JP2023036535A - Control device of rotary electric machine, and program - Google Patents

Abstract

To provide a control device of a rotary electric machine capable of reducing ripple current flowing through a capacitor common to a plurality of power conversion circuits.SOLUTION: A control device is applied to a control system having first and second inverters converting DC power of DC power supply by a switching operation into AC power to be outputted, a first rotary electric machine provided corresponding to the first inverter, a second rotary electric machine provided corresponding to the second inverter, and a smoothing capacitor connected to the DC power supply in parallel, provided on an input side of each inverter, and common to each inverter. The control device performs the switching operation of each inverter so that a phase difference φ between the rotary electric machines may be larger than 0 degree, and an output period of reactive voltage vectors V0 and V7 of each rotary electric machine and the output period of effective voltage vectors V1, V2, and V6 of each rotary electric machine may be equal.SELECTED DRAWING: Figure 20

Description

The present invention relates to a control device for a rotating electric machine and a program.

This type of control device includes a plurality of power conversion circuits, a rotating electric machine provided corresponding to each power conversion circuit, and a capacitor provided on the input side of each power conversion circuit and common to each power conversion circuit. Some apply to control systems. DC power is supplied to each power conversion circuit from a DC power supply. The switching operation converts the DC power supplied to each power conversion circuit into AC power, and the converted AC power is supplied to the corresponding rotating electric machine. In this case, the capacitor is charged and discharged according to the switching operation of each power conversion circuit, and a ripple current flows through the capacitor. For example, in Patent Document 1, in order to reduce the ripple current of a capacitor, in a control device that performs a switching operation based on a comparison between a command voltage and a carrier signal of each power conversion circuit, the carrier signal of each power conversion circuit is It is described that shift control is performed.

JP 2012-120296 A

There is concern that a problem may arise in the configuration provided in common for a plurality of power conversion circuits. For example, if the torque and rotation speed of the rotating electrical machines corresponding to each power conversion circuit are different, the output period of the effective voltage vector to each rotating electrical machine may not be adjusted to an appropriate output period to suppress the ripple current of the capacitor. have a nature. In this case, even if the control described in Patent Document 1, for example, is performed, there is concern that the ripple current flowing through the capacitor will increase.

In this respect, in order to prevent problems from occurring in a configuration that is provided in common for a plurality of power conversion circuits, a control technique is desired that allows a voltage vector to be appropriately output to each rotating electric machine.

The present invention has been made in view of the above circumstances, and its main object is to control a rotating electric machine that can suppress the occurrence of a situation in which a problem occurs in a configuration that is commonly provided for a plurality of power conversion circuits. It is to provide the device and the program.

The present invention provides a plurality of power conversion circuits for converting DC power of a DC power supply into AC power by switching operation and outputting AC power, and AC power output from the power conversion circuit provided corresponding to each of the power conversion circuits. is supplied to a rotating electric machine, and a capacitor connected in parallel to the DC power supply and provided on the input side of each power conversion circuit and common to each power conversion circuit. an adjustment unit that performs an adjustment process for adjusting an output mode of a voltage vector to a rotating electric machine; and an operation unit that performs a switching operation of each of the power conversion circuits so as to output the voltage vector adjusted by the adjustment unit. Prepare.

According to the present invention, the output mode of the voltage vector to each rotating electric machine is adjusted. By performing the switching operation of each inverter so as to output the adjusted voltage vector, it is possible to suppress the occurrence of a problem in the configuration provided in common for the plurality of power conversion circuits.

1 is a schematic diagram showing an electric vehicle according to a first embodiment; FIG. The block diagram of a control system. FIG. 4 is a diagram showing the relationship between the torque of each rotating electric machine and the steering angle; FIG. 5 is a diagram showing the relationship between the torque difference of each rotating electric machine and the steering angle; FIG. 4 is a diagram showing the relationship between the rotational speed of each rotating electrical machine and the steering angle; FIG. 5 is a diagram showing the relationship between the rotation speed difference of each rotating electric machine and the steering angle; FIG. 4 is a diagram showing the relationship between the torque of each rotating electric machine and the steering angle; FIG. 5 is a diagram showing the relationship between the torque difference of each rotating electric machine and the steering angle; FIG. 4 is a diagram showing the relationship between the rotational speed of each rotating electrical machine and the steering angle; FIG. 5 is a diagram showing the relationship between the rotation speed difference of each rotating electric machine and the steering angle; FIG. 4 is a diagram showing a correspondence relationship between each voltage vector and upper and lower arm switches of each phase; The figure which shows an example which produces|generates a command voltage vector from a 60 degrees voltage vector. FIG. 4 is a diagram showing a current path when a first effective voltage vector is applied during power running drive control; FIG. 11 is a diagram showing a current path when a seventh reactive voltage vector is applied during power running drive control; FIG. 4 is a diagram showing current paths when a first effective voltage vector is applied during regenerative drive control; The figure which shows a current path when the 7th reactive voltage vector is applied at the time of regenerative drive control. The figure which shows the control of the comparative example which the ripple current of a smoothing capacitor increases. The figure which shows the control of the comparative example which the ripple current of a smoothing capacitor increases. The figure which shows a 60-degree voltage vector, a 120-degree voltage vector, and a composite voltage vector. FIG. 4 is a diagram showing an example of control for adjusting the output period of an effective voltage vector; FIG. 4 is a diagram showing an example of control for adjusting the output period of an effective voltage vector; The figure which shows the relationship between an inverter current and a ratio coefficient. The figure which shows transition of a 1st, 2nd inverter electric current, and a capacitor|condenser electric current. 4 is a flowchart showing a control procedure performed by a control device; 8 is a flowchart showing a control procedure performed by a control device according to a second embodiment; The figure which shows an example of the control which adjusts the output period of each effective voltage vector which concerns on 3rd Embodiment. The vector diagram of the dq-axis coordinate system according to the fourth embodiment. Vector diagram of the dq-axis coordinate system. FIG. 4 is a diagram showing an example of control for adjusting the output period of an effective voltage vector; The figure which shows an example of the control for reducing the ripple current of the smoothing capacitor which concerns on 5th Embodiment. The block diagram of the control system which concerns on 6th Embodiment. The figure which shows a transfer characteristic. 4 is a flowchart showing a control procedure performed by a control device; 9 is a flowchart showing the procedure of a third adjustment process; 4 is a time chart showing an example of frequency change processing; FIG. 14 is a time chart showing an example of frequency change processing according to a modification of the sixth embodiment; FIG. 4 is a time chart showing an example of frequency change processing; FIG. 14 is a flow chart showing the procedure of a third adjustment process according to the seventh embodiment; FIG.

<First embodiment>
Hereinafter, a first embodiment embodying a control device according to the present invention will be described with reference to the drawings. In this embodiment, the control device is mounted on an electric vehicle.

As shown in FIG. 1 , the vehicle 10 includes a control system including left and right front wheels 11 , left and right rear wheels 12 and a rotating electric machine 21 . The rotating electric machine 21 is an in-wheel motor integrally provided on the inner peripheral side of the front wheel 11 . In this embodiment, a first rotating electrical machine 21a is provided corresponding to the left front wheel 11a with respect to the traveling direction of the vehicle 10, and a second rotating electrical machine 21b is provided corresponding to the right front wheel 11b. there is Therefore, each front wheel 11 is a drive wheel that can be driven to rotate independently of each other. Each rear wheel 12 is a driven wheel that follows as the vehicle 10 travels.

The control system includes a first inverter 22 a , a second inverter 22 b , a smoothing capacitor 23 , an inverter case 24 and a DC power supply 30 . The first inverter 22a is provided corresponding to the first rotating electrical machine 21a, and the second inverter 22b is provided corresponding to the second rotating electrical machine 21b. Each inverter 22a, 22b is a power conversion circuit that converts the DC power supplied from the DC power supply 30 into AC power by switching operation and supplies the converted AC power to the corresponding rotating electric machines 21a, 21b. A smoothing capacitor 23 common to the inverters 22a and 22b is provided on the DC power supply 30 side of each of the inverters 22a and 22b.

The control system includes an accelerator sensor 31 , a steering angle sensor 32 and a control device 33 . The accelerator sensor 31 detects an accelerator stroke, which is the depression amount of an accelerator pedal as an accelerator operation member of the driver. The steering angle sensor 32 detects the steering angle of the steering wheel by the driver. The left and right front wheels 11a and 11b are steered according to the steering angle. Detection values of the accelerator sensor 31 and the steering angle sensor 32 are input to the control device 33 . The first and second inverters 22a and 22b, the smoothing capacitor 23 and the control device 33 are housed in the inverter case 24. As shown in FIG.

The control device 33 is mainly composed of a microcomputer 33a (corresponding to a "computer"), and the microcomputer 33a includes a CPU. The functions provided by the microcomputer 33a can be provided by software recorded in a physical memory device, a computer that executes the software, only software, only hardware, or a combination thereof. For example, if the microcomputer 33a is provided by an electronic circuit that is hardware, it can be provided by a digital circuit including many logic circuits, or an analog circuit. For example, the microcomputer 33a executes a program stored in a non-transitory tangible storage medium as its own storage unit. The programs include, for example, programs for processing shown in FIGS. A method corresponding to the program is executed by executing the program. The storage unit is, for example, a non-volatile memory. Note that the program stored in the storage unit can be updated via a network such as the Internet, for example.

As shown in FIG. 2, the first rotating electric machine 21a is a three-phase synchronous machine, and includes a U-phase winding 26U, a V-phase winding 26V, and a W-phase winding 26W which are star-connected as stator windings. ing. The phase windings 26U, 26V, and 26W are arranged with an electrical angle shift of 120°. The first rotating electric machine 21a is, for example, a permanent magnet synchronous machine.

The first inverter 22a has three phases of series connections of upper arm switches QUH to QWH and lower arm switches QUL to QWL. As each of the switches QUH, QVH, QWH, QUL, QVL, and QWL, a voltage-controlled semiconductor switching element is used, and more specifically, an N-channel MOSFET is used. Therefore, the high potential side terminal of each switch QUH, QVH, QWH, QUL, QVL, QWL is the drain and the low potential side terminal is the source. Each switch QUH, QVH, QWH, QUL, QVL, QWL has a body diode DUH, DVH, DWH, DUL, DVL, DWL.

A first end of a U-phase winding 26U is connected to the source of the U-phase upper arm switch QUH and the drain of the U-phase lower arm switch QUL via a conductive member such as a bus bar. A first end of the V-phase winding 26V is connected to the source of the V-phase upper arm switch QVH and the drain of the V-phase lower arm switch QVL via a conductive member such as a bus bar. A first end of a W-phase winding 26W is connected to the source of the W-phase upper arm switch QWH and the drain of the W-phase lower arm switch QWL via a conductive member such as a bus bar. Second ends of the phase windings 26U, 26V, and 26W are connected at a neutral point O. In this embodiment, each phase winding 26U, 26V, 26W is set to have the same number of turns.

The drains of the upper arm switches QUH, QVH, QWH and the positive terminal of the DC power supply 30 are connected by a positive electrode side bus line Lp such as a bus bar. The sources of the lower arm switches QUL, QVL, QWL and the negative terminal of the DC power supply 30 are connected by a negative bus line Ln such as a bus bar. A smoothing capacitor 23 connects the positive electrode side bus line Lp and the negative electrode side bus line Ln.

The second rotating electrical machine 21b is a three-phase synchronous machine, and includes windings 26U to 26W for each phase, like the first rotating electrical machine 21a. Like the first inverter 22a, the second inverter 22b has three phases of serially connected upper arm switches QUH to QWH and lower arm switches QUL to QWL. In this embodiment, the configurations of the rotating electric machines 21a and 21b and the inverters 22a and 22b are basically the same. Therefore, detailed description of the second rotating electric machine 21b and the second inverter 22b is omitted.

The DC power supply 30 is, for example, an assembled battery configured as a series connection body of battery cells as single cells, and has a terminal voltage of, for example, several hundred volts. In this embodiment, the terminal voltages (for example, rated voltages) of the battery cells forming the DC power supply 30 are set to be the same. As a battery cell, for example, a secondary battery such as a lithium ion battery can be used.

