Control device for rotary electrical machine, program, and method for controlling rotary electrical machine

Abstract

A control device (70) comprises: a setting unit (95) for setting the control mode of first upper and lower arm switches (SUHa-SWHa, SULa-SWLa) and second upper and lower arm switches (SUHb-SWHb, SULb-SWLb) to Y drive control or H drive control; and a switch control unit (96) for controlling whether to turn the first upper and lower arm switches and the second upper and lower arm switches on or off on the basis of the set control mode. The control device comprises a determination unit (97) for determining whether wheels (220) are in a skid condition when a vehicle (200) is traveling. The setting unit prohibits the switching from one of the Y drive control and the H drive control that is the currently set control mode to the other when the determination unit determines that the wheels are in a skid condition.

Description

Rotating electric machine control device, program, and rotating electric machine control method CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based on Japanese Application No. 2024-012323 filed on January 30, 2024, the contents of which are incorporated herein by reference.

[0002] The present disclosure relates to a control device for a rotating electric machine, a program, and a control method for a rotating electric machine.

[0003] Conventionally, a system for controlling the drive of a rotating electric machine using two inverters has been known. In this system, a first inverter is electrically connected to first ends of a multi-phase armature winding of the rotating electric machine, and a second inverter is electrically connected to second ends of the armature winding. The drive of the rotating electric machine is controlled by controlling the first and second inverters. An example of such a technology is disclosed in Patent Document 1.

[0004] Japanese Patent Application Laid-Open No. 2017-175747

[0005] The above system may be installed in a vehicle. In this case, it is desirable to control the first and second inverters so as to minimize the loss of vehicle running stability.

[0006] A primary object of the present disclosure is to provide a control device, a program, and a control method for a rotating electric machine that can minimize the impairment of vehicle running stability.

[0007] The present disclosure relates to a control device for a rotating electric machine that is applied to a system including: a rotating electric machine having a multi-phase armature winding; a first inverter having first upper arm switches and first lower arm switches connected in series for the same number of phases, and a series connection of the first upper arm switches and the first lower arm switches connected in parallel to a DC power source; a second inverter having second upper arm switches and second lower arm switches connected in series for the same number of phases; a positive side bus bar that electrically connects, in each phase, a high potential side terminal of the first upper arm switch and a high potential side terminal of the second upper arm switch; a negative side bus bar that electrically connects, in each phase, a low potential side terminal of the first lower arm switch and a low potential side terminal of the second lower arm switch; and a changeover switch provided on a target bus bar that is at least one of the positive side bus bar and the negative side bus bar, wherein the system is provided on a vehicle and configured so that a rotational force of a rotor of the rotating electric machine is transmitted to wheels of the vehicle, In each phase, the low potential side terminal of the first upper arm switch and the high potential side terminal of the first lower arm switch are electrically connected to a first end of the armature winding, and in each phase, the low potential side terminal of the second upper arm switch and the high potential side terminal of the second lower arm switch are electrically connected to a second end of the armature winding, and when the changeover switch is turned on, it electrically connects the first inverter and the second inverter via the target bus, and when turned off, it cuts off the electrical connection between the first inverter and the second inverter via the target bus.

[0008] The present disclosure comprises a setting unit that sets Y drive control or H drive control as the control mode of the first upper arm switch, the first lower arm switch, the second upper arm switch, and the second lower arm switch; and a switch control unit that controls the on or off of the first upper arm switch, the first lower arm switch, the second upper arm switch, and the second lower arm switch based on the set control mode, wherein the Y drive control is control that fixes the second upper arm switch of each phase on and fixes the second lower arm switch of each phase off when the changeover switch is off, or fixes the second lower arm switch of each phase on and fixes the second upper arm switch of each phase off when the changeover switch is off, and turns the first upper arm switch and the first lower arm switch on and off; and the H drive control is control that turns the first upper arm switch, the first lower arm switch, the second upper arm switch, and the second lower arm switch on and off.

[0009] The present disclosure includes a determination unit that determines whether or not the wheels are in a state where they will slip while the vehicle is traveling, and when the determination unit determines that the wheels are in a state where they will slip, the setting unit prohibits switching from one of the currently set control modes of the Y drive control and the H drive control to the other control mode.

[0010] When the currently set control mode of either the Y drive control or the H drive control is switched to the other control mode, the rotational force transmitted from the rotor to the wheels may change significantly. Therefore, if the control mode is switched when the vehicle wheels are slipping, there is a concern that the running stability of the vehicle may be impaired.

[0011] Therefore, when it is determined that a slip situation is occurring, the setting unit prohibits switching from the currently set control mode of either the Y drive control or the H drive control to the other control mode, thereby maintaining the currently set control mode and minimizing the loss of vehicle running stability.

[0012] The present disclosure can be embodied, for example, as follows: When it is determined that the slip situation occurs when the currently set control mode is the Y drive control, the setting unit prohibits switching the control mode to the H drive control.

[0013] The maximum value of the potential difference between the first end and the second end of the armature winding is larger when H drive control is being executed than when Y drive control is being executed. Therefore, the maximum value of the torque generated by the rotating electric machine is larger when H drive control is being executed than when Y drive control is being executed. Therefore, if the control is switched from Y drive control to H drive control when the vehicle wheels are slipping, there is a concern that the running stability of the vehicle may be impaired.

[0014] Therefore, when it is determined that a slip situation will occur when the currently set control mode is Y drive control, the setting unit prohibits switching of the control mode to H drive control, thereby continuing the currently set Y drive control and minimizing the loss of vehicle running stability.

[0015] The above and other objects, features, and advantages of the present disclosure will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which Fig. 1 is a schematic diagram of a vehicle according to a first embodiment, Fig. 2 is an overall configuration diagram of a control system, Fig. 3 is a functional block diagram of control processing executed by a motor ECU, Fig. 4 is a diagram showing a control mode of Y drive control, Fig. 5 is a diagram showing a control mode of H drive control, Fig. 6 is a diagram showing control map information, Fig. 7 is a flowchart of processing executed by the motor ECU, Fig. 8 is a time chart for explaining a method for determining a prohibition condition, Fig. 9 is a time chart for explaining a method for determining a first permission condition, and Fig. 10 is a time chart for explaining a method for determining a second permission condition. FIG. 11 is a diagram showing an example of the transition of the operating point of the rotating electric machine when slippage occurs; FIG. 12 is a flowchart of processing executed by the motor ECU according to the second embodiment; FIG. 13 is a time chart showing a method of determining prohibition and permission conditions; FIG. 14 is a time chart showing a method of determining prohibition and permission conditions according to another embodiment; FIG. 15 is an overall configuration diagram of a control system according to another embodiment; and FIG. 16 is a diagram showing the control mode of Y drive control according to another embodiment.

