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

Abstract

A control device (70) comprises: a request determining unit (86) that determines whether or not there is a system heat generation request; and a switch control unit (84) that, when it is determined that there is a heat generation request, performs switching control of first upper and lower arm switches (SUHa to SWHa, SULa to SWLa) and second upper and lower arm switches (SUHb to SWHb, SULb to SWLb) so as to satisfy a first condition and a second condition. The first condition is the condition that the voltage of a positive polarity DC power source (10) and the voltage of a negative polarity DC power source are alternately applied to armature windings (51U to 51W). The second condition is the condition that the proportion of a period (K2) overlapping a period (K1) is 0.75 or more and 1 or less, where the period (K2) is a period, in one switching cycle (Tsw), in which a zero voltage is applied to the armature windings from a second inverter (30) and the period (K1) is a period, in the one switching cycle, in which the voltage of the positive polarity DC power source is applied to the armature windings from a first inverter (20).

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. 2023-219446 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] Patent No. 7235588

[0005] There is still room for improvement in the technology for increasing the amount of heat produced in the above systems.

[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 increase the amount of heat generated.

[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 request determination unit that determines whether there is a heat generation request for the system; and a switch control unit that, when it is determined that there is a heat generation request, performs switching control of the first upper arm switch, the first lower arm switch, the second upper arm switch, and the second lower arm switch so as to satisfy a first condition and a second condition.

[0008] The switch control unit sets, as the first condition, a condition that a positive polarity voltage of the DC power supply and a negative polarity voltage of the DC power supply are alternately applied to the armature winding, and sets, as the second condition, a condition that a ratio of a period in one switching period in which a zero voltage is applied from the second inverter to the armature winding, which overlaps with a period in one switching period in which the positive polarity voltage of the DC power supply is applied from the first inverter to the armature winding, is 0.75 or more and 1 or less.

[0009] According to the first condition, the fluctuation of the voltage difference between both ends of the armature winding can be increased, and the current ripple flowing through the armature winding increases, which in turn increases the iron loss of the rotating electric machine and the heat generated by the rotating electric machine.

[0010] According to the second condition, the effective value of the current flowing through the armature winding can be increased, and the copper loss of the rotating electric machine can be increased, which in turn increases the heat generated by the rotating electric machine.

[0011] According to the present disclosure described above, it is possible to increase the heat generated in the rotating electric machine.

[0012] The first and second conditions can also be set as follows.

[0013] The switch control unit sets, as the first condition, a condition that one switching cycle of the first upper arm switch, the first lower arm switch, the second upper arm switch, and the second lower arm switch is the same cycle; a first period in which the first upper arm switch is turned off and the first lower arm switch is turned on in one switching cycle, and a second period in which the second upper arm switch is turned on and the second lower arm switch is turned off in one switching cycle, are the same period; a third period in which the first upper arm switch is turned on and the first lower arm switch is turned off in one switching cycle, and a period in which the second upper arm switch is turned off and the second lower arm switch is turned on in one switching cycle, are the same period; and at least a portion of the second period overlaps with the first period; and the switch control unit sets, as the second condition, a condition that the phase difference between the center timing of the second period and the center timing of the third period is 120° or more and 180° or less.

[0014] 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 diagram showing a cooling device, Fig. 3 is a functional block diagram of control processing executed by a control device, Fig. 4 is a diagram showing a control mode of H drive control, Fig. 5 is a diagram showing a control mode of Y drive control, Fig. 6 is a flowchart of control processing executed by the control device, Fig. 7 is a diagram showing calculation results of the relationship between the phase current effective value, the capacitor current ripple effective value, and the carrier phase difference, Fig. 8 is a time chart showing each waveform when the carrier phase difference is 0°, Fig. 9 is a time chart showing each waveform when the carrier phase difference is 120°, and Fig. 10 is a time chart showing each waveform when the carrier phase difference is 180°. FIG. 11 is a flowchart of the control process executed by the control device according to the second embodiment. FIG. 12 is a diagram showing the calculation results of the relationship between the phase current effective value, the capacitor current ripple effective value, and the carrier phase difference. FIG. 13 is a time chart showing the waveforms when the carrier phase difference is 180° according to the third embodiment. FIG. 14 is a time chart showing the waveforms when the carrier phase difference is 120°. FIG. 15 is a time chart showing the waveforms when the carrier phase difference is 0°. FIG. 16 is an overall configuration diagram of a control system according to another embodiment. FIG. 17 is a diagram showing the control mode of Y drive control according to another embodiment.

[0015] 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.

[0016] 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.

[0017] 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.

[0018] 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 .

[0019] 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.

[0020] 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.

[0021] 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.

[0022] 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.

[0023] 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.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] The control system 100 includes a changeover switch 13. The changeover switch 13 is provided on the positive bus 11 (corresponding to the "target bus"). The changeover switch 13 is, for example, a semiconductor switching element or a mechanical relay. When the changeover switch 13 is turned on, the changeover switch 13 electrically connects the collectors of the upper phase arm switches SUHa, SVHa, and SWHa of the first inverter 20 to the collectors of the upper phase arm switches SUHb, SVHb, and SWHb of the second inverter 30. When the changeover switch 13 is turned off, the changeover switch 13 electrically disconnects the collectors of the upper phase arm switches SUHa, SVHa, and SWHa of the first inverter 20 from the collectors of the upper phase arm switches SUHb, SVHb, and SWHb of the second inverter 30.