The control system comprises phase current sensors 34 , voltage sensors 35 and angle sensors 36 . The phase current sensors 34 individually detect currents flowing through the rotating electric machines 21a and 21b. A phase current sensor 34 detects currents for at least two phases among the U-, V-, and W-phase currents Iu, Iv, and Iw flowing through the rotating electric machines 21a and 21b. The sign of each phase current Iu, Iv, Iw is positive when the current flows from the connection point of the series connection of the upper and lower arm switches of each phase to each phase winding. It is negative when the current flows to the connection point of the series connection of the lower arm switches. Voltage sensor 35 detects the terminal voltage of smoothing capacitor 23 . The angle sensor 36 is, for example, a resolver, and detects the rotation angles of the rotors of the rotating electric machines 21a and 21b. Detected values of the phase current sensor 34 , the voltage sensor 35 and the angle sensor 36 are input to the control device 33 .

The control device 33 performs power running drive control. Powering drive control is switching control of inverters 22a and 22b for converting DC power output from DC power supply 30 into AC power and supplying the converted AC power to rotating electric machines 21a and 21b. When this control is performed, each rotating electric machine 21a, 21b functions as an electric motor and generates power running torque. Further, the control device 33 performs regenerative drive control. Regenerative drive control is switching control of inverters 22 a and 22 b for converting AC power generated by rotating electric machines 21 a and 21 b into DC power and supplying the converted DC power to DC power supply 30 . When this control is performed, each rotating electric machine 21a, 21b functions as a generator and generates regenerative braking torque.

Based on the accelerator stroke detected by the accelerator sensor 31 and the steering angle detected by the steering angle sensor 32, the control device 33 calculates command rotational speeds of the rotors of the rotating electric machines 21a and 21b. The control device 33 calculates a command torque as an operation amount for feedback-controlling the rotation speed of the rotor of each of the rotating electric machines 21a and 21b to the calculated command rotation speed. The rotation speed of the rotors of the rotating electric machines 21 a and 21 b may be calculated based on the detection value of the angle sensor 36 .

When the calculated command torque is a positive value, power running drive control is performed. Further, when the calculated command torque is a negative value, regenerative drive control is performed. As a result, the torque and rotational speed of the left and right front wheels 11a and 11b, which are drive wheels, are controlled.

By the way, in the vehicle 10, as the steering angle of the steering wheel increases, the length of the trajectory drawn by the inner front wheel of the left and right front wheels 11a and 11b during cornering becomes shorter than the length of the trajectory drawn by the outer front wheel. . Therefore, the greater the steering angle, the greater the torque difference and rotational speed difference between the rotating electric machines 21a and 21b corresponding to the left and right front wheels 11a and 11b. 3 to 10 show an example of the relationship between the driving state of the rotating electric machines 21a and 21b and the steering angle during left turning.

3 to 6 are diagrams showing an example of the relationship between the driving states of the rotating electric machines 21a and 21b and the steering angle when the vehicle 10 turns left from a stopped state. FIG. 3 shows the relationship between the torque of each rotating electrical machine 21a, 21b and the steering angle, and FIG. 4 shows the relationship between the torque difference between each rotating electrical machine 21a, 21b and the steering angle. FIG. 5 shows the relationship between the rotation speed of each rotating electric machine 21a, 21b and the steering angle, and FIG. 6 shows the relationship between the rotation speed difference between each rotating electric machine 21a, 21b and the steering angle.

When the vehicle 10 turns to the left from a stopped state, the rotating electric machines 21a and 21b corresponding to the left and right front wheels 11a and 11b both perform power running drive control. In this case, as the steering angle increases, the torque and rotation speed of the first rotating electric machine 21a corresponding to the left front wheel 11a become lower than the torque and rotating speed of the second rotating electric machine 21b corresponding to the right front wheel 11b. Therefore, the greater the steering angle, the greater the difference in torque and the difference in rotational speed between the rotating electric machines 21a and 21b.

7 to 10 show an example of the relationship between the driving states of the rotary electric machines 21a and 21b and the steering angle when the vehicle 10 turns left from a state in which the vehicle 10 is running straight. FIG. 7 shows the relationship between the torque of each rotating electrical machine 21a, 21b and the steering angle, and FIG. 8 shows the relationship between the torque difference between each rotating electrical machine 21a, 21b and the steering angle. FIG. 9 shows the relationship between the rotational speed of each rotating electrical machine 21a, 21b and the steering angle, and FIG. 10 shows the relationship between the rotational speed difference between each rotating electrical machine 21a, 21b and the steering angle.

When the vehicle 10 turns to the left from a state in which the vehicle 10 is running straight ahead, regenerative drive control is performed in the first rotating electric machine 21a corresponding to the left front wheel 11a which is the inner wheel, and the second rotating electric machine 21a corresponding to the right front wheel 11b which is the outer wheel is performed. Power running drive control is performed in the rotary electric machine 21b. In this case, as the steering angle increases, the torque of the first rotating electrical machine 21a increases to the negative side, and the torque of the second rotating electrical machine 21b increases to the positive side. Therefore, as the steering angle increases, the torque difference between the rotating electric machines 21a and 21b increases. Further, the rotation speed of the first rotating electrical machine 21a becomes lower than the rotating speed of the second rotating electrical machine 21b as the steering angle increases. Therefore, the greater the steering angle, the greater the rotational speed difference between the rotating electric machines 21a and 21b.

The control device 33 calculates a command voltage vector Vtr for controlling the torque of each rotating electric machine 21a, 21b to the calculated command torque. The command voltage vector Vtr is calculated for each rotating electric machine 21a, 21b. Each inverter 22a, 22b is switched such that the voltage vector to each phase winding 26U to 26W of each rotary electric machine 21a, 21b becomes the command voltage vector Vtr. As a result, sinusoidal phase currents that are shifted by 120 degrees from each other flow in the rotating electric machines 21a and 21b.

FIG. 11 shows how the phase upper and lower arm switches QUH-QWL corresponding to the voltage vectors V0-V7 are driven. In each phase, in the driving mode indicated by H, the upper arm switch is turned on and the lower arm switch is turned off. Also, in the driving mode indicated by L, the upper arm switch is turned off and the lower arm switch is turned on.

Further, FIG. 11 shows the correspondence relationship between the inverter current Idc and the phase currents Iu, Iv, and Iw in each of the voltage vectors V0 to V7. The inverter current Idc is a current that flows from the connection point of the positive bus line Lp with the high-potential terminal of the smoothing capacitor 23 to the drain side of each of the upper arm switches QUH to QWH. When each effective voltage vector V1-V6 is applied, the phase current corresponding to each effective voltage vector V1-V6 flows as the inverter current Idc. The directions of the inverter current Idc are opposite to each other during the power running drive control and the regenerative drive control.

When each reactive voltage vector V0, V7 is applied, a closed circuit including each phase winding 26U, 26V, 26W and the turned-on switch is formed. does not correspond to

FIG. 12 shows an example in which the command voltage vector Vtr is generated by 60-degree voltage vectors, which are two types of effective voltage vectors having a phase difference of 60 degrees with the command voltage vector Vtr in between. In the example of FIG. 12, the first and second effective voltage vectors V1 and V2 are used to generate the command voltage vector Vtr. In this case, the time ratio of appearance of the first effective voltage vector V1 and the second effective voltage vector V2 in one switching period Tsw is calculated based on the terminal voltage of the smoothing capacitor 23 and each phase voltage. Here, a detected value of the voltage sensor 35 may be used as the terminal voltage of the smoothing capacitor 23 . Also, the voltage of each phase may be calculated based on the detected value of the voltage sensor 35 and the driving mode of the upper and lower arm switches QUH to QWL of each phase. Any one of the 0th and 7th ineffective voltage vectors V0 and V7 appears in a period other than the period in which the 1st and 2nd effective voltage vectors V1 and V2 appear in one switching period Tsw.

13 to 16 illustrate current paths of currents flowing through the rotating electric machines 21a and 21b, the inverters 22a and 22b, the smoothing capacitor 23, and the DC power supply 30. FIG. 13 to 16, the first and second rotating electrical machines 21a and 21b are simply referred to as rotating electrical machines 21 for convenience.

FIG. 13 shows current paths when the first effective voltage vector V1 is applied while power running drive control is being performed. The current path is high potential side terminal of smoothing capacitor 23→U-phase upper arm switch QUH→rotating electric machine 21→V-phase lower arm switch QVL and W-phase lower arm switch QWL→low potential side terminal of smoothing capacitor 23. In this case, the inverter current Idc corresponds to the U-phase current Iu, and the sign of the U-phase current Iu is positive. In this current path, the sign of the capacitor current Icf flowing through the smoothing capacitor 23 is negative. That is, the smoothing capacitor 23 is discharged. Note that the sign of the capacitor current Icf is positive in the direction from the connection point with the high-potential terminal of the smoothing capacitor 23 to the high-potential terminal of the smoothing capacitor 23 on the positive bus Lp.

FIG. 14 shows current paths when the seventh reactive voltage vector V7 is applied while power running drive control is being performed. The current path is the low potential side terminal of the smoothing capacitor 23 →the DC power supply 30 →the high potential side terminal of the smoothing capacitor 23 . In this case, a positive capacitor current Icf flows from DC power supply 30 to smoothing capacitor 23, and smoothing capacitor 23 is charged. Note that the inverter current Idc does not flow.

FIG. 15 shows current paths when the first effective voltage vector V1 is applied when regenerative drive control is performed. The current path is low potential side terminal of smoothing capacitor 23→V-phase lower arm switch QVL and W-phase lower arm switch QWL→rotating electric machine 21→U-phase upper arm switch QUH→high potential side terminal of smoothing capacitor 23 . In this case, the inverter current Idc corresponds to the U-phase current Iu, and the sign of the U-phase current Iu is negative. In this current path, the sign of the capacitor current Icf flowing through the smoothing capacitor 23 is positive. That is, the smoothing capacitor 23 is charged.

FIG. 16 shows current paths when the seventh reactive voltage vector V7 is applied when regenerative drive control is performed. The current path is high potential side terminal of smoothing capacitor 23 →DC power supply 30 →low potential side terminal of smoothing capacitor 23 . In this case, a negative capacitor current Icf flows from smoothing capacitor 23 to DC power supply 30, and smoothing capacitor 23 is discharged. Note that the inverter current Idc does not flow.

In this manner, when power running drive control or regenerative drive control is performed in each inverter 22a, 22b, the smoothing capacitor 23 is charged and discharged. Along with this, a ripple current flows through the smoothing capacitor 23 . Here, the ripple current flowing through the smoothing capacitor 23 may increase depending on the drive state of each rotating electric machine 21a, 21b.

17 and 18 show control of a comparative example in which the ripple current of the smoothing capacitor 23 increases unlike the present embodiment. 17 and 18, (a) shows the voltage vector to the first rotating electrical machine 21a, (b) shows the voltage vector to the second rotating electrical machine 21b, and (c) shows the first voltage vector flowing through the first inverter 22a. (d) shows the transition of the second inverter current Idcb flowing through the second inverter 22b, and (e) shows the transition of the total value of the first inverter current Idca and the second inverter current Idcb. , (f) show the transition of the capacitor current Icf. Note that FIGS. 17 and 18 show an example in which power running drive control is performed in both the rotating electric machines 21a and 21b.

In the first inverter 22a, the first inverter current Idca is a current that flows from the connection point with the high-potential terminal of the smoothing capacitor 23 on the positive bus line Lp to the drain side of each of the upper arm switches QUH to QWH. is. In addition, the second inverter current Idcb is a current that flows from the connection point with the high potential side terminal of the smoothing capacitor 23 to the drain side of each of the upper arm switches QUH to QWH in the second inverter 22b on the positive bus line Lp. is.

In FIG. 17, the inter-rotating electrical machine phase difference φ between the voltage vector to the first rotating electrical machine 21a and the voltage vector to the second rotating electrical machine 21b is set to 0 degrees. Here, the inter-rotating electrical machine phase difference φ is, for example, the timing at which the first effective voltage vector V1 starts to be applied to the first rotating electrical machine 21a and the timing at which the first effective voltage vector V1 starts being applied to the second rotating electrical machine 21b within a half period of one switching period Tsw. It is the difference from the timing when one effective voltage vector V1 starts to be applied. One switching period Tsw is, for example, the period from the application of the seventh reactive voltage vector V7 to the application of the next seventh reactive voltage vector V7. Note that FIG. 17 shows half Tsw/2 of one switching period.