[0016] Several embodiments will be described with reference to the drawings. In several embodiments, functionally and / or structurally corresponding and / or associated parts may be designated by the same reference numerals or reference numerals that differ in the hundredth or more digit. For corresponding and / or associated parts, reference may be made to the descriptions of other embodiments.

[0017] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment A first embodiment of a control device according to the present disclosure will now be described with reference to the drawings. The control device of this embodiment is applied to an electric vehicle.

[0018] As shown in Fig. 1, a vehicle 200 includes a vehicle body 201, left and right front wheels 210, left and right rear wheels 220, and a rotating electric machine 40. The rotating electric machine 40 of this embodiment is an on-board motor provided on the vehicle body 201. The rotating electric machine 40 of this embodiment transmits rotational force to the rear wheels 220. Therefore, the rear wheels 220 are drive wheels, and the front wheels 210 are driven wheels.

[0019] The vehicle 200 is equipped with a mechanical brake device 230. The brake device 230 is provided corresponding to each of the wheels 210, 220, and is a device that generates a braking force by applying a frictional force to the wheel.

[0020] As shown in Figures 1 and 2, a vehicle 200 includes a control system 100. The control system 100 includes a battery 10, which is a DC power supply, a first inverter 20, a second inverter 30, and the rotating electrical machine 40. The battery 10 is, for example, a battery pack including a series connection of unit cells. The unit cell is a single battery cell or a series connection of multiple battery cells. The battery cell is, for example, a secondary battery such as a lithium-ion battery.

[0021] The first inverter 20 and the second inverter 30 are power conversion circuits that convert DC power supplied from the battery 10 into three-phase AC power and supply it to the rotating electric machine 40 .

[0022] The first inverter 20 includes a series connection of U-, V-, and W-phase first upper arm switches SUHa, SVHa, and SWHa and U-, V-, and W-phase first lower arm switches SULa, SVLa, and SWLa. The second inverter 30 includes a series connection of U-, V-, and W-phase second upper arm switches SUHb, SVHb, and SWHb and U-, V-, and W-phase second lower arm switches SULb, SVLb, and SWLb.

[0023] In this embodiment, each of the switches SUHa to SWLa and SUHb to SWLb is a voltage-controlled semiconductor switching element, more specifically, an IGBT. In this case, the high-potential terminal of each of the switches SUHa to SWLa and SUHb to SWLb is the collector, and the low-potential terminal is the emitter. A freewheel diode is connected in anti-parallel to each of the switches SUHa to SWLb. Specifically, U-, V-, and W-phase first upper-arm diodes DUHa, DVHa, and DWHa are connected in anti-parallel to the U-, V-, and W-phase first upper-arm switches SUHa, SVHa, and SWHa, respectively, and U-, V-, and W-phase first lower-arm diodes DULa, DVLa, and DWLa are connected in anti-parallel to the U-, V-, and W-phase first lower-arm switches SULa, SVLa, and SWLa, respectively. U, V, W-phase second upper-arm diodes DUHb, DVHb, DWHb are connected in anti-parallel to the U, V, W-phase second upper-arm switches SUHb, SVHb, SWHb, and U, V, W-phase second lower-arm diodes DULb, DVLb, DWLb are connected in anti-parallel to the U, V, W-phase second lower-arm switches SULb, SVLb, SWLb.

[0024] The collectors of the first upper arm switches SUHa, SVHa, SWHa for each phase and the collectors of the second upper arm switches SUHb, SVHb, SWHb for each phase are connected via a positive bus 11, which is an electrical path such as a bus bar. The emitters of the first lower arm switches SULa, SVLa, SWLa for each phase and the emitters of the second lower arm switches SULb, SVLb, SWLb for each phase are connected via a negative bus 12, which is an electrical path such as a bus bar. The emitters of the second lower arm switches SULb, SVLb, SWLb for each phase are connected to the negative bus 12.

[0025] The control system 100 includes a power switch 14. The power switch 14 is, for example, a semiconductor switching element or a mechanical relay. The power switch 14 connects the positive bus 11 and the positive terminal of the battery 10. When the power switch 14 is turned on, the positive terminal of the battery 10 is electrically connected to the collectors of the first upper arm switches SUHa, SVHa, and SWHa of each phase. When the power switch 14 is turned off, the positive terminal of the battery 10 is electrically disconnected from the collectors of the first upper arm switches SUHa, SVHa, and SWHa of each phase.

[0026] The control system 100 includes a capacitor 15. The capacitor 15 functions as a smoothing capacitor. The capacitor 15 is connected in parallel to the series-connected body of the first upper arm switches SUHa to SWHa of each phase and the first lower arm switches SULa to SWLa of each phase.

[0027] The rotating electric machine 40 is an on-board main engine that serves as a power source for running the vehicle 200. The rotating electric machine 40 includes a rotor 41 and a stator 50. The rotor 41 is capable of transmitting power to the rear wheels 220. In this embodiment, the rotating electric machine 40 is a permanent magnet field type synchronous machine. The rotor 41 includes permanent magnets 42 (e.g., neodymium magnets) as field poles.

[0028] The stator 50 includes a U-phase winding 51U, a V-phase winding 51V, and a W-phase winding 51W as armature windings. The phase windings 51U, 51V, and 51W are arranged at intervals of 120 electrical degrees on the stator core that constitutes the stator 50. The phase windings 51U, 51V, and 51W are open windings.

[0029] In each phase, the emitters of first upper switches SUHa, SVHa, SWHa and the collectors of first lower switches SULa, SVLa, SWLa are connected to first ends 51Ua, 51Va, 51Wa of the windings 51U, 51V, 51W, respectively. In each phase, the emitters of second upper switches SUHb, SVHb, SWHb and the collectors of second lower switches SULb, SVLb, SWLb are connected to second ends 51Ub, 51Vb, 51Wb of the windings 51U, 51V, 51W, respectively.

[0030] The control system 100 includes a changeover switch QH and a diode DH. The changeover switch QH is provided on the positive bus 11 (corresponding to the "target bus"). The changeover switch QH is, for example, a semiconductor switching element or a mechanical relay. In this embodiment, the changeover switch QH is an IGBT. The collector of the changeover switch QH is connected to the first inverter 20 side, and the emitter of the changeover switch QH is connected to the second inverter 30 side. A diode DH is connected in antiparallel to the changeover switch QH.

[0031] When the changeover switch QH is turned on, it electrically connects the collectors of the upper phase arm switches SUHa, SVHa, SWHa of the first inverter 20 to the collectors of the upper phase arm switches SUHb, SVHb, SWHb of the second inverter 30. On the other hand, when the changeover switch QH is turned off, it electrically disconnects the collectors of the upper phase arm switches SUHa, SVHa, SWHa of the first inverter 20 from the collectors of the upper phase arm switches SUHb, SVHb, SWHb of the second inverter 30.

