neodymium magnets.

The first magnets 131 are spaced apart from each other in the circumferential direction so that the poles on the side facing the stator 50 (inside in the radial direction) are alternately N and S poles. Further, the second magnets 132 are arranged next to each of the first magnets 131 so that the directions of the magnetic poles in the circumferential direction are alternately opposite to each other.

Further, a magnetic body 133 made of a soft magnetic material is arranged on the radially outer side of the first magnet 131, that is, on the side of the magnet holding part 43 of the rotor main body 41. For example, the magnetic body 133 is preferably made of an electromagnetic steel plate, soft iron, or powder core material. In this case, the circumferential length of the magnetic body 133 is the same as the circumferential length of the first magnet 131, particularly the circumferential length of the outer circumference of the first magnet 131. Further, the radial thickness of the first magnet 131 and the magnetic body 133 in the integrated state is the same as the radial thickness of the second magnet 132. In other words, the first magnet 131 is thinner in the radial direction than the second magnet 132 by the amount of the magnetic body 133 . The magnets 131, 132 and the magnetic body 133 are fixed to each other, for example, with an adhesive. In the magnet portion 42 , the radially outer side of the first magnet 131 is opposite to the stator 50 . The magnetic body 133 is provided on the opposite side to the stator 50 (on the anti-stator side) among both sides of the first magnet 131 in the radial direction.

A key 134 is formed on the outer peripheral portion of the magnetic body 133 as a convex portion that protrudes radially outward, that is, toward the magnet holding portion 43 of the rotor body 41 . Further, a key groove 135 is formed in the inner circumferential surface of the magnet holding portion 43 as a recess for accommodating the key 134 of the magnetic body 133. The protruding shape of the key 134 and the groove shape of the key groove 135 are the same, and the same number of key grooves 135 as the keys 134 are formed corresponding to the keys 134 formed in each magnetic body 133.

The engagement of the key 134 and the keyway 135 suppresses misalignment between the first magnet 131 and the second magnet 132 and the rotor body 41 in the circumferential direction (rotational direction). Note that the key 134 and the keyway 135 (convex portion and concave portion) may be provided on either the magnet holding portion 43 of the rotor main body 41 or the magnetic body 133 as desired. It is also possible to provide a key groove 135 in the rotor body 41 and a key 134 in the inner peripheral part of the magnet holding part 43 of the rotor main body 41.

Here, in the magnet section 42, by alternately arranging the first magnets 131 and the second magnets 132, it is possible to increase the magnetic flux density in the first magnets 131. Therefore, in the magnet portion 42, the magnetic flux is concentrated on one side, and the magnetic flux can be strengthened on the side closer to the stator 50.

Further, by arranging the magnetic body 133 on the radially outer side of the first magnet 131, that is, on the anti-stator side, it is possible to suppress partial magnetic saturation on the radially outer side of the first magnet 131, and as a result, magnetic saturation caused by magnetic saturation can be suppressed. Demagnetization of the first magnet 131 that occurs due to this can be suppressed. This makes it possible to increase the magnetic force of the magnet portion 42 as a result. In other words, the magnet portion 42 has a structure in which a portion of the first magnet 131 where demagnetization is likely to occur is replaced with a magnetic body 133.

FIG. 24 is a diagram specifically showing the flow of magnetic flux in the magnet section 42, in which (a) shows the case where a conventional configuration in which the magnet section 42 does not have the magnetic body 133 is used, and (b) , a case is shown in which a configuration in which the magnet portion 42 includes a magnetic body 133 is used. In addition, in FIG. 24, the magnet holding part 43 and the magnet part 42 of the rotor main body 41 are shown developed linearly, and the lower side of the figure is the stator side and the upper side is the anti-stator side.

In the configuration of FIG. 24A, the magnetic pole surface of the first magnet 131 and the side surface of the second magnet 132 are in contact with the inner circumferential surface of the magnet holding part 43, respectively. Further, the magnetic pole surface of the second magnet 132 is in contact with the side surface of the first magnet 131. In this case, in the magnet holding part 43, there is a magnetic flux F1 that passes through the outer path of the second magnet 132 and enters the contact surface with the first magnet 131, and a magnetic flux F1 that is substantially parallel to the magnet holding part 43 and of the second magnet 132. A composite magnetic flux with the magnetic flux that attracts F2 is generated. Therefore, there is a concern that magnetic saturation may occur partially in the vicinity of the contact surface between the first magnet 131 and the second magnet 132 in the magnet holder 43.

On the other hand, in the configuration of FIG. 24(b), the magnetic body 133 is provided between the magnetic pole face of the first magnet 131 and the inner peripheral surface of the magnet holding part 43 on the anti-stator side of the first magnet 131. Therefore, the magnetic body 133 allows the magnetic flux to pass through. Therefore, magnetic saturation in the magnet holder 43 can be suppressed, and resistance to demagnetization is improved.

Moreover, in the configuration of FIG. 24(b), unlike FIG. 24(a), F2 that promotes magnetic saturation can be turned off. Thereby, the permeance of the entire magnetic circuit can be effectively improved. With this configuration, the magnetic circuit characteristics can be maintained even under severe high temperature conditions.

Furthermore, compared to the radial magnet in a conventional SPM rotor, the magnet magnetic path passing through the inside of the magnet is longer. Therefore, the magnet permeance increases, the magnetic force can be increased, and the torque can be enhanced. Furthermore, by concentrating the magnetic flux at the center of the d-axis, it is possible to increase the sinusoidal matching rate. In particular, the torque can be increased more effectively by using PWM control to make the current waveform a sine wave or trapezoidal wave, or by using a 120-degree energizing switching IC.

In the above example, the outer circumferential surface of the stator core 52 is curved without irregularities, and the plurality of conducting wire groups 81 are arranged on the outer circumferential surface at predetermined intervals, but this may be changed. For example, in the example shown in FIG. 25, the stator core 52 includes an annular yoke portion 141 provided on the opposite side from the rotor (lower side in the figure) among both radial sides of the stator winding 51; It has a protrusion 142 extending from the yoke portion 141 so as to protrude between circumferentially adjacent straight portions 83 . The protrusions 142 are provided at predetermined intervals on the radially outer side of the yoke portion 141, that is, on the rotor 40 side. Each conducting wire group 81 of the stator winding 51 engages with the protrusion 142 in the circumferential direction, and is arranged side by side in the circumferential direction using the protrusion 142 as a positioning part.

The protruding portion 142 has a radial thickness dimension from the yoke portion 141 that is equal to the radial thickness dimension of the straight portion 83 adjacent to the yoke portion 141 in the radial direction among the multiple layers of straight portions 83 inside and outside the radial direction. The structure is smaller than 1/2 (H1 in the figure). Due to the limited thickness of the protrusion 142, the protrusion 142 does not function as a tooth between the circumferentially adjacent conductor groups 81 (that is, the straight portions 83), and the teeth do not form a magnetic path. . The protrusions 142 do not need to be provided between all of the conductive wire groups 81 arranged in the circumferential direction, but may be provided between at least one set of conductive wire groups 81 adjacent in the circumferential direction. The shape of the protrusion 142 may be any shape such as a rectangular shape or an arc shape.

Note that the straight portion 83 may be provided in one layer on the outer peripheral surface of the stator core 52. Therefore, in a broad sense, the thickness of the projection 142 in the radial direction from the yoke portion 141 may be smaller than 1/2 of the thickness of the straight portion 83 in the radial direction.

Assuming an imaginary circle centered on the axis of the rotating shaft 11 and passing through the radial center position of the straight portion 83 radially adjacent to the yoke portion 141, the protrusion 142 will fit within the yoke within the range of the imaginary circle. It is preferable to have a shape that projects from the portion 141, in other words, a shape that does not project outward in the radial direction from the virtual circle (that is, toward the rotor 40).

