JP6870577B2 - Rotating machine control device - Google Patents

Description

The present invention relates to a control device for a rotary electric machine.

Conventionally, as seen in Patent Document 1, a control device for controlling a current flowing through a stator winding of a rotating electric machine and controlling a field current flowing through a field winding of a rotating electric machine is known. When the rotation speed of the rotary electric machine is equal to or less than a predetermined value, the control device controls the field current and implements a PWM control mode in which the PWM-controlled current is passed through the stator winding to generate electricity in the rotary electric machine. When the rotation speed of the rotating electric machine exceeds a predetermined value, the control device implements a field control mode in which the rotating electric machine generates electricity by controlling the field current.

International Publication No. 2016/006386

In the PWM control mode, the current flowing through the stator winding is controlled by driving the switch of the inverter that transmits power between the DC power supply and the stator winding. The switching frequency of the switch when the field control mode is implemented is lower than the switching frequency of the switch when the PWM control mode is implemented. Therefore, the frequency of the main operating sound generated when the field control mode is executed is lower than the frequency of the main operating sound generated when the PWM control mode is executed.

Here, if the rotation speed of the rotary electric machine fluctuates in the vicinity of a predetermined value, a situation may occur in which the PWM control mode and the field control mode are frequently switched from one control mode to the other control mode. If the control mode is frequently switched, the frequencies of the main operating sounds are frequently switched, and there is a concern that the NVH characteristics may be deteriorated.

Of the PWM control mode and the field control mode, the control device is not limited to the control device that switches from one control mode to the other control mode, but any control device that switches between two control modes having different switching frequencies. , The problems mentioned above can occur as well.

An object of the present invention is to provide a control device for a rotary electric machine capable of improving NVH characteristics in drive control of the rotary electric machine.

The present invention is applied to a control system including a rotary electric machine having a stator winding and an inverter having a switch and transmitting power between a DC power supply and the stator winding by driving the switch. It is a control device for a rotating electric machine. The present invention comprises a first control unit that switches and controls the switch, a second control unit that switches and controls the switch at a switching frequency different from the switching frequency of the switch in the first control unit, and rotation of the rotary electric machine. When it is determined that the speed is equal to or higher than the high rotation side threshold value, the switching control by the second control unit is switched to the switching control by the first control unit, and the rotation speed of the rotating electric machine is smaller than the high rotation side threshold value. When it is determined that the frequency is equal to or lower than the low rotation side threshold value, a switching unit for switching from the switching control by the first control unit to the switching control by the second control unit is provided.

In the present invention, the switching frequency of the inverter switch in the second control unit and the switching frequency of the switch in the first control unit are different. On the premise of this configuration, in the present invention, when it is determined that the rotation speed of the rotary electric machine exceeds the threshold value on the high rotation side, the switching control by the second control unit is switched to the switching control by the first control unit. On the other hand, when it is determined that the rotation speed of the rotary electric machine is equal to or less than the low rotation side threshold value smaller than the high rotation side threshold value, the switching control by the first control unit is switched to the switching control by the front two control units. Therefore, even when the rotation speed of the rotary electric machine fluctuates, it is possible to suppress frequent switching from one of the switching control by the first control unit and the switching control by the second control unit to the other. This makes it possible to improve the NVH characteristics in the drive control of the rotary electric machine.

The whole block diagram of the in-vehicle control system which concerns on one Embodiment. Block diagram of PWM power generation control mode. A time chart showing the driving mode of the inverter switch and the transition of the phase current in the PWM power generation control mode. Block diagram of synchronous rectification control mode. A time chart showing the driving mode of the inverter switch and the transition of the phase current in the synchronous rectification control mode. The flowchart which shows the procedure of the control mode switching process. A time chart showing a mode of switching from the PWM power generation control mode to the synchronous rectification control mode. A time chart showing a mode of switching from the synchronous rectification control mode to the PWM power generation control mode. A time chart showing a control mode switching mode according to a comparative example.

Hereinafter, an embodiment in which the control device according to the present invention is mounted on a vehicle will be described with reference to the drawings.

As shown in FIG. 1, the vehicle includes an engine 10 as an in-vehicle main engine. The engine 10 is provided with a fuel injection valve or the like, and generates power by burning fuel such as gasoline or light oil injected from the fuel injection valve. The generated power is output from the output shaft 10a of the engine 10.

The vehicle includes a battery 20 as a DC power source and a rotary electric machine 21. The battery 20 is, for example, a lead storage battery having a rated voltage of 12 V. The rotary electric machine device 21 includes a capacitor 22, an AC-driven rotary electric machine 30, an inverter 40, a field energization circuit 41, and an MGECU 60 which is a control device for controlling the rotary electric machine 30. In the present embodiment, a field winding type synchronous machine is used as the rotary electric machine 30. Further, in the present embodiment, the MGECU 60 controls the rotary electric machine 30 so that the rotary electric machine 30 functions as an ISG (Integrated Starter Generator) which is both an electric motor and a generator. The rotary electric machine device 21 is a mechanical and electrical integrated drive device including a rotary electric machine, an inverter 40, a field energization circuit 41, and an MGECU 60.