[0032] The control system 100 includes a current sensor 60, a rotation angle sensor 61, and a voltage sensor 62. The current sensor 60 detects the phase current flowing through each of the phase windings 51U, 51V, and 51W. In this embodiment, the current sensor 60 is provided on one of both ends of each of the phase windings 51U, 51V, and 51W that is closer to the first inverter 20. Note that the current sensor 60 may also be provided on one of both ends of each of the phase windings 51U, 51V, and 51W that is closer to the second inverter 30.

[0033] The rotation angle sensor 61 is, for example, a resolver, and detects the electrical angle of the rotor 41. The voltage sensor 62 detects the voltage between the terminals of the capacitor 15.

[0034] The control system 100 includes a vehicle speed sensor 63, a wheel speed sensor 64, an outside air temperature sensor 65, and a navigation device 66. The vehicle speed sensor 63 detects the traveling speed of the vehicle 200. The wheel speed sensor 64 detects the rotation speed of the wheels (specifically, the rear wheels 220, which are drive wheels). The outside air temperature sensor 65 detects the outside air temperature around the vehicle 200.

[0035] Map information including road information is stored in a memory unit (e.g., storage) of the navigation device 66. The navigation device 66 receives weather information and current position information of the vehicle 200 detected by a GPS sensor (not shown) provided in the control system 100. The navigation device 66 is configured to be able to communicate with the host ECU 80.

[0036] The control system 100 includes a motor ECU 70 and a host ECU 80. The motor ECU 70 receives detection values ​​from a current sensor 60, a rotation angle sensor 61, and a voltage sensor 62. The host ECU 80 receives detection values ​​from a vehicle speed sensor 63, a wheel speed sensor 64, and an outside air temperature sensor 65, as well as information from a navigation device 66. The motor ECU 70 and the host ECU 80 are configured to be able to communicate the information they have acquired with each other.

[0037] The motor ECU 70 is an electronic control unit that controls the rotating electric machine 40. The motor ECU 70 includes a processor 71 and a storage unit 72 as hardware components. In the motor ECU 70, the processor 71 and the storage unit 72 are connected to each other via a communication bus 73.

[0038] The memory unit 72 includes a memory and a storage as hardware. The memory is a storage device for storing data used in the processing of the motor ECU 70. The memory provides the processor 71 with a working area for temporary use when the processor 71 performs processing, for example. The memory includes, for example, a ROM or a RAM. The storage is a storage device for storing various programs and data to be read and executed by the processor 71, and is a non-transitory tangible storage medium. The storage includes, for example, an HDD or a flash memory. The storage stores program information and the like for the processing shown in FIGS. 3 and 7, which will be described later.

[0039] The host ECU 80 is an electronic control unit that controls the running of the vehicle 200, such as controlling the brake device 230. Similar to the motor ECU 70, the host ECU 80 includes a processor 81 and a storage unit 82 as hardware. In the host ECU 80, the processor 81 and the storage unit 82 are connected to each other via a communication bus 83.

[0040] For example, program information stored on a non-transient physical recording medium is installed in the storage units 72 and 82. The recording medium is, for example, a USB memory, a CD-ROM, or a DVD. Also, for example, program information transmitted via a communication network, such as over the air (OTA), is installed in the storage units 72 and 82.

[0041] FIG. 3 is a block diagram showing the control process of the rotary electric machine 40 executed by the motor ECU 70. As shown in FIG.

[0042] The command value calculation unit 90 calculates a d-axis current command value Id* and a q-axis current command value Iq* in the dq coordinate system based on the command torque Trq* received from the host ECU 80 .

[0043] The two-phase conversion unit 91 calculates the d-axis current value Idr and the q-axis current value Iqr based on the phase currents Iur, Ivr, and Iwr detected by the current sensor 60 and the electrical angle θr detected by the rotation angle sensor 61.

[0044] The current feedback unit 92 calculates a d-axis voltage command value Vd* and a q-axis voltage command value Vq* based on the d- and q-axis current command values ​​Id* and Iq* and the d- and q-axis current values ​​Idr and Iqr. Specifically, the current feedback unit 92 calculates a d-axis current deviation, which is the difference between the d-axis current command value Id* and the d-axis current value Idr, and calculates a d-axis voltage command value Vd* as a manipulated variable for feedback-controlling the calculated d-axis current deviation to zero. The current feedback unit 92 calculates a q-axis current deviation, which is the difference between the q-axis current command value Iq* and the q-axis current value Iqr, and calculates a q-axis voltage command value Vq* as a manipulated variable for feedback-controlling the calculated q-axis current deviation to zero. The feedback control is, for example, proportional-plus-integral control.

[0045] The three-phase converter 93 calculates U-, V-, and W-phase voltage command values ​​Vu*, Vv*, and Vw* based on the d- and q-axis voltage command values ​​Vd*, Vq* and the electrical angle θr. The U-, V-, and W-phase voltage command values ​​Vu*, Vv*, and Vw* are command values ​​for the voltages applied to the U-, V-, and W-phase windings 51U, 51V, and 51W.

[0046] The speed calculation unit 94 calculates the rotation speed Nr of the rotor 41 based on the electrical angle θr.

[0047] The setting unit 95 generates drive signals for the switches SUHa to SWLa and SUHb to SWLb of the first and second inverters 20 and 30. The drive signals are made up of on and off commands for the switches.

[0048] Specifically, the setting unit 95 calculates U-, V-, and W-phase normalized command values ​​Dutyu, Dutyv, and Dutyw by normalizing the U-, V-, and W-phase voltage command values ​​Vu*, Vv*, and Vw* by the power supply voltage Vsr, which is the detection voltage of the voltage sensor 62. Specifically, the U-, V-, and W-phase normalized command values ​​Dutyu, Dutyv, and Dutyw are values ​​obtained by dividing the U-, V-, and W-phase voltage command values ​​Vu*, Vv*, and Vw* by 1 / 2 of the power supply voltage Vsr.

[0049] The setting unit 95 selects whether the drive state of the control system 100 should be Y drive control or H drive control. In the present embodiment, the setting unit 95 selects whether the drive state should be Y drive control or H drive control based on the operating point of the rotating electric machine 40, which is determined by the calculated rotation speed Nr and command torque Trq*, and on the control map information. As shown in FIG. 6 , the control map information is information that defines the Y drive control region and the H drive control region in association with the rotation speed Nr and the command torque Trq*. The control map information is stored in the storage unit 72.

[0050] 6 shows control map information according to this embodiment. The control map information defines an operating region of the rotating electrical machine 40, bounded by the first maximum torque line Ltmax1, the second maximum torque line Ltmax2, the first line L1, the second line L2, the axis of the rotational speed Nr (hereinafter referred to as the horizontal axis), and the axis of the command torque Trq* (hereinafter referred to as the vertical axis). The first and second maximum torque lines Ltmax1 and Ltmax2 define the maximum torque Tmax, which is the maximum value of the command torque Trq*, and extend along the horizontal axis (specifically, extend parallel to the horizontal axis). The first maximum torque line Ltmax1 is a line extending from the vertical axis. The second maximum torque line Ltmax2 is a line extending from one end of the first maximum torque line Ltmax1 along the horizontal axis (specifically, extend parallel to the horizontal axis).