[0028] The changeover switch 13 may be, for example, an IGBT. In this case, a freewheel diode is connected in anti-parallel to the changeover switch 13. The collector of the IGBT is connected to the first inverter 20 side, and the emitter of the IGBT is connected to the second inverter 30 side.

[0029] As shown in FIG. 2 , the control system 100 includes a cooling device that cools the first and second inverters 20, 30, the rotating electric machine 40, and the battery 10 when switching control of the first and second inverters 20, 30 is performed to run the vehicle. Specifically, the cooling device includes a circulation path 200 through which coolant circulates, an electric water pump 201, a radiator 202, and an electric fan 203. The water pump 201 is powered and driven to circulate the coolant. In the example shown in FIG. 2 , the first inverter 20, the second inverter 30, the rotating electric machine 40, and the battery 10 are arranged in this order downstream of the water pump 201 in the circulation path 200. Note that the arrangement order of the devices in the circulation path 200 is not limited to the order shown in FIG. 2 .

[0030] A radiator 202 is provided in circulation path 200 between water pump 201 and battery 10. Radiator 202 cools the coolant flowing in through circulation path 200 and supplies the cooled coolant to water pump 201. The coolant flowing into radiator 202 is cooled by wind blown against radiator 202 as the vehicle travels and wind blown against radiator 202 by rotating fan 203.

[0031] In this embodiment, the circulation path 200, the coolant circulating through the circulation path 200, and the water pump 201 correspond to a "heat transfer unit."

[0032] Returning to the explanation of FIG. 1, the control system 100 includes a current sensor 60 , a rotation angle sensor 61 , a voltage sensor 62 , an inverter temperature sensor 63 , a motor temperature sensor 64 , a water temperature sensor 65 , and a battery temperature sensor 66 .

[0033] 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.

[0034] 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 inverter temperature sensor 63 detects the temperatures of the first inverter 20 and the second inverter 30. For example, the inverter temperature sensor 63 detects the temperatures of the switches SUHa to SWLa and SUHb to SWLb that constitute each inverter 20, 30 as the temperatures of the first and second inverters 20, 30.

[0035] The motor temperature sensor 64 detects the temperature of the rotating electrical machine 40. The motor temperature sensor 64 detects, for example, the temperatures of the armature windings 51U to 51W. The water temperature sensor 65 detects the temperature of the cooling water circulating through the circulation path 200. The battery temperature sensor 66 detects the temperature of the battery 10.

[0036] The detection values ​​of the sensors 60 to 66 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.

[0037] 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. 3 and 6, which will be described later.

[0038] 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.

[0039] The water pump 201 and the fan 203 may be driven by a control device separate from the control device 70. However, in this embodiment, for convenience, it is assumed that the water pump 201 and the fan 203 are driven by the control device 70.

[0040] In order to control the control variable of the rotary electric machine 40 to the command value, the control device 70 controls the changeover switch 13, the switches SUHa to SWLa of the first inverter 20, and the switches SUHb to SWLb of the second inverter 30 to turn on or off while the power switch 14 is on. In this embodiment, the control variable is torque.

[0041] FIG. 3 is a block diagram showing the control process of the rotating electrical machine 40 executed by the control device 70. As shown in FIG.

[0042] 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 .

[0043] 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.

[0044] 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.

[0045] 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.

[0046] The switch control unit 84 selects whether the drive state of the control system 100 should be Y drive control or H drive control. The switch control unit 84 may select either of the Y drive control and H drive control based on, for example, the electrical angular velocity ωr calculated based on the electrical angle θr and the operating point of the rotating electric machine 40 determined by the command torque Trq*.

[0047] The carrier generating unit 85 generates a carrier signal for generating drive signals for the switches SUHa to SWLa and SUHb to SWLb of the first and second inverters 20 and 30. In this embodiment, the carrier signal is a triangular wave signal with equal increasing and decreasing speeds. The drive signals are comprised of switch on and off commands.

[0048] The switch control unit 84 generates drive signals for the switches SUHa to SWLa and SUHb to SWLb of the first and second inverters 20 and 30 based on the U-, V-, and W-phase voltage command values ​​Vu*, Vv*, and Vw*, the power supply voltage Vsr, which is the voltage detected by the voltage sensor 62, and the generated carrier signal.

[0049] Specifically, the switch control unit 84 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. 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 half the power supply voltage Vsr.

[0050] 4, the switch control unit 84 turns on the selector switch 13 to PWM-drive the switches SUHa to SWLa of the first inverter 20 and PWM-drive the switches SUHb to SWLb of the second inverter 30. The switch control unit 84 generates drive signals for the switches SUHa to SWLa and SUHb to SWLb of the first and second inverters 20 and 30 based on a magnitude comparison between the U-, V-, and W-phase normalized command values ​​Dutyu, Dutyv, and Dutyw and the carrier signal.

[0051] On the other hand, when Y drive control is selected, the switch control unit 84 turns off the selector switch 13 and controls the switches SUHa to SWLa of the first inverter 20 to be PWM-driven, as shown in FIG. 5 . The switch control unit 84 also fixes the upper arm switches SUHb, SVHb, and SWHb of the second inverter 30 to be on, and fixes the lower arm switches SULb, SVLb, and SWLb of the second inverter 30 to be off. This results in a star connection of the phase windings 51U, 51V, and 51W via the second inverter 30. The switch control unit 84 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.

[0052] Based on the generated drive signal, the switch control unit 84 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 on / off of the switches SUHa to SWLa and SUHb to SWLb of the first and second inverters 20 and 30 is controlled in accordance with the drive signal.