When the phase difference φ between the rotating electric machines is set to 0 degrees, the output periods of the first and second valid voltage vectors V1 and V2 overlap in the first rotating electrical machine 21a and the second rotating electrical machine 21b, and the 0th and 7th invalid voltage vectors V1 and V2 overlap. The output periods of voltage vectors V0 and V7 overlap. In this case, the first inverter current Idca flows in the positive direction and the second inverter current Idcb flows in the positive direction during the output period of the first and second effective voltage vectors V1 and V2. This increases the total value of the first and second inverter currents Idca and Idcb. Also, in the first rotating electrical machine 21a and the second rotating electrical machine 21b, a period Ta occurs during which the output periods of the 0th and 7th reactive voltage vectors V0 and V7 overlap. As a result, there occurs a period during which both the first and second inverter currents Idca and Idcb become 0 in the period Ta. In this case, the charging current flowing through the smoothing capacitor 23 increases. An increase in the total value of the first and second inverter currents Idca and Idcb, or a period in which both the first and second inverter currents Idca and Idcb are 0, causes a large fluctuation in the capacitor current Icf. put away. As a result, the ripple current of smoothing capacitor 23 increases.

In FIG. 18, the output periods of the first and second effective voltage vectors V1 and V2 are shifted from each other in the first and second rotating electric machines 21a and 21b. Specifically, the phase difference φ between the rotating electric machines is set to 90 degrees. This prevents the first and second inverter currents Idca and Idcb from flowing in the same direction at the same timing. However, in this case, although an increase in the total value of the first and second inverter currents Idca and Idcb can be avoided, in the first and second rotating electric machines 21a and 21b, the 0th and 7th reactive voltage vectors V0 and V7 A period Ta is generated in which the output periods of . As a result, there occurs a period during which the first and second inverter currents Idca and Idcb are both zero. In this case, the charging current flowing through the smoothing capacitor 23 increases. Therefore, there is a concern that the fluctuation of the capacitor current Icf will increase and the ripple current of the smoothing capacitor 23 will increase.

In FIGS. 17 and 18, it has been explained that there is concern about an increase in the ripple current of the smoothing capacitor 23 when power running drive control is performed in both of the rotary electric machines 21a and 21b. It is not limited to this case. For example, when regenerative drive control is performed in both the rotating electric machines 21a and 21b, even if the phase difference φ between the rotating electric machines is set to 90 degrees, the output periods of the 0th and 7th reactive voltage vectors V0 and V7 may overlap. There is As a result, the periods during which the first and second inverter currents Idca and Idcb are 0 overlap. In this case, the discharge current flowing through the smoothing capacitor 23 increases. Therefore, the fluctuation of the capacitor current Icf becomes large. As a result, there is concern that the ripple current of the smoothing capacitor 23 will increase.

Further, for example, even when the power running drive control is performed in the first rotating electric machine 21a and the regenerative drive control is performed in the second rotating electric machine 21b, the fluctuation of the capacitor current Icf increases. There is concern that the ripple current will increase.

Specifically, the output period of each of the effective voltage vectors V1 to V6 to the first rotating electrical machine 21a and the output period of each of the reactive voltage vectors V0 and V7 to the second rotating electrical machine 21b may overlap. In this case, the smoothing capacitor 23 is discharged by outputting the effective voltage vectors V1 to V6 to the first rotating electrical machine 21a, and the reactive voltage vectors V0 and V7 are output to the second rotating electrical machine 21b. Smoothing capacitor 23 is discharged. As a result, the discharge current flowing through the smoothing capacitor 23 increases, and the fluctuation of the capacitor current Icf increases. Moreover, the output period of each of the reactive voltage vectors V0 and V7 to the first rotating electric machine 21a may overlap with the output period of each of the valid voltage vectors V1 to V6 to the second rotating electric machine 21b. In this case, the smoothing capacitor 23 is charged by outputting the reactive voltage vectors V0 and V7 to the first rotating electrical machine 21a, and the effective voltage vectors V1 to V6 are output to the second rotating electrical machine 21b. Smoothing capacitor 23 is charged. As a result, the charging current flowing through the smoothing capacitor 23 increases, and the fluctuation of the capacitor current Icf increases.

The above-described situation in which the ripple current of the smoothing capacitor 23 increases occurs because the output periods of the voltage vectors V0 to V7 to the rotating electric machines 21a and 21b are not properly adjusted.

In this embodiment, the rotating electric machines 21a and 21b are in-wheel motors provided individually corresponding to the left and right front wheels 11a and 11b. In this case, the greater the steering angle of the steering wheel, the greater the torque difference and rotational speed difference between the rotating electric machines 21a and 21b. From the viewpoint of reducing the ripple current of the smoothing capacitor 23, the output period of each of the voltage vectors V0 to V7 is set to an appropriate output period due to the increase in the torque difference and the rotation speed difference between the rotating electric machines 21a and 21b. There is concern that it will become easier for the situation to disappear.

Therefore, the control device 33 of the present embodiment performs control to adjust the output period of each of the effective voltage vectors V1 to V6 to each of the rotating electric machines 21a and 21b. In this embodiment, in order to adjust the output period of each of the effective voltage vectors V1 to V6, two types of effective voltages having a phase difference of 120 degrees with a 60-degree voltage vector and a command voltage vector Vtr interposed therebetween. A vector 120 degree voltage vector is used.

Control device 33 determines the ratio between the period in which the 60-degree voltage vector is used and the period in which the 120-degree voltage vector is used, based on ratio coefficient k (0≦k≦1), so that each effective voltage vector V1 Adjust the output period of ~V6. Here, the ratio coefficient k determines the ratio of the period during which the 120-degree voltage vector is used among the periods during which the effective voltage vectors V1 to V6 are selected in one switching cycle Tsw. The value "1-k" obtained by subtracting the ratio coefficient k from 1 determines the period during which the 60-degree voltage vector is used among the periods during which the effective voltage vectors V1 to V6 are selected in one switching cycle Tsw. be.

FIG. 19 shows an example in which the output period of each effective voltage vector V1, V2, V6 is adjusted with respect to the command voltage vector Vtr sandwiched between the first and second effective voltage vectors V1, V2. In FIG. 19, (a) shows the case where the command voltage vector Vtr is generated by the 60-degree voltage vector consisting of the first and second effective voltage vectors V1 and V2, and (b) shows the second and sixth effective voltages. A case where a command voltage vector Vtr is generated by a 120-degree voltage vector consisting of vectors V2 and V6 is shown. The sum of the lengths of the second and sixth effective voltage vectors V2 and V6, which are 120-degree voltage vectors, is the sum of the lengths of the first and second effective voltage vectors V1 and V2, which are 60-degree voltage vectors. longer than In other words, within one switching cycle Tsw, the output period of the second and sixth effective voltage vectors V2 and V6, which are 120-degree voltage vectors, is the same as that of the first and second effective voltage vectors V1 and V2, which are 60-degree voltage vectors. longer than the output period.

In FIG. 19(c), the command voltage vector Vtr is generated by the combined voltage vector of the 60-degree voltage vector multiplied by the coefficient "1-k" and the 120-degree voltage vector multiplied by the coefficient "k". indicates when As the ratio coefficient k increases within the range of 0≦k≦1, the total length of the first, second, and sixth effective voltage vectors V1, V2, and V6, which are composite voltage vectors, increases. be enlarged. As a result, the output periods of the first, second, and sixth effective voltage vectors V1, V2, and V6 can be adjusted to be longer within one switching period Tsw.

20 and 21 show an example of control in which the output periods of the first, second and sixth effective voltage vectors V1, V2 and V6 are adjusted by using the composite voltage vector. 20(a) to (f) correspond to FIGS. 17(a) to (f), and FIGS. 21(a) to (d) correspond to FIGS. 17(a) to (d). there is In FIG. 20, both the rotating electric machines 21a and 21b perform power running drive control. In FIG. 21, power running drive control is performed in the first rotating electric machine 21a, and regenerative drive control is performed in the second rotating electric machine 21b.

In FIG. 20, the phase difference φ between the rotating electric machines is set to be greater than 0 degrees, and the output period of each of the reactive voltage vectors V0 and V7 to one of the rotating electric machines 21a and 21b and the output period of each of the reactive voltage vectors V0 and V7 to the other. The output periods of the valid voltage vectors V1, V2, V6 are made the same. For example, the output period of the 0th reactive voltage vector V0 to the first rotating electrical machine 21a and the output period of the first, second and sixth active voltage vectors V1, V2, V6 to the second rotating electrical machine 21b are set to be the same. be. In this case, the period during which the first inverter current Idca flows in the positive direction and the period during which the second inverter current Idcb flows in the positive direction can be prevented from overlapping, and the total value of the first and second inverter currents Idca and Idcb is increase can be avoided. In addition, it is possible to avoid overlapping of the output periods of the 0th and 7th reactive voltage vectors V0 and V7 to the respective rotary electric machines 21a and 21b, thereby avoiding an increase in the charging current flowing through the smoothing capacitor 23. FIG.

In FIG. 21, the phase difference φ between the rotating electric machines is set to 0 degrees, and in the respective rotating electric machines 21a and 21b, the output periods of the respective effective voltage vectors V1, V2 and V6 are made the same, and each of the reactive voltage vectors V0 , V7 are made the same. During the period in which each effective voltage vector V1, V2, V6 is output, the first inverter current Idca flows in the positive direction and the second inverter current Idcb flows in the negative direction. Therefore, it is possible to avoid an increase in the total value of the first and second inverter currents Idca and Idcb. Further, during the period in which the reactive voltage vectors V0 and V7 are output, the smoothing capacitor 23 is charged by the output of the reactive voltage vectors V0 and V7 to the first rotating electrical machine 21a, and the respective reactive voltage vectors V0 and V7 are output to the second rotating electrical machine 21b. The smoothing capacitor 23 is discharged by outputting the voltage vectors V0 and V7. Therefore, it is possible to avoid an increase in the charge/discharge current flowing through the smoothing capacitor 23 .

Even if the output periods of the effective voltage vectors V1 to V6 to the rotating electric machines 21a and 21b are adjusted, if the difference between the inverter currents Idca and Idcb is large, the fluctuation of the capacitor current Icf will increase. As a result, there is concern that the ripple current of the smoothing capacitor 23 will increase.

Therefore, the control device 33 adjusts the output period of each voltage vector V0 to V7 to each rotating electric machine 21a, 21b by adjusting the value of the ratio coefficient k, while adjusting the magnitude of each inverter current Idca, Idcb. The voltage vectors V0 to V7 of the rotating electric machines 21a and 21b are controlled so that they are brought closer to each other. As shown in FIG. 22, the control device 33 uses the relationship that the magnitudes of the inverter currents Idca and Idcb are reduced as the ratio coefficient k is increased in each of the rotating electrical machines 21a and 21b, and the inverter currents Idca and Idcb are reduced. Adjust the magnitudes of the currents Idca and Idcb.

FIG. 23 shows that when the power running drive control is performed in both the first and second rotating electric machines 21a and 21b, the magnitude IA of the first inverter current Idca and the magnitude IB of the second inverter current Idcb are made the same. shows an example of control. As a result, fluctuations in the capacitor current Icf can be appropriately suppressed, and the ripple current of the smoothing capacitor 23 can be appropriately reduced.

FIG. 24 shows the procedure of control performed by the control device 33. As shown in FIG. This control is, for example, repeatedly executed at a predetermined control cycle.

In step S10, the rotational speed and command torque of the first rotating electric machine 21a are acquired. In this embodiment, a value calculated based on the detection value of the angle sensor 36 is obtained as the rotational speed of the first rotating electric machine 21a. As the command torque for the first rotating electrical machine 21a, a value calculated to feedback-control the acquired rotation speed of the first rotating electrical machine 21a to the command rotation speed is acquired. A command voltage vector Vtr for the first rotating electric machine 21a is calculated based on the acquired command torque.

In step S11, the rotational speed and command torque of the second rotating electric machine 21b are acquired. In the present embodiment, the rotational speed of the second rotating electric machine 21b is calculated based on the detected value of the angle sensor 36 and acquired. As the command torque for the second rotating electrical machine 21b, a value calculated to feedback-control the acquired rotation speed of the second rotating electrical machine 21b to the command rotation speed is acquired. A command voltage vector Vtr for the second rotating electric machine 21b is calculated based on the acquired command torque.

