Control device for rotary electric machine, program, and control method for rotary electric machine

Abstract

A control device (70) is provided with a setting unit (86), a switch control unit (87), and a lock determination unit (88). The setting unit sets control modes of first upper and lower arm switches (SUHa-SWHa, SULa-SWLa) and second upper and lower arm switches (SUHb-SWHb, SULb-SWLb). The switch control unit controls the turning on or off of the first upper arm switches, the first lower arm switches, the second upper arm switches, and the second lower arm switches on the basis of the selected control mode. During control by the switch control unit, the lock determination unit determines whether or not a rotor (41) of a rotary electric machine (40) is in a locked state, which is either a rotation stop state or an extremely low speed rotation state. When it is determined that the rotor (41) is in the locked state, the setting unit executes overheat protection control for suppressing the occurrence of an overheat state in the system.

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. 2023-219450, filed on December 26, 2023, 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. Drive control of the rotating electric machine is performed by switching control of the first and second inverters, thereby achieving high output and high efficiency of the system. An example of such a technology is disclosed in Patent Document 1.

[0004] Japanese Patent Application Laid-Open No. 2023-45715

[0005] In the above system, when the armature winding is energized and the rotating electric machine generates torque, the output torque of the rotating electric machine may become equal to the load torque acting on the rotor of the rotating electric machine. In this case, the rotor stops rotating or rotates at an extremely low speed. This may cause current to concentrate in the armature winding of one of the phases, which may cause the first and second inverters and other components of the system to overheat.

[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 prevent the system from overheating.

[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 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; and a negative 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. 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, 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 the second end of the armature winding, and the system comprises: a setting unit that sets the control modes 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 that controls the first upper arm switch, the first lower arm switch, the second upper arm switch, and the second lower arm switch to the set control mode; and a lock determination unit that determines whether the rotor of the rotating electric machine is in a locked state, which is either a stopped rotation state or an extremely low speed rotation state, during control by the switch control unit, and when it is determined that the rotor is in the locked state, the setting unit executes overheat protection control to suppress the occurrence of an overheating state in the system.

[0008] This can prevent the system from overheating.

[0009] 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 an overall configuration diagram of a control system according to a first embodiment, Fig. 2 is a functional block diagram of control processing executed by a control device, Fig. 3 is a diagram showing a control mode of Y drive control, Fig. 4 is a diagram showing a control mode of H drive control, Fig. 5 is a time chart showing an example of a method for generating a drive signal, Fig. 6 is a diagram showing an example of a current flow mode when a locked state occurs during Y drive control, Fig. 7 is a flowchart of an overheat protection control process, and Fig. 8 is a diagram showing a carrier signal and a voltage before the overheat protection control in the first inverter. 9 is a time chart showing the transition of the carrier signal and PWM signal etc. before overheat protection control in the second inverter, FIG. 10 is a time chart showing the transition of the carrier signal and PWM signal etc. during overheat protection control in the first inverter, FIG. 11 is a time chart showing the transition of the carrier signal and PWM signal etc. during overheat protection control in the second inverter, FIG. 12 is a comparison diagram of the transition of the PWM signal etc. before and after overheat protection control in the V phase, and FIG. 13 is a comparison diagram of the transition of the PWM signal etc. before and after overheat protection control in the A mode. 14 is a diagram showing an example of a current flow mode in B mode, FIG. 15 is a diagram showing an example of a current flow mode in C mode, FIG. 16 is a diagram showing an example of a current flow mode in D mode, FIG. 17 is a flowchart of the overheat protection control process according to the second embodiment, FIG. 18 is a time chart showing the effect of the overheat protection control, FIG. 19 is a functional block diagram of the control process executed by the control device, and FIG. 20 is a flowchart of the overheat protection control process according to the third embodiment. 21 is a diagram showing an overheat protection control mode, FIG. 22 is a diagram showing a current flow mode according to a comparative example, FIG. 23 is a diagram showing an overheat protection control mode according to a modified example of the third embodiment, FIG. 24 is a diagram showing an overheat protection control mode according to a modified example of the third embodiment, FIG. 25 is a flowchart of the overheat protection control process according to the fourth embodiment, FIG. 26 is an overall configuration diagram of a control system according to the fifth embodiment, FIG. 27 is a flowchart of the overheat protection control process, FIG. 28 is a diagram showing an upper arm neutral point control mode, and FIG.FIG. 30 is an overall configuration diagram of a control system according to a sixth embodiment, FIG. 31 is a flowchart of overheat protection control processing, FIG. 32 is a diagram showing a first upper arm neutral point control mode, FIG. 33 is a diagram showing a first lower arm neutral point control mode, FIG. 34 is a diagram showing a second upper arm neutral point control mode, FIG. 35 is a diagram showing a second lower arm neutral point control mode, FIG. 36 is a flowchart of overheat protection control processing according to another embodiment, and FIG. 37 is a flowchart of overheat protection control processing according to another embodiment.

[0010] 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.

[0011] A first embodiment of a control device according to the present disclosure will be described below with reference to the drawings. The control device of the present embodiment is applied to a control system mounted on an electrically powered vehicle such as an electric vehicle or a hybrid vehicle.

[0012] As shown in Fig. 1, the control system 100 includes a battery 10, which is a DC power supply, a first inverter 20, a second inverter 30, and a 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.

[0013] 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 .

[0014] 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.

[0015] 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.

[0016] 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.

[0017] 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.

[0018] 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.

[0019] The rotating electric machine 40 is an on-board main engine that serves as a power source for running the vehicle. The rotating electric machine 40 includes a rotor 41 and a stator 50. The rotor 41 is capable of transmitting power to the drive wheels of the vehicle. 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.

[0020] 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.

[0021] 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.

[0022] 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.

[0023] 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.

[0024] The control system 100 includes a current sensor 60 , a rotation angle sensor 61 , a voltage sensor 62 and a temperature sensor 63 .

[0025] 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 at one of the ends of each of the phase windings 51U, 51V, and 51W that is closer to the first inverter 20. Hereinafter, the sign of the phase current is defined as positive when the current flows from the first terminal 51Ua, 51Va, and 51Wa of each of the windings 51U, 51V, and 51W to the second terminal 51Ub, 51Vb, and 51Wb, and negative when the current flows from the second terminal 51Ub, 51Vb, and 51Wb to the first terminal 51Ua, 51Va, and 51Wa. Note that the current sensor 60 may also be provided at one of the ends of each of the phase windings 51U, 51V, and 51W that is closer to the second inverter 30.

[0026] 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 across the capacitor 15. The temperature sensor 63 detects the temperatures of the first inverter 20 and the second inverter 30. For example, the temperature sensor 63 detects the temperatures of the switches SUHa to SWLa and SUHb to SWLb that constitute each of the inverters 20, 30 as the temperatures of the first and second inverters 20, 30.

[0027] The detection values ​​of the sensors 60 to 63 are input to a control device 70 included in the control system 100. The control device 70 is an electronic control unit (ECU) that performs various controls of the control system 100, and includes a processor 71 and a storage unit 72 as hardware. In the control system 100, each on-board device can be controlled by an ECU corresponding to that device. However, for convenience, multiple ECUs are shown as a single control device 70 in FIG. 1.

[0028] 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 control device 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. 2 and 6, which will be described later.

[0029] For example, program information stored on a non-transient physical recording medium is installed in the storage unit 72. 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 unit 72.

[0030] FIG. 2 is a block diagram showing the control process of the rotating electrical machine 40 executed by the control device 70. As shown in FIG.

[0031] The command value calculation unit 80 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 a higher-level control device than the control device 70 .

[0032] The two-phase conversion unit 81 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.

[0033] The current feedback unit 82 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 82 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 82 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.

[0034] The three-phase converter 83 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 voltages applied to the U-, V-, and W-phase windings 51U, 51V, and 51W. In this embodiment, the sign of the applied voltage to each phase winding is positive when the potential at the first terminal 51Ua, 51Va, and 51Wa of the winding 51U, 51V, and 51W is higher than the potential at the second terminal 51Ub, 51Vb, and 51Wb of the winding 51U, 51V, and 51W, respectively. The sign is negative when the potential at the second terminal 51Ub, 51Vb, and 51Wb of the winding 51U, 51V, and 51W is higher than the potential at the first terminal 51Ua, 51Va, and 51Wa of the winding 51U, 51V, and 51W.

[0035] The speed calculation unit 84 calculates the rotation speed Nr of the rotor 41 based on the electrical angle θr.

[0036] The selection unit 85 selects whether the drive state of the control system 100 should be Y drive control or H drive control. In this embodiment, the selection unit 85 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. 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.

[0037] The setting unit 86 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 comprised of switch on and off commands.

[0038] Specifically, the setting unit 86 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 voltage detected by 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.

[0039] 3 , when the selection unit 85 selects the Y drive control, the setting unit 86 turns off the changeover switch QH and performs PWM drive of the switches SUHa to SWLa of the first inverter 20. The setting unit 86 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.

[0040] The setting unit 86 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. In this embodiment, the carrier signal Sgc is a triangular wave signal with equal increasing and decreasing speeds. The maximum value of the carrier signal Sgc is 1, the minimum value is 0, and the center value of fluctuation is 0.5.