The rotary electric machine 30 includes a rotor 31. The rotor 31 includes a field winding 32. The rotating shaft of the rotor 31 can transmit power to the output shaft 10a of the engine 10 via a pulley or the like (not shown). When the rotary electric machine 30 is driven as a generator, the rotor 31 is rotated by the rotational power supplied from the output shaft 10a, and the rotary electric machine 30 generates electricity. The battery 20 is charged by the generated power of the rotary electric machine 30. On the other hand, when the rotary electric machine 30 is driven as an electric motor, the output shaft 10a rotates with the rotation of the rotor 31, and a rotational force is applied to the output shaft 10a. Thereby, for example, the traveling of the vehicle can be assisted. The drive wheels of the vehicle are connected to the output shaft 10a via a transmission or the like.

The rotary electric machine 30 includes a stator 33. The stator 33 includes a stator winding. The stator windings include U, V, W phase windings 34U, 34V, 34W arranged 120 ° apart from each other in electrical angle.

The inverter 40 includes a series connector of U, V, W phase upper arm switches SUp, SVp, SWp and U, V, W phase lower arm switches SUn, SVn, SWn. U, V, W phase windings 34U, 34V, 34W are connected to the U, V, W phase upper arm switches SUp, SVp, SWp and the U, V, W phase lower arm switches SUn, SVn, SWn. The first end of is connected. The second ends of the U, V, W phase windings 34U, 34V, 34W are connected at a neutral point. That is, in the present embodiment, the U, V, W phase windings 34U, 34V, 34W are connected in a star shape.

In this embodiment, each switch SUP to SWn is an N-channel MOSFET. When the N-channel MOSFET is driven on, current flow is permitted between the drain, which is the high potential side terminal, and the source, which is the low potential side terminal. On the other hand, when the N-channel MOSFET is driven off, the flow of current between the drain and the source is blocked. Body diodes DUp, DVp, DWp, DUn, DVn, and DWn are connected in antiparallel to each switch SUp, SVp, SWp, SUn, SVn, and SWn.

The positive electrode terminal of the battery 20 is connected to the drains of the U, V, and W phase upper arm switches SUp, SVp, and SWp via the high potential side electric path Lp. The negative electrode terminal of the battery 20 is connected to the sources of the U, V, and W phase lower arm switches SUn, SVn, and SWn via the low potential side electric path Ln. Each electric path Lp, Ln is a conductive member such as a bus bar. Of the connection points between the drains of the upper arm switches SUp, SVp, and SWp and the high-potential side electric path Lp, the connection point closest to the positive electrode terminal of the battery 20 and the high-potential side electric path connecting the positive electrode terminal of the battery 20. The high potential side terminal of the capacitor 22 is connected to Lp. Of the connection points between the sources of the lower arm switches SUn, SVn, and SWn and the low-potential side electric path Ln, the connection point closest to the negative electrode terminal of the battery 20 and the low-potential side electric path connecting the negative electrode terminal of the battery 20. The low potential side terminal of the capacitor 22 is connected to Ln.

The field energization circuit 41 is a full bridge circuit, and includes a series connection body of the first upper arm switch SH1 and the first lower arm switch SL1 and a series connection body of the second upper arm switch SH2 and the second lower arm switch SL2. It has. The first end of the field winding 32 is connected to the connection point between the first upper arm switch SH1 and the first lower arm switch SL1 via a brush (not shown). The second end of the field winding 32 is connected to the connection point between the second upper arm switch SH2 and the second lower arm switch SL2 via a brush (not shown). In this embodiment, each arm switch SH1, SL1, SH2, SL2 is an N-channel MOSFET. Each body diode DH1, DL1, DH2, DL2 is connected in antiparallel to each switch SH1, SL1, SH2, SL2.

The drains of the first and second upper arm switches SH1 and SH2 are connected to the inverter 40 side of the high potential side electric path Lp from the connection point with the high potential side terminal of the capacitor 22. The source of the first and second lower arm switches SL1 and SL2 is connected to the inverter 40 side of the low potential side electric path Ln from the connection point with the low potential side terminal of the capacitor 22.

The rotary electric machine 21 includes a voltage detection unit 50, a phase current detection unit 51, a field current detection unit 52, and an angle detection unit 53. The voltage detection unit 50 detects the terminal voltage of the capacitor 22 as the power supply voltage VDC. The phase current detection unit 51 detects the phase current flowing through the U, V, W phase windings 34U, 34V, 34W. The field current detection unit 52 detects the field current flowing through the field winding 32. The angle detection unit 53 outputs an angle signal which is a signal corresponding to the rotation angle of the rotor 31. The output signals of the detection units 50 to 53 are input to the MGECU 60.