In step S12, the driving state of each rotating electric machine 21a, 21b is determined. In this embodiment, it is determined whether or not both of the rotating electric machines 21a and 21b are in a driving state in which power running drive control or regenerative drive control is being performed. For example, determination of the drive state of each of the rotating electric machines 21a and 21b may be performed based on the calculated command torque. Specifically, when the calculated command torque is a positive value, it is determined to be in the power running drive control state, and when the calculated command torque is a negative value, it is determined to be in the regenerative drive control state.

When an affirmative determination is made in step S12, the process proceeds to step S13 to perform phase shift processing. The phase shift process is a process of mutually shifting the output periods of the effective voltage vectors V1 to V6 in the first and second rotating electric machines 21a and 21b. As a result, the output period of each of the effective voltage vectors V1 to V6 to one of the rotating electric machines 21a and 21b is shifted within the output period of each of the reactive voltage vectors V0 and V7 to the other. In this embodiment, as the phase shift processing, the phase difference φ between the rotating electric machines is set to 90 degrees.

In step S14, effective voltage ratios m1 and m2 of the rotating electric machines 21a and 21b are calculated. Here, the effective voltage ratios m1 and m2 are the ratios of the output periods of the effective voltage vectors V1 to V6 in one switching cycle Tsw in the rotating electric machines 21a and 21b. In this embodiment, in steps S10 and S11, effective voltage ratios m1 and m2 are calculated when the calculated command voltage vector Vtr is realized using a 60-degree voltage vector.

In step S15, the total period of the output period of each of the effective voltage vectors V1 to V6 to the first rotating electric machine 21a and the output period of each of the effective voltage vectors V1 to V6 to the second rotating electric machine 21b is one switching cycle Tsw. It is determined whether it is the same as In other words, it is determined whether or not the output period of each of the effective voltage vectors V1 to V6 to the first rotating electrical machine 21a and the output period of each of the reactive voltage vectors V0 and V7 to the second rotating electrical machine 21b have the same length. judge. Specifically, it is determined whether or not the relationship m1-(1-m2)=0 holds. If an affirmative determination is made in step S15, it is determined not to adjust the output periods of the effective voltage vectors V1 to V6 to the rotating electric machines 21a and 21b. On the other hand, if a negative determination is made in step S15, it is determined to adjust the output periods of the effective voltage vectors V1 to V6 to the rotating electric machines 21a and 21b. According to the process of step S15, it can be determined that the output period of each of the effective voltage vectors V1 to V6 to each of the rotating electric machines 21a and 21b should be adjusted. In the present embodiment, the process of step S15 corresponds to the "period determination unit".

If an affirmative determination is made in step S15, the process proceeds to step S16 to select the 60-degree voltage vector used to generate the command voltage vector Vtr for each rotating electric machine 21a, 21b. In this embodiment, in steps S10 and S11, the 60-degree voltage vector used to realize the command voltage vector Vtr is selected as it is. In step S16, the output periods of the effective voltage vectors V1 to V6 to the rotating electric machines 21a and 21b are not adjusted. , because it has already been adjusted.

In step S17, the switching operation of each inverter 22a, 22b is performed. In the switching operation, each active voltage vector V1-V6 and each reactive voltage vector V0, V7 are alternately output based on the output period of each selected voltage vector V0-V7. In this embodiment, the process of step S17 corresponds to the "operation unit".

When a negative determination is made in step S15, the process proceeds to step S18 to perform the first adjustment process. The first adjustment process makes the output period of each of the effective voltage vectors V1 to V6 to one of the rotating electric machines 21a and 21b the same as the output period of each of the reactive voltage vectors V0 and V7 to the other. processing. Here, the output period of each of the effective voltage vectors V1 to V6 to one of the rotating electric machines 21a and 21b is a period shifted within the output period of each of the reactive voltage vectors V0 and V7 to the other by phase shift processing. is. In this embodiment, the output period of each effective voltage vector V1 to V6 is adjusted by using a combined voltage vector of the 60-degree voltage vector and the 120-degree voltage vector. After that, the process proceeds to step S17, and switching operation is performed based on the output period of each effective voltage vector V1 to V6 to each rotating electric machine 21a, 21b adjusted in step S18.

If a negative determination is made in step S12, the process proceeds to step S19. A negative determination in step S12 means that one of the rotary electric machines 21a and 21b is under power running drive control and the other is under regenerative drive control. is the case. In this embodiment, the process of step S12 corresponds to the "driving determination unit".

In step S19, it is determined whether or not the output period of each of the effective voltage vectors V1 to V6 to the first rotating electric machine 21a and the output period of each of the effective voltage vectors V1 to V6 to the second rotating electric machine 21b have the same length. determine whether Specifically, it is determined whether or not the relationship m1-m2=0 holds. If an affirmative determination is made in step S19, it is determined not to adjust the output periods of the effective voltage vectors V1 to V6 to the rotating electric machines 21a and 21b. On the other hand, if a negative determination is made in step S19, it is determined to adjust the output periods of the effective voltage vectors V1 to V6 to the rotating electric machines 21a and 21b. According to the process of step S19, it can be determined that the output periods of the effective voltage vectors V1 to V6 to the rotating electric machines 21a and 21b should be adjusted. In this embodiment, the process of step S19 corresponds to the "period determination unit".

If an affirmative determination is made in step S19, the process proceeds to step S20 to select the 60-degree voltage vector used to generate the command voltage vector Vtr for each rotating electric machine 21a, 21b. In this embodiment, in steps S10 and S11, the 60-degree voltage vector used to generate the calculated command voltage vector Vtr is selected as it is. After that, the process proceeds to step S17. In step S20, the output period of each of the effective voltage vectors V1 to V6 to the rotating electric machines 21a and 21b is not adjusted because the output period is set to an appropriate output period to reduce the ripple current of the smoothing capacitor 23. , because it has already been adjusted.

If a negative determination is made in step S19, the process proceeds to step S21 to perform the second adjustment process. The second adjustment process sets the phase difference φ between the rotating electric machines to 0 degree, sets the output period of each of the effective voltage vectors V1 to V6 to the same value in each of the rotating electric machines 21a and 21b, This is processing for making the output periods the same. In this embodiment, the output period of each effective voltage vector V1 to V6 is adjusted by using a combined voltage vector of the 60-degree voltage vector and the 120-degree voltage vector. After that, the process proceeds to step S17. In the present embodiment, the processes of steps S18 and S21 correspond to the "first selection section" and the "second selection section", and the processes of steps S13, S16, S18, S20 and S21 correspond to the "adjustment section".

According to this embodiment detailed above, the following effects can be obtained.

Even if the driving states of the rotating electrical machines 21a and 21b are different, the output periods of the effective voltage vectors V1 to V6 to the rotating electrical machines 21a and 21b are adjusted according to the driving states of the rotating electrical machines 21a and 21b. , can be adjusted to the appropriate output period. A ripple current flows through the smoothing capacitor 23 by switching the inverters 22a and 22b so that the adjusted effective voltage vectors V1 to V6 and the reactive voltage vectors V0 and V7 are alternately output. can be reduced.

The first adjustment process is performed on the condition that both of the rotating electric machines 21a and 21b are determined to be in a driving state in which power running drive control or regenerative drive control is performed. As a result, the output period of each of the effective voltage vectors V1 to V6 to one of the rotating electrical machines 21a and 21b is made the same as the output period of each of the reactive voltage vectors V0 and V7 to the other. Therefore, in each rotating electric machine 21a, 21b, it is possible to avoid the occurrence of a period in which the output periods of the effective voltage vectors V1 to V6 overlap each other and a period in which the output periods of the ineffective voltage vectors V0, V7 overlap each other. As a result, the ripple current flowing through the smoothing capacitor 23 can be appropriately reduced.

The second adjustment process is performed under the condition that it is determined that one of the rotating electric machines 21a and 21b is under power running drive control and the other is under regenerative drive control. done. As a result, it is possible to avoid occurrence of a period in which the output period of each of the effective voltage vectors V1 to V6 to the first rotating electric machine 21a overlaps with the output period of each of the reactive voltage vectors V0 and V7 to the second rotating electric machine 21b. In addition, it is possible to avoid occurrence of a period in which the output period of each of the ineffective voltage vectors V0 and V7 to the first rotating electric machine 21a overlaps with the output period of each of the effective voltage vectors V1 to V6 to the second rotating electric machine 21b. As a result, the ripple current flowing through the smoothing capacitor 23 can be appropriately reduced.

By bringing the magnitudes of the respective inverter currents Idca and Idcb close to each other, the ripple current flowing through the smoothing capacitor 23 can be appropriately reduced.

In the vehicle 10 that travels by rotationally driving the left and right front wheels 11a and 11b, the greater the steering angle of the vehicle 10, the longer the length of the trajectory drawn by the inner wheels of the left and right front wheels 11a and 11b during cornering. is shorter than the length of the trajectory drawn by Therefore, the torque difference and the rotation speed difference between the rotating electric machines 21a and 21b provided to the left and right front wheels 11a and 11b increase. In this case, in the rotating electric machines 21a and 21b provided to the left and right front wheels 11a and 11b, the output periods of the effective voltage vectors V1 to V6 are not appropriate from the viewpoint of reducing the ripple current of the smoothing capacitor 23. There is concern that the situation will become more likely to occur. Therefore, there is a great advantage in using the above-described configuration in which the output periods of the effective voltage vectors V1 to V6 to the rotating electric machines 21a and 21b are adjusted.

<Second embodiment>
The second embodiment will be described below with reference to the drawings, focusing on differences from the first embodiment.

In this embodiment, in addition to determining whether or not the total period of the output periods of the effective voltage vectors V1 to V6 to the rotating electric machines 21a and 21b is equal to one switching period Tsw, the total period is one switching period. A determination is made as to whether or not it is shorter than the period Tsw. Specifically, as shown in FIG. 25, when a negative determination is made in step S15, the process proceeds to step S22. In step S22, it is determined whether m1+m2<1 holds. The reason why step S22 is performed is that when the total value of the effective voltage ratios m1 and m2 is greater than 1, it is impossible to adjust the output periods of the effective voltage vectors V1 to V6 using the composite voltage vector. When an affirmative determination is made in step S22, the process proceeds to step S18. On the other hand, if a negative determination is made in step S22, the process proceeds to step S16. In this embodiment, the processing of steps S15 and S22 corresponds to the "period determination unit".

According to the process of step S22 of the present embodiment, the situation in which the output period of each of the effective voltage vectors V1 to V6 cannot be adjusted by the composite voltage vector is appropriately determined, and the switching operation is performed using the 60-degree voltage vector. It is possible to appropriately determine that it is a situation that should be performed.

<Third Embodiment>
The third embodiment will be described below with reference to the drawings, focusing on differences from the first embodiment.

In this embodiment, instead of adjusting the output period of each of the effective voltage vectors V1 to V6 to each of the rotating electrical machines 21a and 21b, each effective voltage vector V1 to either one of the rotating electrical machines 21a and 21b V6 are regulated and the output periods of each valid voltage vector V1-V6 to the other are not regulated.

FIG. 26 shows an example of control in which the output periods of the effective voltage vectors V1 to V6 to the first rotating electrical machine 21a are not adjusted, but the output periods of the effective voltage vectors V1 to V6 to the second rotating electrical machine 21b are adjusted. indicates In FIG. 26, (a)-(f) correspond to FIGS. 17(a)-(f). In FIG. 26, both the rotating electric machines 21a and 21b perform power running drive control.

As shown in FIG. 26(d), by adjusting the output period of each of the effective voltage vectors V1, V2, and V6 to the second rotating electrical machine 21b, the 0th reactive voltage vector V0 to the first rotating electrical machine 21a is The output period is made the same as the output period of each effective voltage vector V1, V2, V6 to the second rotating electric machine 21b. In this embodiment, the second rotating electric machine 21b corresponds to the "specific rotating electric machine".

According to the present embodiment, compared to the case where the output periods of the effective voltage vectors V1 to V6 to the rotating electrical machines 21a and 21b are adjusted together, the processing load on the control device 33 is reduced, and the smoothing capacitor 23 The flowing ripple current can be reduced.

<Fourth Embodiment>
The fourth embodiment will be described below with reference to the drawings, focusing on differences from the first embodiment.

In the present embodiment, in the first adjustment process and the second adjustment process, field weakening control is performed instead of using the combined voltage vector of the 60-degree voltage vector and the 120-degree voltage vector.