[0053] The request determination unit 86 determines whether or not there is a heat generation request from the control system 100. In this embodiment, the request determination unit 86 determines that there is a heat generation request when it determines that the battery temperature Tbat detected by the battery temperature sensor 66 is lower than the target temperature.

[0054] When the control device 70 determines that there is a heat generation request, it performs temperature increase control to increase the heat generated by the rotating electrical machine 40. The control device 70 drives the water pump 201 so that the heat generated by the temperature increase control is transferred to the battery 10, which is the target for temperature increase, via the coolant in the circulation path 200. The control device 70 continues the temperature increase control, for example, until the battery temperature Tbat reaches a target temperature. The temperature increase control is one aspect of H drive control. The temperature increase control quickly increases the temperature of the battery 10, thereby shortening the charging time of the battery 10 using an external charger, for example.

[0055] Fig. 6 is a flowchart of the control process of the rotating electric machine 40 executed by the control device 70. The process shown in Fig. 6 is a process when two carrier signals Sg1, Sg2 are used. The process shown in Fig. 6 is repeatedly executed by the processor 71 of the control device 70, for example, at a predetermined control period.

[0056] In step S10, the request determination unit 86 determines whether or not there is a heat generation request.

[0057] If it is determined that there is no heat generation request, the process proceeds to step S11, where the phase difference β between the first carrier signal Sg1 and the second carrier signal Sg2 generated by the carrier generator 85 is set to 0°. The first carrier signal Sg1 is a signal for generating drive signals for the switches SUHa to SWLa of the first inverter 20. The second carrier signal Sg2 is a signal for generating drive signals for the switches SUHb to SWLb of the second inverter 30.

[0058] The maximum value, minimum value, amplitude, and period of the first carrier signal Sg1 are the same as those of the second carrier signal Sg2, and therefore one switching period Tsw of each of the switches SUHa to SWLa and SUHb to SWLb is the same period.

[0059] The switch control unit 84 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.

[0060] The switch control unit 84 calculates U-, V-, and W-phase inversion command values ​​1-Dutyu, 1-Dutyv, and 1-Dutyw, which are values ​​obtained by subtracting the U-, V-, and W-phase normalized command values ​​Dutyu, Dutyv, and Dutyw from 1 (100%). The switch control unit 84 generates drive signals for the switches SUHb to SWLb of the second inverter 30 based on a magnitude comparison between the calculated U-, V-, and W-phase inversion command values ​​1-Dutyu, 1-Dutyv, and 1-Dutyw and the second carrier signal Sg2.

[0061] The switching patterns of the switches of the inverters 20 and 30, which are switched in accordance with the drive signals, are shifted in phase by 120° electrical angle in each phase.

[0062] FIG. 8 shows the transitions of each waveform when the phase difference β is 0°. FIG. 8 shows the waveforms for only one phase in the control system 100. In FIG. 8, (a) shows the transitions of the second carrier signal Sg2 and the inversion command value 1-Duty, and (b) shows the transitions of the first carrier signal Sg1 and the standardized command value Duty. (c) shows the transitions of the second voltage V2, which is the voltage on the second inverter 30 side of the winding, and (d) shows the transitions of the first voltage V1, which is the voltage on the first inverter 20 side of the winding. (e) shows the phase currents Iu, Iv, and Iw flowing through the respective phase windings 51U, 51V, and 51W. (f) shows the transitions of the input current flowing from the battery 10 to the first inverter 20 side. (g) shows the transitions of the current flowing through the capacitor 15.

[0063] Referring to the first and second voltages V1 and V2 in Figure 8, the first upper arm switch, the first lower arm switch, the second upper arm switch, and the second lower arm switch are switched on and off once each in one switching period Tsw.

[0064] 6, if it is determined in step S10 that there is a heat generation request, the process proceeds to step S13, where the phase difference β is set to 180° to perform temperature increase control. This setting is for increasing the heat generated by the rotating electrical machine 40.

[0065] 7 shows the calculation results of the relationship between the effective value of the phase current flowing through the windings, the effective value of the current ripple flowing through the capacitor 15, and the phase difference β. By setting the phase difference β in the range Ra of 120° or more and 180° or less, the current ripple flowing through the windings increases. As a result, the iron loss of the rotating electric machine 40 can be increased, and the heat generated by the rotating electric machine 40 can be increased.

[0066] Furthermore, by setting the phase difference β within the range Ra, the effective value of the current flowing through the windings increases, which in turn increases the copper loss of the rotating electrical machine 40 and the heat generated by the rotating electrical machine 40.

[0067] Furthermore, by setting the phase difference β within the range Ra, the current ripple flowing through the capacitor 15 increases, which in turn increases the heat generated by the capacitor 15. When the capacitor 15 is built into the first inverter 20, the heat transferred to the battery 10 can be increased.

[0068] 9 and 10 show the transition of each waveform when the phase difference β is 120° and 180°. Figures 9 and 10 correspond to Figure 8.

[0069] Setting the phase difference β within the range Ra increases the effective current value and other factors because it increases the amount of fluctuation in the voltage difference between both ends of each phase winding 51U, 51V, 51W. As shown in Figures 9 and 10, at least a portion of the period during which the second voltage V2 is positive (e.g., 300 V) overlaps with the period during which the first voltage V1 is zero. As a result, the positive battery 10 voltage (e.g., 300 V) and the negative battery 10 voltage (e.g., -300 V) are alternately applied to each phase winding 51U, 51V, 51W.