[0051] The first line L1 extends from one end of the second maximum torque line Ltmax2 and decreases in value on the vertical axis as the rotational speed Nr increases. The second line L2 extends along the vertical axis from one end of the first line L1 to the horizontal axis (specifically, extends parallel to the vertical axis). The value on the horizontal axis of the second line L2 is the maximum rotational speed Nmax, which is the maximum value of the rotational speed Nr.

[0052] The judgment threshold Jth is made up of a first threshold line J1 and a second threshold line J2. The first threshold line J1 is a line extending along the first line L1 from the boundary between the first maximum torque line Ltmax1 and the second maximum torque line Ltmax2. The first threshold line J1 is a line extending such that the value on the vertical axis decreases as the rotation speed Nr increases. The second threshold line J2 is a line extending from one end of the first threshold line J1 along the second line L2 (specifically, extending parallel to the second line L2). The value on the horizontal axis of the second threshold line J2 is a judgment speed Nth (>0) that is lower than the maximum rotation speed Nmax.

[0053] The region of the operating range where the rotation speed Nr is equal to or less than the judgment threshold Jth is the Y drive control region, while the region of the operating range where the rotation speed Nr exceeds the judgment threshold Jth is the H drive control region.

[0054] The setting unit 95 selects Y drive control when it determines that the operating point determined from the command torque Trq* and the rotation speed Nr is in the Y drive control region, whereas the setting unit 85 selects H drive control when it determines that the operating point is in the H drive control region.

[0055] When Y-drive control is selected, the setting unit 95 turns off the selector switch QH and performs PWM drive of the switches SUHa to SWLa of the first inverter 20 as Y-drive control, as shown in Fig. 4. The setting unit 95 also fixes the upper arm switches SUHb, SVHb, and SWHb of the second inverter 30 to on, and fixes the lower arm switches SULb, SVLb, and SWLb of the second inverter 30 to off. As a result, the phase windings 51U, 51V, and 51W are star-connected via the second inverter 30.

[0056] The setting unit 95 generates drive signals for the switches SUHa to SWLa of the first inverter 20 based on a magnitude comparison between the U-, V-, and W-phase normalized command values ​​Dutyu, Dutyv, and Dutyw and the carrier signal Sgc. The carrier signal Sgc is, for example, a triangular wave signal whose gradual increase and decrease rates are equal.

[0057] On the other hand, when the setting unit 95 selects the H drive control, as shown in FIG. 5, the setting unit 95 turns on the changeover switch QH, PWM-drives each of the switches SUHa to SWLa of the first inverter 20, and PWM-drives each of the switches SUHb to SWLb of the second inverter 30.

[0058] Specifically, the setting unit 95 generates drive signals for the switches SUHa-SWLa of the first inverter 20 based on a magnitude comparison between the U-, V-, and W-phase normalized command values ​​Dutyu, Dutyv, and Dutyw and the first carrier signal Sg1, similar to the Y-drive control. The setting unit 95 generates drive signals for the switches SUHb-SWLb of the second inverter 30 based on a magnitude comparison between the U-, V-, and W-phase normalized command values ​​Dutyu, Dutyv, and Dutyw and the second carrier signal Sg2, similar to the Y-drive control. The first and second carrier signals Sg1 and Sg2 are, for example, triangular wave signals with equal increasing and decreasing speeds. The frequency, amplitude, and fluctuation center value of the second carrier signal Sg2 are the same as those of the first carrier signal Sg1. The phase difference between the first carrier signal Sg1 and the second carrier signal Sg2 is 180°. In this embodiment, the frequency of the carrier signals Sg1 and Sg2 used in the H drive control is the same as the frequency of the carrier signal Sgc used in the Y drive control.

[0059] Based on the generated drive signal, the switch control unit 96 controls the charge / discharge current of the gates of the switches SUHa-SWLa and SUHb-SWLb of the first and second inverters 20 and 30. As a result, the switches SUHa-SWLa and SUHb-SWLb of the first and second inverters 20 and 30 are controlled to be turned on or off in accordance with the drive signal.

[0060] The switching patterns of the switches of the inverters 20, 30, which are switched in accordance with the drive signal in the H drive control, are shifted in phase by 120° in electrical angle in each phase. Also, the switching pattern of the switches of the first inverter 20, which is switched in accordance with the drive signal in the Y drive control, is shifted in phase by 120° in electrical angle in each phase.

[0061] However, when the control mode is switched from one of the currently set Y drive control and H drive control to the other, the rotational force transmitted from the rotor 41 to the rear wheels 220 (drive wheels 220) may change significantly. Therefore, if the control mode is switched in a situation where the drive wheels 220 are slipping, there is a concern that the running stability of the vehicle 200 may be impaired. In particular, if the control mode is switched from Y drive control to H drive control in a situation where the drive wheels 220 are slipping, there is a concern that the running stability of the vehicle 200 may be significantly impaired.

[0062] In order to address the above-mentioned problem, the motor ECU 70 is provided with a determination unit 97. The determination unit 97 determines whether or not the drive wheels 220 are in a state where they will slip while the vehicle 200 is traveling. In this embodiment, the determination unit 97 calculates the slip ratio of the drive wheels 220 and determines whether or not they are in a state where they will slip based on the calculated slip ratio. The slip ratio in this embodiment is expressed by the following equation (eq1):

[0063] In the above equation (eq1), Vlc is the traveling speed Vlc of the vehicle 200 detected by the vehicle speed sensor 63. Vlt is the peripheral speed of the drive wheels 220. The determination unit 97 may calculate the peripheral speed based on the rotation speed of the drive wheels 220 detected by the wheel speed sensor 64.

[0064] When the determination unit 97 determines that a slip situation will occur if the currently set control mode is Y drive control, the setting unit 95 prohibits switching the control mode to H drive control. This allows the currently set Y drive control to continue, and makes it possible to minimize impairment of the running stability of the vehicle 200.

[0065] A flowchart of the control mode switching process is shown in Fig. 7. The process shown in Fig. 7 is repeatedly executed by the processor 71 included in the motor ECU 70 at a predetermined control cycle, for example.

[0066] In step S10, the determination unit 97 determines whether or not there is a request for permission to switch from the user of the vehicle 200. For example, the determination unit 97 may acquire information input by the user to the input unit of the navigation device 66, and determine whether or not there is a request for permission to switch based on the acquired information.

[0067] If it is determined in step S10 that there is a permission request, the process proceeds to step S11, where the setting unit 95 sets flag F to 0. Flag F indicates that switching of the control mode is permitted when it is 0, and indicates that switching of the control mode is prohibited when it is 1. In step S12, switching of the control mode is permitted.

