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

Abstract

Provided is a control device (60) for a rotary electric machine, the control device being applied to a system (100) comprising: a rotary electric machine (40) having armature windings (51U, 51V, 51W) of a plurality of phases; a first inverter (20); a second inverter (30); a positive electrode-side bus bar (11); and a negative electrode-side bus bar (12). The control device (60) is provided with a phase operation unit (68, 79) that, if it was determined that short-circuit control is to be executed, changes the phase difference (Δθ) between the phase (θ1) of each phase voltage applied by the first inverter and the phase (θ2) of each phase voltage applied by the second inverter so as to increase the phase difference (Δθ).

Description

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

[0001] This application is based on Japanese Application No. 2023-219445, 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 control program for a rotating electric machine, 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. 6907171

[0005] Recently, electric vehicles generally employ a rotating electric machine and an inverter in their power units. In vehicles employing such a rotating electric machine and an inverter, as the rotational speed of the rotating electric machine increases, the back electromotive force (back EMF) generated in the coils by the magnetic flux of the rotating electric machine's permanent magnets can become greater than the voltage of the storage battery. Under these circumstances, if the inverter drive power supply for driving the inverter fails due to an accident or other reason, the inverter cannot operate, resulting in a full-phase shutdown and the generation of back EMF. As a result, even if both the upper and lower arm switches are turned off, high-voltage back EMF may be applied from the coils to the storage battery or an electrical load via diodes connected in parallel to the upper and lower arm switches. In this case, the high-voltage back EMF may cause problems such as damage to the storage battery. Furthermore, the back EMF may also generate unintended torque on the drive wheels.

[0006] Therefore, in recent electric vehicles, ASC (Active Short Circuit) control (also called short circuit control) is implemented in the event of an abnormality. ASC control turns on one of the upper and lower arm switches of all phases that make up the inverter and turns off the other. This prevents various problems caused by back electromotive force.

[0007] It is desirable to adopt this ASC control in systems that use the two inverters described above. However, it has been found that when ASC control is adopted, transient voltage changes occur, which may result in overcurrent.

[0008] A primary object of the present disclosure is to provide a control device for a rotating electric machine, a control program for a rotating electric machine, and a control method for a rotating electric machine that can prevent overcurrent when performing short-circuit control.

[0009] A first means for solving the above problem includes a rotating electric machine having a multi-phase armature winding, a first inverter having first upper arm switches and first lower arm switches connected in series for the same number of phases, and a series connection of the first upper arm switches and the first lower arm switches connected in parallel to a DC power source, a second inverter having second upper arm switches and second lower arm switches connected in series for the same number of phases, a positive side bus bar for electrically connecting, 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 low potential side terminal of the first lower arm switch and a low potential side terminal of the second lower arm switch. and a negative side busbar that electrically connects the terminals of the control device for a rotating electric machine, the control device comprising: a phase operation unit that, when it is decided to implement short-circuit control in which all of the first upper arm switches and the second upper arm switches are turned on and all of the first lower arm switches and the second lower arm switches are turned off, or all of the first upper arm switches and the second upper arm switches are turned off and all of the first lower arm switches and the second lower arm switches are turned on, changes the phase difference between the phase of each phase voltage applied by the first inverter and the phase of each phase voltage applied by the second inverter so as to increase the phase difference.

[0010] A second means for solving the above problem includes a rotating electric machine having a multi-phase armature winding, a first inverter having first upper arm switches and first lower arm switches connected in series for the same number of phases, and a series connection of the first upper arm switches and the first lower arm switches connected in parallel to a DC power source, a second inverter having second upper arm switches and second lower arm switches connected in series for the same number of phases, a positive side bus bar for electrically connecting, 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 low potential side terminal of the first lower arm switch and a low potential side terminal of the second lower arm switch. In a control program for a rotating electric machine executed by a control device for a rotating electric machine applied to a system including a negative side busbar connected to the first inverter, when it is determined to perform short-circuit control in which all of the first upper arm switches and the second upper arm switches are turned on and all of the first lower arm switches and the second lower arm switches are turned off, or all of the first upper arm switches and the second upper arm switches are turned off and all of the first lower arm switches and the second lower arm switches are turned on, a phase operation process is performed in which the phase difference between the phase of each phase voltage applied by the first inverter and the phase of each phase voltage applied by the second inverter is changed so as to increase.