According to the above configuration, the protrusion 142 has a limited thickness dimension in the radial direction and does not function as teeth between the circumferentially adjacent straight parts 83. The adjacent straight portions 83 can be brought closer to each other than in the case where the straight portions 83 are provided. Thereby, the cross-sectional area of the conductor can be increased, and the heat generated as the stator winding 51 is energized can be reduced. In this configuration, since there are no teeth, magnetic saturation can be eliminated, and the current flowing to the stator winding 51 can be increased. In this case, it is possible to suitably deal with the fact that the amount of heat generated increases with the increase in the applied current. In addition, in the stator winding 51, the turn portions 84 are shifted in the radial direction and have an interference avoidance portion that avoids interference with other turn portions 84. Therefore, different turn portions 84 are separated from each other in the radial direction. can be placed. Thereby, the heat dissipation performance of the turn portion 84 can also be improved. As described above, it is possible to optimize the heat dissipation performance of the stator 50.

Further, if the yoke portion 141 of the stator core 52 and the magnet portion 42 of the rotor 40 (that is, each magnet 91, 92) are separated by a predetermined distance or more, the radial thickness dimension of the projection portion 142 is It is not bound by H1 of 25. Specifically, as long as the yoke portion 141 and the magnet portion 42 are separated by 2 mm or more, the radial thickness dimension of the projection portion 142 may be equal to or more than H1 in FIG. 25. For example, if the radial thickness of the straight portion 83 exceeds 2 mm and the conductive wire group 81 is composed of two layers of conductive wires 82, inside and outside in the radial direction, the straight portion 83 that is not adjacent to the yoke portion 141 In other words, the protrusion 142 may be provided in a range up to a half-way position of the second layer conductive wire 82 counting from the yoke portion 141. In this case, if the radial thickness dimension of the protrusion 142 is up to "H1 x 3/2", the above-mentioned effect can be obtained to some extent by increasing the cross-sectional area of the conductor in the conductive wire group 81.

Further, the stator core 52 may have the configuration shown in FIG. 26. Note that although the sealing portion 57 is omitted in FIG. 26, the sealing portion 57 may be provided. In FIG. 26, for convenience, the magnet portion 42 and the stator core 52 are shown expanded in a straight line.

In the configuration of FIG. 26, the stator 50 has a protrusion 142 as an inter-winding member between the conductive wires 82 (that is, straight portions 83) adjacent in the circumferential direction. Here, Wt is the circumferential width of the projection 142 that is excited by energization of the stator winding 51 in the range of one pole of the magnet 42, Bs is the saturation magnetic flux density of the projection 142, and Bs is the saturation magnetic flux density of the projection 142. If the circumferential width of one pole is Wm, and the residual magnetic flux density of the magnet portion 42 is Br,
The protrusion 142 satisfies Wt×Bs≦Wm×Br (1)
It is made of magnetic material.

Specifically, the three-phase winding of the stator winding 51 is a distributed winding, and in the stator winding 51, the number of protrusions 142, that is, the number of protrusions 142 between each conductor group 81 for one pole of the magnet part 42 is The number of gaps 56 is 3×m. Note that m is the logarithm of the conducting wire 82. In this case, when the stator winding 51 is energized for each phase in a predetermined order, the projections 142 for two phases are excited within one pole. Therefore, the circumferential width dimension Wt of the protrusion 142 that is excited by energization of the stator winding 51 in the range of one pole of the magnet part 42 is the circumferential width dimension of the protrusion 142 (that is, the gap 56). Letting A be 2×A×m. Then, after the width dimension Wt is defined in this way, the protrusion 142 in the stator core 52 is formed of a magnetic material that satisfies the relationship (1) above. Note that the width dimension Wt is also the circumferential dimension of a portion where the relative magnetic permeability can be larger than 1 within one pole.

Note that when the stator winding 51 is a concentrated winding, the number of protrusions 142, that is, each conducting wire group 81, for one pole pair (that is, two poles) of the magnet portion 42 in the stator winding 51 The number of gaps 56 between the two is 3×m. In this case, when the stator winding 51 is energized for each phase in a predetermined order, the projections 142 for one phase are excited within one pole. Therefore, the circumferential width dimension Wt of the protrusion 142 that is excited by energization of the stator winding 51 within the range of one pole of the magnet portion 42 is “A×m”. After the width dimension Wt is defined in this way, the protrusion 142 is formed of a magnetic material that satisfies the relationship (1) above.

By the way, for magnets with a BH product of 20 [MGOe (kJ/m ³ )] or more, such as neodymium magnets, samarium cobalt magnets, and ferrite magnets, Bd = a little over 1.0 [T], and for iron, Br = a little over 2.0 [T]. It is. Therefore, in the stator core 52, the protrusion 142 may be made of a magnetic material that satisfies the relationship Wt<1/2×Wm for a high-output motor.

In the above example, the sealing portion 57 covering the stator winding 51 is arranged in a range including all of the conductor groups 81 on the radial outer side of the stator core 52, that is, the radial thickness dimension is the diameter of each conductor group 81. Although the configuration is such that it is provided in a range larger than the thickness dimension in the direction, this may be changed. For example, as shown in FIG. 27, the sealing portion 57 is provided so that a portion of the conducting wire 82 protrudes. More specifically, the sealing portion 57 is provided in such a manner that a part of the conductive wire 82 which is the most radially outermost in the conductor group 81 is exposed to the radially outer side, that is, to the stator 50 side. In this case, the radial thickness of the sealing portion 57 is preferably the same as or smaller than the radial thickness of each conducting wire group 81.

Further, as shown in FIG. 28, each conducting wire group 81 may be configured not to be sealed by the sealing portion 57. In other words, the configuration is such that the sealing portion 57 that covers the stator winding 51 is not used. In this case, there is a gap between each of the conducting wire groups 81 arranged in the circumferential direction.

The stator 50 may be configured without the stator core 52. In this case, the stator 50 will be comprised of stator windings 51 shown in FIG. 12. Note that in the stator 50 that does not include the stator core 52, the stator winding 51 may be sealed with a sealing material. Alternatively, the stator 50 may be configured to include an annular winding holding portion made of a non-magnetic material such as synthetic resin instead of the stator core 52 made of a magnetic material.

In the conducting wire group 81 of the stator winding 51, as shown in FIG. 29(a), turn portions 84 are formed in the n-th layer and the The direction of the conductor wire shift may be reversed. In other words, the turn portions 84 connected to the straight portions 83 of the plurality of layers and located at positions that overlap inside and outside in the radial direction are bent in different directions in the radial direction. Thereby, the respective turn portions 84 can be appropriately spaced apart from each other. Note that this configuration is preferably applied to the part where insulation is most severe, or used as the final layer or starting layer among multiple layers.

Alternatively, as shown in FIG. 29(b), the conductor shift position in the axial direction (position in the vertical direction in the figure) may be different between the n-th layer and the (n+1)-th layer. In this case, even if the bending radius at the turn portion 84 of each layer is the same, mutual interference can be suppressed.

In the above example, in the stator winding 51, the straight portions 83 located on the same pitch circle centered on the rotating shaft 11 are connected by the turn portion 84, and the turn portion 84 includes the interference avoidance portion. Although this is the configuration, this may be changed. For example, in the stator winding 51, the straight portions 83 located on different pitch circles around the rotating shaft 11, that is, the straight portions 83 of different layers, may be connected by the turn portions 84. . In any case, it is sufficient that the turn portion 84 is shifted in the radial direction and has an interference avoidance portion that avoids interference with other turn portions 84 .

As shown in FIG. 30(a), in the conductor group 81 of the stator winding 51, the straight portions 83 of each conductor 82 have a pair of opposing surfaces that are radially opposed (up and down in the figure) and are non-parallel to each other. It is also possible to have a configuration in which it is arranged as follows. In addition, in FIG. 30(a), each conducting wire group 81 is sealed by a sealing part 57. According to this configuration, a sealing material as a non-heat generating part can be interposed between each of the straight parts 83 arranged in the radial direction, and in the non-heat generating part, when the stator winding 51 is energized, the straight part The heat generated at step 83 can be diffused. Thereby, the heat dissipation performance of the conducting wire group 81 can be improved.