A part or all of each function of the MGECU 60 may be configured in hardware by, for example, one or a plurality of integrated circuits. Further, each function of the MGECU 60 may be composed of, for example, software recorded on a non-transitional substantive recording medium and a computer that executes the software.

The vehicle includes an engine ECU 11 which is a control device for controlling combustion of the engine 10 and a higher-level ECU 12 which is a higher-level control device for controlling the vehicle. Information can be exchanged between the MGECU 60, the engine ECU 11, and the upper ECU 12 via a communication line such as a CAN.

The engine ECU 11 performs normal operation control and idle-up control as combustion control during idling operation of the engine 10. The normal control is combustion control for controlling the engine rotation speed Ne, which is the rotation speed of the output shaft 10a, to the first command rotation speed Netgt1. The idle-up control is a combustion control for controlling the engine rotation speed Ne to the second command rotation speed Netgt2 which is higher than the first command rotation speed Netgt1. The command rotation speeds Netgt1 and Netgt2 are variably set according to the temperature of the cooling water of the engine 10 and the like. When the engine ECU 11 determines that the predetermined condition is satisfied, the engine ECU 11 switches from the normal operation control to the idle-up control. The predetermined condition is, for example, a condition that the power consumption of the in-vehicle device driven by the power of the output shaft 10a becomes equal to or higher than the predetermined power. The in-vehicle device in this case also includes the rotary electric machine 30.

The MGECU 60 generates drive signals for the switches constituting the inverter 40 and the field energization circuit 41.

First, the inverter 40 will be described. The MGECU 60 acquires the angle signal of the angle detection unit 53, and generates a drive signal for turning on / off the switches SUP to SWn constituting the inverter 40 based on the acquired angle signal. Specifically, when the rotary electric machine 30 is driven as an electric motor, the MGECU 60 converts the DC power output from the battery 20 into AC power and supplies it to the U, V, W phase windings 34U, 34V, 34W. A drive signal for turning on / off the arm switches SUP to SWn is generated, and the generated drive signal is supplied to the gate of each arm switch SUP to SWn. On the other hand, when the rotary electric machine 30 is driven as a generator, the MGECU 60 converts the AC power output from the U, V, W phase windings 34U, 34V, 34W into DC power and supplies the AC power to the battery 20. A drive signal for turning on / off the arm switches SUP to SWn is generated.

Subsequently, the field energization circuit 41 will be described. The MGECU 60 turns on and off each switch constituting the field energization circuit 41 in order to excite the field winding 32. Specifically, the MGECU 60 turns each switch on and off so that the first state and the second state appear alternately. The first state is a state in which the first upper arm switch SH1 and the second lower arm switch SL2 are turned on, and the second upper arm switch SH2 and the first lower arm switch SL1 are turned off. The second state is a state in which the first upper arm switch SH1 and the second lower arm switch SL2 are turned off, and the second upper arm switch SH2 and the first lower arm switch SL1 are turned on.

The MGECU 60 calculates the electric angle θe of the rotary electric machine 30 and the rotation speed Nm of the rotor 31 based on the angle signal of the angle detection unit 53.

Hereinafter, in the present embodiment, a case where the rotary electric machine 30 is driven as a generator will be described. FIG. 2 shows a block diagram of the PWM power generation control mode performed by the MGECU 60. In the present embodiment, the configuration of the MGECU 60 that performs the process shown in FIG. 2 corresponds to the second control unit.

The voltage deviation calculation unit 61 calculates the voltage deviation ΔV by subtracting the power supply voltage VDC detected by the voltage detection unit 50 from the command power generation voltage VD *. The command power generation voltage VD * is a command value of the DC voltage output from the inverter 40 to the battery 20. The command power generation voltage VD * is input from the upper ECU 12 to the MG ECU 60, for example.

The torque calculation unit 62 calculates a command value of the control amount of the rotary electric machine 30 as an operation amount for feedback-controlling the voltage deviation ΔV to 0. In the present embodiment, the control amount is torque, and the command value thereof is command torque Trq *. Further, in the present embodiment, the feedback control used by the torque calculation unit 62 is proportional integration control. The feedback control is not limited to the proportional integral control, and may be, for example, the proportional integral differential control.

The two-phase conversion unit 70 converts U, V, W phase currents IU, IV, and IW in the three-phase fixed coordinate system of the rotary electric machine 30 based on the phase current and the electric angle θe detected by the phase current detection unit 51. It is converted into d and q-axis currents Idr and Iqr in the dq coordinate system which is a two-phase rotation coordinate system.

The d-axis command setting unit 71 sets the d-axis command current Id * for setting the torque of the rotary electric machine 30 to the command torque Trq * based on the command torque Trq *. Specifically, the d-axis command setting unit 71 sets the d-axis command current Id * based on the map information in which the command torque Trq * and the d-axis command current Id * are related.