[0068] If it is determined in step S10 that there is no permission request, the process proceeds to step S13, where the setting unit 95 determines whether the current flag F is 0 or 1.

[0069] If it is determined in step S13 that the flag F is 0, the process proceeds to step S14, where it is determined whether or not a control mode switching prohibition condition is satisfied. In this embodiment, if it is determined that the calculated slip ratio (corresponding to the "determination parameter") exceeds the prohibition threshold value Sth over the prohibition period Tpr, it is determined that the drive wheels 220 are in a slipping state, and it is determined that the prohibition condition is satisfied.

[0070] An example of a method for determining whether or not a prohibition condition exists is shown in Fig. 8. In Fig. 8, (a) shows the transition of the slip ratio, and (b) shows the transition of the flag F.

[0071] Although the slip ratio exceeds the prohibition threshold value Sth during the period from time t1 to t2, this period is shorter than the prohibition period Tpr. Therefore, flag F is maintained at 0. Thereafter, at time t3, the slip ratio exceeds the prohibition threshold value Sth. Since the period from time t3 to t4 is the same length as the prohibition period Tpr, flag F is switched to 1 at time t4.

[0072] Returning to the explanation of FIG. 7 , if it is determined in step S14 that the prohibition condition is not met, the process proceeds to step S11, where flag F is maintained at 0. On the other hand, if it is determined in step S14 that the prohibition condition is met, the process proceeds to step S15, where flag F is changed to 1. As a result, in step S16, switching of the control mode is prohibited. Therefore, if the current control mode is Y drive control, switching to H drive control is prohibited.

[0073] If it is determined in step S13 that flag F is 1, the process proceeds to step S17. In step S17, the determination unit 97 determines whether a first permission condition is met. The first permission condition is that, after the prohibition condition is met in step S14 and flag F is switched to 1, the calculated slip ratio is maintained at or below prohibition threshold value Sth for a first release period Tcc1.

[0074] 9 shows an example of a method for determining whether the first permission condition is satisfied. In FIG. 9, (a) shows the transition of whether or not slip is detected, (b) shows the transition of flag F, and (c) shows the transition of whether switching of the control mode is prohibited or permitted. The presence of slip indicates a state in which the calculated slip ratio exceeds the prohibition threshold value Sth, and the absence of slip detection indicates a state in which the calculated slip ratio is equal to or less than the prohibition threshold value Sth.

[0075] Although the calculated slip ratio is equal to or less than the prohibition threshold value Sth during the period from time t2 to t3 and from time t4 to t5, the period from time t2 to t3 and the period from time t4 to t5 are shorter than the first release period Tcc1. Therefore, flag F is maintained at 1. The setting unit 95 prohibits switching of the control mode from time t1, when flag F is switched to 1, until the first release period Tcc1 has elapsed. This prevents frequent switching of the control mode, for example, in a situation where the drive wheels 220 repeatedly slip and grip. As a result, current flowing through elements used during execution of H drive control, such as the selector switch QH, can be suppressed, thereby suppressing an increase in loss in the control system 100.

[0076] Thereafter, at time t6, the calculated slip ratio becomes equal to or less than the prohibition threshold value Sth. Since the period from time t6 to time t7 is the same length as the first release period Tcc1, the flag F is switched to 0 at time t7.

[0077] Returning to the previous description of Fig. 7, if it is determined in step S17 that the first permission condition is met, the process proceeds to step S11, where the flag F is changed to 0. As a result, in step S12, the switching of the control mode is permitted.

[0078] On the other hand, if it is determined in step S17 that the first permission condition is not satisfied, the process proceeds to step S18. In step S18, the determination unit 97 determines whether the second permission condition is satisfied. The second permission condition is that, after the prohibition condition is satisfied in step S14 and flag F is switched to 1, the calculated slip ratio remains below the release threshold Sa for a second release period Tcc2. The second release period Tcc2 is shorter than the first release period Tcc1. The release threshold Sa is smaller than the prohibition threshold Sth. According to the second permission condition, the control mode can be promptly permitted to be switched when the traveling of the vehicle 200 stabilizes after the prohibition condition is satisfied.

[0079] An example of a method for determining whether the second permission condition is met is shown in Fig. 10. In Fig. 10, (a) shows the transition of the slip ratio, and (b) shows the transition of the flag F.

[0080] At time t1, the slip ratio falls below the release threshold Sa. The period from time t1 to time t2 is the same length as the second release period Tcc2, so the flag F is switched to 0 at time t2.

[0081] Returning to the previous description of Fig. 7, if it is determined in step S18 that the second permission condition is met, the process proceeds to step S11, where the flag F is changed to 0. As a result, in step S12, the switching of the control mode is permitted.

[0082] On the other hand, if it is determined in step S18 that the second permission condition is not met, the process proceeds to step S15, whereby the flag F is maintained at 1, and the prohibition of switching of the control mode continues.

[0083] The effects of this embodiment will be described using Figure 11. In the operating region of Figure 11, P1 indicates a first operating point during Y drive control before the prohibition condition is met. If slippage occurs at the first operating point P1, the operating point changes to a second operating point P2, which has a higher rotation speed Nr than the first operating point. Here, because switching to H drive control is prohibited, the operating point changes along the first threshold line J1 to the second operating point P2. As a result, the torque of the rotating electric machine 40 can be reduced, minimizing the impairment of the running stability of the vehicle 200.

[0084] In contrast, in the comparative example in which switching to H drive control is not prohibited, when slippage occurs, the operating point changes from the first operating point P1 to the third operating point P3. The third operating point P3 is in the H drive control range and is an operating point on the higher torque side than the second operating point P2. Therefore, in the comparative example, torque cannot be reduced when slippage occurs, which may impair the driving stability of the vehicle 200.

[0085] Incidentally, when the motor ECU 70 determines that the prohibition condition is met when the currently set control mode is H drive control, it prohibits switching the control mode to Y drive control and continues H drive control.

[0086] <Modification of First Embodiment> The determination unit 97 may determine that the road surface on which the vehicle 200 is traveling is a low μ road surface if it determines that the road surface is prone to slippage. Here, the determination unit 97 may determine that the road surface is a low μ road surface if it determines that the outside air temperature detected by the outside air temperature sensor 65 is equal to or lower than a determination temperature, for example. The determination temperature may be set to a temperature at which the road surface on which the vehicle 200 is traveling is expected to freeze, specifically, a temperature below freezing. Furthermore, the determination unit 97 may determine that the road surface is a low μ road surface if it determines that the weather around the vehicle 200 is raining or snowing based on weather information received by the navigation device 66, for example.

[0087] Second Embodiment A second embodiment will be described below with reference to the drawings, focusing on differences from the first embodiment. In this embodiment, the method of determining whether or not a slip situation occurs is changed.