Furthermore, even if the teeth are not interposed between the straight portions 83 adjacent to each other in the circumferential direction, the sealing material can be suitably inserted between the straight portions 83 in each conductive wire group 81, and each The straight portion 83 can be fixed well. However, in the configuration of FIG. 30(a), the sealing portion 57 may not be provided. In this case, a gap serving as a non-heat generating portion can be interposed between each of the linear portions 83 arranged in the radial direction, and the heat dissipation performance of the conducting wire group 81 can also be improved.

As shown in FIG. 30(b), in the conductor group 81 of the stator 50, the straight portions 83 of each conductor 82 are arranged in four layers, inside and outside in the radial direction, and the gap size between the pair of opposing surfaces is large and small in the circumferential direction. It is also possible to have a configuration in which the gap is different and the larger side is alternately reversed in each gap arranged in the radial direction. In addition, in FIG. 30(b), each conducting wire group 81 is sealed by a sealing part 57. The number of layers of the straight portion 83 may be three or more. According to this configuration, heat can be suitably diffused in each straight portion 83 arranged in the radial direction.

Further, even if the rotation direction is switched between forward and reverse during operation of the rotating electric machine 10, a good holding force for holding each straight portion 83 can be obtained.

In the stator winding 51, the straight portion 83 of the conducting wire 82 may be provided in a single layer in the radial direction. Further, when the linear portion 83 is arranged in multiple layers inside and outside in the radial direction, the number of layers may be arbitrary, and may be provided in three, four, five, six, etc. layers.

In the example described above, the rotating shaft 11 was provided so as to protrude from both one end side and the other end side of the rotating electric machine 10 in the axial direction, but this may be changed and the rotating shaft 11 may be configured to protrude only from one end side. In this case, the rotating shaft 11 is preferably provided so as to extend outward in the axial direction, with the end portion being supported in a cantilever manner by the bearing portion 20 . In this configuration, since the rotating shaft 11 does not protrude into the inside of the inverter unit 60, the internal space of the inverter unit 60, specifically, the internal space of the cylindrical portion 71, can be used more widely.

As a configuration for rotatably supporting the rotating shaft 11, a configuration may be adopted in which bearings are provided at two locations on one end side and the other end side in the axial direction of the rotor 40. In this case, in terms of the configuration shown in FIG. 1, bearings may be provided at two locations, one end side and the other end side, with the inverter unit 60 interposed therebetween.

In the above example, the intermediate portion 45 of the rotor main body 41 of the rotor 40 is configured to have a step in the axial direction, but this may be changed and the intermediate portion 45 may have a flat plate shape without the step.

In the above example, the conductor 82a of the conductor 82 of the stator winding 51 is configured as an aggregate of a plurality of strands 86, but this may be changed to a configuration in which a square conductor with a rectangular cross section is used as the conductor 82. . Furthermore, a configuration may be adopted in which a round conductor wire having a circular cross section or an elliptical cross section is used as the conductor wire 82.

In the above example, the inverter unit 60 is provided inside the stator 50 in the radial direction, but instead of this, the inverter unit 60 may not be provided inside the stator 50 in the radial direction. In this case, it is possible to leave an internal region on the radially inner side of the stator 50 as a space. Moreover, it is possible to arrange components different from the inverter unit 60 in the internal area.

The rotating electrical machine 10 may be configured without the housing 30. In this case, the rotor 40, stator 50, etc. may be held in a part of a wheel or other vehicle component, for example.

It is also possible to apply the present disclosure to a rotating electrical machine with an inner rotor structure (internal rotation structure). In this case, for example, the stator 50 and the rotor 40 may be provided in the housing 30 in this order from the outside in the radial direction, and the inverter unit 60 may be provided inside the rotor 40 in the radial direction. In the above example, an SPM rotor is used as the rotor, but it is also applicable to an IPM rotor. In this case, the straight portion 83 provides a magnet facing portion that is arranged to face the magnet portion 42 with a predetermined air gap and a rotor core (not shown) in between.

<Control device and rotating electrical machine system>
First, a rotating electrical machine system including the control device 110 will be described based on FIG. 31.

As shown in FIG. 31, the rotating electrical machine system 150 includes the above-described rotating electrical machine 10, an inverter 100, a control device 110, a winding temperature sensor 151, and a current sensor 152. Inverter 100 corresponds to inverters 101 and 102 described above.

The control device 110 is configured to be able to communicate with an ECU 200, which is another electronic control device, via a bus 201, for example. At least one ECU 200 is capable of communicating with the control device 110. One of the ECUs 200 is, for example, an electronic control device at a higher level than the control device 110. One of the ECUs 200 outputs a torque command value to the control device 110.

Winding temperature sensor 151 detects the temperature of stator winding 51. As the winding temperature sensor 151, for example, a thermistor or a thermoelectric stack can be used. In this way, a temperature detection section is provided on the stator 50 side. On the other hand, no temperature detection section is provided on the rotor 40 side.

Current sensor 152 detects the current flowing through stator winding 51 of each phase. That is, phase current is detected. In this embodiment, a current sensor 152 is provided for each of the three phases. However, the current sensor 152 may be provided only for two phases, and the current of the remaining one phase may be detected based on the detection results of the two phases.

Next, processing executed by the control device 110 according to this embodiment will be described based on FIG. 32. The control device 110 repeatedly executes the process shown in FIG. 32 at a predetermined period while the ignition switch is turned on and power is supplied.

As shown in FIG. 32, first, the control device 110 acquires the temperature of the stator winding 51 (stator coil) from the winding temperature sensor 151 (step S10). Below, the temperature of the stator winding 51 may be simply referred to as winding temperature.

Next, the control device 110 estimates the temperature of the magnet section 42 (permanent magnet) included in the rotor 40 based on the acquired winding temperature (step S20). For example, the control device 110 may have a map in advance showing the correlation between the winding temperature and the magnet temperature in its memory, and may estimate the temperature of the magnet portion 42 using this map. The temperature of the magnet section 42 may be estimated using a function that shows the correlation between the winding temperature and the magnet temperature. For example, the control device 110 may estimate the temperature of the magnet section 42 by multiplying the obtained winding temperature by a predetermined damping coefficient.

The control device 110 may estimate the temperature of the magnet section 42 from the winding temperature during a predetermined period. For example, assuming that the temperature of the magnet section 42 changes mainly due to heat received from the stator winding 51, the winding during a predetermined period (m+1) from time (n-m) to time n, as shown in the following formula, Calculate the average value of the temperature _ts . Then, the average value of the calculated winding temperature t _s may be set as the temperature t _rn of the magnet portion 42 at time n. Note that t _sn is the winding temperature at time n, and t _{s (nm)} is the winding temperature at time (n - m) (Formula 1) t _rn = {t _{s (n - m)} + t _s(n-m+1) +...+t _s(n-1) +t _sn }/(m+1)

Next, the control device 110 sets an overcurrent threshold value of the current flowing through the stator winding 51 according to the estimated magnet temperature (step S30). The overcurrent threshold is an overcurrent protection value set so as not to exceed the magnetic pole limit current value. The magnetic pole limit current value changes depending on the temperature of the magnet section 42. The overcurrent threshold value is set by adding a predetermined margin to the demagnetization limit current value. Control device 110 sets a large value as the overcurrent threshold when the estimated magnet temperature is low, and sets a smaller value as the overcurrent threshold when the estimated magnet temperature is high than when the estimated magnet temperature is low.

Next, the control device 110 obtains the current value flowing through each phase from the current sensor 152 (step S40). Then, the control device 110 determines whether the current value is larger than the overcurrent threshold (step S50). That is, it is determined whether there is a possibility that demagnetization will occur.