The q-axis command setting unit 72 sets the q-axis command current Iq * for setting the torque of the rotary electric machine 30 to the command torque Trq * based on the command torque Trq *. Specifically, the q-axis command setting unit 72 sets the q-axis command current Iq * based on the map information in which the command torque Trq * and the q-axis command current Iq * are related.

The stator control unit 73 calculates the d-axis command voltage Vd * as an operation amount for feedback-controlling the d-axis current Idr to the d-axis command current Id *. Specifically, the stator control unit 73 calculates the d-axis current deviation ΔId as a value obtained by subtracting the d-axis current Idr from the d-axis command current Id *, and feedback-controls the calculated d-axis current deviation ΔId to 0. The d-axis command voltage Vd * is calculated as the operation amount of.

The stator control unit 73 calculates the q-axis command voltage Vq * as an operation amount for feedback-controlling the q-axis current Iqr to the q-axis command current Iq *. Specifically, the stator control unit 73 calculates the q-axis current deviation ΔIq as a value obtained by subtracting the q-axis current Iqr from the q-axis command current Iq *, and feedback-controls the calculated q-axis current deviation ΔIq to 0. The q-axis command voltage Vq * is calculated as the operation amount of.

In the present embodiment, the feedback control used by the stator control unit 73 is proportional integration control. The feedback control is not limited to the proportional integral control, and may be, for example, the proportional integral differential control.

The command voltage vector, which is the command value of the voltage vector in the dq coordinate system, is determined by the d-axis command voltage Vd * and the q-axis command voltage Vq *. Here, the voltage vector applied to the stator winding has its d-axis component as the d-axis voltage Vd and the q-axis component as the q-axis voltage Vq. The voltage phase, which is the phase of the voltage vector, is defined as, for example, the positive direction of the d-axis as a reference, and the counterclockwise direction is defined as the positive direction from this reference.

The three-phase conversion unit 74 sets the d, q-axis command voltages Vd *, Vq * based on the d, q-axis command voltages Vd *, Vq * and the electric angle θe to U, V, W in the three-phase fixed coordinate system. Converts to phase command voltage Vu *, Vv *, Vw *. In the present embodiment, the U, V, and W phase command voltages Vu *, Vv *, and Vw * are sinusoidal signals whose phases are 120 ° out of phase with respect to the electrical angle.

The stator generation unit 75 transmits each drive signal for turning on / off each switch SUP to SWn of the inverter 40 by PWM control based on the carrier signal, each phase command voltage Vu *, Vv *, Vw * and the power supply voltage VDC. Generate. Specifically, the PWM control generates each drive signal based on the magnitude comparison between the value obtained by dividing each phase command voltage Vu *, Vv *, Vw * by "VDC / 2" and the carrier signal. .. In this embodiment, the carrier signal is a triangular wave signal. In PWM control, the value obtained by dividing the amplitude of each phase command voltage Vu *, Vv *, Vw * by "VDC / 2" is equal to or less than the amplitude of the carrier signal.

The field command setting unit 80 sets the field command current If * based on the command torque Trq *. Specifically, the field command setting unit 80 sets the field command current If * based on the map information in which the command torque Trq * and the field command current If * are related.

The field current control unit 81 calculates the field command voltage Vf * as an operation amount for feedback-controlling the field current Ifr detected by the field current detection unit 52 to the field command current If *. Specifically, the field current control unit 81 calculates the field current deviation ΔIf as the value obtained by subtracting the field current Ifr from the field command current If *, and feedback-controls the calculated field current deviation ΔIf to 0. The field command voltage Vf * is calculated as the amount of operation for this operation. In the present embodiment, the feedback control used by the field current control unit 81 is proportional integration control. The feedback control is not limited to the proportional integral control, and may be, for example, the proportional integral differential control.

The field generation unit 82 sets the applied voltage of the field winding 32 to the field command voltage based on the magnitude comparison between the value obtained by dividing the field command voltage Vf * by the power supply voltage VDC and the carrier signal which is a triangular wave signal. Each drive signal of each switch SH1 to SL2 of the field energization circuit 41 for controlling to Vf * is generated.

FIG. 3 shows the transition of the gate signal and the phase current for one phase when the PWM power generation control mode is executed. In FIG. 3A, the gate signal indicates that the upper arm switch is driven on and the lower arm switch is driven off by H, and the upper arm switch is driven off and the lower arm switch is driven on by L. Indicates to do. Further, the phase current is defined as positive in the direction of the current flowing from the inverter 40 side to the stator winding side.

Subsequently, FIG. 4 shows a block diagram of the synchronous rectification control mode performed by the MGECU 60. In the present embodiment, the configuration of the MGECU 60 that performs the process shown in FIG. 4 corresponds to the first control unit. In the synchronous rectification control mode, the switch connected in antiparallel to the diode in which the current is going to flow during the period when the current is going to flow in the body diode connected in antiparallel to the switch of the inverter 40 during the power generation of the rotary electric machine 30. Is turned on. The period during which the current tends to flow through the body diode is a period during which the generated voltage (counter electromotive voltage) of the stator winding exceeds the terminal voltage of the battery 20. In the synchronous rectification control mode, the upper arm switch is turned on once in at least a part of the period in which the generated voltage of the stator winding exceeds the terminal voltage of the battery 20 in one electric angle period. As a result, the alternating current output from the stator winding is converted into a direct current.