[0011] A third means for solving the above problem includes a rotating electric machine having a multi-phase armature winding, a first inverter having first upper arm switches and first lower arm switches connected in series for the same number of phases, and a series connection of the first upper arm switches and the first lower arm switches connected in parallel to a DC power source, a second inverter having second upper arm switches and second lower arm switches connected in series for the same number of phases, a positive side bus bar for electrically connecting, 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 low potential side terminal of the first lower arm switch and a low potential side terminal of the second lower arm switch. In a control method for a rotating electric machine implemented by a rotating electric machine control device applied to a system including a negative side busbar connected to the first inverter, when it is decided to implement short-circuit control in which all of the first upper arm switches and the second upper arm switches are turned on and all of the first lower arm switches and the second lower arm switches are turned off, or all of the first upper arm switches and the second upper arm switches are turned off and all of the first lower arm switches and the second lower arm switches are turned on, the control method includes a phase operation process in which the phase difference between the phase of each phase voltage applied by the first inverter and the phase of each phase voltage applied by the second inverter is changed so as to increase.

[0012] According to the above means, when it is determined that short circuit control should be performed, the phase difference between the phase of each phase voltage applied by the first inverter and the phase of each phase voltage applied by the second inverter is increased. This prevents a sudden change in voltage even when short circuit control is performed, thereby suppressing the occurrence of overcurrent and thus preventing element damage.

[0013] The above and other objects, features, and advantages of the present disclosure will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which Fig. 1 is a diagram showing the configuration of a control system, Fig. 2 is a functional block diagram showing functions during current control, Fig. 3 is a functional block diagram showing functions during phase control, Fig. 4 is a diagram showing the state of phase current during short-circuit control in a comparative example, Fig. 5 is a diagram showing the relationship between time and phase difference, Fig. 6 is a flowchart of ASC transition processing, Fig. 7 is a diagram showing the relationship between phase difference and phase current during PWM control, Fig. 8 is a diagram showing the relationship between phase difference and phase current during overmodulation control, and Fig. 9 is a diagram showing the relationship between phase difference and phase current during square wave control. FIG. 10 is a diagram showing the state of the phase current during short circuit control in this embodiment, FIG. 11 is a diagram showing the relationship between the phase difference and the phase current in a modified example, FIG. 12 is a diagram showing the relationship between the phase difference and the phase current in a modified example, FIG. 13 is a diagram showing the relationship between the phase difference and the phase current in a modified example, FIG. 14 is a diagram showing a control device in a modified example, FIG. 15 is a diagram showing the relationship between time and phase difference in a modified example, and FIG. 16 is a diagram showing the relationship between time and phase difference in a modified example.

[0014] The present disclosure will now be described with reference to the drawings with respect to a control device, a control program, and a control method for a rotating electric machine. In the embodiments and the modifications, functionally and / or structurally corresponding and / or associated parts may be designated by the same reference numerals. For corresponding and / or associated parts, the description of the embodiments can be referenced.

[0015] The control device 60 for the rotating electric machine 40 of this embodiment is mounted on an electric vehicle such as an electric car or a hybrid car, and is applied to a control system 100 for the rotating electric machine 40 (hereinafter simply referred to as the control system 100).

[0016] As shown in FIG. 1, the control system 100 of this embodiment includes a battery 10, a first inverter 20, a second inverter 30, a rotating electric machine 40, and a control device 60 for the rotating electric machine (hereinafter, in the first embodiment, simply referred to as the control device 60).

[0017] The battery 10 is, for example, a battery pack including a series connection of unit cells, and is a DC power supply in this embodiment. 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 a U-phase first upper arm switch SUHa and a U-phase first lower arm switch SULa, a V-phase first upper arm switch SVHa and a V-phase first lower arm switch SVLa, and a W-phase first upper arm switch SWHa and a W-phase first lower arm switch SWLa. Hereinafter, these will be collectively referred to as switches SUHa to SWLa.