The control device 33 calculates the d-axis command current and the q-axis command current of each rotating electric machine 21a, 21b based on the acquired command torque. The control device 33 calculates the dq-axis command voltage vector Va* of each rotating electric machine 21a, 21b based on the calculated d-axis and q-axis command currents. The control device 33 calculates a command voltage vector Vtr for each of the rotary electric machines 21a and 21b based on the calculated dq-axis command voltage vector Va*.

Here, the dq-axis voltage vector Va when the field weakening control is performed will be supplementarily explained. 27 and 28 are vector diagrams of the dq-axis coordinate system. FIG. 27 shows the dq-axis voltage vector Va when field weakening control is not performed (Id=0), and FIG. 28 shows the dq-axis voltage vector Va when field weakening control is performed. 27 and 28, ω×Φa is the induced voltage due to the armature interlinkage flux, ω×Lq×Iq is the induced voltage due to the q-axis armature reaction flux, and R×Iq is the armature winding of the q-axis current. This is the voltage drop due to line resistance. In FIG. 28, Id is the d-axis current, ω×Ld×Id is the voltage induced by the d-axis armature reaction magnetic flux, and R×Id is the voltage drop due to the armature winding resistance of the d-axis current. Note that ω is the electrical angular velocity of the rotating electric machine.

The dq-axis voltage vector Va when the field-weakening control is not performed is the induced voltage ω×Φa due to the armature interlinkage flux, the induced voltage ω×Lq×Iq due to the q-axis armature reaction magnetic flux, and the q-axis current of the motor. It is a vector obtained by adding the voltage drop R×Iq due to the child winding resistance. On the other hand, the dq-axis voltage vector Va when the field weakening control is performed is the induced voltage ω×Φa due to the armature interlinkage flux and the induced voltage ω×Ld×Id, ω×Lq× It is the sum of Iq and the voltage drops R×Id and R×Iq due to armature winding resistance of the d- and q-axis currents.

By performing the field-weakening control, an increase in the induced voltage due to the armature reaction magnetic flux is suppressed. Therefore, the magnitude of the dq-axis voltage vector Va when the field weakening control is performed is smaller than the magnitude of the dq-axis voltage vector Va when the field weakening control is not performed.

The controller 33 increases the negative d-axis command current when adjusting to shorten the output period of each of the effective voltage vectors V1 to V6. In this case, the controller 33 reduces the magnitude of the dq-axis command voltage vector Va*. The control device 33 calculates the magnitude of the command voltage vector Vtr to be smaller as the magnitude of the dq-axis command voltage vector Va* is smaller. As a result, adjustment is performed so that the output period of each effective voltage vector V1 to V6 is shortened.

In the process of step S18 in FIG. 24, the control device 33 performs field weakening control instead of performing the first adjustment process, thereby adjusting the output period of each of the effective voltage vectors V1 to V6 to be shorter. I do. Further, in the processing of step S21 of FIG. 24, the control device 33 performs field weakening control instead of performing the second adjustment processing so as to shorten the output period of each of the effective voltage vectors V1 to V6. make adjustments to

FIG. 29 shows an example of control in which the output periods of the effective voltage vectors V1 to V6 are adjusted by performing field weakening control. In FIG. 29, (a) shows transition of the first inverter current Idca flowing through the first inverter 22a, and (b) shows transition of the second inverter current Idcb flowing through the second inverter 22b. Note that FIG. 29 shows an example in which power running drive control is performed in both the rotating electric machines 21a and 21b.

As shown in FIG. 29(a), the output period of each of the effective voltage vectors V1 to V6 of the first inverter current Idca is made shorter than the output period of each of the effective voltage vectors V1 to V6 before adjustment indicated by broken lines. As a result, the output period of each of the reactive voltage vectors V0 and V7 of the first rotating electric machine 21a is lengthened. As a result, the output period of each of the reactive voltage vectors V0 and V7 to the first rotating electric machine 21a and the output period of each of the valid voltage vectors V1 to V6 to the second rotating electric machine 21b are made the same.

According to this embodiment, the field-weakening control is performed, so that the output periods of the effective voltage vectors V1 to V6 to the rotating electric machines 21a and 21b can be accurately adjusted.

<Fifth Embodiment>
The fifth embodiment will be described below with reference to the drawings, focusing on differences from the first embodiment.

In the vehicle 10, the rotary electric machine as the in-wheel motor is not limited to being provided in the left and right front wheels 11a and 11b. For example, in a vehicle having two wheels on the front and rear sides of the vehicle, rotating electric machines may be provided on the two wheels on the rear side of the vehicle or on the four wheels on the front and rear sides of the vehicle. However, in a vehicle in which at least one of the front and rear wheels of the vehicle has one wheel, the rotating electric machines may be provided in the three front and rear wheels of the vehicle.

An example of control for reducing the ripple current of the smoothing capacitor in a vehicle in which the first to third rotating electric machines are provided for each of the three drive wheels will be described below. First to third inverters are provided corresponding to the first to third rotating electric machines. A smoothing capacitor is common to the first to third inverters.

In FIG. 30, (a) shows the voltage vector to the first rotating electric machine, (b) shows the voltage vector to the second rotating electric machine, (c) shows the voltage vector to the third rotating electric machine, ( d) shows transition of the first inverter current Idca, (e) shows transition of the second inverter current Idcb, and (f) shows transition of the third inverter current Idcc. Note that FIG. 30 shows an example in which power running drive control is performed in all of the first to third rotating electric machines.

In FIG. 30, the output periods of the first and second effective voltage vectors V1 and V2 are shifted from each other in the first to third rotating electric machines. Specifically, the phase difference φ1 between the first rotating electric machines is set to 60 degrees, and the phase difference φ2 between the second rotating electric machines is set to 60 degrees. Here, the phase difference φ1 between the first rotating electrical machines is, for example, the timing at which the 0th reactive voltage vector V0 starts to be applied to the first rotating electrical machine 21a and the timing at which the 0th reactive voltage vector V0 starts to be applied to the first rotating electrical machine 21b within a half period of one switching period Tsw. is the difference from the timing at which the 0th reactive voltage vector V0 starts to be applied. The phase difference φ2 between the second rotating electrical machines is, for example, the timing at which the 0th reactive voltage vector V0 starts to be applied to the second rotating electrical machine and the 0th reactive voltage to the third rotating electrical machine within a half period of one switching cycle Tsw. It is the difference from the timing when the vector V0 starts to be applied.

As shown in FIG. 30, the output period of the 0th reactive voltage vector V0 of the first rotating electrical machine and the total output period of the first and second active voltage vectors V1 and V2 of the second and third rotating electrical machines are the same. be done. The output period of the reactive voltage vector of the second rotating electrical machine and the total output period of the active voltage vector of the first and third rotating electrical machines are set to be the same. , is made the same as the total output period of the active voltage vector of the second rotating electric machine. This makes it possible to prevent the periods in which the first to third inverter currents Idca to Idcc flow from overlapping each other. Moreover, it is possible to avoid the occurrence of a period in which the output periods of the reactive voltage vectors V0 and V7 of the first to third rotating electric machines overlap.

Note that if the output period of the 0th reactive voltage vector V0 of the first rotating electrical machine is not the same as the total output period of the first and second active voltage vectors V1 and V2 of the second and third rotating electrical machines, the 60-degree vector and the 120-degree voltage vector may be used. This adjusts the output period of each effective voltage vector V1 to V6. As a result, the periods in which the first to third inverter currents Idca to Idcc flow are suppressed from overlapping with each other, and the occurrence of periods in which the output periods of the reactive voltage vectors V0 and V7 of the first to third rotating electric machines overlap is suppressed. You can

<Sixth embodiment>
The sixth embodiment will be described below with reference to the drawings, focusing on differences from the first embodiment.

In this embodiment, adjustment processing is performed from the viewpoint of reducing the current flowing through the DC power supply 30 in addition to the viewpoint of reducing the ripple current of the smoothing capacitor 23 .

FIG. 31 shows a configuration diagram of the control system of this embodiment. The control system includes a power supply current sensor 37 . A power supply current sensor 37 detects a current IB flowing through the DC power supply 30 . In addition, in FIG. 31, the same reference numerals are assigned to the same configurations as those shown in FIG. 2 for convenience.

Current IB flowing in the DC power supply 30 is amplified with respect to the inverter current Idc due to current resonance caused by the inductance of the wiring connecting the DC power supply 30 and the smoothing capacitor 23 and the capacitance of the smoothing capacitor 23. There is something. Here, the wiring that connects the DC power supply 30 and the smoothing capacitor 23 is, for example, the positive electrode side bus line Lp and the negative electrode side bus line Ln. In this situation, a current larger than the rated current of the DC power supply 30 flows through the DC power supply 30, and there is a concern that the reliability of the DC power supply 30 is lowered.

Specifically, it will be described with reference to the transfer characteristics shown in FIG. The transfer characteristic of FIG. 32 is a diagram showing the relationship between the amplification factor (=IB/Idc), which is the ratio of the current IB flowing through the DC power supply 30 to the inverter current Idc, and the frequency fb of the current IB flowing through the DC power supply 30. . The amplification factor is maximized at the resonance frequency fr determined by the inductance of the wiring such as the positive-side bus Lp and the negative-side bus Ln and the capacitance of the smoothing capacitor 23, and the frequency fb of the current IB flowing through the DC power supply 30 is the resonance frequency. It gradually decreases with increasing distance from fr. In this case, when the frequency fb of the current IB flowing through the DC power supply 30 is the resonance frequency fr or a frequency in the vicinity of the resonance frequency fr, the current IB flowing through the DC power supply 30 is amplified with respect to the inverter current Idc, and the DC power supply 30 An unstable state can occur in which a large current flows. In this unstable state, a current larger than the rated current of the DC power supply 30 flows through the DC power supply 30, and there is a concern that the reliability of the DC power supply 30 is lowered.

Therefore, in the present embodiment, the control device 33 adjusts the output mode of each of the voltage vectors V0 to V7 to each of the rotary electric machines 21a and 21b in order to change the frequency fb of the current IB flowing through the DC power supply 30. process. In this embodiment, as shown in FIG. 33, after the processing of steps S16, S18, S20, and S21, the process proceeds to step S30, and the control device 33 performs the third adjustment processing. After the process of step S30, the process proceeds to step S17.

FIG. 34 shows the procedure of the third adjustment process in step S30 of FIG.

In step S40, current parameters are obtained. In this embodiment, the current parameter is the current IB flowing through the DC power supply 30 . A value detected by the power supply current sensor 37 may be used as the current IB flowing through the DC power supply 30 .

In step S41, it is determined whether or not the DC power supply 30 is in an unstable state based on the current parameter. In this embodiment, it is determined whether or not the amplitude of the current IB flowing through the DC power supply 30 exceeds the current threshold. If a negative determination is made in step S41, it is determined that the DC power supply 30 is in a stable state, and the third adjustment process ends. On the other hand, when an affirmative determination is made in step S41, it is determined that the DC power supply 30 is in an unstable state, and the process proceeds to step S42. Instead of determining whether the amplitude of the current IB flowing through the DC power supply 30 has exceeded the current threshold, it may be determined whether the effective value of the current IB flowing through the DC power supply 30 has exceeded the current threshold. good.

In step S42, frequency change processing is performed. The frequency changing process is a process of changing the frequency fb of the current flowing through the DC power supply 30 . In the present embodiment, in the frequency changing process, the frequency fb of the current IB flowing through the DC power supply 30 is lowered so as to be separated from the resonance frequency fr.

In the frequency change process, the control device 33 controls the overlapping period of the output period of each of the effective voltage vectors V1 to V6 to the first rotating electrical machine 21a and the output period of each of the reactive voltage vectors V0 and V7 to the second rotating electrical machine 21b. shorten the period. Here, a case where the third adjustment process is performed after the first adjustment process in step S18 will be described. After the first adjustment process, as shown in FIG. 20, the inter-rotating machine phase difference φ is set to a value greater than 0 degrees. In the frequency changing process, the control device 33 shifts the output periods of the voltage vectors V0, V1, V2, V6, and V7 to the rotating electrical machines 21a and 21b, respectively, so that the phase difference φ between the rotating electrical machines is set in advance. is reduced by a predetermined phase difference Δφ. This shortens the overlap period.