The synchronization generation unit 90 is a drive signal for turning on / off each switch SUP to SWn of the inverter 40 based on the electric angle θe, the dead time DT of the upper and lower arm switches of the inverter 40, and the command value δ of the voltage phase. To generate. The drive signal generated by the synchronization generation unit 90 is a signal for turning on each of the upper arm switch and the lower arm switch once in one electric angle period of each phase. The phase of this drive signal is 120 ° out of phase with respect to each phase.

In FIG. 4, the voltage deviation calculation unit 61, the torque calculation unit 62, the field command setting unit 80, the field current control unit 81, and the field generation unit 82 have the same configuration as shown in FIG. Therefore, even when the PWM power generation control mode or the synchronous rectification control mode is switched from one to the other, the continuity of field current control based on the command torque Trq * is maintained.

FIG. 5 shows the transition of the gate signal and the phase current for one phase when the synchronous rectification control mode is executed. Note that FIGS. 5 (a) and 5 (b) correspond to FIGS. 3 (a) and 3 (b) above.

Subsequently, the control mode switching process during the idling operation will be described. In this process, when it is determined that the calculated rotation speed Nm of the rotor 31 is equal to or higher than the high rotation side threshold value Nth2, the PWM power generation control mode is switched to the synchronous rectification control mode, and the rotation speed Nm is higher than the high rotation side threshold value Nth2. It is a process of switching from the synchronous rectification control mode to the PWM power generation control mode when it is determined that the threshold value Nth1 or less on the low rotation speed side is small. Here, the high rotation side threshold value Nth2 and the low rotation side threshold value Nth1 of the present embodiment will be described.

The rotation speed of the rotor 31 corresponding to the first command rotation speed Netgt1 is defined as the first rotor rotation speed Nm1. The first rotor rotation speed Nm1 is determined based on the gear ratio from the output shaft 10a to the rotor 31 determined by the pulley ratio or the like and the first command rotation speed Netgt1. For example, when the first command rotation speed Netgt1 is 700 rpm and the gear ratio is 3, the first rotor rotation speed Nm1 is 2100 rpm.

The rotation speed of the rotor 31 corresponding to the second command rotation speed Netgt2 is set to the second rotor rotation speed Nm2 (> Nm1). The second rotor rotation speed Nm2 is determined based on the gear ratio from the output shaft 10a to the rotor 31 determined by the pulley ratio or the like and the second command rotation speed Netgt2.

The maximum assumed fluctuation amount of the engine rotation speed Ne to the high rotation side with respect to the first and second command rotation speeds Netgt1 and Netgt2 is set as the engine fluctuation amount ΔNe (> 0), and the rotation speed of the rotor 31 corresponding to the engine fluctuation amount ΔNe The maximum assumed fluctuation amount to the high rotation speed side is defined as the rotor fluctuation amount ΔNm. The rotor fluctuation amount ΔNm is determined based on the gear ratio from the output shaft 10a to the rotor 31 determined by the pulley ratio or the like and the engine fluctuation amount ΔNe. For example, when the engine fluctuation amount ΔNe is 80 rpm and the gear ratio is 3, the rotor fluctuation amount ΔNm is 240 rpm.

The high rotation side threshold Nth2 is set to a value larger than the added value of the first rotor rotation speed Nm1 and the rotor fluctuation amount ΔNm, and is set to a value larger than this added value and equal to or less than the second rotor rotation speed Nm2. Has been done. In the present embodiment, the high rotation side threshold value Nth2 is set to the second rotor rotation speed Nm2.

The low rotation side threshold value Nth1 is set to a value smaller than the high rotation side threshold value Nth2, for example, a value smaller than the high rotation side threshold value Nth2 and set to a value equal to or higher than the first rotor rotation speed Nm1. In the present embodiment, the low rotation side threshold value Nth1 is set to the first rotor rotation speed Nm1.

FIG. 6 shows a procedure for switching the control mode during idling operation. This process is repeatedly executed by the MGECU 60, for example, at predetermined control cycles.

In step S10, it is determined whether or not the idle-up control is being executed by the engine ECU 11. Whether or not the idle-up control is executed may be determined based on, for example, an external signal input from the engine ECU 11 via the host ECU 12 and the communication line. Incidentally, it may be determined whether or not the idle-up control is executed based on the external signal input from the engine ECU 11 to the MG ECU 60 without going through the host ECU 12. Further, the MGECU 60 itself may determine whether or not the idle-up control is executed based on, for example, the rotation speed Nm of the rotor 31, regardless of the external signal from the external device of the host ECU 12 or the engine ECU 11. In this case, if the MGECU 60 determines that the idle-up control is executed when it is determined that the rotation speed Nm is controlled by the second rotor rotation speed Nm2, for example, based on the rotation speed Nm of the rotor 31. Good.