[0070] 9 and 10 , the period during which the first voltage V1 has a positive polarity in one switching period Tsw is defined as K1, and the period during which zero voltage is applied from the second inverter 30 to the windings 51U, 51V, and 51W in one switching period Tsw is defined as K2. In this case, when examining the relationship between the ratio (= K2 / K1) of the period K2 that overlaps with the period K1 and the phase difference β, the ratio is 1 when the phase difference β is 1. Furthermore, the range of "120°≦β≦180°" corresponds to the range of "0.75≦ratio≦1." When the phase difference β is 180°, the ratio is 1.

[0071] Instead of setting the phase difference β to 180°, the control device 70 may set it to, for example, "120°≦β<180°," "140°≦β<180°," "160°≦β<180°," or "170°≦β<180°." Furthermore, instead of setting the ratio to 1, the control device 70 may set it to, for example, "0.75≦ratio<1," "0.8≦ratio<1," "0.85≦ratio<1," "0.9≦ratio<1," or "0.95≦ratio<1."

[0072] Instead of defining the switching pattern of each of the switches SUHa to SWLb by the phase difference β of the carrier signals, the switching pattern can also be defined as follows.

[0073] As shown in Figures 9 and 10, first to fourth periods L1 to L4 are set. The first period L1 is a period during which the first upper arm switch is turned off and the first lower arm switch is turned on in one switching period Tsw. The second period L2 is a period during which the second upper arm switch is turned on and the second lower arm switch is turned off in one switching period Tsw. The third period L3 is a period during which the first upper arm switch is turned on and the first lower arm switch is turned off in one switching period Tsw. The fourth period L4 is a period during which the second upper arm switch is turned off and the second lower arm switch is turned on in one switching period Tsw.

[0074] The control device 70 sets a switching pattern in which the first period L1 and the second period L2 are the same period, and the third period L3 and the fourth period L4 are the same period. The control device 70 sets a switching pattern in which at least a portion of the second period L2 overlaps with the first period L1.

[0075] The control device 70 sets a switching pattern that sets the phase difference α between the center timing ta of the second period L2 and the center timing tb of the third period L3 to be 120° or more and 180° or less. The phase difference α has the same value as the phase difference β of the carrier signal. Therefore, by setting the phase difference α to 180°, the amount of heat generated can be suitably increased.

[0076] In addition, instead of setting the phase difference α to 180°, the control device 70 may set it to, for example, "120°≦α<180°", "140°≦α<180°", "160°≦α<180°", or "170°≦α<180°".

[0077] According to the present embodiment described above, it is possible to increase the heat generated in the rotating electrical machine.

[0078] Second Embodiment A second embodiment will be described below with reference to the drawings, focusing on differences from the first embodiment. In this embodiment, the control modes that are set when it is determined that there is a heat generation request include a motor heat generation mode.

[0079] 11 is a flowchart showing the control process of the rotary electric machine 40 executed by the control device 70. The process shown in FIG. 11 is repeatedly executed by the processor 71, for example, at a predetermined control period.

[0080] If it is determined in step S10 that there is a heat generation request, the process proceeds to step S13, where it is determined whether to select the second mode. In this embodiment, if it is determined that the temperature of the capacitor 15 exceeds the temperature threshold, the second mode is selected. The temperature threshold is set to prevent the capacitor 15 from overheating, and is set to, for example, the upper limit temperature allowable for the capacitor 15. The temperature of the capacitor 15 compared with the temperature threshold may be a value detected by a sensor that detects the temperature of the capacitor 15, or an estimated temperature value of the capacitor 15.

[0081] If the determination in step S13 is negative, the process proceeds to step S12. Note that the control executed in step S12 with the phase difference β set to 180° corresponds to the "first mode."

[0082] If the determination in step S13 is affirmative, the process proceeds to step S14, where the phase difference β is set to 90° to execute the second mode.

[0083] 12, like FIG. 7, shows the calculation results of the relationship between the effective value of the phase current flowing through the winding, the effective value of the current ripple flowing through the capacitor 15, and the phase difference β.

[0084] The range Rb of the phase difference β, in which the ripple current in the capacitor 15 is equal to or less than the effective value when the phase difference β is 0°, is from 65° to 105°. By setting the phase difference β within the range Rb, it is possible to perform temperature rise control while reducing the effective value of the ripple current in the capacitor 15. In particular, when the phase difference β is 90°, the effective value of the ripple current is minimized.

[0085] In addition, instead of setting the phase difference β in the second mode to 90°, the control device 70 may set it to, for example, "65°≦β<90°", "75°≦β<90°", "80°≦β<90°", "85°≦β<90°", "90°<β≦95°", "90°<β≦100°", or "90<β≦105°".

[0086] Third Embodiment The first and second embodiments will be described below with reference to the drawings, focusing on differences from the first embodiment. This embodiment is characterized by the detection timing of the detection value of the current sensor 60 used to calculate the d-axis and q-axis current values ​​Idr and Iqr in the two-phase conversion unit 81 (corresponding to the "current detection unit").

[0087] Figure 13 shows the transitions of each waveform when the phase difference β is 180°. In Figure 13, (a) shows the transitions of first and second carrier signals Sg1 and Sg2. (b), (c), and (d) show the transitions of first U-, V-, and W-phase voltages Vu1, Vv1, and Vw1, which are voltages on the first inverter 20 side of U-, V-, and W-phase windings 51U, 51V, and 51W. (e), (f), and (g) show the transitions of second U-, V-, and W-phase voltages Vu2, Vv2, and Vw2, which are voltages on the second inverter 30 side of U-, V-, and W-phase windings 51U, 51V, and 51W. (h), (i), and (j) show the transitions of the U-, V-, and W-phase voltage differences ΔVu, ΔVv, and ΔVw, respectively, which are obtained by subtracting the second U-, V-, and W-phase voltages Vu2, Vv2, and Vw2 from the first U-, V-, and W-phase voltages Vu1, Vv1, and Vw1. (k) shows the phase currents Iu, Iv, and Iw flowing through the respective phase windings 51U, 51V, and 51W.