[0041] 5, when the U-phase normalized command value Dutyu is greater than the carrier signal Sgc, the setting unit 86 generates a U-phase PWM signal GU* of logic H, and when the U-phase normalized command value Dutyu is smaller than the carrier signal Sgc, the setting unit 86 generates a U-phase PWM signal GU* of logic L. The setting unit 86 also generates a logically inverted signal of the U-phase PWM signal GU*.

[0042] The setting unit 86 generates a signal in which the timing at which U-phase PWM signal GU* is switched to logic H is delayed by the dead time DT as the drive signal GUH for the first U-phase upper arm switch SUHa. The setting unit 86 generates a signal in which the timing at which the inverted signal is switched to logic H is delayed by the dead time DT as the drive signal GUL for the first U-phase lower arm switch SULa.

[0043] When the H drive control is selected by the selection unit 85, the setting unit 86 turns on the changeover switch QH as the H drive control, as shown in FIG. 4, and controls the switches SUHa to SWLa of the first inverter 20 to be PWM-driven, and also controls the switches SUHb to SWLb of the second inverter 30 to be PWM-driven.

[0044] Specifically, the setting unit 86 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 first carrier signal Sg1, similar to the Y-drive control. The setting unit 86 generates drive signals for the switches SUHb to 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. In this embodiment, the first and second carrier signals Sg1 and Sg2 are 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. In this embodiment, the maximum value of each carrier signal Sg1, Sg2 is 1, the minimum value is 0, and the center value of fluctuation is 0.5. 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, Sg2 used in the H drive control is the same as the frequency of the carrier signal Sgc used in the Y drive control.

[0045] Based on the generated drive signal, the switch control unit 87 controls the charge / discharge current of the gates of the switches SUHa to SWLa and SUHb to SWLb of the first and second inverters 20 and 30. As a result, the switches SUHa to SWLa and SUHb to SWLb of the first and second inverters 20 and 30 are controlled to be turned on or off in accordance with the drive signal.

[0046] 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.

[0047] During torque control of the rotating electric machine 40, if the output torque of the rotating electric machine 40 becomes equal to the load torque acting on the rotor 41, the rotor 41 may stop rotating or rotate at an extremely slow speed. In this case, the electrical angle may stop changing or change only slightly, causing current to concentrate in one of the armature windings of each phase. As a result, the inverter switches may overheat, potentially reducing inverter reliability. Such situations may occur, for example, when the drive wheels attempt to go over a step, when the drive wheels attempt to run onto a wheel chock in a parking space, or when starting up a steep slope. Figure 6 shows an example of current concentration in the W-phase armature winding 51W during Y-drive control.

[0048] Therefore, the control device 70 performs overheat protection control to prevent the occurrence of the above-described overheat state. As shown in FIG. 2, the control device 70 includes a lock determination unit 88. The lock determination unit 88 determines whether the rotor 41 is in a locked state, which is either a rotation-stop state or a very low-speed rotation state. In this embodiment, the lock determination unit 88 determines whether the rotor 41 is in a locked state based on the rotation speed Nr and the command torque Trq*. If it is determined that the rotor 41 is in a locked state, the setting unit 86 of the control device 70 performs overheat protection control.

[0049] 7 shows a flowchart of the overheat protection control process executed during the execution of torque control of the rotary electric machine 40. The process shown in FIG. 7 is repeatedly executed by the processor 71 of the control device 70, for example, at a predetermined control period.

[0050] In steps S10 and S11, the lock determination unit 88 determines whether or not the rotor 41 is in a locked state. More specifically, in step S10, it determines whether or not the rotation speed Nr is lower than a speed threshold Nth. The speed threshold Nth is set to a value that enables determination that the rotor 41 is in an extremely low rotation speed state in which the rotor 41 is stopped or rotating while close to a stopped state. The speed threshold Nth is, for example, a value greater than or equal to 10 rpm and less than or equal to 15 rpm, a value greater than or equal to 5 rpm and less than or equal to 2 rpm, or 0 rpm. Note that the value that the lock determination unit 88 compares with the speed threshold Nth may be, for example, the electrical angular speed ωr of the rotor 41 calculated based on the electrical angle θr.

[0051] If the determination in step S10 is affirmative, the process proceeds to step S11, where it is determined whether the command torque Trq* exceeds a torque threshold Trqth. The torque threshold Trqth may be set to the continuous allowable torque of the rotary electric machine 40, for example.

[0052] If the determination in either step S10 or S11 is negative, the overheat protection control is not executed, and normal torque control is executed. On the other hand, if the determination in step S11 is positive, it is determined that the motor is locked, and the process proceeds to step S12. In step S12, it is determined whether or not Y drive control is being executed.

[0053] If it is determined in step S12 that Y drive control is being executed, the process proceeds to step S13, where the control is forcibly switched to H drive control, which starts PWM drive in the second inverter 30 as well, thereby preventing current concentration in the upper arm of the second inverter 30.

[0054] When the process of step S13 is completed, or when it is determined in step S12 that H drive control is being executed, the process proceeds to step S14, where overheat protection control is performed. This control will be described below with reference to FIGS. 8 to 16.

[0055] 8 and 9 show the transitions of waveforms when the rotor 41 is stopped and before overheat protection control is executed. In FIG. 8, (a) shows the transitions of the first carrier signal Sg1 and the U-, V-, and W-phase normalized command values ​​Dutyu, Dutyv, and Dutyw. (b), (c), and (d) show the transitions of the U-, V-, and W-phase PWM signals GU1*, GV1*, and GW1* in the first inverter 20. In FIG. 9, (a) shows the transitions of the second carrier signal Sg2 and the U-, V-, and W-phase normalized command values ​​Dutyu, Dutyv, and Dutyw. (b), (c), and (d) show the transitions of the U-, V-, and W-phase PWM signals GU2*, GV2*, and GW2* in the second inverter 30. 8 and 9, Dc is the central value of fluctuation of each of the carrier signals Sg1 and Sg2.

[0056] In this embodiment, overheat protection control is performed by reducing the U-, V-, and W-phase normalized command values ​​Dutyu, Dutyv, and Dutyw by a predetermined command value ΔD. The predetermined command value ΔD is set to a value such that the minimum value among the U-, V-, and W-phase normalized command values ​​Dutyu, Dutyv, and Dutyw does not become less than 0. For example, the predetermined command value ΔD is set to a value between 0.1 and 0.4, between 0.1 and 0.3, between 0.15 and 0.3, or between 0.2 and 0.3. In this embodiment, the predetermined command value ΔD is set to 0.25. When overheat protection control is performed, the normalized command values ​​used to generate the drive signals are "Dutyu - ΔD, Dutyv - ΔD, Dutyw - ΔD." In other words, the normalized command value shifts relative to the fluctuation center value Dc of the first carrier signal Sg1 and the second carrier signal Sg2.

[0057] 10 and 11 show the transition of each waveform when the normalized command value is shifted by overheat protection control. Figures 10 and 11(a) to (d) correspond to Figures 8 and 9(a) to (d).

[0058] In this embodiment, the overheat protection control alternates between a process of decreasing the U-, V-, and W-phase normalized command values ​​Dutyu, Dutyv, and Dutyw by a predetermined command value ΔD and a process of returning the decreased U-, V-, and W-phase normalized command values ​​Dutyu, Dutyv, and Dutyw to their original values. This control is intended to switch the current flow paths in each inverter 20, 30 when the inverters are in a locked state. The following description will be given using the V phase as an example.

[0059] Fig. 12 shows the transitions of the V-phase PWM signals GV1* and GV2* shown in Fig. 8 to 11. In Fig. 12, (a) and (b) show the V-phase PWM signals GV1* and GV2* before being shifted by the predetermined command value ΔD, and (d) and (e) show the V-phase PWM signals GV1* and GV2* after being shifted by the predetermined command value ΔD.

[0060] 12(c) shows the current flow mode realized by the V-phase PWM signals GV1* and GV2* of (a) and (b). For convenience, it is assumed here that the dead time DT is 0.

[0061] When the V-phase PWM signal GV1* is at logic L and the V-phase PWM signal GV2* is at logic H, the A mode shown in Fig. 13 is entered. In the A mode, current flows through the second upper arm switch SVHb and the first lower arm switch SVLa. Note that Fig. 13 and Figs. 14 to 16 illustrate the case where the direction of the phase current flowing through the armature winding 51V is negative.

[0062] When the V-phase PWM signals GV1* and GV2* are at logic L, the mode is set to B mode shown in Fig. 14. In B mode, a current flows through the second lower-arm diode DVLb and the first lower-arm switch SVLa.

[0063] When the V-phase PWM signals GV1* and GV2* are at logic H, the C mode shown in Fig. 15 is entered. In the C mode, a current flows through the first upper-arm diode DVHa and the second upper-arm switch SVHb.

[0064] Before the shift, in the example shown in FIG. 12, one switching period of "A→B→A→C" (that is, one period of the carrier signal) is repeated.

[0065] On the other hand, FIG. 12(f) shows the current flow mode realized by the V-phase PWM signals GV1* and GV2* of (d) and (e).

