JP4374376B2 - Controller-integrated rotating electrical machine - Google Patents

Description

  The present invention relates to a controller-integrated rotating electrical machine in which a rotating electrical machine for driving a load such as an internal combustion engine and a control device for controlling the rotating electrical machine are integrated.

A conventional rotating electrical machine has, for example, a motor generator for controlling start of an engine, and is connected to an inverter device for controlling torque and generated current of the motor generator by a power cable. The inverter device has an intelligent power module (hereinafter referred to as “power module”), an excitation circuit, and a motor controller. Since the power module generates a large amount of heat from the switching element that controls the current that drives the motor generator, A radiator (heat sink) is attached and cooled.
The power module adjusts the current according to a command from the motor controller to drive the motor generator, starts the stopped engine, or causes the motor generator to function as a generator by rotating the engine to charge the battery and operate the auxiliary machine . (For example, refer to Patent Document 1).

JP 2004-304902 A (paragraph numbers 0015 to 0026, FIGS. 1 and 2)

Such a rotating electrical machine has a problem that its performance is limited by the temperature environment of the control device. In other words, the power module of the inverter device is air-cooled by a heat sink, but the water-cooled type is sometimes adopted because the requirement for the reliability of an air-cooling cooling fan that is installed in a severe temperature environment such as an engine room is severe. However, inexpensive natural convection heat sinks are often used because the system becomes expensive.
However, in such a natural convection heat sink, the temperature of the cooling air is high and the heat dissipation performance of the heat sink is poor, so if the switching element temperature does not exceed the upper limit of the operating temperature, the current that drives the motor generator is reduced. There is a limit, the size of the engine that can be started is limited, and the use of a large number of switching elements to start a large engine has been an obstacle to miniaturization.
The present invention has been made to solve the above-described problems, and an object thereof is to realize a rotating electrical machine having improved torque performance for driving a load.

The controller-integrated rotating electrical machine according to the present invention has a rotor and a stator, generates an electric force for starting a load connected to the rotor, and generates a power by receiving the driving force generated by the load. A rotating electrical machine, a control device that incorporates a switching element that controls the rotating electrical machine and is formed integrally with the rotating electrical machine, and a cooling fan that interlocks with the rotor and cools the control device. A first control unit that detects the number of rotations of the cooling fan, and a number of rotations of the cooling fan detected by the first control unit that allows the switching element to operate without exceeding the upper limit of the operating temperature; And second control means for continuously powering the rotating electrical machine.

In the controller-integrated rotating electrical machine of the present invention, the temperature rise of the switching element is estimated by detecting the number of rotations of the cooling fan that is integrated with the rotor and synchronously rotates, thereby energizing time (hereinafter referred to as “power running time”), By controlling the power running time of the rotating electrical machine, the driving performance of the controller-integrated rotating electrical machine can be efficiently exhibited, and the time during which the internal combustion engine or the like can be operated can be lengthened.
In particular, when the rotational speed is more than a predetermined rotational speed that greatly exceeds the cooling performance than the heat generation, the ultimate temperature of the switching element in the control device may exceed the upper limit of the use temperature even when the current for continuously driving the load is supplied. Therefore, the switching element can be normally operated without being destroyed, and the performance of the rotating electrical machine can be sufficiently obtained even when the load is continuously driven.