FIG. 35 shows an example of a case where the voltage vector to the second rotating electric machine 21b is shifted due to the frequency changing process being performed. In FIG. 35, (a) shows the voltage vector to the first rotating electrical machine 21a, (b) shows the voltage vector to the second rotating electrical machine 21b before the frequency changing process is performed, and (c) shows the frequency changing process. shows a voltage vector to the second rotating electrical machine 21b after the is performed. In the voltage vector to each of the rotating electric machines 21a and 21b after the frequency changing process is performed, the phase difference φ between the rotating electric machines is reduced by a predetermined phase difference Δφ corresponding to the output period of the sixth effective voltage vector V6. . As a result, in a half period of one switching cycle Tsw, the overlap period Tb2 after the frequency change process is performed is compared with the overlap period Tb1 before the frequency change process, and the output of the sixth effective voltage vector V6 is Only the period is shortened. In FIG. 35, the inter-rotating electric machine phase difference φ is defined by the timing at which the sixth effective voltage vector V6 starts to be applied to the first rotating electric machine 21a and the timing at which the sixth effective voltage vector V6 starts to be applied to the second rotating electric machine 21b. is exemplarily shown as a difference between .

By performing the frequency change process, the period of output of each of the effective voltage vectors V1 to V6 to the first rotating electric machine 21a and the period of output of each of the reactive voltage vectors V0 and V7 to the second rotating electric machine 21b overlap each other. shortened. This reduces the number of oscillations of the total current of the first inverter current Idca and the second inverter current Idcb within one switching cycle Tsw. Therefore, the frequency of the total current of the first inverter current Idca and the second inverter current Idcb is lowered. Along with this, it becomes possible to lower the frequency fb of the current IB flowing in the DC power supply 30 so as to separate it from the resonance frequency fr.

In the frequency changing process, the control device 33 preferably lowers the frequency fb of the current IB flowing through the DC power supply 30 so that the amplitude of the current IB flowing through the DC power supply 30 becomes smaller. For example, if the control device 33 determines that the amplitude of the current IB flowing through the DC power supply 30 is smaller than a predetermined current amplitude value after reducing the phase difference φ between the rotating electric machines by a predetermined phase difference, It is preferable to end the frequency change process. Here, the current amplitude value is preferably set to a value smaller than the current threshold. On the other hand, when the control device 33 determines that the above conditions are not satisfied, the control device 33 may further reduce the phase difference φ between the rotating electric machines by a predetermined phase difference. As a result, the frequency fb of the current IB flowing through the DC power supply 30 is lowered so that the amplitude of the current IB flowing through the DC power supply 30 becomes smaller. Instead of determining whether the conditions described above are satisfied, control device 33 may determine whether or not the effective value of current IB flowing through DC power supply 30 is smaller than a predetermined effective current value.

According to this embodiment, the voltage vectors V0 to V7 to the rotating electrical machines 21a and 21b can be adjusted to appropriate output modes according to the current IB flowing through the DC power supply 30. FIG. By switching the inverters 22a and 22b to output the adjusted voltage vectors, the frequency fb of the current IB flowing through the DC power supply 30 is lowered. This makes it possible to separate the frequency fb of the current IB flowing through the DC power supply 30 from the resonance frequency fr. As a result, it is possible to suppress the occurrence of a situation in which a current larger than the rated current of the DC power supply 30 flows and the reliability of the DC power supply 30 is lowered.

When it is determined that the amplitude of the current IB flowing through the DC power supply 30 exceeds the current threshold, the output period of each of the effective voltage vectors V1 to V6 to the first rotating electrical machine 21a and each of the reactive voltage vectors to the second rotating electrical machine 21b. The overlapping period with the output period of V0 and V7 is shortened. As a result, the frequency fb of the current IB flowing through the DC power supply 30 is lowered so that the amplitude of the current IB flowing through the DC power supply 30 becomes smaller. As a result, the occurrence of a situation in which a current larger than the rated current flows through the DC power supply 30 can be suppressed accurately.

<Modified Example of Sixth Embodiment>
It should be noted that the sixth embodiment may be implemented with the following changes.

- The current parameter is not limited to the current IB flowing through the DC power supply 30 . For example, the current parameter may be the terminal voltage of smoothing capacitor 23 . In this case, the terminal voltage of the smoothing capacitor 23 may be acquired in the process of step S40. A value detected by the voltage sensor 35 may be used as the terminal voltage of the smoothing capacitor 23 . In step S41, it may be determined whether or not the amplitude of the terminal voltage of the smoothing capacitor 23 exceeds the voltage threshold. In this case, the control system may not be equipped with the power supply current sensor 37 . Instead of determining whether the amplitude of the terminal voltage of the smoothing capacitor 23 has exceeded the voltage threshold, it may be determined whether the effective value of the terminal voltage of the smoothing capacitor 23 has exceeded the voltage threshold.

- In the process of step S40, instead of acquiring the detection value of the power supply current sensor 37, an estimated value of the current IB flowing through the DC power supply 30 may be acquired. The estimated value of the current IB flowing through the DC power supply 30 is based on at least one of the detected value of the phase current sensor 34 and the detected value of the voltage sensor 35, and each voltage vector V0 to V7 to each rotating electric machine 21a, 21b. It is sufficient to use the value estimated by In this case, the control system may not be equipped with the power supply current sensor 37 .

In the frequency change process, the overlapping period of the output period of each of the effective voltage vectors V1 to V6 to the first rotating electrical machine 21a and the output period of each of the reactive voltage vectors V0 and V7 to the second rotating electrical machine 21b is short. Instead of being shortened, it may be lengthened. Here, a case where the third adjustment process is performed after the second adjustment process in step S21 will be described. In this case, as shown in FIG. 21, the phase difference φ between the rotating electric machines is set to 0 degree. In the frequency changing process, the control device 33 shifts the output periods of the voltage vectors V0, V1, V2, V6, and V7 to the rotating electrical machines 21a and 21b, respectively, so that the phase difference φ between the rotating electrical machines is set in advance. is increased by a predetermined phase difference. This lengthens the overlap period.

FIG. 36 shows an example of a case where the voltage vector to the second rotating electric machine 21b is shifted by performing the frequency changing process. In FIG. 36, (a) shows the voltage vector to the first rotating electrical machine 21a, and (b) shows the voltage vector to the second rotating electrical machine 21b after the frequency changing process is performed. FIG. 36 shows an example in which the phase difference φ between the rotating electric machines is increased by the predetermined phase difference Δφ corresponding to the output period of the sixth effective voltage vector V6 after the frequency changing process. As a result, the overlap period Tc is lengthened by the output period of the sixth effective voltage vector V6 in half the period of one switching period Tsw. In FIG. 36, the inter-rotating electric machine phase difference φ is defined by the timing at which the sixth effective voltage vector V6 starts to be applied to the first rotating electric machine 21a and the timing at which the sixth effective voltage vector V6 starts to be applied to the second rotating electric machine 21b. is exemplarily shown as a difference between . The overlapping period Tc is exemplarily shown as the output period of the sixth valid voltage vector V6.

By performing the frequency change process, the period of output of each of the effective voltage vectors V1 to V6 to the first rotating electric machine 21a and the period of output of each of the reactive voltage vectors V0 and V7 to the second rotating electric machine 21b overlap each other. lengthened. This increases the number of oscillations of the total current of the first inverter current Idca and the second inverter current Idcb within one switching cycle Tsw. Therefore, the frequency of the total current of the first inverter current Idca and the second inverter current Idcb is increased. Along with this, it becomes possible to increase the frequency fb of the current IB flowing in the DC power supply 30 so as to separate it from the resonance frequency fr.

In the frequency changing process, the control device 33 preferably increases the frequency fb of the current IB flowing through the DC power supply 30 so that the amplitude of the current IB flowing through the DC power supply 30 becomes small. For example, if the control device 33 determines that the amplitude of the current IB flowing through the DC power supply 30 is smaller than a predetermined current amplitude value after increasing the phase difference φ between the rotating electric machines by a predetermined phase difference, It is preferable to end the frequency change processing. Here, the current amplitude value is preferably set to a value smaller than the current threshold. On the other hand, when the control device 33 determines that the above-described conditions are not satisfied, the control device 33 may further increase the phase difference φ between the rotating electric machines by a predetermined phase difference. As a result, the frequency fb of the current IB flowing through the DC power supply 30 is increased so that the amplitude of the current IB flowing through the DC power supply 30 becomes smaller. Instead of determining whether the conditions described above are satisfied, control device 33 may determine whether or not the effective value of current IB flowing through DC power supply 30 is smaller than a predetermined effective current value.

According to the present embodiment, when it is determined that the amplitude of the current IB flowing through the DC power supply 30 exceeds the current threshold, the output period of each of the effective voltage vectors V1 to V6 to the first rotating electric machine 21a and the output period of the effective voltage vectors V1 to V6 to the second rotating electric machine 21b, the overlap period with the output period of each reactive voltage vector V0, V7 to 21b is lengthened. As a result, the frequency fb of the current IB flowing through the DC power supply 30 is increased so that the amplitude of the current IB flowing through the DC power supply 30 becomes smaller. As a result, the occurrence of a situation in which a current larger than the rated current flows through the DC power supply 30 can be suppressed accurately.

- In the frequency changing process, the process of increasing the frequency fb of the current IB flowing through the DC power supply 30 is not limited to lengthening the overlapping period described above. In the frequency changing process, the frequency fb of the current IB flowing through the DC power supply 30 may be increased by inserting the reactive voltage vector to each rotating electric machine 21a, 21b between two different active voltage vectors.

Here, a case where the third adjustment process is performed after the first adjustment process in step S18 will be described. In this case, for example, the voltage vectors to the rotating electrical machines 21a and 21b change from the state shown in FIGS. changed to state. Specifically, when the seventh reactive voltage vector V7 is inserted, the voltage vector to the first rotating electric machine 21a is V7→V2→V7→V1→V7→V6→V0→V6→V7→V1→V7→ V2 is output in order, and the voltage vector to the second rotary electric machine 21b is output in order of V2->V7->V2->V7->V1->V7->V6->V0. The output period of the inserted seventh reactive voltage vector V7 is set longer than the time required for the upper arm switches QUH to QWH to be turned on and the lower arm switches QUL to QWL to be turned off. good.

By inserting the seventh reactive voltage vector V7 into the voltage vectors to the rotating electrical machines 21a and 21b, the number of times the total current of the first inverter current Idca and the second inverter current Idcb oscillates within one switching period Tsw. increases. Therefore, the frequency of the total current of the first inverter current Idca and the second inverter current Idcb is increased. Along with this, it becomes possible to increase the frequency fb of the current IB flowing in the DC power supply 30 so as to separate it from the resonance frequency fr.

Note that the control device 33 is not limited to inserting the ineffective voltage vector between two different effective voltage vectors within one switching period Tsw in the frequency changing process. For example, the control device 33 may insert one reactive voltage vector between two different active voltage vectors within one switching period Tsw. In this case, the voltage vector to the first rotating electrical machine 21a is output in the order of V7→V2→V7→V1→V6→V0→V6→V1→V2, and the voltage vector to the second rotating electrical machine 21b is output in the order of V2→V7. →V2→V7→V1→V6→V0. Note that the frequency fb of the current IB flowing through the DC power supply 30 is made higher when there are many places where the reactive voltage vectors are inserted, compared to when there are few places where the reactive voltage vectors are inserted.

In the frequency changing process, the control device 33 may insert the 0th reactive voltage vector V0 into the voltage vector to the first rotating electric machine 21a instead of inserting the 7th reactive voltage vector V7. In this case, for example, the control device 33 outputs the voltage vector to the first rotating electric machine 21a in the order of V7→V2→V0→V1→V0→V6→V0→V6→V0→V1→V0→V2. The voltage vector to the two-rotating electric machine 21b may be output in the order of V2->V7->V2->V0->V1->V0->V6->V0. The output period of the inserted 0th reactive voltage vector V0 is set longer than the time required for the upper arm switches QUH to QWH to be turned off and the lower arm switches QUL to QWL to be turned on. good.

In the frequency change process, the control device 33 maintains the output period adjusted by the first adjustment process and is suitable for reducing the ripple current of the smoothing capacitor 23, while maintaining the output period to the rotating electric machines 21a and 21b. It is recommended to insert the reactive voltage vector into the voltage vector of . For example, as shown in FIGS. 37(c) and 37(d), the output period of the first, second and sixth voltage vectors V1, V2 and V6 to the first rotating electric machine 21a and the inserted reactive voltage vector It is preferable that the total output period and the output period of the seventh reactive voltage vector V7 to the second rotating electric machine 21b are made equal. As a result, the frequency fb of the current IB flowing through the DC power supply 30 can be increased while reducing the ripple current of the smoothing capacitor 23 .