[0066] After the shift, one switching cycle of "B → A → B → D" is repeated. The D mode is a mode shown in Fig. 16 that appears when the logic of the V-phase PWM signal GV1* is H and the logic of the V-phase PWM signal GV2* is L. In the D mode, a current flows through the first upper-arm diode DVHa and the second lower-arm diode DVLb.

[0067] 12, by shifting the normalized command value, mode C disappears and mode D appears. In this case, the element included in the current flow path changes from the second upper arm switch SVHb to the second lower arm diode DVLb.

[0068] Therefore, by shifting the normalized command value when the inverters are locked, the heating elements in the inverters 20 and 30 can be switched, and the occurrence of an overheating state in the inverters 20 and 30 can be suppressed.

[0069] The relative relationships between the U-, V-, and W-phase normalized command values ​​Dutyu, Dutyv, and Dutyw are maintained before and after the shift, which suppresses changes in the line voltage of the armature winding before and after the shift, thereby suppressing changes in the torque of the rotary electric machine 40 before and after the shift.

[0070] The control device 70 may, for example, switch between a process of decreasing the standardized command value by the predetermined command value ΔD and a process of restoring the decreased standardized command value to its original state at predetermined intervals. The control device 70 may also switch between a process of decreasing the standardized command value by the predetermined command value ΔD and a process of restoring the decreased standardized command value to its original state based on the temperatures of the first and second inverters 20, 30 detected by the temperature sensor 63.

[0071] Second Embodiment A second embodiment will now be described with reference to the drawings, focusing on differences from the first embodiment. In this embodiment, the control device 70 performs overheat protection control using a zero-phase current.

[0072] 17 shows a flowchart of the overheat protection control process executed during the execution of torque control of the rotary electric machine 40. The process shown in FIG. 17 is repeatedly executed by the processor 71, for example, at a predetermined control period.

[0073] If the process of step S13 is completed or if it is determined in step S12 that H drive control is being executed, the process proceeds to step S14, where the setting unit 86 performs overheat protection control. Specifically, H drive control is performed to satisfy a first condition and a second condition. The first condition is that a zero-phase current ΔI0 is passed through the armature windings 51U, 51V, and 51W of each phase so as to reduce the largest current among the U-, V-, and W-phase currents detected by the current sensor 60. In the example shown in FIG. 18 , a locked state is determined at time t1, and the U-phase current Iur is the largest among the U-, V-, and W-phase currents Iur, Ivr, and Iwr. Note that from time t1 onward in FIG. 18 , the solid line indicates the current transition when overheat protection control is executed, and the dashed line indicates the current transition in a comparative example in which overheat protection control is not executed.

[0074] The second condition is that a zero-phase current ΔI0 is caused to flow through the armature windings 51U, 51V, and 51W of each phase so that the magnitudes of the U-, V-, and W-phase currents Iur, Ivr, and Iwr other than those reduced by the first condition are equal to or less than the reduced currents. In the example shown in Figure 18, the magnitude of the W-phase current Iwr when overheat protection control is executed is equal to or less than the magnitude of the U-phase current Iur when overheat protection control is executed.

[0075] FIG. 19 shows an example of a block diagram for executing the overheat protection control of this embodiment.

[0076] The zero-phase-sequence signal generator 89 generates a zero-phase-sequence signal V0* for controlling the zero-phase-sequence currents flowing through the U-, V-, and W-phase windings 51U, 51V, and 51W to a target value, and outputs the signal to the U-, V-, and W-phase superimposing units 90U, 90V, and 90W. The zero-phase-sequence signal V0* is a DC signal for causing the zero-phase-sequence current ΔI0 shown in FIG. 18 to flow through the armature windings 51U, 51V, and 51W of each phase.

[0077] The U, V, and W phase superimposing units 90U, 90V, and 90W add a common zero-phase sequence signal V0* to the U, V, and W phase voltage command values ​​Vu*, Vv*, and Vw*, and output the result to the switch control unit 87. The switch control unit 87 uses "Vu*+V0*, Vv*+V0*, and Vw*+V0*" to generate drive signals in the H drive control.

[0078] According to the present embodiment described above, when a locked state occurs, it is possible to prevent the first inverter 20 and the second inverter 30 from becoming overheated.

[0079] Third Embodiment A third embodiment will now be described with reference to the drawings, focusing on differences from the first embodiment. In this embodiment, a control device 70 performs overheat protection control of the changeover switch QH.

[0080] 20 shows a flowchart of the overheat protection control process executed during the execution of torque control of the rotary electric machine 40. The process shown in FIG. 20 is repeatedly executed by the processor 71, for example, at a predetermined control period.

[0081] If the process of step S13 is completed or if it is determined in step S12 that H drive control is being executed, the process proceeds to step S16, where the setting unit 86 performs overheat protection control. Specifically, while continuing PWM drive of the first inverter 20, at least one of the second lower arm switches SULb, SVLb, and SWLb for each phase of the second inverter 30 is fixed on. In this embodiment, as shown in FIG. 21 , the second lower arm switches SULb, SVLb, and SWLb for three phases are fixed on. This prevents current from flowing through the selector switch QH. In FIG. 21 , IH denotes the current flowing through the positive bus 11, and IL denotes the current flowing through the negative bus 12. During H drive control in which the selector switch QH is turned on, the relationship "Iur + Ivr + Iwr + IH + IL = 0" holds.

[0082] 22 shows a comparative example in which the second lower arm switches SULb, SVLb, and SWLb for three phases are turned on. In this case, phase currents for three phases flow through the changeover switch QH.

[0083] According to the present embodiment described above, when the changeover switch QH is in a locked state, it is possible to prevent the changeover switch QH from overheating.

[0084] <Modification of Third Embodiment> The setting unit 86 may fix the second lower arm switches for two phases to ON, as shown in FIG. 23 .

[0085] As shown in FIG. 24, the setting unit 86 may fix the second lower arm switch for one phase to ON.

[0086] Fourth Embodiment A fourth embodiment will be described below with reference to the drawings, focusing on differences from the first embodiment. In this embodiment, the content of the overheat protection control is changed.

[0087] 25 shows a flowchart of the overheat protection control process executed during the execution of torque control of the rotary electric machine 40. The process shown in FIG. 25 is repeatedly executed by the processor 71, for example, at a predetermined control period.

[0088] If it is determined in step S12 that Y drive control is being executed, the process proceeds to step S20, where overheat protection control is performed. More specifically, as in the first embodiment, control is performed to alternately switch between a process of reducing the U-, V-, and W-phase normalized command values ​​Dutyu, Dutyv, and Dutyw by a predetermined command value ΔD and a process of restoring the reduced U-, V-, and W-phase normalized command values ​​Dutyu, Dutyv, and Dutyw to their original values.

[0089] This allows the heat generating elements in the first inverter 20 to be switched, and the occurrence of an overheated state in the first inverter 20 can be suppressed.

[0090] Fifth Embodiment The fifth embodiment will be described below with reference to the drawings, focusing on differences from the fourth embodiment. In this embodiment, as shown in FIG. 26 , the control system 100 includes a second changeover switch QL in addition to a 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.

[0091] 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.

[0092] In this embodiment, when the control device 70 selects H drive control, it turns on the first changeover switch QH and the second changeover switch QL. On the other hand, when the control device 70 selects Y drive control, it turns off the first changeover switch QH and the second changeover switch QL.

[0093] 27 shows a flowchart of the overheat protection control process executed during the execution of torque control of the rotary electric machine 40. The process shown in FIG. 27 is repeatedly executed by the processor 71, for example, at a predetermined control period.

[0094] If it is determined in step S12 that Y drive control is being executed, the process proceeds to step S21, where overheat protection control is performed while continuing Y drive control. Specifically, control is performed to alternate between upper-arm neutral point control and lower-arm neutral point control. The upper-arm neutral point control is the control shown in FIG. 28 and corresponds to the control shown in FIG. 3. The lower-arm neutral point control is the control shown in FIG. 29, in which the upper-arm switches SUHb, SVHb, and SWHb of each phase of the second inverter 30 are fixed to OFF and the lower-arm switches SULb, SVLb, and SWLb of each phase of the second inverter 30 are fixed to ON. In this case, the lower-arm side of the second inverter 30 functions as the neutral point.

[0095] Note that the control device 70 may, for example, alternately switch between the upper arm neutral point control and the lower arm neutral point control every predetermined period.

[0096] According to the present embodiment described above, if a locked state occurs during execution of the Y drive control, it is possible to prevent the second inverter 30 from overheating.

[0097] <Modification of Fifth Embodiment> In step S21, the process of step S20 in FIG. 25 in the fourth embodiment may also be executed.

[0098] Sixth Embodiment A sixth embodiment will now be described with reference to the drawings, focusing on differences from the fifth embodiment. In this embodiment, as shown in Fig. 30 , a configuration is provided in which either the first inverter 20 or the second inverter 30 is selectively disconnected from the battery 10.

[0099] Specifically, the control system 100 includes a second power switch 16 in addition to the first power switch 14. The second power switch 16 is, for example, a semiconductor switching element or a mechanical relay. The second power switch 16 connects the positive terminal of the battery 10 to the collectors of the upper arm switches SUHb, SVHb, and SWHb of each phase of the second inverter 30. When the second power switch 16 is turned on, it electrically connects the positive terminal of the battery 10 to the collectors of the upper arm switches SUHb, SVHb, and SWHb of each phase. When the second power switch 16 is turned off, it electrically disconnects the positive terminal of the battery 10 from the collectors of the upper arm switches SUHb, SVHb, and SWHb of each phase. In this embodiment, the first power switch 14 and the second power switch 16 correspond to a "connection switching unit."