Embodiment 1 FIG.
In the control apparatus-integrated dynamoelectric machine according to the first embodiment, the rotor rotates in conjunction with the load. Therefore, the cooling fan that is integrated with the rotor and rotates synchronously stops, for example, a load such as an internal combustion engine. During cooling, no cooling air is generated, and at the same time when the load is started by the rotating electrical machine, the cooling fan begins to rotate and cooling air is generated. Therefore, the performance of cooling the control device is improved by increasing the amount of cooling air as the rotational speed of the load increases. For this reason, immediately after starting, the temperature of the switching element in the control device rises, but the temperature of the switching element saturates due to the improvement in cooling performance accompanying the increase in the number of rotations of the rotor, that is, the cooling fan. And if a cooling fan exceeds predetermined rotation speed, since cooling performance will be greatly exceeded rather than heat_generation | fever, the temperature of a switching element will be saturated in the range which does not exceed an operating temperature upper limit.
From this point of view, in the first embodiment, each predetermined rotational speed set while monitoring the rotational speed of the cooling fan is sequentially detected, and the reached rotational speed is equal to or higher than the predetermined rotational speed where the cooling performance greatly exceeds the heat generation. In this case, since the switching element temperature in the control device does not exceed the upper limit of the use temperature even when a current for continuously driving the load is supplied, in such a state, the rotating electric machine is continuously operated.
On the other hand, below the predetermined number of rotations, the cooling performance is small, and the saturation temperature of the switching element exceeds the upper limit of the use temperature. In such a state, the switching element causes thermal destruction by driving the load after setting the powering time to a predetermined powering time at which the temperature of the switching element does not exceed the upper limit of the operating temperature of the switching element. Not work in normal condition.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
In addition, the same code | symbol shows the same or an equivalent part between each figure.
1 is a schematic cross-sectional view of a controller-integrated dynamoelectric machine according to Embodiment 1 of the present invention.
In FIG. 1, the controller-integrated rotating electrical machine 1 has a stator 23 and a rotor 24 housed inside a front bracket 20 and a rear bracket 21.
The stator 23 and the rotor 24 are respectively provided with windings 23 a and 24 a, and the rotor winding 24 a is connected to a brush 28 accommodated in a brush holder 26 through a sliding electrode 27 provided on the shaft 22. They are electrically connected, and current is supplied from the outside.
The control device 2 is placed on the rear bracket 21. In the control unit 2, a power circuit unit 30, a control circuit unit 32, and a shaft rotation detection unit 4 are housed in a resin case 34.
The power circuit unit 30 includes switching elements 30a and 30b for controlling the line current of the rotating electrical machine and heat sinks 30g and 30f for cooling the switching elements. The switching elements 30a and 30b are included in the control circuit unit 32. In response to the gate drive signal from the accommodated controller circuit board 32a, the current flowing through the stator winding 23a is controlled to control the operation of the rotating electrical machine.
On the other hand, the rotation detector 4 is attached to the rear end of the shaft 22. The rotation angle of the shaft 22 enters the controller board 32a from the rotation detection unit 4 through the signal terminal 34b, and is processed as rotation position and rotation number information.

A pulley 25 is attached to the front bracket 20 side opposite to the rear bracket 21 on which the rotation detection unit 4 and the control device unit 2 are mounted. The pulley 25 is connected to a load such as an internal combustion engine such as an engine (not shown) via the pulley 25, and the load is driven using the rotating electrical machine 1.
A cooling fan 24 b synchronized with the rotor 24 is integrally attached to the rotor 24 in the first embodiment.
The cooling fan 24 b sucks cooling air from the shaft axial direction to cool the heat sinks 30 g and 30 f of the power circuit unit 30, and also cools the stator winding 23 a and is discharged outside the rotating electrical machine 1.