If the current value exceeds the overcurrent threshold, there is a risk that demagnetization will occur, so the control device 110 executes current limiting control (step S60). On the other hand, if the current value is less than or equal to the overcurrent threshold, there is no possibility that demagnetization will occur, so the control device 110 executes normal control in which the energizing current is not limited (step S70). In this way, the control device 110 controls the driving of the rotating electric machine 10, specifically, the switches Sp and Sn of the inverter 100, based on the result of the overcurrent determination. After executing the process of step S60 or step S70, the control device 110 ends the series of processes.

Control device 110 calculates a target current value based on the torque command value acquired from ECU 200 during execution of normal control. Then, feedback control (the above-mentioned PI control) is executed so that the actual current value acquired from the current sensor 152 follows the target current value, and a switch operation signal with a predetermined duty ratio is generated.

The control device 110 limits the energizing current when executing the current limiting control compared to the normal control. For example, in a configuration in which an upper limit guard value of the duty ratio is set, the control device 110 sets a lower value than during normal control as the upper limit guard value. Since the duty ratio of the switch operation signal is set so as not to exceed the upper limit guard value, the energizing current can be limited with respect to normal control.

Further, the target current value may be corrected. For example, a value corresponding to the overcurrent threshold value may be subtracted from the target current value to obtain the corrected target current value. Since the feedback control is executed based on the corrected target current value, the energizing current can be limited compared to the normal control.

Note that the processing in steps S10 and S20 corresponds to the temperature estimation section. The processing in steps S30, S40, and S50 corresponds to an overcurrent determination section. The processing in steps S60 and S70 corresponds to the control section.

<Summary of the first embodiment>
FIG. 33 is a diagram showing the gap between the magnet section and the stator winding. FIG. 33(a) shows a comparative example, and FIG. 33(b) shows the configuration of this embodiment. In FIG. 33, the rotor 40 and stator 50 are illustrated in a simplified manner. In the comparative example, r is added to the end of the code of the corresponding element in the present embodiment.

In the comparative example shown in FIG. 33(a), the stator 50r has teeth 52r. The stator winding 51r is arranged in the slot formed by the teeth 52r of the stator core. The stator winding 51r is located further away from the magnet portion 42r of the rotor 40r than the tip end surface of the teeth 52r. Heat transfer between the magnet portion 42r and the stator winding 51r is performed via the stator core (teeth 52r) and the air gap.

As shown in FIG. 33(b), in this embodiment, the stator 50 has a slotless structure without slots formed by magnetic teeth. Heat transfer between the magnet portion 42 and the stator winding 51 is performed not through the stator core 52 but through the air gap. Since there are no teeth, the stator winding 51 can be placed closer to the magnet portion 42 than in the comparative example. Therefore, the temperature of the magnet section 42 can be estimated with high accuracy based on the temperature of the stator winding 51.

FIG. 34 is a diagram showing the relationship between ampere turns of the stator winding and magnetic flux. As mentioned above, torque and magnetic flux are in a proportional relationship. The broken line shown in FIG. 34 shows the above-described comparative example, and the solid line shows the configuration of this embodiment. In the comparative example, convergence occurs due to magnetic saturation. On the other hand, in this embodiment, since a slotless structure is adopted, there is no convergence due to magnetic saturation. For this reason, control is performed by determining the demagnetization limit.

Demagnetization of a permanent magnet is affected not only by external magnetic fields, for example those caused by current flowing through the stator windings, but also by temperature. In the case of rare earth magnets, demagnetization occurs especially on the high temperature side. For example, the demagnetizing limit current value is 1000 A at the upper limit temperature of use (180° C.), and 1200 A at room temperature (20° C.). Thus, the higher the temperature, the lower the demagnetization limit. If the demagnetization limit is exceeded, irreversible demagnetization occurs.

As in the past, when temperature is not considered, a fixed value is set as the overcurrent threshold. When setting an overcurrent threshold value based on the demagnetization limit current value at room temperature, it is necessary to provide a large margin in order to prevent the demagnetization limit current value from being exceeded even at high temperatures. Therefore, there was a problem that the usable current range was narrow.

In contrast, the control device 110 according to the present embodiment can switch the overcurrent threshold depending on the estimated magnet temperature. As described above, the demagnetization limit changes depending on the temperature of the magnet section 42. The control device 110 can set the overcurrent threshold according to the temperature of the magnet section 42. The control device 110 can set a value corresponding to the demagnetization limit current value at the estimated magnet temperature as the overcurrent threshold. In this way, since an excessive margin is not provided, the usable current range can be widened while suppressing demagnetization.

As described above, the example in which the control device 110 includes the driver 117 has been shown, but the control device 110 is not limited thereto. A driver 117 may be provided separately from the control device 110. Further, the control device 110 may have at least part of the functions of the ECU 200, for example, the function of generating a torque command value. Although the control device 110 is shown as an example of the control device that controls the rotating electric machine 10, the inverter 100 may also be included. Further, a winding temperature sensor 151 may be included together with the control device 110 as a control device that controls the rotating electric machine 10.

(Second embodiment)
This embodiment is a modification based on the previous embodiment. In the above embodiment, no particular mention was made of the arrangement of the winding temperature sensor. Instead, in this embodiment, the winding temperature sensor is fixed to the coil side of the stator winding.

In the example shown in FIG. 35, a rotating electric machine 10 having an inner rotor structure is employed. Winding temperature sensor 151 is directly fixed to stator winding 51 of stator 51 . The winding temperature sensor 151 is fixed to the stator winding 51 by adhesion, fitting, or the like. The winding temperature sensor 151 is fixed to a coil side portion 53, which is a portion of the stator winding 51 that faces the magnet portion 42 (rotor 40). In this embodiment, the stator 50 does not have a magnetic stator core 52 and is fixed to the outer peripheral surface of the stator winding 51.

<Summary of the second embodiment>
In this embodiment, the winding temperature sensor 151 is fixed to the stator winding 51. Therefore, the temperature of the stator winding 51 can be detected with higher accuracy than, for example, in a configuration in which the stator core 52 is fixed. Thereby, the temperature of the magnet part 42 can be estimated with high accuracy.

In particular, in this embodiment, the winding temperature sensor 151 is fixed to the coil side portion 53 of the stator winding 51, and the distance between the winding temperature sensor 151 and the magnet portion 42 (not shown) is close. Broken arrows shown in FIG. 35 indicate heat transfer paths between the stator winding 51 and the magnet section 42 (rotor 40). The winding temperature sensor 151 can detect the temperature of a portion of the stator winding 51 that has a value closer to the temperature of the magnet portion 42 . Therefore, based on the temperature of the stator winding 51, the temperature of the magnet section 42 can be estimated with higher accuracy.

Although FIG. 35 shows an example of the rotating electric machine 10 having an inner rotor structure, the present invention is not limited to this. As shown in FIG. 36, it can also be applied to a rotating electric machine 10 having an outer rotor structure. Also in FIG. 36, the winding temperature sensor 151 is fixed to the coil side portion 53 of the stator winding 51. Winding temperature sensor 151 is fixed to the inner peripheral surface of stator winding 51. The winding temperature sensor 151 of this embodiment is fixed to either the outer peripheral surface or the inner peripheral surface of the coil side portion 53.

Stator 50 may include a stator core 52. For example, the stator core 52 functioning as a back yoke may be provided so as to avoid the portion to which the winding temperature sensor 151 is fixed.

(Third embodiment)
This embodiment is a modification based on the previous embodiment. In the above embodiment, the winding temperature sensor was fixed to the coil side. Instead, in this embodiment the winding temperature sensor is fixed to the coil end of the stator winding.

In the example shown in FIG. 37, a rotating electric machine 10 having an inner rotor structure is employed. The winding temperature sensor 151 of this embodiment is also directly fixed to the stator winding 51. The winding temperature sensor 151 is fixed to a coil end portion 54 of the stator winding 51 that extends from the coil side portion 53. Also in this embodiment, the stator 50 does not have a magnetic stator core 52 and is fixed to the end face of the stator winding 51.

<Summary of the third embodiment>
Also in this embodiment, the winding temperature sensor 151 is fixed to the stator winding 51. Therefore, the temperature of the stator winding 51 can be detected with high accuracy. Thereby, the temperature of the magnet part 42 can be estimated with high accuracy.