[0020] Similarly, the second inverter 30 includes a series connection of a U-phase second upper arm switch SUHb and a U-phase second lower arm switch SULb, a series connection of a V-phase second upper arm switch SVHb and a V-phase second lower arm switch SVLb, and a series connection of a W-phase second upper arm switch SWHb and a W-phase second lower arm switch SWLb. Hereinafter, these will be collectively referred to as switches SUHb to SWLb.

[0021] In this embodiment, voltage-controlled semiconductor switching elements, more specifically, IGBTs, are used as the switches SUHa to SWLa and SUHb to SWLb. In this embodiment, the high-potential terminal of each switch is the collector, and the low-potential terminal is the emitter. Freewheeling diodes DUHa, DVHa, DWHa, DULa, DVLa, DWLa, DUHb, DVHb, DWHb, DULb, DVLb, and DWLb are connected in anti-parallel to the switches SUHa, SVHa, SWHa, SULa, SVLa, SWLa, SUHb, SVHb, SWHb, SULb, SVLb, and SWLb, respectively.

[0022] The collectors of the first upper arm switches SUHa, SVHa, SWHa of each phase and the collectors of the second upper arm switches SUHb, SVHb, SWHb of each phase are electrically connected by a positive bus 11 serving as a high-potential side connecting line such as a bus bar. The emitters of the first lower arm switches SULa, SVLa, SWLa of each phase and the emitters of the second lower arm switches SULb, SVLb, SWLb of each phase are electrically connected by a negative bus 12 serving as a low-potential side connecting line such as a bus bar.

[0023] The positive terminal of the battery 10 is electrically connected to the positive bus 11, and the negative terminal of the battery 10 is electrically connected to the negative bus 12. The battery 10 is electrically connected to the buses 11, 12 on the opposite side of the first inverter 20 from the second inverter 30.

[0024] The rotating electric machine 40 is, for example, a main motor mounted on a vehicle. A rotor 41 of the rotating electric machine 40 is capable of transmitting power to drive wheels (not shown) 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 (for example, neodymium magnets) as field poles.

[0025] The rotating electric machine 40 includes a stator 50. The stator 50 includes armature windings, namely, a U-phase winding 51U, a V-phase winding 51V, and a W-phase winding 51W. The phase windings 51U, 51V, and 51W are arranged with an electrical angle of 120°. The phase windings 51U, 51V, and 51W are open-connected, and both ends of each phase winding 51U, 51V, and 51W are electrically connected to the first inverter 20 or the second inverter 30.

[0026] Specifically, in each phase, first ends 51Ua, 51Va, 51Wa of the windings 51U, 51V, 51W are electrically connected to first upper switches SUHa, SVHa, SWHa and first lower switches SULa, SVLa, SWLa of the corresponding phase. Also, second ends 51Ub, 51Vb, 51Wb of the windings 51U, 51V, 51W are electrically connected to second upper switches SUHb, SVHb, SWHb and second lower switches SULb, SVLb, SWLb of the corresponding phase.

[0027] The control system 100 includes a changeover switch 13. The changeover switch 13 is provided on the positive electrode side bus 11 between the first inverter 20 and the second inverter 30. When the changeover switch 13 is turned on, it electrically connects the first inverter 20 and the second inverter 30, and when turned off, it electrically disconnects the first inverter 20 and the second inverter 30. The changeover switch 13 is controlled by the control device 60. The changeover switch 13 is provided to switch the driving state of the control system 100, as will be described later.

[0028] For example, the changeover switch 13 is a semiconductor switching element such as an IGBT or a relay. When an IGBT is used as the changeover switch 13, a freewheel diode is connected in parallel to the changeover switch 13. In this case, the anode of the freewheel diode is electrically connected to the second inverter 30 side, and the cathode is electrically connected to the first inverter 20 side.