[0088] A flowchart of the control mode switching process is shown in Fig. 12. The process shown in Fig. 12 is repeatedly executed by the processor 71 included in the motor ECU 70, for example, at a predetermined control cycle.

[0089] If it is determined in step S10 that there is no permission request, the process proceeds to step S20, where it is determined whether the calculated slip ratio exceeds the prohibition threshold value Sth. If it is determined that the slip ratio is equal to or less than the prohibition threshold value Sth, it is determined that the vehicle is not in a slipping state, and the process proceeds to step S11, where the flag F is maintained at 0.

[0090] On the other hand, if it is determined in step S20 that the slip ratio exceeds the prohibition threshold value Sth, it is determined that a slip situation exists, and the process proceeds to step S15, where the flag F is set to 1. As a result, switching of the control mode is prohibited in step S16.

[0091] An example of a method for determining whether or not a slip situation is occurring is shown in Fig. 13. In Fig. 13, (a) shows the transition of the slip ratio, and (b) shows the transition of the flag F.

[0092] It is determined that the slip ratio exceeds the prohibition threshold value Sth during the period from time t1 to t2. Therefore, during the period from time t1 to t2, flag F is set to 1. Thereafter, at time t3, it is determined that the slip ratio exceeds the prohibition threshold value Sth. Therefore, flag F is set to 1 from time t3 onwards.

[0093] According to the present embodiment described above, it is possible to obtain effects similar to those of the first embodiment.

[0094] Other Embodiments The above-described embodiments may be modified as follows.

[0095] The determination unit 97 may determine whether or not a slip situation is occurring based on the rotational acceleration of the drive wheels 220 (hereinafter referred to as wheel acceleration). The determination unit 97 may calculate the wheel acceleration based on, for example, the detection value of the wheel speed sensor 64. If the determination unit 97 determines that the wheel acceleration exceeds the determination threshold Ath, the determination unit 97 may switch the flag F to 1.

[0096] 14 shows an example of a method for determining whether or not a slip situation is occurring. In FIG. 14, (a) shows the transition of the wheel speed, which is the rotational speed of the drive wheels 220, (b) shows the transition of the wheel acceleration, and (c) shows the transition of the flag F.

[0097] During the period from time t1 to t3, slippage occurs, causing a temporary increase in wheel speed. As a result, during the period from time t1 to t2, it is determined that the wheel acceleration exceeds the determination threshold Ath. Therefore, during the period from time t1 to t2, flag F is set to 1.

[0098] The determination unit 97 may switch the flag F to 1 when it determines that the state in which the wheel acceleration exceeds the determination threshold Ath has continued for a predetermined period of time.

[0099] In the processes shown in FIGS. 7 to 10, for example, the wheel acceleration (corresponding to the "determination parameter") may be used instead of the slip ratio.

[0100] As shown in Fig. 15, the control system 100 may include a second changeover switch QL in addition to the first changeover switch QH. The second changeover switch QL is provided on the negative bus 12 (corresponding to the "target bus"). The second changeover switch QL is, for example, a semiconductor switching element or a mechanical relay. In this embodiment, the second changeover switch QL is an IGBT. A freewheel diode DL is connected in anti-parallel to the second changeover switch QL. The collector of the second changeover switch QL is connected to the second inverter 30 side, and the emitter of the second changeover switch QL is connected to the first inverter 20 side.

[0101] When the second changeover switch QL is turned on, it electrically connects the emitters of the lower phase arm switches SULa, SVLa, SWLa of the first inverter 20 to the emitters of the lower phase arm switches SULb, SVLb, SWLb of the second inverter 30. When the second changeover switch QL is turned off, it electrically disconnects the emitters of the lower phase arm switches SULa, SVLa, SWLa of the first inverter 20 from the emitters of the lower phase arm switches SULb, SVLb, SWLb of the second inverter 30.

[0102] When the motor ECU 70 selects the H drive control, it turns on the first changeover switch QH and the second changeover switch QL. On the other hand, when the motor ECU 70 selects the Y drive control, it turns off the first changeover switch QH and the second changeover switch QL.

[0103] 16, in the Y drive control, the motor ECU 70 may fix the upper arm switches SUHb, SVHb, and SWHb of the second inverter 30 to OFF and fix the lower arm switches SULb, SVLb, and SWLb of the second inverter 30 to ON. In this case, the lower arm side of the second inverter 30 functions as a neutral point.

[0104] The vehicle is not limited to a rear-wheel drive vehicle, and may be, for example, a front-wheel drive vehicle or a front-and-rear wheel drive (four-wheel drive) vehicle.

[0105] The rotating electric machine is not limited to an on-board motor provided on the vehicle body, and may be an in-wheel motor.

[0106] In the above embodiments, the carrier signal is not limited to a triangular wave signal, and may be, for example, a sawtooth wave signal.

[0107] In each of the above embodiments, the motor ECU 70 may perform PWM driving based on space vector modulation instead of PWM driving based on a magnitude comparison between the command value and the carrier signal.

[0108] The DC power source is not limited to a battery, and may be, for example, a fuel cell.

[0109] The rotating electric machine is not limited to a permanent magnet field type synchronous machine, and may be, for example, an induction machine.

[0110] The rotating electric machine is not limited to a three-phase one, but may be a two-phase one or a four-phase or more phase one.

[0111] The semiconductor switches constituting the first inverter and the second inverter are not limited to IGBTs, but may be, for example, N-channel MOSFETs. In this case, the high-potential terminal of the switch is the drain, and the low-potential terminal is the source. Each switch also has a body diode.

[0112] The control unit and method described herein may be implemented by a special-purpose computer configured by configuring a processor and memory programmed to perform one or more functions embodied in a computer program. Alternatively, the control unit and method described herein may be implemented by a special-purpose computer configured by configuring a processor with one or more dedicated hardware logic circuits. Alternatively, the control unit and method described herein may be implemented by one or more special-purpose computers configured by combining a processor and memory programmed to perform one or more functions with a processor configured with one or more hardware logic circuits. Furthermore, the computer program may be stored in a computer-readable non-transitory tangible recording medium as instructions executed by a computer.