In particular, in this embodiment, the winding temperature sensor 151 is fixed to the coil end portion 54 of the stator winding 51. Therefore, the radial size can be reduced compared to the configuration in which the winding temperature sensor 151 is fixed to the coil side portion 53 as shown by the broken line in FIG. 37.

Although FIG. 37 shows an example of the rotating electric machine 10 having an inner rotor structure, the present invention is not limited to this. It can also be applied to a rotating electric machine 10 having an outer rotor structure. Further, the stator 50 may include a stator core 52. Although an example is shown in which the winding temperature sensor 151 is provided at the coil end portion 54, it may be provided at the coil end portion 55.

(Fourth embodiment)
This embodiment is a modification based on the previous embodiment. In the above embodiment, only the temperature of the stator winding is used as temperature information for estimating the temperature of the permanent magnet. Instead, in this embodiment, the temperature of the stator winding and the temperature of the elements constituting the inverter are used as the temperature information.

As shown in FIG. 38, the rotating electric machine system 150 according to this embodiment further includes a plurality of element temperature sensors 153. The element temperature sensor 153 is provided in each semiconductor module 66 that is an element constituting the inverter 100. The element temperature sensor 153 detects the temperature of the semiconductor module 66, that is, the element temperature. The rotating electric machine system 150 includes only one winding temperature sensor 151.

As the element temperature sensor 153, for example, a temperature-sensitive diode formed on the same semiconductor chip as the switches Sp and Sn can be employed. Furthermore, as the element temperature sensor 153, a thermistor or the like that is integrally sealed with a resin on a semiconductor chip can be used.

In this embodiment, the inverter 100 includes three semiconductor modules 66. The semiconductor module 66 has a 2-in-1 package structure including two arms, one upper arm and one lower arm. One semiconductor module 66 constitutes an upper and lower arm for one phase. As shown in FIG. 39, the rotating electric machine 10 has an outer rotor structure. The three semiconductor modules 66 are arranged circumferentially along the stator 50. A plurality of semiconductor modules 66 constituting the inverter 100 are arranged along the inner peripheral surface of the stator 50. That is, the plurality of element temperature sensors 153 are also arranged along the inner peripheral surface of the stator 50.

Winding temperature sensor 151 is fixed to stator 50 , for example stator core 52 . The arrangement of the plurality of element temperature sensors 153 with respect to the winding temperature sensor 151 is uneven. One of the element temperature sensors 153 is placed near the winding temperature sensor 151. The remaining two element temperature sensors 153 are located apart from the winding temperature sensor 151.

FIG. 40 shows processing executed by the control device 110 according to this embodiment. In this embodiment, the process of step S11, specifically, the process of acquiring the element temperature is added. The control device 110 acquires the element temperature from each of the element temperature sensors 153. Then, based on the winding temperature acquired in step S10 and the element temperature acquired in step S11, the process of step S20, that is, the temperature of the magnet section 42 is estimated. Other processing is the same as in the preceding embodiment (see FIG. 32). The process in step S11 also corresponds to the temperature estimation section.

When the rotating electrical machine 10 is driven, the temperature of the stator winding 51 becomes substantially uniform over the entire region. On the other hand, when the current applied to a particular phase increases, such as when the motor is locked, the temperature of the stator winding 51 becomes uneven. In this embodiment, the rotating electric machine system 150 includes one winding temperature sensor 151 and three element temperature sensors 153. Therefore, even if the temperature of the stator winding 51 is uneven, it is possible to estimate the temperature of the portion where the temperature is high. Thereby, the temperature of the high-temperature portion of the magnet portion 42 can also be estimated.

The control device 110 calculates the difference Δtp between the detected temperature tp1 of the element temperature sensor 153 disposed near the winding temperature sensor 151 and the higher temperature tp2 of the remaining element temperature sensors 153, for example. As described above, the difference Δtp during driving is approximately zero. If the difference Δtp is less than or equal to the predetermined value, the control device 110 estimates the magnet temperature based on the temperature detected by the winding temperature sensor 151. When the difference Δtp exceeds a predetermined value, the control device 110 estimates the magnet temperature based on the value obtained by adding the difference Δtp to the temperature detected by the winding temperature sensor 151.

<Summary of the fourth embodiment>
As described above, the control device 110 according to the present embodiment estimates the magnet temperature based on the temperature of the stator winding 51 and the temperature of the plurality of semiconductor modules 66. Therefore, even if the current applied to a particular phase becomes large and the temperature of the magnet section 42 becomes uneven due to its influence, the magnet temperature of the high temperature section can be estimated from the plurality of element temperature sensors 153. . In other words, even if the temperature at a position away from the winding temperature sensor 151 becomes high, the magnet temperature at the high temperature part can be estimated from the plurality of element temperature sensors 153 provided. Thereby, it is possible to estimate the magnet temperature of a portion where the temperature is high without providing the winding temperature sensor 151 corresponding to each phase. Even if the temperature of the magnet portion 42 is uneven, the usable current range can be widened while suppressing demagnetization.

When the rotating electric machine 10 has an inner rotor structure, the plurality of semiconductor modules 66 are arranged along the outer peripheral surface of the stator 50. The semiconductor module 66 is not limited to a 2-in-1 package structure. For example, a 1-in-1 package structure including only one arm may be adopted.

The magnet temperature estimation method is not limited to the above example. For example, the magnet temperature may be estimated based on the highest temperature detected by the plurality of element temperature sensors 153 and the temperature detected by the winding temperature sensor 151. The magnet temperature may be estimated based on the average value of the temperatures detected by the plurality of element temperature sensors 153 and the temperature detected by the winding temperature sensor 151. Since the higher the temperature, the lower the magnetic pole limit of the magnet section 42 made of rare earth magnets is, it is preferable to use at least the highest detected temperature of the element temperature sensor 153.

Although an example has been shown in which the temperature of the elements constituting the inverter 100 is used as the temperature information together with the temperature of the stator winding 51, the present invention is not limited thereto. Instead of the temperature of the elements constituting the inverter 100, the temperature of a refrigerant in a cooler that cools the rotating electric machine 10 may be used. The cooler is water-cooled or oil-cooled. The cooler is fixed to the outer surface of the housing 30 of the rotating electric machine 10, for example. The cooler is provided integrally with the housing 30, for example. In this case, the refrigerant flows within the housing 30.

For example, the amount of heat transferred from the rotating electrical machine 10 to the refrigerant is calculated from the difference between the refrigerant temperature on the inflow (IN) side and the refrigerant temperature on the discharge (OUT) side of the cooler. The amount of heat transferred changes depending on the amount of heat generated by the rotating electric machine 10. Therefore, the temperature of the magnet portion 42 may be estimated by correcting the winding temperature based on the amount of transferred heat. Alternatively, the average value of the refrigerant temperature over a predetermined period may be calculated, and the temperature of the magnet portion 42 may be estimated based on the calculated average value and the winding temperature. Note that the temperature of the stator winding 51, the temperature of the elements constituting the inverter 100, and the temperature of a refrigerant in a cooler that cools the rotating electric machine 10 may be used as the temperature information.

(Fifth embodiment)
This embodiment is a modification based on the previous embodiment. In the embodiment described above, the overcurrent threshold value is set according to the magnet temperature estimated this time. Instead, in this embodiment, the overcurrent threshold is set using the previously estimated magnet temperature. The previously estimated magnet temperature may hereinafter be referred to as the previous value of the estimated magnet temperature.

As shown in FIG. 41, the rotating electric machine system 150 according to this embodiment further includes a water temperature sensor 154. Water temperature sensor 154 detects the temperature of the cooling water that cools inverter 100, that is, the temperature of the cooling water. At least a portion of the water temperature sensor 154 is arranged in a flow path that cools the inverter 100 (semiconductor module 66). The water temperature sensor 154 is provided on the downstream side of the inverter 100 and detects the cooling water temperature after heat exchange by the inverter 100.