If it is determined in step S10 that the idle-up control is not being executed, it is determined that the normal time control is being executed, and the process proceeds to step S11. In step S11, it is determined whether or not the calculated fluctuation amount of the rotation speed Nm of the rotor 31 is smaller than the predetermined amount. In the process of step S11, it is determined whether or not the fluctuation amount of the rotation speed of the rotor 31 and the output shaft 10a capable of transmitting power is small, and the high rotation side threshold value Nth2 for determining the switching of the control mode can be reduced. It is a process of determining whether or not there is. That is, the high rotation side threshold value Nth2 is set with a margin including the rotor fluctuation amount ΔNm with respect to the low rotation side threshold value Nth1. Therefore, if the fluctuation amount of the rotation speed of the output shaft 10a is small and the rotor fluctuation amount ΔNm is small, the high rotation side threshold value Nth2 can be reduced.

For example, when it is determined that the warm-up of the engine 10 is completed, it may be determined that the fluctuation amount of the rotation speed Nm is smaller than the predetermined amount. Here, for example, when it is determined that the elapsed time from the start of combustion in the combustion chamber of the engine 10 has exceeded the determination time, or the temperature of the engine 10 or its correlation value (for example, oil or cooling of the engine 10). When it is determined that the detection value of the detection unit that detects (water temperature) is equal to or higher than a predetermined temperature, it may be determined that the warm-up is completed.

Further, for example, when it is determined that the driving of the in-vehicle device other than the rotary electric machine 30 which can be driven by being supplied with power from the output shaft 10a is stopped, it is determined that the fluctuation amount of the rotation speed Nm is smaller than the predetermined amount. You may. Here, examples of the in-vehicle device include a compressor for air conditioning.

Further, for example, it may be determined from the engine rotation speed Ner calculated by the speed calculation unit based on the output signal of the crank angle sensor or the like that the fluctuation amount of the rotation speed Nm is smaller than the predetermined amount.

If it is determined in step S11 that the amount of fluctuation of the rotation speed Nm is equal to or greater than a predetermined amount, the process proceeds to step S12, and the high rotation side threshold value Nth2 is set to the first threshold value Nα. On the other hand, when it is determined in step S11 that the fluctuation amount of the rotation speed Nm is smaller than the predetermined amount, the process proceeds to step S13, and the high rotation side threshold value Nth2 is set to a value larger than the low rotation side threshold value Nth1 described later. And the second threshold value Nβ smaller than the first threshold value Nα is set. According to the process of step S15, the chance of executing the synchronous rectification control mode can be increased, and the switching loss generated in the inverter 40 can be reduced.

After the processing of steps S12 and S13 is completed, the process proceeds to step S14, and it is determined whether or not the calculated rotation speed Nm of the rotor 31 is equal to or higher than the high rotation side threshold value Nth2. If it is determined in step S14 that the rotation speed Nm is lower than the high rotation side threshold value Nth2, the process proceeds to step S15, and it is determined whether or not the calculated rotation speed Nm of the rotor 31 is equal to or less than the low rotation side threshold value Nth1. To do.

If it is determined in step S15 that the rotation speed Nm is equal to or less than the low rotation side threshold value Nth1, the process proceeds to step S16 and the determination flag F is set to 0. The determination flag F indicates the execution of the PWM power generation control mode by 0, and indicates the execution of the synchronous rectification control mode by 1. In the present embodiment, the initial value of the determination flag F is 0.

If it is determined in step S14 that the rotation speed Nm is equal to or higher than the high rotation side threshold value Nth2, the process proceeds to step S17 and the determination flag F is set to 1. If it is determined in step S15 that the rotation speed Nm is higher than the low rotation side threshold value Nth1, the currently executed control mode is continuously executed.

If the processing of steps S16 and S17 is completed, or if a negative determination is made in step S15, the process proceeds to step S18. In step S18, it is determined whether or not the determination flag F is 1. If it is determined in step S18 that the determination flag F is 0, the process proceeds to step S19, instructing the execution of the PWM power generation control mode shown in FIG. On the other hand, if it is determined in step S18 that the determination flag F is 1, the process proceeds to step S20, and the execution of the synchronous rectification control mode shown in FIG. 4 is instructed. In this embodiment, the processes of steps S14 to S20 correspond to the switching unit for switching the control mode.

If it is determined in step S10 that the idle-up control is performed, the process proceeds to step S17. As a result, the determination flag F is set to 1. As a result, regardless of the rotation speed Nm of the rotor 31, the execution of the synchronous rectification control mode is instructed in step S20 thereafter. Therefore, the switching loss generated in the inverter 40 can be reduced as compared with the case where the PWM power generation control mode is implemented.