[0029] The control system 100 includes a power switch 14 as a power switch unit, and a capacitor 15. The power switch 14 is, for example, a semiconductor switching element or a relay. The power switch 14 is provided on the positive bus 11 between the positive terminal of the battery 10 and the first inverter 20. When the power switch 14 is turned on, it electrically connects the battery 10 and the rotating electric machine 40, and when it is turned off, it electrically disconnects the battery 10 and the rotating electric machine 40. The power switch 14 is driven by the control device 60.

[0030] A first end of the capacitor 15 is electrically connected to the positive bus 11 between the power switch 14 and the first inverter 20. A second end of the capacitor 15 is electrically connected to the negative bus 12 between the negative terminal of the battery 10 and the first inverter 20.

[0031] The control system 100 includes a current sensor 16 and a rotation angle sensor 17. The current sensor 16 detects phase currents Iu, Iv, and Iw flowing through the respective phase windings 51U, 51V, and 51W. In this embodiment, the current sensor 16 is provided at one of the ends of each phase winding 51U, 51V, and 51W closer to the first inverter 20. The sign of the detected value of the current sensor 16 is positive when the current flows from the first terminal 51Ua, 51Va, and 51Wa of each phase winding 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 16 may also be provided at one of the ends of each phase winding 51U, 51V, and 51W closer to the second inverter 30.

[0032] The rotation angle sensor 17 is, for example, a resolver, and detects the electrical angle θ of the rotor 41. The phase currents Iur, Ivr, and Iwr detected by the current sensor 16 and the electrical angle θr detected by the rotation angle sensor 17 are input to the control device 60.

[0033] The control system 100 includes a voltage sensor 18 that detects a system voltage Vsys between the positive bus 11 and the negative bus 12. The voltage sensor 18 is connected in parallel with the capacitor 15. That is, a first end of the voltage sensor 18 is electrically connected to the positive bus 11 between the power switch 14 and the first inverter 20. A second end of the voltage sensor 18 is electrically connected to the negative bus 12 between the negative terminal of the battery 10 and the first inverter 20. The detection result of the voltage sensor 18 is input to the control device 60. When the power switch 14 is turned on, the system voltage Vsys matches the power supply voltage of the battery 10, and when the power switch 14 is turned off, the system voltage Vsys matches the voltage across the capacitor 15.

[0034] The control device 60 is primarily composed of a microcomputer including a processing unit 60a such as a CPU and a storage unit 60b such as various types of memory. The functions provided by the microcomputer can be provided by software stored in a physical memory device and a computer executing the software, software alone, hardware alone, or a combination thereof. For example, when the microcomputer is provided by electronic circuits, which are hardware, the functions can be provided by digital circuits including numerous logic circuits or analog circuits. For example, the processing unit 60a of the microcomputer executes programs stored in a non-transitory tangible storage medium (non-transitory tangible storage medium) that serves as the storage unit 60b. The programs include, for example, control programs that realize the functions shown in Figures 2 and 3. Execution of a program (e.g., a control program) results in the execution of a method (e.g., a control method) corresponding to the program. The storage unit 60b is, for example, a non-volatile memory. The programs stored in the storage unit 60b can be downloaded and updated via a communication network such as the Internet, for example, via OTA (Over the Air).

[0035] The control device 60 has a function of switching the drive state of the control system 100 between a Y drive state and an H drive state by controlling the selector switch 13. The control device 60 sets the control system 100 to the Y drive state (first mode) by turning off the selector switch 13, turning on the second upper arm switches SUHb, SVHb, and SWHb of each phase, and turning off the lower arm switches SULb, SVLb, and SWLb of each phase. In the Y drive state, the phase windings 51U, 51V, and 51W are Y-connected via the second inverter 30. On the other hand, the control device 60 sets the control system 100 to the H drive state (second mode) by turning on the selector switch 13.

[0036] In the Y drive state, the control device 60 controls the switching of the switches SUHa to SWLa in the first inverter 20. In addition, in the H drive state, the control device 60 controls the switching of both the switches SUHa to SWLa in the first inverter 20 and the switches SUHb to SWLb in the second inverter 30. By appropriately switching between the Y drive state and the H drive state and executing switching control, the control system 100 can be made to have a high output and high efficiency.