The control device 33 may insert the reactive voltage vectors V0 and V7 into the voltage vector to either one of the rotating electric machines 21a and 21b.

- In FIG. 33, steps S15, S18, S19, and S21 may not be performed. That is, only the third adjustment process may be performed without performing the first adjustment process and the second adjustment process.

<Seventh embodiment>
The seventh embodiment will be described below with reference to the drawings, focusing on differences from the sixth embodiment. In the present embodiment, the embodiment of the third adjustment process is changed, and the frequency fb is changed higher or the frequency fb is changed lower according to the frequency fb of the current IB flowing through the DC power supply 30 .

FIG. 38 shows the procedure of the third adjustment process in step S30 of FIG. In addition, in FIG. 38, the same components as those shown in FIG. 34 are denoted by the same reference numerals for convenience.

If an affirmative determination is made in step S41, the process proceeds to step S43. In step S43, the frequency fb of the current IB flowing through the DC power supply 30 is calculated. The frequency fb of the current IB flowing through the DC power supply 30 is determined by the detection value of the phase current sensor 34, the detection value of the voltage sensor 35, the detection value of the power supply current sensor 37, and the voltage vectors V0 to V7 to the rotating electric machines 21a and 21b. It may be calculated based on at least one of

In step S44, it is determined whether or not the frequency fb of the current IB flowing through the DC power supply 30 is lower than the resonance frequency fr. When an affirmative determination is made in step S44, the process proceeds to step S45. On the other hand, if a negative determination is made in step S44, the process proceeds to step S46. In step S44, instead of determining whether or not the frequency fb of the current IB flowing through the DC power supply 30 is lower than the resonance frequency fr, It may be determined whether

In step S45, a frequency lowering process for lowering the frequency fb of the current IB flowing through the DC power supply 30 is performed. Specifically, in the frequency reduction process, the output period of each of the effective voltage vectors V1 to V6 to the first rotating electrical machine 21a overlaps with the output period of each of the reactive voltage vectors V0 and V7 to the second rotating electrical machine 21b. This is processing for shortening the overlap period.

In step S46, a high-frequency process is performed to increase the frequency fb of the current IB flowing through the DC power supply 30 . Specifically, in the frequency increasing process, the output period of each of the effective voltage vectors V1 to V6 to the first rotating electric machine 21a overlaps with the output period of each of the reactive voltage vectors V0 and V7 to the second rotating electric machine 21b. This is at least one of a process of lengthening the overlapping period and a process of inserting a reactive voltage vector to each rotating electric machine 21a, 21b between two different active voltage vectors.

According to the transfer characteristics shown in FIG. 32, the amplification factor has a peak value at the resonance frequency fr. Therefore, in order to appropriately reduce the current IB flowing through the DC power supply 30, it is desirable to change the frequency fb in consideration of the relationship between the frequency fb of the current IB flowing through the DC power supply 30 and the resonance frequency fr.

According to this embodiment, when the frequency fb of the current IB flowing through the DC power supply 30 is lower than the resonance frequency fr, the frequency reduction process is performed. On the other hand, when the frequency fb of the current IB flowing through the DC power supply 30 is equal to or higher than the resonance frequency fr, frequency increasing processing is performed. As a result, the frequency fb of the current IB flowing through the DC power supply 30 is changed in such a direction that the amplification factor is reduced. As a result, the current IB flowing through the DC power supply 30 can be appropriately reduced.

<Other embodiments>
It should be noted that the above embodiment may be modified as follows.

In the process of step S15, instead of determining whether m1-(1-m2)=0 holds, it is also possible to determine whether |m1-(1-m2)|<εa holds. good. Here, εa is a first allowable value, and the mismatch between the output period of each of the effective voltage vectors V1 to V6 of the first rotating electrical machine 21a and the output period of each of the reactive voltage vectors V0 and V7 of the second rotating electrical machine 21b. Duration tolerance. For example, if the relationship |m1-(1-m2)| It is sufficient that the mismatch period is set to be shorter than that. Specifically, in FIG. 26, the first allowable value εa may be set such that the mismatch period is shorter than the first effective voltage vector V1 output to the first rotating electric machine 21a.

In the process of step S19, instead of determining whether m1-m2=0 holds, it may be determined whether |m1-m2|<εb holds. Here, εb is a second allowable value, which is a mismatch between the output period of each of the effective voltage vectors V1 to V6 of the first rotating electric machine 21a and the output period of each of the effective voltage vectors V1 to V6 of the second rotating electric machine 21b. Duration tolerance. For example, when the relationship |m1−m2|<εb holds, the second allowable value εb is less than the voltage vector with the shortest output period among the voltage vectors V0 to V7 output in one switching cycle Tsw. It is sufficient if the period is set to be short.

In the process of step S18, instead of performing the first adjustment process, for example, one of the rotating electric machines 21a and 21b is adjusted so that the relationship |m1-(1-m2)|<εa described above holds. A process of bringing the output periods of one of the effective voltage vectors V1 to V6 closer to the output periods of the other ineffective voltage vectors V0 and V7 may be performed. Even in this case, the ripple current flowing through the smoothing capacitor 23 can be reduced.

In the process of step S21, instead of performing the second adjustment process, in each of the rotating electric machines 21a and 21b, each of the effective voltage vectors V1 to V6 is adjusted so that the above-mentioned relationship |m1-m2|<εb holds, for example. and the output periods of the invalid voltage vectors V0 and V7 may be brought closer to each other. Even in this case, the ripple current flowing through the smoothing capacitor 23 can be reduced.

- The semiconductor switch that constitutes the inverter is not limited to the N-channel MOSFET, and may be, for example, an IGBT. In this case, the high side terminal of the switch is the collector and the low side terminal is the emitter. Also, a freewheel diode may be connected in anti-parallel to each switch.

- The controller and techniques described in this disclosure can be performed by a dedicated computer provided by configuring a processor and memory programmed to perform one or more functions embodied by a computer program; may be implemented. Alternatively, the controls and techniques described in this disclosure may be implemented by a dedicated computer provided by configuring the processor with one or more dedicated hardware logic circuits. Alternatively, the control units and techniques described in this disclosure can be implemented by a combination of a processor and memory programmed to perform one or more functions and a processor configured by one or more hardware logic circuits. It may also be implemented by one or more dedicated computers configured. The computer program may also be stored as computer-executable instructions on a computer-readable non-transitional tangible recording medium.

- Characteristic configurations extracted from each of the above-described embodiments will be described below.
[Configuration 1]
a plurality of power conversion circuits (22a, 22b) for converting DC power of a DC power supply (30) into AC power by switching operation and outputting the AC power;
Rotating electric machines (21a, 21b) provided corresponding to the respective power conversion circuits and supplied with AC power output from the power conversion circuits;
Applied to a control system comprising a capacitor (23) connected in parallel to the DC power supply and provided on the input side of each power conversion circuit and common to each power conversion circuit,
an adjustment unit that performs an adjustment process for adjusting an output mode of the voltage vector to each rotating electric machine;
A control device for a rotating electrical machine, comprising: an operation unit that performs a switching operation of each of the power conversion circuits so as to output the voltage vector adjusted by the adjustment unit.
[Configuration 2]
The adjustment unit performs, as the adjustment process, a process of adjusting an output period of the effective voltage vector to each of the rotating electric machines according to the drive state of each of the rotating electric machines,
The operation unit alternately outputs the effective voltage vector and the reactive voltage vector to each rotating electric machine while setting the output period of the effective voltage vector to each rotating electric machine to the output period adjusted by the adjusting unit. , the control device for a rotary electric machine according to configuration 1, which performs the switching operation.
[Configuration 3]
a drive determination unit that determines whether each of the rotating electric machines is in a power running state in which the rotating electric machine functions as an electric motor or in a regenerative drive state in which the rotating electric machine functions as a generator;
The adjustment unit, on the condition that the drive determination unit determines that all of the rotary electric machines are in the power running state or the regenerative drive state, performs the adjustment process on any one of the rotary electric machines. The output periods of the active voltage vector to each of the rotating electrical machines are shifted so that the output period of the reactive voltage vector to one reference rotating electrical machine includes the output period of the active voltage vector to the remaining rotating electrical machines. 3. The controller for a rotating electrical machine according to configuration 2, wherein the output period of the reactive voltage vector to the reference rotating electrical machine and the output period of the effective voltage vector to the remaining rotating electrical machines are brought closer to each other.
[Configuration 4]
Determining whether or not the output period of the reactive voltage vector to the reference rotating electric machine and the output period of the effective voltage vector to the remaining rotating electric machines have different lengths in one switching cycle of the switching operation. and a period determination unit for
The adjustment unit is determined by the period determination unit that the output period of the reactive voltage vector to the reference rotating electrical machine and the output period of the effective voltage vector to the remaining rotating electrical machines have different lengths. The control device for a rotating electric machine according to configuration 3, wherein the adjustment process is performed on the condition that
[Configuration 5]
The plurality of power conversion circuits are a first power conversion circuit (22a) and a second power conversion circuit (22b),
As the rotating electrical machines, a first rotating electrical machine (21a) corresponding to the first power conversion circuit and a second rotating electrical machine (21b) corresponding to the second power conversion circuit are provided,
a drive determination unit that determines, as the drive state, whether the first rotating electric machine and the second rotating electric machine are in a power running state in which they function as electric motors or in a regenerative drive state in which they function as generators. ,
On the condition that the drive determining unit determines that the first rotating electric machine is in the power running drive state and the second rotating electric machine is in the regenerative driving state, the adjustment unit performs the adjustment process as described above. 3. The control device for a rotating electrical machine according to configuration 2, which performs a process of bringing the effective voltage vector output period to the first rotating electrical machine closer to the output period of the effective voltage vector to the second rotating electrical machine.
[Configuration 6]
determining whether or not the output period of the effective voltage vector to the first rotating electrical machine and the output period of the effective voltage vector to the second rotating electrical machine have different lengths in one switching cycle of the switching operation; A period determination unit for determining,
The adjusting unit determines, by the period determining unit, that the effective voltage vector output period to the first rotating electrical machine and the effective voltage vector output period to the second rotating electrical machine have different lengths. 6. The control device for a rotary electric machine according to configuration 5, wherein the adjustment process is performed on the condition that
[Configuration 7]
The adjustment unit
a first selection unit that selects two types of effective voltage vectors having a phase difference of 60 degrees with respect to each of the rotating electrical machines;
an effective voltage vector selected by the first selection unit from among two types of effective voltage vectors having a phase difference of 120 degrees with respect to each of the rotating electric machines, with the command voltage vector for the rotating electric machine interposed therebetween; has a second selector that selects a different effective voltage vector, and
Configurations 2 to 6, wherein in the adjustment process, three types of effective voltage vectors selected by the first selection unit and the second selection unit are used to adjust the output period of the effective voltage vector to each rotating electric machine. A control device for a rotary electric machine according to any one of the above.
[Configuration 8]
8. The control device for a rotary electric machine according to claim 7, wherein in the adjustment process, the adjustment unit brings the magnitudes of the currents flowing through the power conversion circuits closer to each other.
[Configuration 9]
The adjustment unit
a first selection unit that selects two types of effective voltage vectors having a phase difference of 60 degrees with respect to a command voltage vector to a specific rotating electrical machine, which is a part of the rotating electrical machines, among the rotating electrical machines; ,
An effective voltage vector that is different from the effective voltage vector selected by the first selection unit from among two types of effective voltage vectors that sandwich the command voltage vector for the specific rotating electric machine and have a phase difference of 120 degrees from each other. and a second selection unit that selects
Configurations 2 to 6, wherein in the adjustment process, the three types of effective voltage vectors selected by the first selection unit and the second selection unit are used to adjust the output period of the effective voltage vector to the specific rotating electric machine. A control device for a rotary electric machine according to any one of the above.
[Configuration 10]
Any one of configurations 2 to 6, wherein in the adjustment process, the adjustment unit adjusts an output period of the effective voltage vector to each of the rotating electrical machines by controlling a field-weakening current flowing through each of the rotating electrical machines. The control device for the rotary electric machine according to 1.
[Configuration 11]
The adjustment unit, in the adjustment process,
Acquiring a current parameter containing an AC component, which is the current flowing in the DC power supply or a correlation value of the current,
Control of the rotating electrical machine according to any one of configurations 1 to 10, wherein an output mode of a voltage vector to each rotating electrical machine is adjusted in accordance with the current parameter so as to change the frequency of the current flowing through the DC power supply. Device.
[Configuration 12]
The plurality of power conversion circuits are a first power conversion circuit (22a) and a second power conversion circuit (22b),
As the rotating electrical machines, a first rotating electrical machine (21a) corresponding to the first power conversion circuit and a second rotating electrical machine (21b) corresponding to the second power conversion circuit are provided,
The adjustment unit, in the adjustment process,
Determining whether the acquired current parameter exceeds a threshold,
When it is determined that the current parameter exceeds the threshold, the output period of the effective voltage vector to the first rotating electrical machine and the output of the reactive voltage vector to the second rotating electrical machine are set so that the amplitude of the current parameter becomes small. 12. The control device for a rotary electric machine according to configuration 11, wherein the frequency of the current flowing through the DC power supply is changed by adjusting the overlapping period overlapping with the period.
[Configuration 13]
The adjustment unit, in the adjustment process,
Determining whether the acquired current parameter exceeds a threshold,
When it is determined that the current parameter exceeds the threshold, the DC 12. A control device for a rotary electric machine according to Configuration 11, which increases the frequency of the current flowing through the power supply.
[Configuration 14]
The plurality of power conversion circuits are a first power conversion circuit (22a) and a second power conversion circuit (22b),
As the rotating electrical machines, a first rotating electrical machine (21a) corresponding to the first power conversion circuit and a second rotating electrical machine (21b) corresponding to the second power conversion circuit are provided,
The adjustment unit, in the adjustment process,
Acquiring a current parameter containing an AC component, which is the current flowing in the DC power supply or a correlation value of the current,
Determining whether the acquired current parameter exceeds a threshold,
When it is determined that the current parameter exceeds the threshold, the frequency of the current flowing in the DC power supply is higher than the resonance frequency determined by the inductance of the wiring connecting the DC power supply and the capacitor and the capacitance of the capacitor. determine whether it is high or low,
When it is determined that the frequency of the current flowing through the DC power supply is lower than the resonance frequency, reducing the frequency of the current flowing through the DC power supply so that the amplitude of the current parameter becomes small,
Any one of configurations 1 to 10, wherein, when it is determined that the frequency of the current flowing in the DC power supply is higher than the resonance frequency, the frequency of the current flowing in the DC power supply is increased so that the amplitude of the current parameter becomes small. The control device for the rotary electric machine according to 1.
[Configuration 15]
The control system is applied to a vehicle (10) that travels by rotating drive wheels (11a, 11b),
each of the rotating electrical machines is individually provided corresponding to each of the driving wheels;
2. The greater the steering angle of the left and right steered wheels (11a, 11b) of the vehicle among the drive wheels, the greater the difference in torque and the difference in rotational speed between the rotating electric machines provided corresponding to the steered wheels. 15. The control device for a rotary electric machine according to any one of items 1 to 14.