[0088] When H drive control is executed, the zero-phase voltages of the phase windings 51U, 51V, and 51W are maximum during the first zero vector period TV70 and the second zero vector period TV07 shown in Fig. 13. The first zero vector period TV70 is a period during which the upper arm switches SUHa, SVHa, and SWHa of the first inverter 20 and the lower arm switches SULb, SVLb, and SWLb of the second inverter 30 are turned on, and the other switches SULa, SVLa, SWLa, SUHb, SVHb, and SWHb are turned off. The second zero vector period TV07 is a period during which the lower arm switches SULa, SVLa, and SWLa of the first inverter 20 and the upper arm switches SUHb, SVHb, and SWHb of the second inverter 30 are turned on, and the other switches SUHa, SVHa, SWHa, SULb, SVLb, and SWLb are turned off. The zero-phase sequence voltage is maximum when the phase difference β is 180°.

[0089] When a zero-phase sequence voltage occurs, a zero-phase sequence current flows through each of the phase windings 51U, 51V, and 51W. The zero-phase sequence current generates current ripples of the same phase in each of the phase windings 51U, 51V, and 51W, as shown in FIG. 13(k). The current ripples increase the detection error of the current sensor 60. To reduce the detection error, it is necessary to detect the current when the ripple current is zero or close to zero.

[0090] In the case of an inductive load such as the armature winding of the rotating electric machine 40, the phase of the current ripple lags behind the phase of the zero-phase voltage by 90° in electrical angle. Taking this into consideration, the two-phase conversion unit 81 uses the detection values ​​of the current sensor 60 detected at the center timing Tsp of each of the first zero vector period TV70 and the second zero vector period TV07. At the center timing, the zero-phase current ripple becomes zero or close to zero, thereby suppressing the influence of the zero-phase current and reducing current detection errors. The control device 70 uses the method of this embodiment to determine the detection timing of the current used to control the rotating electric machine 40 in the processes of FIGS. 6 and 11 . The two-phase conversion unit 81 may determine the current detection timing based on, for example, the amount of change in the electrical angle θr from the timing at which either one of the carrier signals Sg1 and Sg2 reaches its maximum or minimum value. Incidentally, the two-phase conversion unit 81 may use the center timing Tsp of either the first zero vector period TV70 or the second zero vector period TV07 as the current detection timing.

[0091] 14 and 15 show the transition of each waveform when the phase difference β is 120° and 0°. When the phase difference β becomes smaller, the appearance period of each zero vector period TV70 and TV07 becomes shorter.

[0092] Other Embodiments The above-described embodiments may be modified as follows.

[0093] As shown in FIG. 16 , the control system 100 may include a second changeover switch 16 in addition to the first changeover switch 13. The second changeover switch 16 is provided on the negative bus 12. The second changeover switch 16 is, for example, a semiconductor switching element or a mechanical relay. When turned on, the second changeover switch 16 electrically connects the emitters of the lower phase arm switches SULa, SVLa, and SWLa of the first inverter 20 to the emitters of the lower phase arm switches SULb, SVLb, and SWLb of the second inverter 30. When turned off, the second changeover switch 16 electrically disconnects the emitters of the lower phase arm switches SULa, SVLa, and SWLa of the first inverter 20 from the emitters of the lower phase arm switches SULb, SVLb, and SWLb of the second inverter 30. The second changeover switch 16 may be, for example, an IGBT. In this case, a freewheel diode is connected in anti-parallel to the second changeover switch 16. The collector of the IGBT is connected to the second inverter 30 side, and the emitter of the IGBT is connected to the first inverter 20 side.

[0094] When H drive control is selected, the control device 70 turns on the first changeover switch 13 and the second changeover switch 16. On the other hand, when Y drive control is selected, the control device 70 turns off the first changeover switch 13 and the second changeover switch 16. In Y drive control, as shown in Fig. 17 , the control device 70 fixes the upper arm switches SUHb, SVHb, and SWHb of each phase of the second inverter 30 to off, and fixes the lower arm switches SULb, SVLb, and SWLb of the second inverter 30 to on. Note that in the configuration in which the control of Fig. 17 is performed, the first changeover switch 13 does not have to be provided in the control system 100.

[0095] In step S13 of FIG. 11 in the second embodiment, the second mode may be selected if it is determined that the detected value Tinv of the inverter temperature sensor 63 or the detected value Tmt of the motor temperature sensor 64 exceeds the temperature threshold value.

[0096] The control system 100 does not have to be provided with a changeover switch. In this case, the control system is a system that is always in the H drive state.

[0097] The target to be heated by the temperature rise control may be, for example, the coolant in the circulation path 200. If the vehicle is equipped with an air conditioning system that uses the coolant as a heat source for heating the passenger compartment, the temperature of the heating heat source can be quickly raised by the temperature rise control. In this case, the control device 70 may determine that a heat generation request exists when, for example, it determines that the detected value Thw of the water temperature sensor 65 is lower than the target temperature.

[0098] The heat transfer unit is not limited to a unit that uses cooling water as a cooling fluid, and may be, for example, an air-cooled unit that uses gas (air) as a cooling fluid, or may be a metal heat sink. When a heat sink is used as the heat transfer unit, for example, the first and second inverters 20, 30 and the battery 10 may be provided on the heat sink.