[0037] The control device 60 has various functions for executing current control and phase control. These controls are executed at least in the H drive state. The control device 60 selects and executes either phase control or current control based on the operating conditions of the rotating electric machine 40. For example, the control device 60 executes current control when the modulation factor of the inverters 20, 30 is less than a predetermined threshold and PWM control is performed. On the other hand, the control device 60 executes phase control when the modulation factor of the inverters 20, 30 is equal to or greater than a predetermined threshold and overmodulation control or square wave control is performed. Note that the current control corresponds to current feedback control, and the phase control corresponds to torque feedback control.

[0038] First, the function for executing current control will be described with reference to Fig. 2. Current control is performed when PWM control is performed. Note that PWM control is performed, for example, when the modulation rate is less than a threshold, in a low rotation range and a low output range, etc. In this embodiment, the modulation rate of the first inverter 20 and the modulation rate of the second inverter 30 are the same.

[0039] 2 is a functional block diagram illustrating various functions for realizing current control. The various functions of the control device 60 are realized, for example, by the arithmetic processing unit 60a executing a program stored in the storage unit 60b.

[0040] As shown in FIG. 2, the control device 60 includes a current command generating unit 61, a dq conversion unit 62, a current control unit 63, a UVW conversion unit 64, and a modulation unit 65 as functions for executing current control.

[0041] The current command generating unit 61 receives a torque command value Trq* from a higher-level control device than the control device 60. Based on the received torque command value Trq*, the current command generating unit 61 calculates a d-axis current command value Id* and a q-axis current command value Iq* in a dq coordinate system using a torque-dq map or the like. Hereinafter, the d-axis current command value Id* and the q-axis current command value Iq* may be collectively referred to as d- and q-axis current command values ​​Id* and Iq*.

[0042] The dq converter 62 receives the phase currents Iur, Ivr, and Iwr detected by the current sensor 16 and the electrical angle θr detected by the rotation angle sensor 17. The dq converter 62 calculates a d-axis current value Idr and a q-axis current value Iqr based on the detected phase currents Iur, Ivr, and Iwr and the electrical angle θr. The d-axis current value Idr and the q-axis current value Iqr may be collectively referred to as the d- and q-axis current values ​​Idr and Iqr.

[0043] The current control unit 63 receives the difference between the d-axis and q-axis current command values ​​Id* and Iq* and the d-axis and q-axis current values ​​Idr and Iqr. More specifically, the current control unit 63 receives the 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 input d-axis current deviation to zero. The current control unit 63 also receives the 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 input q-axis current deviation to zero. The feedback control is, for example, proportional-plus-integral control.

[0044] The d- and q-axis voltage command values ​​Vd* and Vq* and the detected electrical angle θr are input to the UVW converter 64. Based on the input d- and q-axis voltage command values ​​Vd* and Vq* and the electrical angle θr, the UVW converter 64 calculates a U-phase voltage command value Vu*, a V-phase voltage command value Vv*, and a W-phase voltage command value Vw*. Hereinafter, these may be collectively referred to as the respective phase voltage command values ​​Vu*, Vv*, and Vw*.

[0045] The phase voltage command values ​​Vu*, Vv*, and Vw* are command values ​​for the phase voltages Vu, Vv, and Vw. In this embodiment, the signs of the phase voltages Vu, Vv, and Vw are positive when the potentials of the first terminals 51Ua, 51Va, and 51Wa of the windings 51U, 51V, and 51W are higher than the potentials of the second terminals 51Ub, 51Vb, and 51Wb of the windings 51U, 51V, and 51W, respectively, and negative when the potentials of the second terminals 51Ub, 51Vb, and 51Wb of the windings 51U, 51V, and 51W are higher than the potentials of the first terminals 51Ua, 51Va, and 51Wa of the windings 51U, 51V, and 51W.