[0100] In this embodiment, the capacitor 15 is connected in parallel to the battery 10. When the H drive control is selected, the control device 70 turns on the first power switch 14 and turns off the second power switch 16.

[0101] 31 shows a flowchart of the overheat protection control process executed during the execution of torque control of the rotary electric machine 40. The process shown in FIG. 31 is repeatedly executed by the processor 71, for example, at a predetermined control period.

[0102] If it is determined in step S12 that Y drive control is being executed, the process proceeds to step S22, where overheat protection control is performed. Specifically, control is performed to switch between first upper arm neutral point control, first lower arm neutral point control, second upper arm neutral point control, and second lower arm neutral point control.

[0103] 32, in a state in which the first power switch 14 is turned on and the second power switch 16 is turned off, the first upper arm neutral point control PWM drives the switches SUHa to SWLa of the first inverter 20. Also, the upper arm switches SUHb, SVHb, and SWHb of the second inverter 30 are fixed on, and the lower arm switches SULb, SVLb, and SWLb of the second inverter 30 are fixed off.

[0104] When the first power switch 14 is turned on and the second power switch 16 is turned off, the first mode is entered in which the battery 10 and the first inverter 20 are electrically connected and the battery 10 and the second inverter 30 are electrically disconnected.

[0105] 33, in a state where the first power switch 14 is turned on and the second power switch 16 is turned off, the first lower upper arm neutral point control PWM drives the switches SUHa to SWLa of the first inverter 20. Also, the lower arm switches SULb, SVLb, SWLb of the second inverter 30 are fixed on, and the upper arm switches SUHb, SVHb, SWHb of the second inverter 30 are fixed off.

[0106] 34, in a state in which the first power switch 14 is turned off and the second power switch 16 is turned on, the second upper arm neutral point control PWM drives the switches SUHb to SWLb of the second inverter 30. Also, the upper arm switches SUHa, SVHa, SWHa of the first inverter 20 are fixed on, and the lower arm switches SULa, SVLa, SWLa of the second inverter 30 are fixed off.

[0107] When the first power switch 14 is turned off and the second power switch 16 is turned on, the battery 10 and the second inverter 30 are electrically connected and the battery 10 and the first inverter 20 are electrically disconnected, entering a second mode.

[0108] 35, in a state in which the first power switch 14 is turned off and the second power switch 16 is turned on, the second lower arm neutral point control PWM drives the switches SUHb to SWLb of the second inverter 30. Also, the lower arm switches SULa, SVLa, SWLa of the first inverter 20 are fixed on, and the upper arm switches SUHa, SVHa, SWHa of the second inverter 30 are fixed off.

[0109] The control device 70 can use various methods to switch between the controls shown in Figures 32 to 35. Examples of the switching methods will be described below.

[0110] In a first example, the control device 70 may sequentially switch among the first upper arm neutral point control, the first lower arm neutral point control, the second upper arm neutral point control, and the second lower arm neutral point control at a specified cycle. In this case, the specified cycle may be, for example, a predetermined period.

[0111] In a second example, when the control device 70 is alternately switching between the first upper arm neutral point control and the first lower arm neutral point control at a predetermined period, if it determines that the temperature of the second inverter 30 detected by the temperature sensor 63 (for example, the highest temperature of each switch SUHb to SWLb of the second inverter 30) exceeds a temperature threshold, it may transition to a process of alternately switching between the second upper arm neutral point control and the second lower arm neutral point control at a predetermined period.

[0112] When the control device 70 is alternately switching between the second upper arm neutral point control and the second lower arm neutral point control at a predetermined period, if it determines that the temperature of the first inverter 20 detected by the temperature sensor 63 (for example, the highest temperature of each switch SUHa to SWLa of the first inverter 20) exceeds the temperature threshold value, it may proceed to a process of alternately switching between the first upper arm neutral point control and the first lower arm neutral point control at a predetermined period.

[0113] According to the present embodiment described above, it is possible to prevent the first inverter 20 and the second inverter 30 from becoming overheated.

[0114] <Modification of Sixth Embodiment> The overheat protection control during H drive control described in the third embodiment may be applied to the circuit shown in Fig. 30. In this case, in addition to the control of the switches in Figs. 21, 23, and 24 in the second inverter 30, the control of the switches in Figs. 21, 23, and 24 can also be performed in the first inverter 20.

[0115] Other Embodiments The above-described embodiments may be modified as follows.

[0116] The process for determining whether a locked state has occurred is not limited to the processes shown in steps S10 and S11 of Fig. 7, but may be the process of step S17 of Fig. 36. In step S17, the control device 70 determines whether the condition that the rotation speed Nr is lower than the speed threshold Nth and the condition that the command torque Trq* is higher than the torque threshold Trqth are met continuously for a predetermined period of time.

[0117] Furthermore, the control device 70 may use, for example, the detection value of the current sensor 60 instead of the command torque Trq* to determine whether or not the locked state is occurring. For example, instead of the process of step S11, the control device 70 may perform a process of determining whether or not the detection value of the current sensor 60 exceeds a predetermined current value.

[0118] The control system does not need to be provided with a changeover switch. In this case, the control system is a system in which the Y drive control is not executed and the H drive state is executed. In this case, the processing related to the Y drive control may be deleted from each flowchart. For example, using FIG. 7 as an example, if the processing related to the Y drive control is deleted, the flowchart will be as shown in FIG. 37.

[0119] The carrier signal is not limited to a triangular wave signal, but may be, for example, a sawtooth wave signal.

[0120] In each of the above embodiments, the control device 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.

[0121] The DC power source is not limited to a battery, and may be, for example, a fuel cell.

[0122] The rotating electric machine is not limited to a permanent magnet field type synchronous machine, and may be, for example, an induction machine.

[0123] 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.

[0124] 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.

[0125] The inverter, rotating electric machine, and control device may be installed in a mobile body other than a vehicle, such as an aircraft or a ship. If the mobile body is an aircraft, the rotating electric machine serves as a power source for the aircraft's flight, and if the mobile body is a ship, the rotating electric machine serves as a power source for the ship's navigation. Furthermore, the inverter, rotating electric machine, and control device may be installed in a mobile body other than a vehicle.

[0126] 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.

[0127] 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 multiple phase armature windings (51U to 51W), A first inverter (20) has a number of first upper arm switches (SUHa to SWHa) and first lower arm switches (SULa to SWLa) connected in series for each phase, and the series connection of the first upper arm switches and the first lower arm switches is connected in parallel to a DC power supply (10), A second inverter (30) having a number of second upper arm switches (SUHb to SWHb) and second lower arm switches (SULb to SWLb) connected in series for each phase, In each phase, a positive-side busbar (11) electrically connects the high-potential terminal of the first upper arm switch and the high-potential terminal of the second upper arm switch, In each phase, a negative-side busbar (12) electrically connects the low-potential terminal of the first lower arm switch and the low-potential terminal of the second lower arm switch, A changeover switch (QH, QL) is provided on the target bus, which is at least one of the positive-side bus and the negative-side bus, In a control device (70) for a rotating electric machine applied to a system comprising: In each phase, the low-potential terminal of the first upper arm switch and the high-potential terminal of the first lower arm switch are electrically connected to the first end of the armature winding. In each phase, the low-potential terminal of the second upper arm switch and the high-potential terminal of the second lower arm switch are electrically connected to the second end of the armature winding. When the changeover switch is turned on, it electrically connects the first inverter and the second inverter via the target bus, and when it is turned off, it disconnects the electrical connection between the first inverter and the second inverter via the target bus. A setting unit (86) sets 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 to Y drive control or H drive control, A switch control unit (87) controls the first upper arm switch, the first lower arm switch, the second upper arm switch, and the second lower arm switch to the set control mode, During control by the switch control unit, a lock determination unit (88) determines whether the rotor (41) of the rotating electric machine is in a locked state, which is either a state where rotation has stopped or a state where rotation is at an extremely low speed. Equipped with, The aforementioned Y drive control is, With the changeover switch turned off, the second upper arm switch for each phase is fixed to ON and the second lower arm switch for each phase is fixed to OFF, or with the changeover switch turned off, the second lower arm switch for each phase is fixed to ON and the second upper arm switch for each phase is fixed to OFF, This is a control that drives the first upper arm switch and the first lower arm switch using PWM. The H drive control is a control that drives the first upper arm switch, the first lower arm switch, the second upper arm switch, and the second lower arm switch using PWM. The control device for a rotating electric machine, wherein the setting unit, when it is determined that the system is locked during the execution of the Y drive control by the switch control unit, executes a control to switch the control mode from the Y drive control to the H drive control as an overheat protection control to suppress the occurrence of an overheating state in the system.