[0099] 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.

[0100] The carrier signal is not limited to a triangular wave signal, but may be, for example, a sawtooth wave signal.

[0101] The DC power source is not limited to a battery, and may be, for example, a fuel cell.

[0102] The rotating electric machine is not limited to a permanent magnet field type synchronous machine, and may be, for example, an induction machine.

[0103] 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.

[0104] 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.

[0105] 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.

[0106] 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.

[0107] The following describes characteristic configurations extracted from the above-described embodiments. [Configuration 1] A rotating electric machine (40) having a multi-phase armature winding (51U to 51W); a first inverter (20) having first upper arm switches (SUHa to SWHa) and first lower arm switches (SULa to SWLa) connected in series for the number of phases, the series-connected body of the first upper arm switches and the first lower arm switches being connected in parallel to a DC power source (10); a second inverter (30) having second upper arm switches (SUHb to SWHb) and second lower arm switches (SULb to SWLb) connected in series for the number of phases; a positive bus (11) for each phase electrically connecting a high potential side terminal of the first upper arm switch and a high potential side terminal of the second upper arm switch; and a negative bus (12) for each phase electrically connecting a low potential side terminal of the first lower arm switch and a low potential side terminal of the second lower arm switch. a control device (70) for a rotating electric machine applied to a system including the above, wherein, in each phase, a low potential side terminal of the first upper arm switch and a high potential side terminal of the first lower arm switch are electrically connected to a first end of the armature winding, and in each phase, a low potential side terminal of the second upper arm switch and a high potential side terminal of the second lower arm switch are electrically connected to a second end of the armature winding; a request determination unit (86) that determines whether or not there is a heat generation request for the system; and a switch control unit (84) that, when it is determined that there is a heat generation request, performs switching control of the first upper arm switch, the first lower arm switch, the second upper arm switch, and the second lower arm switch so as to satisfy a first condition and a second condition, wherein the switch control unit sets, as the first condition, a condition that a voltage of the DC power supply having a positive polarity and a voltage of the DC power supply having a negative polarity are alternately applied to the armature winding, The control device for a rotating electric machine sets, as the second condition, a condition that a ratio of a period (K2) in one switching period (Tsw) in which a zero voltage is applied from the second inverter to the armature winding, which period (K1) in one switching period (Tsw) overlaps with a period (K1) in which a positive polarity voltage of the DC power supply is applied from the first inverter to the armature winding, is 0.75 or more and 1 or less. [Configuration 2]the switch control unit sets, as the first condition, the following conditions: setting one switching cycle of the first upper arm switch, the first lower arm switch, the second upper arm switch, and the second lower arm switch to the same cycle; setting a first period (L1) in one switching cycle in which the first upper arm switch is turned off and the first lower arm switch is turned on to the same period; setting a second period (L2) in one switching cycle in which the second upper arm switch is turned on and the second lower arm switch is turned off to the same period; setting a third period (L3) in one switching cycle in which the first upper arm switch is turned on and the first lower arm switch is turned off to the same period; and setting at least a part of the second period to overlap the first period. 2. The control device for a rotating electric machine according to configuration 1, wherein the switch control unit sets, as the second condition, a condition that a phase difference (α) between a center timing (ta) of the second period and a center timing (tb) of the third period is 120° or more and 180° or less. [Configuration 3] A rotating electric machine (40) having a multi-phase armature winding (51U to 51W); a first inverter (20) having first upper arm switches (SUHa to SWHa) and first lower arm switches (SULa to SWLa) connected in series for the number of phases, and a series connection of the first upper arm switches and the first lower arm switches connected in parallel to a DC power source (10); a second inverter (30) having second upper arm switches (SUHb to SWHb) and second lower arm switches (SULb to SWLb) connected in series for the number of phases; a positive side bus (11) electrically connecting a high potential side terminal of the first upper arm switch and a high potential side terminal of the second upper arm switch in each phase; and a negative side bus (12) electrically connecting a low potential side terminal of the first lower arm switch and a low potential side terminal of the second lower arm switch in each phase. In a control device (70) for a rotating electric machine applied to a system including the above, in each phase, a low potential side terminal of the first upper arm switch and a high potential side terminal of the first lower arm switch are electrically connected to a first end of the armature winding,In each phase, a low potential side terminal of the second upper arm switch and a high potential side terminal of the second lower arm switch are electrically connected to a second end of the armature winding, and the system comprises: a request determination unit (86) that determines whether or not there is a heat generation request for the system; and a switch control unit (84) that, when it is determined that there is a heat generation request, performs switching control of the first upper arm switch, the first lower arm switch, the second upper arm switch, and the second lower arm switch so as to satisfy a first condition and a second condition, wherein the switch control unit sets, as the first condition, one switching period of the first upper arm switch, the first lower arm switch, the second upper arm switch, and the second lower arm switch to be the same period, and sets a first period (L1) in which the first upper arm switch is turned off and the first lower arm switch is turned on in one switching period to be the same period, and a second period (L2) in which the second upper arm switch is turned on and the second lower arm switch is turned off in one switching period to be the same period, a third period (L3) in which the first upper arm switch is turned on and the first lower arm switch is turned off in one switching cycle, and a period (L4) in which the second upper arm switch is turned off and the second lower arm switch is turned on in one switching cycle, are set to the same period, a condition is set that at least a part of the second period overlaps with the first period, and the switch control unit sets, as the second condition, a condition that a phase difference (α) between a center timing (ta) of the second period and a center timing (tb) of the third period is 120° or more and 180° or less. [Configuration 4] The control device for a rotating electric machine according to Configuration 1 or 2, wherein the switch control unit sets, as the second condition, a condition that the ratio is 1. [Configuration 5] The control device for a rotating electric machine according to Configuration 2 or 3, wherein the switch control unit sets, as the second condition, a condition that the phase difference is 180°. [Configuration 6] When the request determination unit determines that there is a heat generation request, the request determination unit selects either a first mode or a second mode, and when the first mode is selected, the switch control unit performs the switching control so as to satisfy the first condition and the second condition,The control device for a rotating electric machine according to configuration 2 or 3, wherein, when the second mode is selected, the switching control is performed so as to satisfy the first condition and the third condition, and the third condition is set to be the third condition, that is, to set the phase difference to be equal to or greater than 65° and equal to or less than 105°. [Configuration 7] The control device for a rotating electric machine according to any one of configurations 2 to 6, further comprising: a current detection unit (81) that detects a current flowing through the armature winding at at least one of a center timing (Tsp) of a first zero vector period (TV70) in which the first upper arm switch of each phase and the second lower arm switch of each phase are turned on and the first lower arm switch of each phase and the second upper arm switch of each phase are turned off, and a center timing (Tsp) of a second zero vector period (TV07) in which the first upper arm switch of each phase and the second lower arm switch of each phase are turned off and the first lower arm switch of each phase and the second upper arm switch of each phase are turned on. [Configuration 8] The control device for a rotating electric machine according to any one of Configurations 1 to 7, wherein the system includes a heat transfer unit (200, 201) that transfers heat generated in the rotating electric machine, the first inverter, and the second inverter to a temperature-raising target (10).