FIG. 2 shows a circuit diagram of the controller-integrated dynamoelectric machine according to the first embodiment.
In FIG. 2, the circuit of the rotating electrical machine mainly includes a power circuit section 30, a field circuit section 31, and winding sections 23a and 24a. The power circuit section 30 is connected 35 to the battery 101 side and the stator winding 23a side. The field circuit section 31 is connected 36 to the battery 101 side and the rotor winding 24a. Each phase includes a switching element 30a on the upper arm side 30A and a switching element 30b on the lower arm side 30B, and constitutes a three-phase bridge circuit.
A capacitor 102 is provided between the positive and negative electrodes of the battery 101 in parallel with the battery, and is responsible for supplying a current that changes sharply by switching.
In addition, the power circuit unit 30 and the field circuit unit 31 receive instructions from the control circuit unit 32 and control the switching elements 30a and 30b.
That is, the current supplied to the stator winding 23a is controlled by controlling the switching timing of the switching elements 30a and 30b of the power circuit section 30, while the switching elements 31a and 31b of the field circuit section 31 are controlled. As a result, the current supplied to the rotor winding 24a is controlled, and the torque of the rotating electrical machine 1 is adjusted.
For example, a rotating electrical machine for starting an internal combustion engine such as an engine first turns on the switching elements 30a and 30b while being instructed by the control circuit unit 32 to energize the stator winding 23a to generate torque and rotate the rotating element. Start and start the load.
After that, the control circuit 32 adjusts the timing for increasing the rotation speed of the cooling fan and the timing for turning on / off the switching elements 30a and 30b for each phase, and the state is such that the load is driven with the optimum torque, that is, the power running operation state. .
At this time, while the switching elements 30a and 30b are turned on, the switching elements selectively generate heat due to the resistance inside the switching elements, and the temperature of the switching elements increases with time.
On the other hand, until the rotation of the rotating electrical machine 1 is started, the cooling fan 24b is stopped together with the rotor 24, so that the cooling air does not flow, and the cooling air is generated simultaneously with the rotation.
Since the amount of cooling air increases as the number of rotations of the cooling fan increases, the heat dissipation performance of the heat sink 30g for cooling the switching elements 30a and 30b increases as the number of rotations of the cooling fan increases.
Therefore, the temperature reached by the switching elements 30a and 30b is finally determined by the number of rotations of the cooling fan reached by the rotating electrical machine.

According to the results calculated by the inventors, as shown in FIG. 3, the temperature of the switching element rises after starting, and the temperature rise becomes slow due to the improvement of the heat dissipation performance with the passage of time, that is, the increase of the rotation speed of the cooling fan. Finally, it was found that the tendency to saturation was followed, and that the saturation temperature became lower as the reached rotation speed increased.
The operating temperature of the switching elements 30a and 30b is limited by the characteristics of the material and structure. For example, in the case of a mold packaged MOSFET made of a silicon chip, the upper limit of the operating temperature is 150 ° C. Table 1 shows the time exceeding 150 ° C. after starting.

（注）スイッチング素子の使用温度上限としてＴｊ＝１７５℃を想定。

(Note) Tj = 175 ° C is assumed as the upper limit of operating temperature of switching element

According to Table 1, for example, if the ultimate rotational speed is 1000 rpm, the ultimate temperature of the switching element is 150 ° C. or higher and exceeds the operating temperature. In this case, the switching element is energized by giving a command from the control circuit unit 32 to the power circuit unit 30 by setting the time from the start of start within 30 seconds, and the power running is performed while keeping the temperature of the switching element below the operating temperature. Operation (hereinafter referred to as “operation”) can be performed.
By incorporating such settings into the algorithm of the control circuit, the performance of the rotating electrical machine can be maximized.

There is a positive correlation between the reached rotational speed and the air volume. The smaller the reached rotational speed, the lower the heat dissipation performance of the heat sinks 30g and 30f. For example, the operable time at 1000 rpm is 33 seconds, and at 500 rpm, 18 seconds.
Therefore, if the reached rotation speed is in the range of 500 rpm and 1000 rpm, the operation can be performed satisfactorily without exceeding the upper limit temperature by driving the load by setting the operable time as 18 seconds.
Further, if the number of rotations of the cooling fan reaches 1500 rpm or more, the heat dissipation performance of the heat sinks 30g and 30f will be sufficiently high, so that the temperature reached by the switching element is saturated without exceeding the upper limit of the operating temperature of the switching element.
Accordingly, if it is detected that the motor rotates at 1500 rpm or more, it can be continuously operated.