2. The setting unit sets the control mode to the H drive control, The setting unit is, Based on a comparison of the magnitudes of the voltage command values ​​(Duty, Dutyv, Dutyw) applied to the armature windings of each phase and the first carrier signal (Sg1), the control modes of the first upper arm switch and the first lower arm switch in the H drive control are set. Based on a comparison of the magnitudes of a second carrier signal (Sg2), which has the same frequency, amplitude, and fluctuation center value as the first carrier signal but is shifted in phase by 180°, and the voltage command value, the control modes of the second upper arm switch and the second lower arm switch in the H drive control are set. If the lock state is determined to be present during the execution of the H drive control by the switch control unit, the overheat protection control is performed as follows: A process to shift the voltage command value relative to the fluctuation center value of the first carrier signal and the second carrier signal, A process to return the shifted voltage command value to its original value, A control device for a rotating electric machine according to claim 1, which performs control to switch between.

3. A rotating electric machine (40) having multiple phase armature windings (51U to 51W), A first inverter (20) has a number of first upper arm switches (SUHa to SWHa) and first lower arm switches (SULa to SWLa) connected in series for each phase, and the series connection of the first upper arm switches and the first lower arm switches is connected in parallel to a DC power supply (10), A second inverter (30) having a number of second upper arm switches (SUHb to SWHb) and second lower arm switches (SULb to SWLb) connected in series for each phase, In each phase, a positive-side busbar (11) electrically connects the high-potential terminal of the first upper arm switch and the high-potential terminal of the second upper arm switch, In each phase, a negative-side busbar (12) electrically connects the low-potential terminal of the first lower arm switch and the low-potential terminal of the second lower arm switch, In a control device (70) for a rotating electric machine applied to a system comprising: In each phase, the low-potential terminal of the first upper arm switch and the high-potential terminal of the first lower arm switch are electrically connected to the first end of the armature winding. In each phase, the low-potential terminal of the second upper arm switch and the high-potential terminal of the second lower arm switch are electrically connected to the second end of the armature winding. A setting unit (86) sets 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 to an H drive control that drives the first upper arm switch, the first lower arm switch, the second upper arm switch, and the second lower arm switch with PWM, A switch control unit (87) controls the first upper arm switch, the first lower arm switch, the second upper arm switch, and the second lower arm switch to the set control mode, During control by the switch control unit, a lock determination unit (88) determines whether the rotor (41) of the rotating electric machine is in a locked state, which is either a state where rotation has stopped or a state where rotation is at an extremely low speed. Equipped with, The setting unit is, Based on a comparison of the magnitudes of the voltage command values ​​(Duty, Dutyv, Dutyw) applied to the armature windings of each phase and the first carrier signal (Sg1), the control modes of the first upper arm switch and the first lower arm switch in the H drive control are set. Based on a comparison of the magnitudes of a second carrier signal (Sg2), which has the same frequency, amplitude, and fluctuation center value as the first carrier signal but is shifted in phase by 180°, and the voltage command value, the control modes of the second upper arm switch and the second lower arm switch in the H drive control are set. If the lock state is determined to occur during the execution of the H drive control by the switch control unit, an overheat protection control is implemented to suppress the occurrence of an overheating state in the system, A process to shift the voltage command value relative to the fluctuation center value of the first carrier signal and the second carrier signal, A process to return the shifted voltage command value to its original value, A control device for a rotating electric machine that performs switching control.

4. The setting unit is, The control mode is set to the H drive control, A control device for a rotating electric machine according to claim 1, wherein, if the lock state is determined during the execution of the H drive control by the switch control unit, the H drive control is performed as an overheat protection control, which involves supplying a zero-sequence current to each phase's armature winding to reduce the current with the largest magnitude among the currents flowing through each phase's armature winding.

5. A rotating electric machine (40) having multiple phase armature windings (51U to 51W), A first inverter (20) has a number of first upper arm switches (SUHa to SWHa) and first lower arm switches (SULa to SWLa) connected in series for each phase, and the series connection of the first upper arm switches and the first lower arm switches is connected in parallel to a DC power supply (10), A second inverter (30) having a number of second upper arm switches (SUHb to SWHb) and second lower arm switches (SULb to SWLb) connected in series for each phase, In each phase, a positive-side busbar (11) electrically connects the high-potential terminal of the first upper arm switch and the high-potential terminal of the second upper arm switch, In each phase, a negative-side busbar (12) electrically connects the low-potential terminal of the first lower arm switch and the low-potential terminal of the second lower arm switch, In a control device (70) for a rotating electric machine applied to a system comprising: In each phase, the low-potential terminal of the first upper arm switch and the high-potential terminal of the first lower arm switch are electrically connected to the first end of the armature winding. In each phase, the low-potential terminal of the second upper arm switch and the high-potential terminal of the second lower arm switch are electrically connected to the second end of the armature winding. A setting unit (86) sets 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 to an H drive control that drives the first upper arm switch, the first lower arm switch, the second upper arm switch, and the second lower arm switch with PWM, A switch control unit (87) controls the first upper arm switch, the first lower arm switch, the second upper arm switch, and the second lower arm switch to the set control mode, During control by the switch control unit, a lock determination unit (88) determines whether the rotor (41) of the rotating electric machine is in a locked state, which is either a state where rotation has stopped or a state where rotation is at an extremely low speed. Equipped with, The setting unit, when it is determined that the system is in the locked state during the execution of the H drive control by the switch control unit, performs the H drive control as an overheat protection control to suppress the occurrence of an overheat state in the system, by supplying a zero-sequence current to each phase of the armature winding to reduce the current with the largest magnitude among the currents flowing through each phase of the armature winding, thereby controlling the rotating electric machine.

6. The aforementioned changeover switch (QH) is provided on the positive side busbar, The setting unit is, The control mode is set to the H drive control, The control device for a rotating electric machine according to claim 1, wherein, if the lock state is determined during the execution of the H drive control by the switch control unit, the control device performs the overheat protection control by turning on at least one of the second lower arm switches of each phase and turning off the second upper arm switch connected in series with the turned-on second lower arm switch.

7. A rotating electric machine (40) having multiple phase armature windings (51U to 51W), A first inverter (20) has a number of first upper arm switches (SUHa to SWHa) and first lower arm switches (SULa to SWLa) connected in series for each phase, and the series connection of the first upper arm switches and the first lower arm switches is connected in parallel to a DC power supply (10), A second inverter (30) having a number of second upper arm switches (SUHb to SWHb) and second lower arm switches (SULb to SWLb) connected in series for each phase, In each phase, a positive-side busbar (11) electrically connects the high-potential terminal of the first upper arm switch and the high-potential terminal of the second upper arm switch, In each phase, a negative-side busbar (12) electrically connects the low-potential terminal of the first lower arm switch and the low-potential terminal of the second lower arm switch, A changeover switch (QH, QL) is provided on the target bus, which is at least one of the positive-side bus and the negative-side bus, In a control device (70) for a rotating electric machine applied to a system comprising: In each phase, the low-potential terminal of the first upper arm switch and the high-potential terminal of the first lower arm switch are electrically connected to the first end of the armature winding. In each phase, the low-potential terminal of the second upper arm switch and the high-potential terminal of the second lower arm switch are electrically connected to the second end of the armature winding. When the changeover switch is turned on, it electrically connects the first inverter and the second inverter via the target bus, and when it is turned off, it disconnects the electrical connection between the first inverter and the second inverter via the target bus. A setting unit (86) sets 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 to Y drive control, A switch control unit (87) controls the first upper arm switch, the first lower arm switch, the second upper arm switch, and the second lower arm switch to the set control mode, During control by the switch control unit, a lock determination unit (88) determines whether the rotor (41) of the rotating electric machine is in a locked state, which is either a state where rotation has stopped or a state where rotation is at an extremely low speed. Equipped with, The aforementioned Y drive control is, With the changeover switch turned off, the second upper arm switch for each phase is fixed to ON and the second lower arm switch for each phase is fixed to OFF, or with the changeover switch turned off, the second lower arm switch for each phase is fixed to ON and the second upper arm switch for each phase is fixed to OFF, This is a control that drives the first upper arm switch and the first lower arm switch using PWM. The setting unit is, Based on a comparison of the magnitudes of the voltage command values ​​(Duty, Dutyv, Dutyw) applied to the armature windings of each phase and the carrier signal (Sgc), the control modes of the first upper arm switch and the first lower arm switch in the Y drive control are set. If the Y drive control by the switch control unit determines that the system is in a locked state, an overheat protection control is implemented to suppress the occurrence of an overheating state in the system. A process to shift the voltage command value with respect to the fluctuation center value of the carrier signal, A process to return the shifted voltage command value to its original value, A control device for a rotating electric machine that performs switching control.