[0108] 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 electrical machine (40) having a multi-phase armature winding (51U to 51W), a first inverter (20) having a number of series-connected first upper arm switches (SUHa to SWHa) and first lower arm switches (SULa to SWLa) corresponding to the number of phases, with the series connection of the first upper arm switches and the first lower arm switches being connected in parallel to a DC power supply (10), a second inverter (30) having a number of series-connected second upper arm switches (SUHb to SWHb) and second lower arm switches (SULb to SWLb) corresponding to the number of phases, a positive bus bar (11) electrically connecting the high-potential side terminals of the first upper arm switches and the high-potential side terminals of the second upper arm switches in each phase, and a negative bus bar (12) electrically connecting the low-potential side terminals of the first lower arm switches and the low-potential side terminals of the second lower arm switches in each phase. In a control device (70) for the rotating electrical machine applied to a system comprising: 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 the 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; a request determination unit (86) for determining whether there is a heat generation request for the system; and a switch control unit (84) for performing switching control of the first upper arm switch, the first lower arm switch, the second upper arm switch, and the second lower arm switch so as to satisfy a first condition and a second condition when it is determined that there is a heat generation request. The switch control unit sets, as the first condition, a condition that the voltage of the DC power supply with positive polarity and the voltage of the DC power supply with negative polarity are alternately applied to the armature winding, and sets, as the second condition, a condition that the ratio of a period (K2) in which a voltage of 0 is applied to the armature winding from the second inverter in one switching period to a period (K1) in which the voltage of the DC power supply with positive polarity is applied to the armature winding from the first inverter in one switching period and which overlaps with the period (K1) is 0.75 or more and 1 or less. A control device for a rotating electrical machine.

2. The switch control unit sets, as the first condition, the switching periods of the first upper arm switch, the first lower arm switch, the second upper arm switch, and the second lower arm switch to the same period, and sets a first period (L1) in which the first upper arm switch is turned off and the first lower arm switch is turned on in one switching period, and a second period (L2) in which the second upper arm switch is turned on and the second lower arm switch is turned off in one switching period to the same period, and sets a third period (L3) in which the first upper arm switch is turned on and the first lower arm switch is turned off in one switching period, and a period (L4) in which the second upper arm switch is turned off and the second lower arm switch is turned on in one switching period to the same period, and sets a condition that at least a part of the second period overlaps with the first period. The switch control unit sets, as the second condition, a condition that a phase difference (α) between the center timing (ta) of the second period and the center timing (tb) of the third period is 120° or more and 180° or less. The control device for a rotating electrical machine according to claim 1.

3. A rotating electrical machine (40) having a multi-phase armature winding (51U to 51W), a first inverter (20) having a number of series-connected first upper arm switches (SUHa to SWHa) and first lower arm switches (SUL a to SWL a) corresponding to the number of phases, and a series connection of the first upper arm switch and the first lower arm switch being connected in parallel to a DC power supply (10); a second inverter (30) having a number of series-connected second upper arm switches (SUHb to SWHb) and second lower arm switches (SULb to SWLb) corresponding to the number of phases; a positive bus bar (11) electrically connecting the high-potential side terminals of the first upper arm switch and the second upper arm switch in each phase; and a negative bus bar (12) electrically connecting the low-potential side terminals of the first lower arm switch and the second lower arm switch in each phase. In a control device (70) of a rotating electrical machine applied to a system, 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 a second end of the armature winding; a request determination unit (86) for determining whether there is a heat generation request for the system; and a switch control unit (84) for performing switching control of the first upper arm switch, the first lower arm switch, the second upper arm switch, and the second lower arm switch so as to satisfy a first condition and a second condition when it is determined that there is a heat generation request. The switch control unit sets, as the first condition, the same period for one switching cycle of the first upper arm switch, the first lower arm switch, the second upper arm switch, and the second lower arm switch, and sets the same period for a first period (L1) in which the first upper arm switch is turned off and the first lower arm switch is turned on in one switching cycle and a second period (L2) in which the second upper arm switch is turned on and the second lower arm switch is turned off in one switching cycle.A control device for a rotating electrical machine sets a third period (L3) in which the first upper arm switch is turned on and the first lower arm switch is turned off in one switching period, and a period (L4) in which the second upper arm switch is turned off and the second lower arm switch is turned on in one switching period to be the same period, and sets a condition that at least a part of the second period overlaps with the first period. The switch control unit sets, as the second condition, a condition that a phase difference (α) between a center timing (ta) of the second period and a center timing (tb) of the third period is 120° or more and 180° or less.