[0113] The following describes characteristic configurations extracted from the above-described embodiments. [Configuration 1] A rotating electric machine (40) having a multi-phase armature winding (51U to 51W); a first inverter (20) having first upper arm switches (SUHa to SWHa) and first lower arm switches (SULa to SWLa) connected in series for the number of phases, the series-connected body of the first upper arm switches and the first lower arm switches being connected in parallel to a DC power source (10); a second inverter (30) having second upper arm switches (SUHb to SWHb) and second lower arm switches (SULb to SWLb) connected in series for the number of phases; a positive bus (11) for each phase electrically connecting a high potential side terminal of the first upper arm switch and a high potential side terminal of the second upper arm switch; and a negative bus (12) for each phase electrically connecting a low potential side terminal of the first lower arm switch and a low potential side terminal of the second lower arm switch. a changeover switch (QH, QL) provided on a target bus, which is at least one of the positive bus and the negative bus; the system is provided on a vehicle (200) and configured so that a rotational force of a rotor (41) of the rotating electric machine is transmitted to wheels (220) of the vehicle; in each phase, a low potential side terminal of the first upper arm switch and a high potential side terminal of the first lower arm switch are electrically connected to first ends (51Ua to 51Wa) of the armature winding; in each phase, a low potential side terminal of the second upper arm switch and a high potential side terminal of the second lower arm switch are electrically connected to second ends (51Ub to 51Wb) of the armature winding; when the changeover switch is turned on, the changeover switch electrically connects the first inverter and the second inverter via the target bus, and when the changeover switch is turned off, the changeover switch cuts off the electrical connection between the first inverter and the second inverter via the target bus; a setting unit (95) that sets Y drive control or H drive control as a control mode of the first upper arm switch, the first lower arm switch, the second upper arm switch, and the second lower arm switch;a switch control unit (96) that controls the on or off of the first upper arm switch, the first lower arm switch, the second upper arm switch, and the second lower arm switch based on the set control mode, wherein the Y drive control is a control that fixes the second upper arm switch of each phase on and fixes the second lower arm switch of each phase off when the changeover switch is off, or fixes the second lower arm switch of each phase on and fixes the second upper arm switch of each phase off when the changeover switch is off, and turns the first upper arm switch and the first lower arm switch on and off, and the H drive control is a control that turns the first upper arm switch, the first lower arm switch, the second upper arm switch, and the second lower arm switch on and off, and a determination unit (97) that determines whether or not the wheels are in a slipping state while the vehicle is traveling, The control device for a rotating electric machine according to Configuration 1, wherein the setting unit prohibits switching from a currently set control mode out of the Y drive control and the H drive control to the other control mode when the determination unit determines that the slip situation exists. [Configuration 2] The control device for a rotating electric machine according to Configuration 1, wherein the setting unit prohibits switching of the control mode to the H drive control when the currently set control mode is the Y drive control and it is determined that the slip situation exists. [Configuration 3] The control device for a rotating electric machine according to Configuration 1 or 2, wherein the setting unit prohibits the switching for a period from when it is determined that the slip situation exists until a release period (Tcc1) has elapsed. [Configuration 4] The control device for a rotating electric machine according to Configuration 3, wherein the setting unit permits the switching if, after it is determined that the slip situation exists, it is continuously determined that the slip situation does not exist for the release period. [Configuration 5] The release period is a first release period, and the determination unit calculates a determination parameter that is either a slip ratio of the wheel or a rotational acceleration of the wheel, and determines that the slip situation exists when it is determined that the calculated determination parameter continuously exceeds a prohibition threshold (Sth) over a prohibition period (Tpr),The control device for a rotating electric machine according to Configuration 4, wherein after it is determined that a slip situation is occurring, the setting unit determines whether the calculated determination parameter is continuously below a release threshold (Sa) that is smaller than the prohibition threshold over a second release period (Tcc2) that is shorter than the first release period, and the setting unit permits the switching if it is determined that the determination parameter is continuously below the release threshold over the second release period. [Configuration 6] The control device for a rotating electric machine according to any one of Configurations 1 to 3, wherein the determination unit calculates a determination parameter that is either a slip ratio of the wheel or a rotational acceleration of the wheel, and determines that the slip situation is occurring if it is determined that the calculated determination parameter is continuously above the prohibition threshold (Sth) over a prohibition period (Tpr) or if it is determined that the calculated determination parameter is above the prohibition threshold (Sth). [Configuration 7] The control device for a rotating electric machine according to any one of Configurations 1 to 6, wherein the determination unit acquires information indicating that a user of the vehicle permits the switching, and the setting unit permits the switching when the determination unit determines that the switching is permitted based on the acquired information.

[0114] Although the present disclosure has been described with reference to the embodiments, it is understood that the present disclosure is not limited to the embodiments or structures. The present disclosure also encompasses various modifications and equivalent modifications. In addition, various combinations and forms, including only one element, more than one element, or less than one element, are also within the scope and spirit of the present disclosure.

Claims

1. A rotating electric machine (40) having a multi-phase armature winding (51U to 51W); a first inverter (20) having first upper arm switches (SUHa to SWHa) and first lower arm switches (SULa to SWLa) connected in series for the number of phases, the series-connected first upper arm switches and the first lower arm switches being connected in parallel to a DC power source (10); a second inverter (30) having second upper arm switches (SUHb to SWHb) and second lower arm switches (SULb to SWLb) connected in series for the number of phases; a positive bus (11) electrically connecting a high potential side terminal of the first upper arm switch and a high potential side terminal of the second upper arm switch in each phase; and a negative bus (12) electrically connecting a low potential side terminal of the first lower arm switch and a low potential side terminal of the second lower arm switch in each phase. a changeover switch (QH, QL) provided on a target busbar that is at least one of the positive busbar and the negative busbar; and a control device (70) for a rotating electric machine applied to a system (100) including: the system is provided on a vehicle (200) and is configured so that a rotational force of a rotor (41) of the rotating electric machine is transmitted to wheels (220) of the vehicle; in each phase, a low potential side terminal of the first upper arm switch and a high potential side terminal of the first lower arm switch are electrically connected to first ends (51Ua to 51Wa) of the armature winding; in each phase, a low potential side terminal of the second upper arm switch and a high potential side terminal of the second lower arm switch are electrically connected to second ends (51Ub to 51Wb) of the armature winding; the changeover switch electrically connects the first inverter and the second inverter via the target bus when turned on, and cuts off the electrical connection between the first inverter and the second inverter via the target bus when turned off; a setting unit (95) that sets Y-drive control or H-drive control as the control mode of the first upper arm switch, the first lower arm switch, the second upper arm switch, and the second lower arm switch;a switch control unit (96) that controls the on or off of the first upper arm switch, the first lower arm switch, the second upper arm switch, and the second lower arm switch based on the set control mode, wherein the Y drive control is a control that fixes the second upper arm switch of each phase on and fixes the second lower arm switch of each phase off when the changeover switch is off, or fixes the second lower arm switch of each phase on and fixes the second upper arm switch of each phase off when the changeover switch is off, and turns the first upper arm switch and the first lower arm switch on and off, and the H drive control is a control that turns the first upper arm switch, the first lower arm switch, the second upper arm switch, and the second lower arm switch on and off, and a determination unit (97) that determines whether or not the wheels are in a slipping state while the vehicle is traveling, The control device for a rotating electric machine, wherein the setting unit prohibits switching from one of the currently set control modes of the Y drive control and the H drive control to the other control mode when the determination unit determines that the slip situation is occurring.