8. A rotating electric machine (40) having multiple phase armature windings (51U to 51W), A first inverter (20) has a number of first upper arm switches (SUHa to SWHa) and first lower arm switches (SULa to SWLa) connected in series for each phase, and the series connection of the first upper arm switches and the first lower arm switches is connected in parallel to a DC power supply (10), A second inverter (30) having a number of second upper arm switches (SUHb to SWHb) and second lower arm switches (SULb to SWLb) connected in series for each phase, In each phase, a positive-side busbar (11) electrically connects the high-potential terminal of the first upper arm switch and the high-potential terminal of the second upper arm switch, In each phase, a negative-side busbar (12) electrically connects the low-potential terminal of the first lower arm switch and the low-potential terminal of the second lower arm switch, A changeover switch (QH, QL) is provided on the target bus, which is at least one of the positive-side bus and the negative-side bus, In a control device (70) for a rotating electric machine applied to a system comprising: In each phase, the low-potential terminal of the first upper arm switch and the high-potential terminal of the first lower arm switch are electrically connected to the first end of the armature winding. In each phase, the low-potential terminal of the second upper arm switch and the high-potential terminal of the second lower arm switch are electrically connected to the second end of the armature winding. When the changeover switch is turned on, it electrically connects the first inverter and the second inverter via the target bus, and when it is turned off, it disconnects the electrical connection between the first inverter and the second inverter via the target bus. A setting unit (86) sets 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 to Y drive control, A switch control unit (87) controls the first upper arm switch, the first lower arm switch, the second upper arm switch, and the second lower arm switch to the set control mode, During control by the switch control unit, a lock determination unit (88) determines whether the rotor (41) of the rotating electric machine is in a locked state, which is either a state where rotation has stopped or a state where rotation is at an extremely low speed. Equipped with, The aforementioned Y drive control is, With the changeover switch turned off, the second upper arm switch for each phase is fixed to ON and the second lower arm switch for each phase is fixed to OFF, or with the changeover switch turned off, the second lower arm switch for each phase is fixed to ON and the second upper arm switch for each phase is fixed to OFF, This is a control that drives the first upper arm switch and the first lower arm switch using PWM. When the setting unit determines that the Y drive control is in the locked state during the execution of the Y drive control by the switch control unit, it performs control to switch between upper arm neutral point control and lower arm neutral point control as an overheat protection control to suppress the occurrence of an overheat state in the system. The upper arm neutral point control is a control that, with the changeover switch turned off, fixes the second upper arm switch for each phase to the ON position and the second lower arm switch for each phase to the OFF position, while simultaneously driving the first upper arm switch and the first lower arm switch with PWM. The control device for a rotating electric machine is a control that, with the changeover switch turned off, fixes the second lower arm switch for each phase to the ON position and the second upper arm switch for each phase to the OFF position, while simultaneously driving the first upper arm switch and the first lower arm switch with PWM.

9. The system includes connection switching units (14, 16) that switch between a first mode in which the DC power supply and the first inverter are electrically connected and the DC power supply and the second inverter are electrically disconnected, and a second mode in which the DC power supply and the second inverter are electrically connected and the DC power supply and the first inverter are electrically disconnected. The upper arm neutral point control is a first upper arm neutral point control performed in the state set to the first mode by the connection switching unit, The lower arm neutral point control is a first lower arm neutral point control performed in the state set to the first mode by the connection switching unit, If the setting unit determines that the lock state is in place during the execution of the Y drive control, it performs the overheat protection control by switching the first upper arm neutral point control, the first lower arm neutral point control, the second upper arm neutral point control, and the second lower arm neutral point control. The second upper arm neutral point control is a control that, when the system is set to the second mode by the connection switching unit and the changeover switch is turned off, fixes the first upper arm switch for each phase to the ON position and the first lower arm switch for each phase to the OFF position, and drives the second upper arm switch and the second lower arm switch using PWM. The control device for a rotating electric machine according to claim 8, wherein the second lower arm neutral point control is a control that, when the connection switching unit has set the machine to the second mode and the switching switch is turned off, fixes the first lower arm switch for each phase to the ON position and fixes the first upper arm switch for each phase to the OFF position, and drives the second upper arm switch and the second lower arm switch with PWM.

10. A rotating electric machine (40) having multiple phase armature windings (51U to 51W), A first inverter (20) has a number of first upper arm switches (SUHa to SWHa) and first lower arm switches (SULa to SWLa) connected in series for each phase, and the series connection of the first upper arm switches and the first lower arm switches is connected in parallel to a DC power supply (10), A second inverter (30) having a number of second upper arm switches (SUHb to SWHb) and second lower arm switches (SULb to SWLb) connected in series for each phase, In each phase, a positive-side busbar (11) electrically connects the high-potential terminal of the first upper arm switch and the high-potential terminal of the second upper arm switch, In each phase, a negative-side busbar (12) electrically connects the low-potential terminal of the first lower arm switch and the low-potential terminal of the second lower arm switch, A changeover switch (QH, QL) is provided on the target bus, which is at least one of the positive-side bus and the negative-side bus, In a program applied to a system that includes the following features, In each phase, the low-potential terminal of the first upper arm switch and the high-potential terminal of the first lower arm switch are electrically connected to the first end of the armature winding. In each phase, the low-potential terminal of the second upper arm switch and the high-potential terminal of the second lower arm switch are electrically connected to the second end of the armature winding. When the changeover switch is turned on, it electrically connects the first inverter and the second inverter via the target bus, and when it is turned off, it disconnects the electrical connection between the first inverter and the second inverter via the target bus. The processor (71) A setting process to set 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 to Y drive control or H drive control, A control process that controls the first upper arm switch, the first lower arm switch, the second upper arm switch, and the second lower arm switch to the set control mode, During the control process described above, a process is performed to determine whether the rotor (41) of the rotating electric machine is in a locked state, which is either a state where rotation has stopped or a state where rotation is at an extremely low speed. Make it run, The aforementioned Y drive control is, With the changeover switch turned off, the second upper arm switch for each phase is fixed to ON and the second lower arm switch for each phase is fixed to OFF, or with the changeover switch turned off, the second lower arm switch for each phase is fixed to ON and the second upper arm switch for each phase is fixed to OFF, This is a control that drives the first upper arm switch and the first lower arm switch using PWM. The H drive control is a control that drives the first upper arm switch, the first lower arm switch, the second upper arm switch, and the second lower arm switch using PWM. A program that, in the setting process, if it is determined that the system is locked during the execution of the Y drive control by the control process, executes a control to switch the control mode from the Y drive control to the H drive control as an overheat protection control to suppress the occurrence of an overheating state in the system.

11. A rotating electric machine (40) having multiple phase armature windings (51U to 51W), A first inverter (20) has a number of first upper arm switches (SUHa to SWHa) and first lower arm switches (SULa to SWLa) connected in series for each phase, and the series connection of the first upper arm switches and the first lower arm switches is connected in parallel to a DC power supply (10), A second inverter (30) having a number of second upper arm switches (SUHb to SWHb) and second lower arm switches (SULb to SWLb) connected in series for each phase, In each phase, a positive-side busbar (11) electrically connects the high-potential terminal of the first upper arm switch and the high-potential terminal of the second upper arm switch, In each phase, a negative-side busbar (12) electrically connects the low-potential terminal of the first lower arm switch and the low-potential terminal of the second lower arm switch, In a program applied to a system that includes the following features, In each phase, the low-potential terminal of the first upper arm switch and the high-potential terminal of the first lower arm switch are electrically connected to the first end of the armature winding. In each phase, the low-potential terminal of the second upper arm switch and the high-potential terminal of the second lower arm switch are electrically connected to the second end of the armature winding. The processor (71) A setting process to set 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 to an H drive control that drives the first upper arm switch, the first lower arm switch, the second upper arm switch, and the second lower arm switch with PWM, A control process that controls the first upper arm switch, the first lower arm switch, the second upper arm switch, and the second lower arm switch to the set control mode, During the control process described above, a process is performed to determine whether the rotor (41) of the rotating electric machine is in a locked state, which is either a state where rotation has stopped or a state where rotation is at an extremely low speed. Make it run, In the aforementioned setting process, Based on a comparison of the magnitudes of the voltage command values ​​(Duty, Dutyv, Dutyw) applied to the armature windings of each phase and the first carrier signal (Sg1), the control modes of the first upper arm switch and the first lower arm switch in the H drive control are set. Based on a comparison of the magnitudes of a second carrier signal (Sg2), which has the same frequency, amplitude, and fluctuation center value as the first carrier signal but is shifted in phase by 180°, and the voltage command value, the control modes of the second upper arm switch and the second lower arm switch in the H drive control are set. If it is determined that the system is locked during the execution of the H drive control by the control process described above, an overheat protection control is implemented to suppress the occurrence of an overheating state in the system, A process to shift the voltage command value relative to the fluctuation center value of the first carrier signal and the second carrier signal, A process to return the shifted voltage command value to its original value, A program that controls the switching of [something].

12. A rotating electric machine (40) having multiple phase armature windings (51U to 51W), A first inverter (20) has a number of first upper arm switches (SUHa to SWHa) and first lower arm switches (SULa to SWLa) connected in series for each phase, and the series connection of the first upper arm switches and the first lower arm switches is connected in parallel to a DC power supply (10), A second inverter (30) having a number of second upper arm switches (SUHb to SWHb) and second lower arm switches (SULb to SWLb) connected in series for each phase, In each phase, a positive-side busbar (11) electrically connects the high-potential terminal of the first upper arm switch and the high-potential terminal of the second upper arm switch, In each phase, a negative-side busbar (12) electrically connects the low-potential terminal of the first lower arm switch and the low-potential terminal of the second lower arm switch, In a program applied to a system that includes the following features, In each phase, the low-potential terminal of the first upper arm switch and the high-potential terminal of the first lower arm switch are electrically connected to the first end of the armature winding. In each phase, the low-potential terminal of the second upper arm switch and the high-potential terminal of the second lower arm switch are electrically connected to the second end of the armature winding. The processor (71) A setting process to set 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 to an H drive control that drives the first upper arm switch, the first lower arm switch, the second upper arm switch, and the second lower arm switch with PWM, A control process that controls the first upper arm switch, the first lower arm switch, the second upper arm switch, and the second lower arm switch to the set control mode, During the control process described above, a process is performed to determine whether the rotor (41) of the rotating electric machine is in a locked state, which is either a state where rotation has stopped or a state where rotation is at an extremely low speed. Make it run, In the setting process, if it is determined that the system is locked during the execution of the H drive control by the control process, the program performs the H drive control as an overheat protection control to suppress the occurrence of an overheating state in the system, by supplying a zero-sequence current to each phase of the armature winding to reduce the current with the largest magnitude among the currents flowing through each phase of the armature winding.