FIG. 42 shows processing executed by the control device 110 according to this embodiment. In this embodiment, steps S8, S9, S11, S12, S20B, S20C, and S80 are added to the process shown in FIG. 32. Further, step S20A is executed instead of the process in step S20.

First, the control device 110 determines whether there is a previous value for the estimated temperature of the magnet section 42 (step S8). The control device 110 determines whether the previous value of the estimated magnet temperature is stored in a memory, for example, a RAM built in the microcomputer. The previous value is held when the power of the control device 110 is turned off, for example, when the ignition switch is turned off (IG off). The ignition switch is a starting switch for the mobile object.

If there is a previous value, then the control device 110 determines whether or not the timing has come when the ignition switch was turned from off to on (step S9). If it is determined that it is not the timing to switch from off to on, the control device 110 executes the processes of steps S11 and S12, as described above, and obtains the winding temperature and the element temperature. Furthermore, in this embodiment, the control device 110 acquires the cooling water temperature from the water temperature sensor 154 (step S12).

Then, the current value of the magnet temperature is estimated based on the stored previous value and the winding temperature, element temperature, and cooling water temperature acquired in steps S10, S11, and S12 (step S20A).

The control device 110 calculates the current value t _n of the estimated magnet temperature, that is, the estimated temperature in the current state, based on the following equation, for example. t _n-1 is the previous value of the estimated magnet temperature, ts is the winding temperature, tp is the element temperature, and tc is the cooling water temperature. α, β, and γ are heat conversion coefficients. In this embodiment, α>β>γ (Formula 2)t _n =t _n-1 +α(t _n-1 -ts)+β(t _n-1 -tp)+γ(t _n-1 - tc)

On the other hand, if it is determined in step S9 that it is the timing to switch from off to on, the control device 110 sets the current value of the estimated magnet temperature according to the stop time from off to on (step S20B).

The stop time can be obtained, for example, from a timer counter that continues to supply power even when the ignition switch is turned off and counts and stores the stop time from OFF to ON. The count value of the timer counter is cleared by saving the stop time. The rotating electric machine system 150 includes such a timer counter. In a configuration in which the control device 110 includes a microcomputer, a timer counter may be provided separately from the microcomputer. The control device 110 may obtain time information from the outside via the bus 201 and calculate the stop time based on this.

Control device 110 compares the stop time with a predetermined value. If the stop time is shorter than a predetermined value, the current value of the estimated magnet temperature is set to, for example, the previous value of the estimated magnet temperature. When the stop time is longer than a predetermined value, the current value of the estimated magnet temperature is set to, for example, the winding temperature obtained by acquiring the winding temperature.

Note that if the stop time is short, the current value of the estimated magnet temperature may be set by acquiring the winding temperature, element temperature, and cooling water temperature and performing the same process as step S20A. Further, a damping coefficient may be provided depending on the stop time. The damping coefficient indicates the temperature change per unit time. For example, the current value may be set by multiplying the previous value of the estimated magnet temperature by the damping coefficient and the stop time.

If it is determined in step S8 that there is no previous value of the estimated magnet temperature, the control device 110 sets a predetermined value as the estimated magnet temperature (step S20C). When the control device 110 is reset by replacing the battery installed in the vehicle, removing the battery terminal, etc., the previous value stored in the memory is also cleared. When initialization such as reset is performed, the control device 110 sets a predetermined value as the current value of the estimated magnet temperature.

As the predetermined value, for example, an allowable upper limit temperature (for example, 180° C.) for suppressing demagnetization of the magnet portion 42 can be set. The winding temperature may be acquired and the acquired winding temperature may be set as the predetermined value. The magnet temperature estimated by a method that does not use the previous value may be set as the predetermined value. For example, the winding temperature may be acquired and the magnet temperature estimated based on the acquired winding temperature may be set as the predetermined value.

After setting the current value of the estimated magnet temperature in any one of steps S20A, S20B, and S20C, the control device 110 then executes the process of step S30, and sets an overcurrent threshold according to the current value of the estimated magnet temperature. The processing from steps S30 to S70 is the same as in the preceding embodiment.

After executing the process of step S60 or step S70, the control device 110 then stores the current value of the estimated magnet temperature set in any one of steps S20A, S20B, and S20C in the memory as the previous value of the estimated magnet temperature (step S80). The previous value of the estimated magnet temperature is updated. Then, the series of processing ends.

Note that the process in step S9 corresponds to the activation determination section. The processing of steps S8, S10, S11, S12, S20A, S20B, S20C, and S80 corresponds to the temperature estimation section.

<Summary of the fifth embodiment>
The stator winding 51 generates heat when energized. The temperature of the magnet section 42 increases due to heat transfer from the stator winding 51. However, since the magnet portion 42 and the stator winding 51 have different thermal masses, there is a difference between the change in the winding temperature and the change in the magnet temperature.

On the other hand, according to the control device 110 according to the present embodiment, as shown in FIG. 43, the current value of the estimated magnet temperature used for overcurrent determination is saved as the previous value of the estimated magnet temperature. Then, the temperature of the magnet section 42 is newly estimated based on the stored previous value and the acquired temperature information such as the winding temperature. In this way, by using the previous value, it is possible to take into account the influence of the amount of heat held by the magnet section 42 itself. Therefore, the accuracy of estimating the temperature of the magnet section 42 can be improved. Thereby, it is possible to suppress the occurrence of demagnetization while making the margin smaller and widening the usable current range.

The temperature information used together with the previous value may include at least the winding temperature. When estimating the current value of the magnet temperature based on the previous value and the winding temperature, the rotating electrical machine system 150 does not include the element temperature sensor 153 and the water temperature sensor 154 as sensors for detecting temperature information, but instead uses the winding temperature sensor 151. All you have to do is prepare.

In this embodiment, winding temperature, element temperature, and cooling water temperature are used as temperature information correlated with magnet temperature. Therefore, even if the temperature of the magnet portion 42 is uneven, the magnet temperature of the higher temperature portion can be estimated. Note that the temperature information used together with the winding temperature may include at least one of the element temperature and the cooling water temperature. Instead of using the cooling water temperature, the winding temperature and the element temperature may be used as shown in the previous embodiment.

As shown in FIG. 44, after the ignition switch is turned off, the winding temperature decreases due to the de-energized state and approaches the magnet temperature. If the stop time is long, the winding temperature will approximately match the magnet temperature. According to the control device 110 according to the present embodiment, when the ignition switch is switched from off to on, the stop time from off to on is acquired, and the current value of the estimated magnet temperature is set according to the stop time.

If the stop time is short, the control device 110 sets the current value of the estimated magnet temperature based on the previous value. When the stop time is long, the control device 110 sets the current value of the estimated magnet temperature based on the acquired temperature information including the winding temperature, without using the previous value. Therefore, the magnet temperature can be estimated with high accuracy when starting the vehicle. Furthermore, by using the attenuation coefficient, the accuracy of estimating the magnet temperature can be further improved.

As described above, when the control device 110 is initialized, the previous value stored in the memory is also cleared. In other words, the previous value cannot be held. It is not preferable to set the winding temperature as the estimated magnet temperature in a state where the winding temperature and the magnet temperature are significantly different from each other. On the other hand, if the allowable upper limit temperature is set as the estimated magnet temperature, demagnetization can be avoided in the state after the control device 110 is initialized. Furthermore, if the magnet temperature is estimated based on temperature information such as the winding temperature when there is no previous value, demagnetization can be suppressed more effectively than when the winding temperature is set as the estimated magnet temperature. .

Although an example has been shown in which the control device 110 executes the process of step S20B when the ignition switch is switched from off to on, the present invention is not limited thereto. The processes of steps S10 to S20A may be executed at the timing of switching from off to on. That is, a configuration may be adopted in which the processes in steps S9 and S20B are not executed.

The timing at which the current value of the estimated magnet temperature is stored as the previous value is not limited to the above example. This may be done after setting the overcurrent threshold according to the estimated magnet temperature.