2. A control device for a rotating electric machine as described in claim 1, wherein the setting unit prohibits switching the control mode to the H drive control when it is determined that the slip situation occurs when the currently set control mode is the Y drive control.

3. The control device for a rotating electric machine according to claim 1 or 2, wherein the setting unit prohibits the switching for a period from when it is determined that the slip situation exists until a release period (Tcc1) has elapsed.

4. A control device for a rotating electric machine as described in claim 3, wherein the setting unit permits the switching if, after it has been determined that the slip situation exists, it is continuously determined that the slip situation does not exist over the release period.

5. The control device for a rotating electric machine according to claim 4, wherein the release period is a first release period, the determination unit calculates a determination parameter which is either a slip ratio of the wheel or a rotational acceleration of the wheel, determines that the slip situation exists if it is determined that the calculated determination parameter continuously exceeds a prohibition threshold (Sth) over a prohibition period (Tpr), and determines, after it is determined that the slip situation exists, whether the calculated determination parameter continuously falls below a release threshold (Sa) which is smaller than the prohibition threshold over a second release period (Tcc2) which is shorter than the first release period, and the setting unit permits the switching if it is determined that the determination parameter continuously falls below the release threshold over the second release period.

6. A control device for a rotating electric machine as described in claim 1 or 2, wherein the judgment unit calculates a judgment parameter which is either the slip ratio of the wheel or the rotational acceleration of the wheel, and judges that the slip situation exists if it determines that the calculated judgment parameter continuously exceeds a prohibition threshold (Sth) over a prohibition period (Tpr), or if it determines that the calculated judgment parameter exceeds the prohibition threshold (Sth).

7. A control device for a rotating electric machine as described in claim 1 or 2, wherein the judgment unit acquires information indicating that the user of the vehicle has authorized the switching, and the setting unit permits the switching if the judgment unit determines that the switching is authorized based on the acquired information.

8. A rotating electric machine (40) having a multi-phase armature winding (51U to 51W); a first inverter (20) having first upper arm switches (SUHa to SWHa) and first lower arm switches (SULa to SWLa) connected in series for the number of phases, and a series connection of the first upper arm switches and the first lower arm switches connected in parallel to a DC power source (10); a second inverter (30) having second upper arm switches (SUHb to SWHb) and second lower arm switches (SULb to SWLb) connected in series for the number of phases; a positive side bus (11) electrically connecting a high potential side terminal of the first upper arm switch and a high potential side terminal of the second upper arm switch in each phase; and a negative side bus (12) electrically connecting a low potential side terminal of the first lower arm switch and a low potential side terminal of the second lower arm switch in each phase. a changeover switch (QH, QL) provided on a target busbar that is at least one of the positive busbar and the negative busbar, the system being provided on a vehicle (200) and configured so that a rotational force of a rotor (41) of the rotating electric machine is transmitted to wheels (220) of the vehicle, wherein in each phase, a low potential side terminal of the first upper arm switch and a high potential side terminal of the first lower arm switch are electrically connected to first ends (51Ua to 51Wa) of the armature winding, and in each phase, a low potential side terminal of the second upper arm switch and a high potential side terminal of the second lower arm switch are electrically connected to second ends (51Ub to 51Wb) of the armature winding, and the changeover switch electrically connects the first inverter and the second inverter via the target busbar when turned on, and cuts off the electrical connection between the first inverter and the second inverter via the target busbar when turned off, A processor (71) performs a setting process to set Y drive control or H drive control as the control mode of the first upper arm switch, the first lower arm switch, the second upper arm switch, and the second lower arm switch, and a process to control the on or off of the first upper arm switch, the first lower arm switch, the second upper arm switch, and the second lower arm switch based on the set control mode.the Y drive control is a control for fixing the second upper arm switch of each phase on and fixing the second lower arm switch of each phase off when the changeover switch is off, or for fixing the second lower arm switch of each phase on and fixing the second upper arm switch of each phase off when the changeover switch is off, and for turning the first upper arm switch and the first lower arm switch on and off; the H drive control is a control for turning the first upper arm switch, the first lower arm switch, the second upper arm switch, and the second lower arm switch on and off; the program causes the processor to execute a determination process for determining whether or not the wheels are in a situation where they will slip while the vehicle is traveling, and when it is determined by the determination process that the wheels are in a situation where they will slip in the setting process, prohibiting switching from one control mode currently set of the Y drive control and the H drive control to the other control mode.

9. A rotating electric machine (40) having a multi-phase armature winding (51U to 51W); a first inverter (20) having first upper arm switches (SUHa to SWHa) and first lower arm switches (SULa to SWLa) connected in series for the number of phases, the series-connected first upper arm switches and the first lower arm switches being connected in parallel to a DC power source (10); a second inverter (30) having second upper arm switches (SUHb to SWHb) and second lower arm switches (SULb to SWLb) connected in series for the number of phases; a positive bus (11) for each phase electrically connecting a high potential side terminal of the first upper arm switch and a high potential side terminal of the second upper arm switch; and a negative bus (12) for each phase electrically connecting a low potential side terminal of the first lower arm switch and a low potential side terminal of the second lower arm switch. A control method for a rotating electric machine applied to a system (100) including: a changeover switch (QH, QL) provided on a target busbar that is at least one of the positive busbar and the negative busbar, wherein the system is provided on a vehicle (200) and is configured so that a rotational force of a rotor (41) of the rotating electric machine is transmitted to wheels (220) of the vehicle, and in each phase, a low potential side terminal of the first upper arm switch and a high potential side terminal of the first lower arm switch are electrically connected to first ends (51Ua to 51Wa) of the armature winding, and in each phase, a low potential side terminal of the second upper arm switch and a high potential side terminal of the second lower arm switch are electrically connected to second ends (51Ub to 51Wb) of the armature winding, the changeover switch electrically connects the first inverter and the second inverter via the target bus when turned on, and cuts off the electrical connection between the first inverter and the second inverter via the target bus when turned off; a setting step of setting Y-drive control or H-drive control as the control mode of the first upper arm switch, the first lower arm switch, the second upper arm switch, and the second lower arm switch; and a step of controlling the on or off of the first upper arm switch, the first lower arm switch, the second upper arm switch, and the second lower arm switch based on the set control mode,The Y drive control is a control that fixes the second upper arm switch of each phase on and fixes the second lower arm switch of each phase off when the changeover switch is off, or fixes the second lower arm switch of each phase on and fixes the second upper arm switch of each phase off when the changeover switch is off, and turns the first upper arm switch and the first lower arm switch on and off; the H drive control is a control that turns the first upper arm switch, the first lower arm switch, the second upper arm switch, and the second lower arm switch on and off; and the method includes a determination step of determining whether or not the wheels are in a situation where they will slip while the vehicle is traveling, and if it is determined in the determination step that the wheels are in a situation where they will slip in the setting step, switching from one of the currently set control modes of the Y drive control and the H drive control to the other control mode is prohibited.

Images