[0046] The modulator 65 receives the phase voltage command values ​​Vu*, Vv*, and Vw* and the system voltage Vsys. The modulator 65 generates operation signals for the switches SUHa to SWLa of the first inverter 20 and operation signals for the switches SUHb to SWLb of the second inverter 30 based on the phase voltage command values ​​Vu*, Vv*, and Vw*, the system voltage Vsys, and a carrier signal. The carrier signal is, for example, a triangular wave signal. Based on the generated operation signals, switching control of the first inverter 20 and the second inverter 30 is performed. Note that phase correction may be performed by phase correctors 66a and 66b before the operation signals (switching signals) are input to the first inverter 20 and the second inverter 30. The phase correctors 66a and 66b will be described later.

[0047] Next, phase control will be described. This phase control is performed when overmodulation control or square wave control is performed. Square wave control is mainly used for the purpose of increasing the output power of the rotating electric machine 40 and reducing losses under operating conditions where the modulation rate is equal to or higher than a threshold value and the output voltage of each inverter 20, 30 is high, such as in high rotation ranges and high output ranges. On the other hand, overmodulation control is performed in medium rotation ranges and medium output ranges, where the modulation rate is equal to or higher than a threshold value. In other words, overmodulation control is performed in rotation ranges and output ranges higher than PWM control and in rotation ranges and output ranges lower than square wave control.

[0048] 3 is a functional block diagram for explaining various functions for realizing phase control. As shown in FIG. 3, the control device 60 includes, as functions for executing phase control, a current command generating unit 71, a dq conversion unit 72, a torque estimating unit 73, an amplitude control unit 74, a phase control unit 75, a modulation unit 76, and the like.

[0049] The current command generator 71 receives the torque command value Trq* and the electrical angular velocity ω obtained by time-differentiating the electrical angle θr as input, and calculates a d-axis current command value Id*. The current command generator 71 may be configured in the same manner as the current command generator 61. The dq transformer 72, like the dq transformer 62, calculates a d-axis current value Idr and a q-axis current value Iqr based on the respective phase currents Iur, Ivr, Iwr and the electrical angle θr.

[0050] The torque estimation unit 73 calculates the torque estimation value Te based on the d-axis current value Idr and the q-axis current value Iqr converted by the dq conversion unit 72. The torque estimation value Te is calculated based on, for example, map information or mathematical formula information that associates the d-axis current value Idr, the q-axis current value Iqr, and the torque estimation value Te.

[0051] The amplitude control unit 74 receives the deviation between the d-axis current command value Id* and the d-axis current value Idr, and, based on the deviation, calculates a voltage amplitude command Va, which is a command value for the amplitude of the output voltage vector of each inverter 20, 30. The voltage amplitude command Va is defined as the square root of the sum of the square of the d-axis voltage, which is the d-axis component of the output voltage vector in the dq coordinate system, and the square of the q-axis voltage, which is the q-axis component.

[0052] The phase control unit 75 receives the deviation between the torque command value Trq* and the torque estimate value Te, and, based on the deviation, calculates a voltage phase command Vθ that is a command value for the phase of the output voltage vector of each of the inverters 20, 30. For example, the phase control unit 75 calculates the voltage phase command Vθ using a PI feedback method based on the deviation of the torque estimate value Te from the torque command value Trq*.

[0053] The modulator 76 generates operation signals for the switches SUHa to SWLa of the first inverter 20 and operation signals for the switches SUHb to SWLb of the second inverter 30 based on the voltage amplitude command Va, the voltage phase command Vθ, and the system voltage Vsys. For example, the modulator 76 calculates phase voltage command values ​​Vu*, Vv*, and Vw* based on the voltage amplitude command Va, the voltage phase command Vθ, and the system voltage Vsys, and generates the operation signals by PWM control based on a magnitude comparison between signals obtained by normalizing the calculated phase voltage command values ​​Vu*, Vv*, and Vw* with the system voltage Vsys and a carrier signal such as a triangular wave signal. Alternatively, for example, the modulator 76 may refer to pulse pattern information, which is map information, and generate the operation signals based on the voltage amplitude command Va, the voltage phase command Vθ, and the power supply voltage Vdc. Note that the phases may be corrected by the phase correctors 77a and 77b before the operation signals are input to the first inverter 20 and the second inverter 30. The phase correctors 77a and 77b will be described later.