FIG. 4 is an example of a flow for controlling the above method.
A combination of the range of the rotational speed of the cooling fan to reach and the power running time during which the switching element is operated to continue driving the load is stored in the control circuit unit as a map in advance.
Time measurement is started with the start of operation (S1), and the rotational speed (Xrpm) is detected (S3) after a predetermined time (t1) has elapsed (S2).
Next, the rotation speed range in the map described above and the detected rotation speed are compared and collated (S4), and a time during which operation can be performed (powering time td) is determined by arithmetic processing such as a microcomputer (S5).
While continuing to measure the time, the driving of the load is continued until the power running time td elapses, and the driving is stopped immediately after elapse of td (S6) (S7).
On the other hand, when the detected rotational speed is equal to or higher than the predetermined rotational speed (Xn), the reached rotational speed is sufficiently high and does not exceed the upper limit of the operating temperature of the switching element. ).
If this flowchart is repeatedly executed each time a plurality of predetermined times (t1, t2,..., Tn) have elapsed, more accurate control can be performed (S4).

  As described above, by estimating the temperature rise of the switching element by detecting the rotation speed of the cooling fan and controlling the power running time, the driving performance of the controller-integrated rotating electrical machine can be efficiently exhibited, It is possible to increase the operating time when starting an internal combustion engine or the like. Further, it is possible to drive and assist even at a low rotation.

Embodiment 2. FIG.
FIG. 5 is a temperature rise curve for explaining another embodiment 2 of the present invention, and the two curves in the figure show a case where the initial temperature of the entire rotating electrical machine is different.
The rotating electrical machine has various initial temperature states as the ambient temperature around the rotating electrical machine changes. Especially when it is installed in the engine room of a car, it may start when it is cold, such as when it is first driven, or when it is running continuously and the rotating electrical machine body is hot. The temperature is in a wide range. Therefore, as shown in FIG. 5, when the initial temperature is high (A), even if it exceeds the upper limit of the operating temperature of the switching element, the allowable temperature is sufficiently high when starting from a low temperature (B). The following operation is possible continuously.
Therefore, if the initial temperature of the rotating electrical machine is observed and the operating time, that is, the power running time td is set small when the initial temperature is high, the performance of the controller-integrated rotating electrical machine can be further extracted.

  Further, the stator current varies depending on the state of the rotating electrical machine and the state of the load connected to the rotating electrical machine. In other words, it can be driven with a small stator current when the load is light. In such a case, even if the number of rotations of the cooling fan is small and the cooling capacity is small, the temperature rise of the switching element is reduced. It is possible to further reduce the rotation speed region for driving.

FIG. 6 shows an example of a flow for explaining the second embodiment.
In FIG. 6, the initial temperature of the rotating electrical machine 1 is measured at the start of operation (S1). The initial temperature is the temperature of the rotating electrical machine main body, and a location that can be measured at a position closer to the power circuit unit 30 is measured by a temperature sensor such as a thermistor.
Time measurement is started at the start of operation (S2), and a relationship map between the rotational speed and the power running time is created in advance for each predetermined range of the initial temperature, that is, a plurality of maps are generated for each predetermined range of the initial temperature. The map to which the measured initial temperature is applied is selected (S3).
When the predetermined time (t1) has elapsed (S4), the rotational speed (Xrpm) of the cooling fan is detected (S5). The rotation speed range in the map selected according to the initial temperature is compared with the detected rotation speed (S6), and the time during which the operation can be performed (power running time td) is determined (S7).
While continuing to measure the time, the driving of the load is continued until the power running time td elapses, and the driving is stopped immediately after elapse of td (S8) (S9).

On the other hand, when the detected rotational speed is equal to or higher than the predetermined rotational speed (Xn), the reached rotational speed is sufficiently high and does not exceed the upper limit of the operating temperature of the switching element, so that the operation is continuously performed (S10). ).
Similar to the first embodiment, this flowchart is repeated each time a plurality of predetermined times (t1, t2,..., Tn) elapse (S4), and more accurate control can be performed.