4. The switch control unit sets, as the second condition, a condition that the ratio is 1. The control device for a rotating electrical machine according to claim 1 or 2.

5. The switch control unit sets, as the second condition, a condition that the phase difference is 180°. The control device for a rotating electrical machine according to claim 2 or 3.

6. When the requirement determination unit determines that there is a heat generation requirement, it selects either the first mode or the second mode. When the first mode is selected, the switch control unit performs the switching control so as to satisfy the first condition and the second condition. When the second mode is selected, the switch control unit performs the switching control so as to satisfy the first condition and the third condition. As the third condition, a condition that the phase difference is 65° or more and 105° or less is set. The control device for a rotating electrical machine according to claim 2 or 3.

7. A control device for a rotating electrical machine according to claim 2 or 3, comprising a current detection unit (81) that detects a current flowing through the armature winding at least at one of the center timing (Tsp) of a first zero vector period (TV70) in which the first upper arm switch of each phase and the second lower arm switch of each phase are turned on and the first lower arm switch of each phase and the second upper arm switch of each phase are turned off, and the center timing (Tsp) of a second zero vector period (TV07) in which the first upper arm switch of each phase and the second lower arm switch of each phase are turned off and the first lower arm switch of each phase and the second upper arm switch of each phase are turned on.

8. The control device for a rotating electrical machine according to any one of claims 1 to 3, wherein the system is provided with a heat transfer unit (200, 201) that transfers heat generated in the rotating electrical machine, the first inverter, and the second inverter to a temperature-rising target (10).

9. A rotating electrical machine (40) having a multi-phase armature winding (51U to 51W), a first inverter (20) having a number of series-connected first upper arm switches (SUHa to SWHa) and first lower arm switches (SULa to SWLa) corresponding to the number of phases, and a series connection of the first upper arm switches and the first lower arm switches being connected in parallel to a DC power supply (10); a second inverter (30) having a number of series-connected second upper arm switches (SUHb to SWHb) and second lower arm switches (SULb to SWLb) corresponding to the number of phases; a positive bus bar (11) electrically connecting the high-potential side terminals of the first upper arm switches and the high-potential side terminals of the second upper arm switches in each phase; and a negative bus bar (12) electrically connecting the low-potential side terminals of the first lower arm switches and the low-potential side terminals of the second lower arm switches in each phase. In a program applied to a system including these components, 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 the first end of the armature winding, and in each phase, the low-potential side terminal of the second upper arm switch and the high-potential side terminal of the second lower arm switch are electrically connected to the second end of the armature winding. A processor (71) is caused to execute a process of determining whether there is a heat generation requirement for the system, and when it is determined that there is a heat generation requirement, a switching control process of performing switching control of the first upper arm switch, the first lower arm switch, the second upper arm switch, and the second lower arm switch so as to satisfy a first condition and a second condition. In the switching control process, as the first condition, a condition is set to alternately apply the voltage of the DC power supply with positive polarity and the voltage of the DC power supply with negative polarity to the armature winding. As the second condition, a condition is set such that the ratio of a period (K2) in which a voltage of 0 is applied to the armature winding from the second inverter in one switching period (Tsw) and that overlaps a period (K1) in which the voltage of the DC power supply with positive polarity is applied to the armature winding from the first inverter in one switching period is 0.75 or more and 1 or less.

10. A rotating electrical machine (40) having a multi-phase armature winding (51U to 51W), a first inverter (20) having a number of series-connected first upper arm switches (SUHa to SWHa) and first lower arm switches (SULa to SWLa) corresponding to the number of phases, with the series connection of the first upper arm switches and the first lower arm switches being connected in parallel to a DC power supply (10), a second inverter (30) having a number of series-connected second upper arm switches (SUHb to SWHb) and second lower arm switches (SULb to SWLb) corresponding to the number of phases, a positive bus bar (11) electrically connecting the high-potential terminals of the first upper arm switches and the high-potential terminals of the second upper arm switches in each phase, and a negative bus bar (12) electrically connecting the low-potential terminals of the first lower arm switches and the low-potential terminals of the second lower arm switches in each phase. In a control method for the rotating electrical machine applied to a system comprising these components, 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 step of determining whether there is a heat generation requirement for the system, and a control step of performing switching control of the first upper arm switch, the first lower arm switch, the second upper arm switch, and the second lower arm switch so as to satisfy a first condition and a second condition when it is determined that there is a heat generation requirement. In the control step, as the first condition, a condition is set to alternately apply the voltage of the DC power supply with positive polarity and the voltage of the DC power supply with negative polarity to the armature winding, and as the second condition, a condition is set such that the ratio of a period (K2) during which a voltage of 0 is applied to the armature winding from the second inverter in one switching period (Tsw) overlapping a period (K1) during which the voltage of the DC power supply with positive polarity is applied to the armature winding from the first inverter in one switching period is 0.75 or more and 1 or less. A control method for a rotating electrical machine.

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