13. A rotating electric machine (40) having multiple phase armature windings (51U to 51W), A first inverter (20) has a number of first upper arm switches (SUHa to SWHa) and first lower arm switches (SULa to SWLa) connected in series for each phase, and the series connection of the first upper arm switches and the first lower arm switches is connected in parallel to a DC power supply (10), A second inverter (30) having a number of second upper arm switches (SUHb to SWHb) and second lower arm switches (SULb to SWLb) connected in series for each phase, In each phase, a positive-side busbar (11) electrically connects the high-potential terminal of the first upper arm switch and the high-potential terminal of the second upper arm switch, In each phase, a negative-side busbar (12) electrically connects the low-potential terminal of the first lower arm switch and the low-potential terminal of the second lower arm switch, A changeover switch (QH, QL) is provided on the target bus, which is at least one of the positive-side bus and the negative-side bus, In a program applied to a system that includes the following features, In each phase, the low-potential terminal of the first upper arm switch and the high-potential terminal of the first lower arm switch are electrically connected to the first end of the armature winding. In each phase, the low-potential terminal of the second upper arm switch and the high-potential terminal of the second lower arm switch are electrically connected to the second end of the armature winding. When the changeover switch is turned on, it electrically connects the first inverter and the second inverter via the target bus, and when it is turned off, it disconnects the electrical connection between the first inverter and the second inverter via the target bus. The processor (71) A setting process to set 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 to Y drive control, A control process that controls the first upper arm switch, the first lower arm switch, the second upper arm switch, and the second lower arm switch to the set control mode, During the control process described above, a process is performed to determine whether the rotor (41) of the rotating electric machine is in a locked state, which is either a state where rotation has stopped or a state where rotation is at an extremely low speed. Make it run, The aforementioned Y drive control is, With the changeover switch turned off, the second upper arm switch for each phase is fixed to ON and the second lower arm switch for each phase is fixed to OFF, or with the changeover switch turned off, the second lower arm switch for each phase is fixed to ON and the second upper arm switch for each phase is fixed to OFF, This is a control that drives the first upper arm switch and the first lower arm switch using PWM. In the aforementioned setting process, Based on a comparison of the magnitudes of the voltage command values ​​(Duty, Dutyv, Dutyw) applied to the armature windings of each phase and the carrier signal (Sgc), the control modes of the first upper arm switch and the first lower arm switch in the Y drive control are set. If it is determined that the system is locked during the execution of the Y drive control by the control process described above, an overheat protection control is implemented to suppress the occurrence of an overheating state in the system, A process to shift the voltage command value with respect to the fluctuation center value of the carrier signal, A process to return the shifted voltage command value to its original value, A program that controls the switching of [something].

14. A rotating electric machine (40) having multiple phase armature windings (51U to 51W), A first inverter (20) has a number of first upper arm switches (SUHa to SWHa) and first lower arm switches (SULa to SWLa) connected in series for each phase, and the series connection of the first upper arm switches and the first lower arm switches is connected in parallel to a DC power supply (10), A second inverter (30) having a number of second upper arm switches (SUHb to SWHb) and second lower arm switches (SULb to SWLb) connected in series for each phase, In each phase, a positive-side busbar (11) electrically connects the high-potential terminal of the first upper arm switch and the high-potential terminal of the second upper arm switch, In each phase, a negative-side busbar (12) electrically connects the low-potential terminal of the first lower arm switch and the low-potential terminal of the second lower arm switch, A changeover switch (QH, QL) is provided on the target bus, which is at least one of the positive-side bus and the negative-side bus, In a program applied to a system that includes the following features, In each phase, the low-potential terminal of the first upper arm switch and the high-potential terminal of the first lower arm switch are electrically connected to the first end of the armature winding. In each phase, the low-potential terminal of the second upper arm switch and the high-potential terminal of the second lower arm switch are electrically connected to the second end of the armature winding. When the changeover switch is turned on, it electrically connects the first inverter and the second inverter via the target bus, and when it is turned off, it disconnects the electrical connection between the first inverter and the second inverter via the target bus. The processor (71) A setting process to set 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 to Y drive control, A control process that controls the first upper arm switch, the first lower arm switch, the second upper arm switch, and the second lower arm switch to the set control mode, During the control process described above, a process is performed to determine whether the rotor (41) of the rotating electric machine is in a locked state, which is either a state where rotation has stopped or a state where rotation is at an extremely low speed. Make it run, The aforementioned Y drive control is, With the changeover switch turned off, the second upper arm switch for each phase is fixed to ON and the second lower arm switch for each phase is fixed to OFF, or with the changeover switch turned off, the second lower arm switch for each phase is fixed to ON and the second upper arm switch for each phase is fixed to OFF, This is a control that drives the first upper arm switch and the first lower arm switch using PWM. In the setting process, if it is determined that the system is locked during the execution of the Y drive control by the control process, the system performs an overheat protection control to suppress the occurrence of an overheating state by switching between the upper arm neutral point control and the lower arm neutral point control. The upper arm neutral point control is a control that, with the changeover switch turned off, fixes the second upper arm switch for each phase to the ON position and the second lower arm switch for each phase to the OFF position, while simultaneously driving the first upper arm switch and the first lower arm switch with PWM. The lower arm neutral point control is a program that, with the changeover switch turned off, fixes the second lower arm switch for each phase to the ON position and the second upper arm switch for each phase to the OFF position, while simultaneously driving the first upper arm switch and the first lower arm switch via PWM.

15. A rotating electric machine (40) having multiple phase armature windings (51U to 51W), A first inverter (20) has a number of first upper arm switches (SUHa to SWHa) and first lower arm switches (SULa to SWLa) connected in series for each phase, and the series connection of the first upper arm switches and the first lower arm switches is connected in parallel to a DC power supply (10), A second inverter (30) having a number of second upper arm switches (SUHb to SWHb) and second lower arm switches (SULb to SWLb) connected in series for each phase, In each phase, a positive-side busbar (11) electrically connects the high-potential terminal of the first upper arm switch and the high-potential terminal of the second upper arm switch, In each phase, a negative-side busbar (12) electrically connects the low-potential terminal of the first lower arm switch and the low-potential terminal of the second lower arm switch, A changeover switch (QH, QL) is provided on the target bus, which is at least one of the positive-side bus and the negative-side bus, In a control method for a rotating electric machine applied to a system comprising the following: In each phase, the low-potential terminal of the first upper arm switch and the high-potential terminal of the first lower arm switch are electrically connected to the first end of the armature winding. In each phase, the low-potential terminal of the second upper arm switch and the high-potential terminal of the second lower arm switch are electrically connected to the second end of the armature winding. When the changeover switch is turned on, it electrically connects the first inverter and the second inverter via the target bus, and when it is turned off, it disconnects the electrical connection between the first inverter and the second inverter via the target bus. A setting step to set 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 to Y drive control or H drive control, A control step of controlling the first upper arm switch, the first lower arm switch, the second upper arm switch, and the second lower arm switch to the set control mode, The control step includes determining whether the rotor (41) of the rotating electric machine is in a locked state, either in a state where it has stopped rotating or in a state where it is rotating at an extremely low speed, during the control process described above. The aforementioned Y drive control is, With the changeover switch turned off, the second upper arm switch for each phase is fixed to ON and the second lower arm switch for each phase is fixed to OFF, or with the changeover switch turned off, the second lower arm switch for each phase is fixed to ON and the second upper arm switch for each phase is fixed to OFF, This is a control that drives the first upper arm switch and the first lower arm switch using PWM. The H drive control is a control that drives the first upper arm switch, the first lower arm switch, the second upper arm switch, and the second lower arm switch using PWM. A control method for a rotating electric machine, wherein, in the setting step, if it is determined that the system is locked during the execution of the Y drive control by the control step, a control is executed to switch the control mode from the Y drive control to the H drive control as an overheat protection control to suppress the occurrence of an overheating state in the system.