  According to the above, it is possible to sufficiently exhibit the driving performance of the rotating electrical machine according to the change in the environmental temperature. In particular, the present invention is particularly effective in an in-vehicle rotating electrical machine that is exposed to a wide range of temperature usage environments from a cold region to a tropical region.

Embodiment 3 FIG.
FIG. 7 is a temperature rise curve for explaining the third embodiment, and a plurality of curves have different stator currents.
The heat generation of the switching element and the wiring resistance has a positive correlation with the stator current. Due to heat generation, the temperature of the switching element and the wiring rises, and as the temperature rises, the specific resistance further increases and the temperature rise is accelerated. In particular, in a controller-integrated rotating electrical machine, a portion having a large wiring resistance such as a stator winding is disposed near the switching element, and heat generated by the wiring resistance is proportional to the square of the stator current. The effect of the stator current on the temperature rise is remarkable, and the temperature rise can be reduced as the stator current is smaller.
On the other hand, in a rotating electrical machine that drives an internal combustion engine, torque pulsation is large at low speeds, so a large stator current is necessary to prevent a drop in rotation. If it becomes small, it can drive with a small stator current.
Therefore, by adjusting the stator current to a smaller value along with the torque pulsation that decreases as the rotational speed increases, heat generation due to the stator current can be suppressed, and moreover, a rapid synergistic effect with an increase in cooling capacity can be achieved. In addition, since the temperature rise becomes slow, it is possible to drive the load for a longer time or continuously.
Also in the second and third embodiments described above, by setting the predetermined rotational speed (Xn) to be smaller as the stator current is smaller, the operation can be performed from a lower rotational range, and the ability to drive the load is further enhanced. improves.

FIG. 8 is an example of a flow for explaining the operation of the third embodiment.
In FIG. 8, time measurement is started with the start of operation (S1), and after a predetermined time (t1) has elapsed (S2), the rotational speed Xrpm is detected (S3). A driving operation is performed (S8). On the other hand, if the rotational speed is less than or equal to the predetermined rotational speed Xn, the current reduction rate (a (k)%) after the power running time is set for each rotational speed range detected by comparing the rotational speed with the map (S5) In addition, the power is supplied for a predetermined time td (S6), and the operation is stopped (S7). By setting the current reduction rate in a range in which the temperature of the switching element does not exceed the upper limit of the use temperature, the load can be driven while preventing the switching element from being destroyed. Alternatively, the current reduction rate may be adjusted so that continuous energization is possible, and continuous operation can be performed by reducing the current after a predetermined time has elapsed.

The method of setting the current may be a method of setting based on the detected current value other than the method of giving by the current reduction rate, and is not based on the third embodiment. In short, any method of operating the rotating electrical machine by adjusting the current value after the lapse of a predetermined time within a range not exceeding the upper temperature limit of the switching element is not particular.
When the cooling fan has a predetermined number of rotations or less, if the stator current for driving the rotating electrical machine is continuously supplied, the switching element temperature may rise and exceed the upper limit of the use temperature. On the other hand, since it is possible to estimate the switching element temperature from the degree of increase in rotation by setting the predetermined time and observing the number of rotations for the predetermined time, the subsequent drive current is adjusted according to that information as much as possible. It can be driven over time.

It is principal part sectional drawing of the control apparatus integrated rotary electric machine in Embodiment 1 of this invention. FIG. 2 is an electric circuit diagram of the controller-integrated dynamoelectric machine according to Embodiment 1 of the present invention. It is a figure explaining the relationship between the rotation speed of load, and the temperature rise of a switching element. It is a flowchart for demonstrating operation | movement of Embodiment 1 of this invention. It is a figure explaining the relationship between the initial temperature around the rotary electric machine in Embodiment 2 of this invention, and the temperature rise of a switching element. It is a flowchart for demonstrating operation | movement of Embodiment 2 of this invention. It is a figure explaining the relationship between the stator current by Embodiment 3 of this invention, and the temperature rise of a switching element. It is a flowchart for demonstrating operation | movement of Embodiment 3 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Controller-integrated rotating electrical machine 2 Controller unit 4 Rotation detector 20 Front bracket 21 Rear bracket 22 Shaft 23 Stator 23a Stator winding 24 Rotor 24a Rotor winding 24b Cooling fan 25 Pulley 26 Brush holder 27 Sliding Electrode 28 Brush 30 Power circuit part 30a, 30b Switching element 30g, 30f Heat sink 31 Field circuit part 32 Control circuit part 32a Controller board 34 Case 34b Signal terminal 101 Battery 102 Capacitor