[0054] In addition to the normal drive control (PWM control, overmodulation control, and square wave control) described above, the control device 60 is configured to be able to perform abnormality control, which is performed to deal with the occurrence of an abnormality such as an overvoltage abnormality. The abnormality control is short-circuit control (ASC (Active Short Circuit) control) that turns on the upper arm switches SUHa, SVHa, SWHa, SUHb, SVHb, and SWHb and turns off the lower arm switches SULa, SVLa, SWLa, SULb, SVLb, and SWLb. Note that in the short-circuit control, the upper arm switches SUHa, SVHa, SWHa, SUHb, SVHb, and SWHb may be turned off and the lower arm switches SULa, SVLa, SWLa, SULb, SVLb, and SWLb may be turned on. The abnormality control will be described later.

[0055] However, when short circuit control is performed, an overcurrent may occur. This will be explained with reference to the comparative example in FIG. 4 . The upper part of FIG. 4 shows the phase current, the middle part shows the state of the ASC signal that notifies (instructs) the start of short circuit control, and the lower part shows the amplitude of the applied voltage. As shown in FIG. 4 , when the ASC signal is switched on, short circuit control is performed to turn on the upper arm switches SUHa, SVHa, SWHa, SUHb, SVHb, and SWHb and turn off the lower arm switches SULa, SVLa, SWLa, SULb, SVLb, and SWLb, resulting in a sudden change in the applied voltage. This may increase the phase current, potentially resulting in an overcurrent. Therefore, an abnormality control is configured as shown below.

[0056] First, the case where current control is performed will be described. As shown in Fig. 2, in addition to the functions described above, the control device 60 includes an abnormality detection unit 67, a phase operation unit 68, a short-circuit control unit 69, and phase correction units 66a and 66b.

[0057] The abnormality detection unit 67 receives detection values ​​such as the system voltage Vsys, the electrical angle θr, and the phase currents Iur, Ivr, and Iwr, and detects the occurrence of an abnormality if any one of these values ​​becomes an abnormal value. The abnormality detection method is not limited to this and may be changed as desired. For example, the abnormality detection unit 67 may detect an abnormality when an abnormality signal is received from an external higher-level control device. The abnormality detection unit 67 may be realized as software by the arithmetic processing unit 60a or may be configured as hardware. Furthermore, the abnormality detection unit 67 may be provided outside the control device 60. When the abnormality detection unit 67 detects an abnormality, it outputs an ASC signal to the phase operation unit 68 and the short-circuit control unit 69 to notify them of the implementation of short-circuit control.

[0058] When the ASC signal is input, the phase manipulation unit 68 determines to increase the phase difference Δθ between the phase θ1 of the phase voltage applied by the first inverter 20 and the phase θ2 of the phase voltage applied by the second inverter 30. The phase manipulation unit 68 then sets the phase difference Δθ based on predetermined map information or a formula. For example, as shown in FIG. 5 , the phase difference Δθ is set based on map information or a formula that gradually increases the phase difference Δθ every predetermined time from when short circuit control is determined (when the ASC signal is input). In FIG. 5 , the time t and the phase difference Δθ are directly proportional. The phase difference Δθ is set within a range from 0 degrees to 180 degrees. The phase manipulation unit 68 updates the phase difference Δθ every predetermined time until the phase difference Δθ reaches a predetermined maximum value (180 degrees in this embodiment).

[0059] Then, the phase manipulation unit 68 calculates a phase correction value θ1a for the phase θ1 of each phase voltage applied by the first inverter 20 and a phase correction value θ2a for the phase θ2 of each phase voltage applied by the second inverter 30 so as to achieve the set phase difference Δθ. Note that, as long as the set phase difference Δθ is achieved, only the phase θ1 may be advanced (or delayed), only the phase θ2 may be advanced (or delayed), or one of the phases θ1 and θ2 may be advanced and the other delayed.