16. A rotating electric machine (40) having multiple phase armature windings (51U to 51W), A first inverter (20) has a number of first upper arm switches (SUHa to SWHa) and first lower arm switches (SULa to SWLa) connected in series for each phase, and the series connection of the first upper arm switches and the first lower arm switches is connected in parallel to a DC power supply (10), A second inverter (30) having a number of second upper arm switches (SUHb to SWHb) and second lower arm switches (SULb to SWLb) connected in series for each phase, In each phase, a positive-side busbar (11) electrically connects the high-potential terminal of the first upper arm switch and the high-potential terminal of the second upper arm switch, In each phase, a negative-side busbar (12) electrically connects the low-potential terminal of the first lower arm switch and the low-potential terminal of the second lower arm switch, In a control method for a rotating electric machine applied to a system comprising the following: In each phase, the low-potential terminal of the first upper arm switch and the high-potential terminal of the first lower arm switch are electrically connected to the first end of the armature winding. In each phase, the low-potential terminal of the second upper arm switch and the high-potential terminal of the second lower arm switch are electrically connected to the second end of the armature winding. Setting step to set 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 to H drive control that drives the first upper arm switch, the first lower arm switch, the second upper arm switch, and the second lower arm switch with PWM, A control step of controlling the first upper arm switch, the first lower arm switch, the second upper arm switch, and the second lower arm switch to the set control mode, During the control according to the control step described above, a step is taken to determine whether the rotor (41) of the rotating electric machine is in a locked state, which is either a state where rotation has stopped or a state where rotation is at an extremely low speed. Equipped with, In the above setting step, Based on a comparison of the magnitudes of the voltage command values ​​(Duty, Dutyv, Dutyw) applied to the armature windings of each phase and the first carrier signal (Sg1), the control modes of the first upper arm switch and the first lower arm switch in the H drive control are set. Based on a comparison of the magnitudes of a second carrier signal (Sg2), which has the same frequency, amplitude, and fluctuation center value as the first carrier signal but is shifted in phase by 180°, and the voltage command value, the control modes of the second upper arm switch and the second lower arm switch in the H drive control are set. If it is determined that the system is locked during the execution of the H drive control by the control step described above, an overheat protection control is implemented to suppress the occurrence of an overheating state in the system, A process to shift the voltage command value relative to the fluctuation center value of the first carrier signal and the second carrier signal, A process to return the shifted voltage command value to its original value, A control method for a rotating electric machine that performs switching control.

17. A rotating electric machine (40) having multiple phase armature windings (51U to 51W), A first inverter (20) has a number of first upper arm switches (SUHa to SWHa) and first lower arm switches (SULa to SWLa) connected in series for each phase, and the series connection of the first upper arm switches and the first lower arm switches is connected in parallel to a DC power supply (10), A second inverter (30) having a number of second upper arm switches (SUHb to SWHb) and second lower arm switches (SULb to SWLb) connected in series for each phase, In each phase, a positive-side busbar (11) electrically connects the high-potential terminal of the first upper arm switch and the high-potential terminal of the second upper arm switch, In each phase, a negative-side busbar (12) electrically connects the low-potential terminal of the first lower arm switch and the low-potential terminal of the second lower arm switch, In a control method for a rotating electric machine applied to a system comprising the following: In each phase, the low-potential terminal of the first upper arm switch and the high-potential terminal of the first lower arm switch are electrically connected to the first end of the armature winding. In each phase, the low-potential terminal of the second upper arm switch and the high-potential terminal of the second lower arm switch are electrically connected to the second end of the armature winding. Setting step to set 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 to H drive control that drives the first upper arm switch, the first lower arm switch, the second upper arm switch, and the second lower arm switch with PWM, A control step of controlling the first upper arm switch, the first lower arm switch, the second upper arm switch, and the second lower arm switch to the set control mode, During the control according to the control step described above, a step is taken to determine whether the rotor (41) of the rotating electric machine is in a locked state, which is either a state where rotation has stopped or a state where rotation is at an extremely low speed. Equipped with, A control method for a rotating electric machine, wherein, in the setting step, if it is determined that the system is in a locked state during the execution of the H drive control by the control step, the H drive control is performed as an overheat protection control to suppress the occurrence of an overheat state in the system, by flowing a zero-sequence current that reduces the current with the largest magnitude among the currents flowing through the armature windings of each phase to the armature windings of each phase.

18. A rotating electric machine (40) having multiple phase armature windings (51U to 51W), A first inverter (20) has a number of first upper arm switches (SUHa to SWHa) and first lower arm switches (SULa to SWLa) connected in series for each phase, and the series connection of the first upper arm switches and the first lower arm switches is connected in parallel to a DC power supply (10), A second inverter (30) having a number of second upper arm switches (SUHb to SWHb) and second lower arm switches (SULb to SWLb) connected in series for each phase, In each phase, a positive-side busbar (11) electrically connects the high-potential terminal of the first upper arm switch and the high-potential terminal of the second upper arm switch, In each phase, a negative-side busbar (12) electrically connects the low-potential terminal of the first lower arm switch and the low-potential terminal of the second lower arm switch, A changeover switch (QH, QL) is provided on the target bus, which is at least one of the positive-side bus and the negative-side bus, In a control method for a rotating electric machine applied to a system comprising the following: In each phase, the low-potential terminal of the first upper arm switch and the high-potential terminal of the first lower arm switch are electrically connected to the first end of the armature winding. In each phase, the low-potential terminal of the second upper arm switch and the high-potential terminal of the second lower arm switch are electrically connected to the second end of the armature winding. When the changeover switch is turned on, it electrically connects the first inverter and the second inverter via the target bus, and when it is turned off, it disconnects the electrical connection between the first inverter and the second inverter via the target bus. A setting step to set 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 to Y drive control, A control step of controlling the first upper arm switch, the first lower arm switch, the second upper arm switch, and the second lower arm switch to the set control mode, During the control according to the control step described above, a step is taken to determine whether the rotor (41) of the rotating electric machine is in a locked state, which is either a state where rotation has stopped or a state where rotation is at an extremely low speed. Equipped with, The aforementioned Y drive control is, With the changeover switch turned off, the second upper arm switch for each phase is fixed to ON and the second lower arm switch for each phase is fixed to OFF, or with the changeover switch turned off, the second lower arm switch for each phase is fixed to ON and the second upper arm switch for each phase is fixed to OFF, This is a control that drives the first upper arm switch and the first lower arm switch using PWM. In the above setting step, Based on a comparison of the magnitudes of the voltage command values ​​(Duty, Dutyv, Dutyw) applied to the armature windings of each phase and the carrier signal (Sgc), the control modes of the first upper arm switch and the first lower arm switch in the Y drive control are set. If it is determined that the system is locked during the execution of the Y drive control by the control step described above, an overheat protection control is implemented to suppress the occurrence of an overheating state in the system, A process to shift the voltage command value with respect to the fluctuation center value of the carrier signal, A process to return the shifted voltage command value to its original value, A control method for a rotating electric machine that performs switching control.

19. A rotating electric machine (40) having multiple phase armature windings (51U to 51W), A first inverter (20) has a number of first upper arm switches (SUHa to SWHa) and first lower arm switches (SULa to SWLa) connected in series for each phase, and the series connection of the first upper arm switches and the first lower arm switches is connected in parallel to a DC power supply (10), A second inverter (30) having a number of second upper arm switches (SUHb to SWHb) and second lower arm switches (SULb to SWLb) connected in series for each phase, In each phase, a positive-side busbar (11) electrically connects the high-potential terminal of the first upper arm switch and the high-potential terminal of the second upper arm switch, In each phase, a negative-side busbar (12) electrically connects the low-potential terminal of the first lower arm switch and the low-potential terminal of the second lower arm switch, A changeover switch (QH, QL) is provided on the target bus, which is at least one of the positive-side bus and the negative-side bus, In a control method for a rotating electric machine applied to a system comprising the following: In each phase, the low-potential terminal of the first upper arm switch and the high-potential terminal of the first lower arm switch are electrically connected to the first end of the armature winding. In each phase, the low-potential terminal of the second upper arm switch and the high-potential terminal of the second lower arm switch are electrically connected to the second end of the armature winding. When the changeover switch is turned on, it electrically connects the first inverter and the second inverter via the target bus, and when it is turned off, it disconnects the electrical connection between the first inverter and the second inverter via the target bus. A setting step to set 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 to Y drive control, A control step of controlling the first upper arm switch, the first lower arm switch, the second upper arm switch, and the second lower arm switch to the set control mode, During the control according to the control step described above, a step is taken to determine whether the rotor (41) of the rotating electric machine is in a locked state, which is either a state where rotation has stopped or a state where rotation is at an extremely low speed. Equipped with, The aforementioned Y drive control is, With the changeover switch turned off, the second upper arm switch for each phase is fixed to ON and the second lower arm switch for each phase is fixed to OFF, or with the changeover switch turned off, the second lower arm switch for each phase is fixed to ON and the second upper arm switch for each phase is fixed to OFF, This is a control that drives the first upper arm switch and the first lower arm switch using PWM. In the setting step, if it is determined that the system is locked during the execution of the Y drive control by the control step, the system performs an overheat protection control to suppress the occurrence of an overheating state by switching between upper arm neutral point control and lower arm neutral point control. The upper arm neutral point control is a control that, with the changeover switch turned off, fixes the second upper arm switch for each phase to the ON position and the second lower arm switch for each phase to the OFF position, while simultaneously driving the first upper arm switch and the first lower arm switch with PWM. A control method for a rotating electric machine, wherein the lower arm neutral point control is a control that, with the changeover switch turned off, fixes the second lower arm switch for each phase to the ON position and the second upper arm switch for each phase to the OFF position, and drives the first upper arm switch and the first lower arm switch using PWM.