Claims (8)

A rotating electrical machine that has a rotor and a stator, generates an electric force for starting a load connected to the rotor, generates electric power by receiving a driving force generated by the load, and a switching element that controls the rotating electric machine. A control device built in and integrally formed with the rotating electrical machine, and a cooling fan that cools the control device in conjunction with the rotor, the control device detecting first rotational speed of the cooling fan. And when the rotational speed of the cooling fan detected by the first control means is the rotational speed that enables the switching element to operate without exceeding the upper limit of the operating temperature, the second control for causing the rotating electrical machine to perform continuous power running. And a controller-integrated dynamoelectric machine. A rotating electrical machine that has a rotor and a stator, generates an electric force for starting a load connected to the rotor, generates electric power by receiving a driving force generated by the load, and a switching element that controls the rotating electric machine. A control device built in and integrated with the rotating electrical machine and a cooling fan that cools the control device in conjunction with the rotor are provided, and the control device detects the number of rotations of the cooling fan after a predetermined time has elapsed. When the rotation speed of the cooling fan detected by the first control means and the first control means is equal to or less than a predetermined rotation speed that enables the switching element to operate without exceeding the upper limit of the operating temperature, the upper limit of the operating temperature is exceeded. And a third control means for setting a power running time of the rotating electrical machine so that the switching element operates within a temperature that is not present. A rotating electrical machine that has a rotor and a stator, generates an electric force for starting a load connected to the rotor, generates electric power by receiving a driving force generated by the load, and a switching element that controls the rotating electric machine. A control device built in and integrated with the rotating electrical machine and a cooling fan that cools the control device in conjunction with the rotor are provided, and the control device detects the number of rotations of the cooling fan after a predetermined time has elapsed. first control means, the rotation speed of the cooling fan is detected by the first control means, when a predetermined number of revolutions that enables operation without exceeding the upper limit of the operating temperature of the switching element, a continuous power operation of the rotating electrical machine A second control means for causing the switching element to operate without causing the switching element to exceed an upper limit of an operating temperature by a rotation speed of the cooling fan detected by the second control means. If the following rolling number, control, characterized in that a third control means for setting the power running time for the rotating electrical machine such that the temperature within the switching element does not exceed the upper limit of the switching element operating temperature is operated Equipment-integrated rotating electrical machine. 4. The control according to claim 1, wherein the powering operation time of the rotating electrical machine is set to be shorter as the initial temperature of the rotating electrical machine is higher when the rotating electrical machine is started. 5. Equipment-integrated rotating electrical machine.   5. The controller-integrated dynamoelectric machine according to claim 1, wherein the stator current is set to decrease with an increase in the number of rotations of the cooling fan. When the number of rotations of the cooling fan is equal to or less than the predetermined number of rotations, the powering operation time of the rotating electrical machine is set to a predetermined time, and the stator current before and after the predetermined time exceeds the upper limit of the operating temperature of the switching element. 4. The controller-integrated rotating electrical machine according to claim 2, wherein the controller is set to have an allowable temperature not higher than the allowable temperature. 4. The controller-integrated dynamoelectric machine according to claim 2, wherein the predetermined number of rotations of the cooling fan is set to be smaller as the stator current is smaller. 4. The power running operation time of the rotating electrical machine is corrected by repeatedly detecting the rotational speed of the cooling fan by the first control means during the power running operation of the rotating electrical machine. Control device-integrated rotary electric machine.

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