21a, 21b, first and second electric rotating machines, 22a, 22b, first and second inverters, 23, smoothing capacitor, 33, control device.

Claims (16)

a plurality of power conversion circuits (22a, 22b) for converting DC power of a DC power supply (30) into AC power by switching operation and outputting the AC power;
Rotating electric machines (21a, 21b) provided corresponding to the respective power conversion circuits and supplied with AC power output from the power conversion circuits;
Applied to a control system comprising a capacitor (23) connected in parallel to the DC power supply and provided on the input side of each power conversion circuit and common to each power conversion circuit,
an adjustment unit that performs an adjustment process for adjusting an output mode of the voltage vector to each rotating electric machine;
A control device for a rotating electrical machine, comprising: an operation unit that performs a switching operation of each of the power conversion circuits so as to output the voltage vector adjusted by the adjustment unit. The adjustment unit performs, as the adjustment process, a process of adjusting an output period of the effective voltage vector to each of the rotating electric machines according to the drive state of each of the rotating electric machines,
The operation unit alternately outputs the effective voltage vector and the reactive voltage vector to each rotating electric machine while setting the output period of the effective voltage vector to each rotating electric machine to the output period adjusted by the adjusting unit. 2. The controller for a rotary electric machine according to claim 1, wherein said switching operation is performed. a drive determination unit that determines whether each of the rotating electric machines is in a power running state in which the rotating electric machine functions as an electric motor or in a regenerative drive state in which the rotating electric machine functions as a generator;
The adjustment unit, on the condition that the drive determination unit determines that all of the rotary electric machines are in the power running state or the regenerative drive state, performs the adjustment process on any one of the rotary electric machines. The output periods of the active voltage vector to each of the rotating electrical machines are shifted so that the output period of the reactive voltage vector to one reference rotating electrical machine includes the output period of the active voltage vector to the remaining rotating electrical machines. 3. The control device for a rotating electrical machine according to claim 2, wherein the output period of the reactive voltage vector to the reference rotating electrical machine and the output period of the effective voltage vector to the remaining rotating electrical machines are brought closer to each other. Determining whether or not the output period of the reactive voltage vector to the reference rotating electric machine and the output period of the effective voltage vector to the remaining rotating electric machines have different lengths in one switching cycle of the switching operation. and a period determination unit for
The adjustment unit is determined by the period determination unit that the output period of the reactive voltage vector to the reference rotating electrical machine and the output period of the effective voltage vector to the remaining rotating electrical machines have different lengths. 4. The control device for a rotary electric machine according to claim 3, wherein said adjustment processing is performed on condition that The plurality of power conversion circuits are a first power conversion circuit (22a) and a second power conversion circuit (22b),
As the rotating electrical machines, a first rotating electrical machine (21a) corresponding to the first power conversion circuit and a second rotating electrical machine (21b) corresponding to the second power conversion circuit are provided,
a drive determination unit that determines, as the drive state, whether the first rotating electric machine and the second rotating electric machine are in a power running state in which they function as electric motors or in a regenerative drive state in which they function as generators. ,
On the condition that the drive determining unit determines that the first rotating electric machine is in the power running drive state and the second rotating electric machine is in the regenerative driving state, the adjustment unit performs the adjustment process as described above. 3. A control apparatus for a rotating electrical machine according to claim 2, wherein a process is performed to bring the effective voltage vector output period to the first rotating electrical machine closer to the output period of the effective voltage vector to the second rotating electrical machine. determining whether or not the output period of the effective voltage vector to the first rotating electrical machine and the output period of the effective voltage vector to the second rotating electrical machine have different lengths in one switching cycle of the switching operation; A period determination unit for determining,
The adjusting unit determines, by the period determining unit, that the effective voltage vector output period to the first rotating electrical machine and the effective voltage vector output period to the second rotating electrical machine have different lengths. 6. The control device for a rotary electric machine according to claim 5, wherein the adjustment process is performed on condition that The adjustment unit
a first selection unit that selects two types of effective voltage vectors having a phase difference of 60 degrees with respect to each of the rotating electrical machines;
an effective voltage vector selected by the first selection unit from among two types of effective voltage vectors having a phase difference of 120 degrees with respect to each of the rotating electric machines, with the command voltage vector for the rotating electric machine interposed therebetween; has a second selector that selects a different effective voltage vector, and
wherein, in the adjusting process, three types of effective voltage vectors selected by the first selection section and the second selection section are used to adjust the output period of the effective voltage vector to each of the rotating electrical machines; 7. The rotating electric machine control device according to any one of items 6 to 7. 8. The control device for a rotary electric machine according to claim 7, wherein in the adjustment process, the adjustment unit brings the magnitudes of the currents flowing through the power conversion circuits closer to each other. The adjustment unit
a first selection unit that selects two types of effective voltage vectors having a phase difference of 60 degrees with respect to a command voltage vector to a specific rotating electrical machine, which is a part of the rotating electrical machines, among the rotating electrical machines; ,
An effective voltage vector that is different from the effective voltage vector selected by the first selection unit from among two types of effective voltage vectors that sandwich the command voltage vector for the specific rotating electric machine and have a phase difference of 120 degrees from each other. and a second selection unit that selects
wherein, in the adjustment process, three types of effective voltage vectors selected by the first selection section and the second selection section are used to adjust an output period of the effective voltage vector to the specific rotating electrical machine; 7. The rotating electric machine control device according to any one of items 6 to 7. 7. The adjustment unit according to any one of claims 2 to 6, wherein in the adjustment process, the adjustment unit adjusts the output period of the effective voltage vector to each of the rotating electrical machines by controlling a field-weakening current flowing through each of the rotating electrical machines. A control device for a rotary electric machine according to claim 1. The adjustment unit, in the adjustment process,
Acquiring a current parameter containing an AC component, which is the current flowing in the DC power supply or a correlation value of the current,
2. The control device for a rotating electric machine according to claim 1, wherein an output mode of a voltage vector to each rotating electric machine is adjusted in accordance with the current parameter so as to change the frequency of the current flowing through the DC power supply. The plurality of power conversion circuits are a first power conversion circuit (22a) and a second power conversion circuit (22b),
As the rotating electrical machines, a first rotating electrical machine (21a) corresponding to the first power conversion circuit and a second rotating electrical machine (21b) corresponding to the second power conversion circuit are provided,
The adjustment unit, in the adjustment process,
Determining whether the acquired current parameter exceeds a threshold,
When it is determined that the current parameter exceeds the threshold, the output period of the effective voltage vector to the first rotating electrical machine and the output of the reactive voltage vector to the second rotating electrical machine are set so that the amplitude of the current parameter becomes small. 12. The controller for a rotating electric machine according to claim 11, wherein the frequency of the current flowing through the DC power supply is changed by adjusting an overlapping period overlapping with the period. The adjustment unit, in the adjustment process,
Determining whether the acquired current parameter exceeds a threshold,
When it is determined that the current parameter exceeds the threshold, the DC 12. The controller for a rotating electric machine according to claim 11, wherein the frequency of the current flowing through the power supply is increased. The plurality of power conversion circuits are a first power conversion circuit (22a) and a second power conversion circuit (22b),
As the rotating electrical machines, a first rotating electrical machine (21a) corresponding to the first power conversion circuit and a second rotating electrical machine (21b) corresponding to the second power conversion circuit are provided,
The adjustment unit, in the adjustment process,
Acquiring a current parameter containing an AC component, which is the current flowing in the DC power supply or a correlation value of the current,
Determining whether the acquired current parameter exceeds a threshold,
When it is determined that the current parameter exceeds the threshold, the frequency of the current flowing in the DC power supply is higher than the resonance frequency determined by the inductance of the wiring connecting the DC power supply and the capacitor and the capacitance of the capacitor. determine whether it is high or low,
When it is determined that the frequency of the current flowing through the DC power supply is lower than the resonance frequency, reducing the frequency of the current flowing through the DC power supply so that the amplitude of the current parameter becomes small,
2. The electric rotating machine according to claim 1, wherein, when it is determined that the frequency of the current flowing through the DC power supply is higher than the resonance frequency, the frequency of the current flowing through the DC power supply is increased so that the amplitude of the current parameter becomes smaller. controller. The control system is applied to a vehicle (10) that travels by rotating drive wheels (11a, 11b),
each of the rotating electrical machines is individually provided corresponding to each of the driving wheels;
2. The greater the steering angle of the left and right steered wheels (11a, 11b) of the vehicle among the drive wheels, the greater the difference in torque and the difference in rotational speed between the rotating electric machines provided corresponding to the steered wheels. The control device for the rotary electric machine according to 1. a plurality of power conversion circuits (22a, 22b) for converting DC power of a DC power supply into AC power by switching operation and outputting the AC power;
Rotating electric machines (21a, 21b) provided corresponding to the respective power conversion circuits and supplied with AC power output from the power conversion circuits;
a capacitor (23) connected in parallel to the DC power supply and provided on the input side of each power conversion circuit and common to each power conversion circuit;
A program applied to a control system comprising a computer (33a),
to the computer;
a process of adjusting the output mode of the voltage vector to each rotating electric machine;
and a process of performing a switching operation of each of the power conversion circuits so as to output the adjusted voltage vector.

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