FIG. 7 shows a mode of switching from the PWM power generation control mode to the synchronous rectification control mode, and FIG. 8 shows a mode of switching from the synchronous rectification control mode to the PWM power generation control mode. 7 (a) and 8 (a) show the transition of the rotation speed Nm of the rotor 31 calculated by the MGECU 60, and FIGS. 7 (b) and 8 (b) show the transition of the control method. The example shown in FIG. 7 is an example in which the control mode is switched when the normal control is executed. The example shown in FIG. 8 is an example in which, for example, after switching from idle-up control to normal time control, it is determined that the rotation speed Nm becomes equal to or less than the low rotation side threshold value Nth1, and the control mode is switched.

FIG. 9 shows a control mode switching mode in the comparative example. Here, in the comparative example, when it is determined that the rotation speed Nm of the rotor 31 exceeds the speed threshold value Nthc, the synchronous rectification control mode is executed, and it is determined that the rotation speed Nm is equal to or less than the speed threshold value Nthc. When this is done, the PWM power generation control mode is executed. 9 (a) and 9 (b) correspond to the above 7 (a) and 7 (b), and FIG. 9 (c) shows the main in the inverter 40 generated when each control mode is executed. The transition of the frequency of the operation sound is shown. FIG. 9D shows the transition of the torque of the rotary electric machine 30, and FIG. 9E shows the transition of the output current flowing from the inverter 40 to the battery 20 with power generation.

When the calculated rotation speed Nm of the rotor 31 fluctuates in the vicinity of the speed threshold value Nthc as shown in FIG. 9A, one of the PWM power generation control mode and the synchronous rectification control mode is shown in FIG. 9B. Frequent switching from one control mode to the other control mode occurs. It should be noted that this frequent switching occurs not only because the actual rotation speed of the rotor 31 fluctuates, but also because a noise component is mixed in the calculated rotation speed Nm.

The switching frequency of the switch of the inverter 40 when the synchronous rectification control mode is implemented is lower than the switching frequency of the switch of the inverter 40 when the PWM power generation control mode is implemented. Therefore, as shown in FIG. 9C, the frequency of the main operating sound generated when the synchronous rectification control mode is executed is the frequency of the main operating sound generated when the PWM power generation control mode is executed. It will be lower than the frequency. If the control mode is frequently switched, the frequencies of the main operating sounds are frequently switched, and the NVH characteristics of the rotary electric machine 21 are deteriorated.

Further, when the control mode is frequently switched, the torque fluctuation of the rotary electric machine 30 frequently occurs as shown in FIG. 9 (d), or the output current is undershooted as shown in FIG. 9 (e). Overshoot may occur. When an overshoot occurs, an overcurrent flows from the inverter 40 to the battery 20, and the reliability of the battery 20, the inverter 40, and the like is lowered, and there is a concern that the reliability of the rotary electric machine 21 is lowered.

On the other hand, in the present embodiment, hysteresis is set in the threshold values Nth1 and Nth2 for switching between the PWM control mode and the synchronous rectification control mode. Therefore, even when the rotation speed Nm of the rotor 31 fluctuates, frequent switching of the control mode can be suppressed. Thereby, the NVH characteristics and reliability of the rotary electric machine 21 can be improved.

<Other Embodiments>
The above embodiment may be modified as follows.

In step S13 of FIG. 6, the smaller the fluctuation amount of the rotation speed Nm, the smaller the second threshold value Nβ may be set.

-In the above embodiment, the synchronous rectification control mode and the PWM power generation control mode can be switched, but the present invention is not limited to this. For example, the synchronous rectification control mode may be switched between the overmodulation control mode having a higher switching frequency than this mode, or the overmodulation control mode and the PWM power generation control mode may be switched.

-The present invention can be applied even when the rotary electric machine is driven as an electric motor. In this case, for example, the rectangular wave control mode corresponding to the switching control of the first control unit and the PWM control mode corresponding to the switching control of the second control unit can be switched. The rectangular wave control mode is a mode in which the upper arm switch and the lower arm switch are turned on once in one electric angle period of each phase of the inverter 40.

When the switching frequency of the switching control executed when it is determined that the rotation speed Nm of the rotor 31 is equal to or higher than the high rotation side threshold Nth2 is determined to be equal to or lower than the low rotation speed Nm. It may be higher than the switching frequency of the switching control performed.

-The field energization circuit is not limited to a full bridge circuit, and may be, for example, a half bridge circuit.

-The switch used in the inverter and the field energization circuit is not limited to the N-channel MOSFET.

The control amount of the rotary electric machine is not limited to torque, and may be, for example, the generated power of the rotary electric machine 30.

-The rotary electric machine is not limited to the one connected in a star shape, and may be connected in a delta shape, for example. Further, the rotary electric machine is not limited to the winding field type having a field winding, and may be, for example, a permanent magnet type having a permanent magnet in the rotor.