(Sixth embodiment)
This embodiment is a modification based on the previous embodiment. In the embodiment described above, the switching elements of the inverter are controlled according to the result of overcurrent determination. Instead, in this embodiment, the number of turns of the stator winding can also be changed according to the result of overcurrent determination.

As shown in FIGS. 45 and 46, in a rotating electrical machine system 150 according to the present embodiment, the number of turns of the stator winding 51 that constitutes the rotating electrical machine 10 is controlled by the control device 110. In the stator winding 51, a first turn portion 51c and a second turn portion 51d are arranged in series with respect to the current direction. Hereinafter, the first turn portion 51c and the second turn portion 52d may be referred to as turn portions 51c and 51d. Switches 51e, 51f, and 51g are provided for changing the number of turns.

The switch 51e is provided between the turn portions 51c and 51d. The switch 51f is provided in parallel to the first turn portion 51c and the switch 51e. The switch 51g is provided in parallel to the switch 51e and the second turn portion 51d. The stator windings 51 of each phase have a similar configuration. The control device 110 controls the number of turns of the stator winding 51 of each phase by turning on and off the switches 51e, 51f, and 51g.

FIG. 47 is a flowchart showing the processing executed by the control device 110 according to this embodiment. The difference from the process shown in the preceding embodiment (first embodiment) is that steps S51 to S54 are added.

The processing in steps S10 to S50 is the same as that in FIG. 32. If the current value exceeds the overcurrent threshold, there is a risk that demagnetization will occur, so the control device 110 first executes a process in which the two turn portions 51c and 51d are connected in series (step S51). Specifically, as shown in FIG. 48, the switch 51e is turned on and the switches 51f and 51g are turned off. As a result, the turn portions 51c and 51d are connected in series via the switch 51e. The series connection increases the number of turns (the number of turns) of the stator winding 51 compared to the parallel connection described below. In this way, when it is determined that an overcurrent is flowing, the control device 110 controls the stator winding 51 so that the number of turns of the stator winding 51 becomes a second number of turns that is greater than a first number of turns, which will be described later. The number of turns of the winding 51 is controlled.

Next, the control device 110 executes the process of step S60, that is, current limit control. Then, the series of processing ends.

In step S50, if the current value is less than or equal to the overcurrent threshold, the control device 110 determines whether there is a high torque request (step S52). Control device 110 determines whether there is a high torque request based on the torque command value from ECU 200. The control device 110 determines that there is a high torque request when the torque command value is higher than a predetermined threshold value, and determines that there is no high torque request when the torque command value is less than or equal to the threshold value.

If there is a high torque request, the control device 110 executes a process in which the two turn portions 51c and 51d are connected in series, similar to the process in step S51 (step S53). As described above, the control device 110 controls the switch 51e to turn on and controls the switches 51f and 51g to turn off. The series connection increases the number of turns of the stator winding 51. Next, the control device 110 executes the process of step S70, that is, normal control. Then, the series of processing ends.

On the other hand, if there is no high torque request, the control device 110 executes a process in which the two turn portions 51c and 51d are connected in parallel (step S54). Specifically, as shown in FIG. 49, the switch 51e is turned off, and the switches 51f and 51g are turned on. Thereby, the two turn portions 51c and 51d are connected in parallel. The parallel connection reduces the number of turns in the stator winding 51 relative to the series connection. Next, the control device 110 executes the process of step S70, that is, normal control. Then, the series of processing ends.

In this way, when it is determined that no overcurrent is flowing, the control device 110 sets the number of turns to the first number of turns if the torque command value is less than or equal to the threshold value, and sets the number of turns to the first number of turns if the torque command value is higher than the threshold value. The number of turns of the stator winding 51 is controlled such that the number of turns is greater than the first number of turns. Note that the processing in steps S51 to S54 corresponds to the control section. The number of turns set by the process in step S51 corresponds to the second number of turns. The number of turns set by the process in step S54 corresponds to the first number of turns. The number of turns set by the process in step S53 corresponds to a number of turns greater than the first number of turns.

<Summary of the sixth embodiment>
According to this embodiment, when an overcurrent is flowing, the turn portions 51c and 51d are connected in series. As a result, the stator winding 51 has a high turn count. Since the back electromotive voltage increases due to the high turn, the current flowing can be suppressed. In this way, by increasing the number of turns, it is possible to suppress the occurrence of demagnetization. In combination with current limit control, the effect of suppressing demagnetization can be enhanced.

Furthermore, when no overcurrent is flowing, the number of turns is switched depending on whether or not there is a high torque request. When a high torque is required, the turn portions 51c and 51d are connected in series, and the stator winding 51 has a high turn. This makes it possible to increase the torque. On the other hand, when there is no high torque requirement, the turn portions 51c and 51d are connected in parallel, and the stator winding 51 is reduced in turns. This makes it possible to achieve high output.

Note that the configuration of the stator winding 51 is not limited to the above example. The number of turns of the stator winding 51 is not limited to the above example. The control device 110 may have a first threshold value and a second threshold value lower than the first threshold value as the threshold values to be compared with the torque command value. Control device 110 switches the number of turns of stator winding 51 to increase the number of turns when the torque command value exceeds the first threshold value. Control device 110 switches the number of turns of stator winding 51 to reduce the number of turns when the torque command value decreases to a second threshold value or less. In this way, the number of turns may be changed with hysteresis.

The switching of the number of turns shown in this embodiment may be combined with previous embodiments other than the first embodiment. In the present embodiment, an example has been shown in which the number of turns (second number of turns) set by the process of step S51 is equal to the number of turns set by the process of step S53, but the present invention is not limited to this. The number of turns set in steps S51 and S53 may be different from each other. Although an example has been shown in which the number of turns is switched depending on the presence or absence of a high torque request when no overcurrent is flowing, the present invention is not limited to this. If no overcurrent is flowing, the process of step S54 may be executed to set the first number of turns, regardless of whether there is a high torque request. That is, the number of turns may not be switched based on the torque command value.

The disclosure in this specification, drawings, etc. is not limited to the illustrated embodiments. The disclosure includes the illustrated embodiments and variations thereon by those skilled in the art. For example, the disclosure is not limited to the combinations of parts and/or elements illustrated in the embodiments. The disclosure can be implemented in various combinations. The disclosure may have additional parts that can be added to the embodiments. The disclosure includes those in which parts and/or elements of the embodiments are omitted. The disclosure encompasses any substitutions or combinations of parts and/or elements between one embodiment and other embodiments. The disclosed technical scope is not limited to the description of the embodiments. The technical scope of some of the disclosed technical scopes is indicated by the description of the claims, and should be understood to include equivalent meanings and all changes within the scope of the claims.

The disclosure in the specification, drawings, etc. is not limited by the scope of the claims. The disclosure in the specification, drawings, etc. includes the technical ideas described in the claims, and further extends to a more diverse and broader range of technical ideas than the technical ideas described in the claims. Therefore, various technical ideas can be extracted from the disclosure of the specification, drawings, etc. without being restricted by the claims.

The control device in this specification may also be referred to as an electronic control unit (ECU). The control device or control system is provided by (a) an algorithm as a plurality of logics called if-then-else, or (b) an algorithm as a trained model tuned by machine learning, e.g. a neural network. .

The control device is provided by a control system including at least one computer. A control system may include multiple computers linked by data communication devices. A computer includes at least one processor that is hardware (hardware processor). The hardware processor can be provided by (i), (ii), or (iii) below.

(i) A hardware processor may be at least one processor core that executes a program stored in at least one memory. In this case, the computer is provided by at least one memory and at least one processor core. The processor core is called a CPU, GPU, RISC-CPU, or the like. Memory is also called a storage medium. Memory is a non-transitory and tangible storage medium that non-temporarily stores "programs and/or data" readable by a processor. The storage medium is provided by a semiconductor memory, a magnetic disk, an optical disk, or the like. A program may be distributed alone or as a storage medium in which the program is stored.