30 ... rotary electric machine, 32 ... field winding, 34U to 34W ... U, V, W phase winding, 40 ... inverter, 60 ... MGECU.

Claims (8)

A rotary electric machine (30) having a stator winding (34U to 34W) and
An inverter (40) having switches (SUP to SWn) and transmitting power between the DC power supply (20) and the stator winding by driving the switch.
In the rotary electric machine control device (60) applied to the control system including
The control system is mounted on a vehicle equipped with an engine (10).
The vehicle has normal control for controlling the combustion of the engine in order to control the rotation speed of the output shaft (10a) of the engine during idling operation to the first command rotation speed (Netgt1), and the output during idling operation. An engine control device (11) for performing idle-up control for controlling combustion of the engine in order to control the rotation speed of the shaft to a second command rotation speed (Netgt2) higher than the first command rotation speed is provided.
The rotary electric machine has a function of receiving power from the output shaft to generate electricity.
A first control unit that switches and controls the switch,
A second control unit that switches and controls the switch at a switching frequency different from the switching frequency of the switch in the first control unit.
When it is determined that the rotation speed of the rotary electric machine is equal to or higher than the high rotation side threshold value (Nth2), the switching control by the second control unit is switched to the switching control by the first control unit, and the rotation speed of the rotary electric machine is changed. When it is determined that the threshold value is equal to or less than the low rotation speed threshold value (Nth1) smaller than the high rotation speed threshold value, a switching unit for switching from the switching control by the first control unit to the switching control by the second control unit is provided .
The switching unit is a control device for a rotary electric machine that causes the first control unit to perform switching control when it is determined that the idle-up control is being performed by the engine control device. The switching unit, when said execution instruction of the idle-up control is determined to have been input from the outside of the engine control device, a motor controller according to claim 1 for implementing the switching control to the first control unit. The control device for a rotary electric machine according to claim 1 or 2 , wherein the switching frequency of the switch in the second control unit is higher than the switching frequency of the switch in the first control unit. When the switching unit determines that the fluctuation amount of the rotation speed of the rotary electric machine is equal to or more than a predetermined amount, the switching unit sets the high rotation side threshold value to the first threshold value (Nα), and the fluctuation amount of the rotation speed of the rotary electric machine is set. When it is determined that is smaller than the predetermined amount, the high rotation speed side threshold value is set to a second threshold value (Nβ) which is larger than the low rotation speed side threshold value and smaller than the first threshold value. The control device for a rotary electric machine according to any one of 1 to 3. A rotary electric machine (30) having a stator winding (34U to 34W) and
An inverter (40) having switches (SUP to SWn) and transmitting power between the DC power supply (20) and the stator winding by driving the switch.
In the rotary electric machine control device (60) applied to the control system including
A first control unit that switches and controls the switch,
A second control unit that switches and controls the switch at a switching frequency different from the switching frequency of the switch in the first control unit.
When it is determined that the rotation speed of the rotary electric machine is equal to or higher than the high rotation side threshold value (Nth2), the switching control by the second control unit is switched to the switching control by the first control unit, and the rotation speed of the rotary electric machine is changed. When it is determined that the threshold value is equal to or less than the low rotation speed threshold value (Nth1) smaller than the high rotation speed threshold value, a switching unit for switching from the switching control by the first control unit to the switching control by the second control unit is provided.
When the switching unit determines that the fluctuation amount of the rotation speed of the rotary electric machine is equal to or more than a predetermined amount, the switching unit sets the high rotation side threshold value to the first threshold value (Nα), and the fluctuation amount of the rotation speed of the rotary electric machine. Is smaller than the predetermined amount, the rotary electric machine sets the high rotation speed side threshold value to a second threshold value (Nβ) which is larger than the low rotation speed side threshold value and smaller than the first threshold value. Control device. The rotary electric machine has a field winding (32) and has a field winding (32).
The control system includes a field energization circuit (41) that controls a field current flowing through the field winding.
The first control unit and the second control unit switch and control the switch so that a field command current for controlling the control amount of the rotary electric machine to the command value flows through the field winding. The control device for a rotary electric machine according to any one of claims 1 to 5, which controls a field energization circuit. The first control unit controls the field energization circuit so that the field command current flows through the field winding while switching and controlling the switch.
The second control unit switches and controls the switch so that a command current for controlling the control amount to the command value flows through the stator winding, and the field command current is transmitted to the field winding. The control device for a rotating electric machine according to claim 6, wherein the field energization circuit is controlled so as to flow. The inverter has an upper arm switch (SUP to SWp) and a lower arm switch (Sun to SWn) in series as the switch.
The first control unit turns on the upper arm switch once during at least a part of the period in which the generated voltage of the stator winding exceeds the voltage of the DC power supply in one electric angle period of the rotating electric machine.
The control device for a rotary electric machine according to any one of claims 1 to 7, wherein the second control unit alternately turns on the upper arm switch and the lower arm switch based on PWM control.

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