(ii) The hardware processor may be a hardware logic circuit. In this case, the computer is provided by a digital circuit containing a large number of programmed logic units (gate circuits). Digital circuits are also called logic circuit arrays, such as ASICs, FPGAs, etc. Digital circuits may include memory that stores programs and/or data. Computers may be provided by analog circuits. Computers may be provided with a combination of digital and analog circuits.

(iii) The hardware processor may be a combination of (i) and (ii) above. (i) and (ii) are placed on different chips or on a common chip. In these cases, part (ii) is also called an accelerator.

The control device 110, the signal source, and the controlled object provide various elements. At least some of those elements can be called blocks, modules, or sections. Moreover, the elements included in the control system are called functional means only if they are intentional.

DESCRIPTION OF SYMBOLS 10... Rotating electric machine, 11... Rotating shaft, 40... Rotor, 42... Magnet part, 50... Stator, 51... Stator winding, 51c... First turn part, 51d... Second turn part, 51e to 51g... Switch, 53... Coil side part, 54, 55... Coil end part, 60... Inverter unit, 66... Semiconductor module, 100... Inverter, 110... Control device, 150... Rotating electric machine system, 151... Winding temperature sensor, 152... Current sensor, 153... Element temperature sensor, 154... Water temperature sensor, 200... Bus, 201... ECU

Claims (12)

A rotating electric machine comprising a rotor (40) having a permanent magnet (42), and a stator (50) having a slotless structure having a stator winding (51) and having no slots formed by magnetic teeth. (10) A control device that controls
a temperature estimation unit (S8, S10, S11, S12, S20, S20A, S20B, S20C, S80) and
An overcurrent threshold for the current flowing through the stator winding is set according to the estimated temperature of the permanent magnet, and the current flowing through the stator winding is acquired, and the stator is adjusted based on the set overcurrent threshold. an overcurrent determination unit (S30, S40, S50) that determines whether the current flowing through the winding is an overcurrent;
a control unit (S51, S52, S53, S54, S60, S70) that controls the rotating electric machine based on the determination result of the overcurrent determination unit ,
The temperature estimating unit stores the estimated temperature of the permanent magnet used in the overcurrent determination as a previous value, and calculates the temperature of the permanent magnet based on the acquired temperature of the stator winding and the previous value. Estimate the temperature,
The temperature estimating unit acquires, as the temperature information, at least one of the temperature of an element (66) constituting the inverter (100) and the temperature of the cooling water that cools the inverter, and calculates the temperature of the element and the cooling water. estimating the temperature of the permanent magnet based on at least one of the temperatures, the obtained temperature of the stator winding, and the previous value;
The rotating electrical machine is applied to a moving body,
further comprising a startup determination unit (S9) that determines whether a startup switch of the mobile body has been switched from off to on;
When the starting switch is switched from off to on, the temperature estimating unit acquires a stop time from when the starting switch is turned off until it is turned on, and when the stopping time is shorter than a predetermined time, The temperature of the permanent magnet is set based on the previous value, and when the stop time is longer than the predetermined time, the temperature of the permanent magnet is set based on the obtained temperature of the stator winding without using the previous value. A control device that estimates The control unit is configured such that when it is determined that the overcurrent is flowing, the number of turns of the stator winding is greater than the first number of turns that is set when it is determined that the overcurrent is not flowing. The control device according to claim 1 , wherein the number of turns of the stator winding is controlled so that the number of second turns is large. A rotating electric machine comprising a rotor (40) having a permanent magnet (42), and a stator (50) having a slotless structure having a stator winding (51) and having no slots formed by magnetic teeth. (10) A control device that controls
a temperature estimation unit (S8, S10, S11, S12, S20, S20A, S20B, S20C, S80) and
An overcurrent threshold for the current flowing through the stator winding is set according to the estimated temperature of the permanent magnet, and the current flowing through the stator winding is acquired, and the stator is adjusted based on the set overcurrent threshold. an overcurrent determination unit (S30, S40, S50) that determines whether the current flowing through the winding is an overcurrent;
a control unit (S51, S52, S53, S54, S60, S70) that controls the rotating electric machine based on the determination result of the overcurrent determination unit ,
The control unit is configured such that when it is determined that the overcurrent is flowing, the number of turns of the stator winding is greater than the first number of turns that is set when it is determined that the overcurrent is not flowing. Controlling the number of turns of the stator winding so that the number of second turns is large,
When it is determined that the overcurrent is not flowing, the control unit controls the number of turns of the stator winding to be the first number of turns when the torque command value for the rotating electric machine is equal to or less than a threshold value, A control device that controls the number of turns of the stator winding such that when the value is higher than the threshold, the number of turns of the stator winding is greater than the first number of turns. The temperature estimating unit acquires temperatures of a plurality of elements (66) constituting the inverter (100) as the temperature information, and estimates the temperature of the permanent magnet based on the temperature of the stator winding and the temperature of the elements. The control device according to claim 3, which estimates temperature. The temperature estimating unit stores the estimated temperature of the permanent magnet used in the overcurrent determination as a previous value, and calculates the temperature of the permanent magnet based on the acquired temperature of the stator winding and the previous value. The control device according to claim 3, which estimates temperature. The temperature estimating unit acquires, as the temperature information, at least one of the temperature of an element (66) constituting the inverter (100) and the temperature of the cooling water that cools the inverter, and calculates the temperature of the element and the cooling water. The control device according to claim 5, wherein the temperature of the permanent magnet is estimated based on at least one of the temperatures, the acquired temperature of the stator winding, and the previous value. The rotating electrical machine is applied to a moving body,
further comprising a startup determination unit (S9) that determines whether a startup switch of the mobile body has been switched from off to on;
When the starting switch is switched from off to on, the temperature estimating unit acquires a stop time from when the starting switch is turned off until it is turned on, and when the stopping time is shorter than a predetermined time, The temperature of the permanent magnet is set based on the previous value, and when the stop time is longer than the predetermined time, the temperature of the permanent magnet is set based on the obtained temperature of the stator winding without using the previous value. The control device according to claim 5 or 6, which estimates . 7. The control device according to claim 5, wherein when the previous value is not held, the temperature estimator sets an allowable upper limit temperature as the estimated temperature of the permanent magnet. A stator with a slotless structure that has a rotor (40) that has a permanent magnet (42) and is rotatably supported, and a stator winding (51), and has no slots formed by magnetic teeth ( 50); a rotating electric machine (10) comprising;
an inverter (100) having a switch (Sp, Sn), which switches energization and disconnection to the stator winding by turning on and off the switch;
a winding temperature sensor (151) that detects the temperature of the stator winding;
a current sensor (152) that detects the current flowing through the stator winding;
A control device (110) that controls driving of the switch,
The control device includes:
a temperature estimation unit (S8, S10, S11, S12, S20, S20A, S20B, S20C, S80) and
An overcurrent threshold for the current flowing through the stator winding is set according to the estimated temperature of the permanent magnet, and the current flowing through the stator winding is acquired, and the stator is adjusted based on the set overcurrent threshold. an overcurrent determination unit (S30, S40, S50) that determines whether the current flowing through the winding is an overcurrent;
a control unit (S51, S52, S53, S54, S60, S70) that controls the rotating electric machine based on the determination result of the overcurrent determination unit ;
The inverter is configured to include a plurality of elements,
The device further includes a plurality of element temperature sensors (153) that individually detect the temperature of the elements.
a plurality of the elements are arranged along the stator;
The temperature estimating unit estimates the temperature of the permanent magnet based on the temperature of the stator winding and the temperature of the plurality of elements. The rotating electric machine system according to claim 9 , wherein the winding temperature sensor is fixed to a coil side (53) of the stator winding that faces the permanent magnet. The winding temperature sensor is fixed to the coil end of a coil side (53) facing the permanent magnet in the stator winding and a coil end (54) extending from the coil side. The rotating electric machine system according to item 9 . The rotating electrical machine system according to any one of claims 9 to 11 , wherein the rotating electrical machine is applied to a moving body.

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