[0060] The phase corrector 66a of the first inverter 20 receives a phase correction value θ1a and, based on the phase correction value θ1a, shifts (corrects) the phases of the operation signals of the switches SUHa to SWLa so that the phase θ1 of each phase voltage applied by the first inverter 20 shifts by the phase correction value θ1a. Similarly, the phase corrector 66b of the second inverter 30 receives a phase correction value θ2a and, based on the phase correction value θ2a, shifts (corrects) the phases of the operation signals of the switches SUHb to SWLb so that the phase θ2 of each phase voltage applied by the second inverter 30 shifts by the phase correction value θ2a. Each of the inverters 20, 30 performs switching control based on the phase-corrected operation signals received from the phase correctors 66a, 66b.

[0061] The short-circuit control unit 69 performs short-circuit control after a predetermined time has elapsed since the ASC signal was input, or after waiting for the phase difference Δθ to reach a predetermined phase difference (e.g., a maximum value). That is, it outputs operation signals to turn on the upper arm switches SUHa, SVHa, SWHa, SUHb, SVHb, and SWHb and to turn off the lower arm switches SULa, SVLa, SWLa, SULb, SVLb, and SWLb. This short-circuit control is performed with priority over other controls (normal drive controls such as current control). Whether the phase difference Δθ has reached the predetermined phase difference can be determined based on a notification from the phase operation unit 68 or by inputting the phase difference Δθ.

[0062] Next, the case where phase control is performed will be described. As shown in Fig. 3, in addition to the functions described above, the control device 60 includes an abnormality detection unit 78, a phase operation unit 79, a short-circuit control unit 80, and phase correction units 77a and 77b.

[0063] The abnormality detection unit 78 detects the occurrence of an abnormality in the same manner as the abnormality detection unit 67. When the abnormality detection unit 78 detects the occurrence of an abnormality, it outputs an ASC signal to the phase operation unit 79 to notify the implementation of short-circuit control.

[0064] When the phase manipulation unit 79 receives the ASC signal, it determines to increase the phase difference Δθ, similar to the phase manipulation unit 68. Then, the phase manipulation unit 79 sets the phase difference Δθ in the same manner as the phase manipulation unit 68.

[0065] Then, the phase manipulation unit 79 calculates a phase correction value θ1a for the phase θ1 of each phase voltage applied by the first inverter 20 and a phase correction value θ2a for the phase θ2 of each phase voltage applied by the second inverter 30 so that the set phase difference Δθ is achieved.

[0066] The phase corrector 77a of the first inverter 20 receives a phase correction value θ1a and, based on the phase correction value θ1a, shifts (corrects) the phases of the operation signals of the switches SUHa to SWLa so that the phase θ1 of each phase voltage applied by the first inverter 20 shifts by the phase correction value θ1a. Similarly, the phase corrector 77b of the second inverter 30 receives a phase correction value θ2a and, based on the phase correction value θ2a, shifts (corrects) the phases of the operation signals of the switches SUHb to SWLb so that the phase θ2 of each phase voltage applied by the second inverter 30 shifts by the phase correction value θ2a. Each of the inverters 20, 30 performs switching control based on the phase-corrected operation signals received from the phase correctors 77a, 77b.

[0067] The short circuit control unit 80 performs short circuit control after a predetermined time has elapsed since the ASC signal was input, or after waiting for the phase difference Δθ to reach a predetermined phase difference, similar to the short circuit control unit 69. This short circuit control is performed with priority over other controls (normal drive controls such as phase control).

[0068] Next, a flowchart of the ASC transition process will be described with reference to FIG. 6. The ASC transition process is executed at predetermined intervals during phase control and current control. The ASC transition process is realized by the arithmetic processing unit 60a of the control device 60 executing a control program stored in the storage unit 60b. The ASC transition process realizes a method for controlling a rotating electric machine.

[0069] The control device 60 determines whether an abnormality has occurred based on the detected value (step S101). If the determination result is negative, the ASC transition process is terminated. On the other hand, if the determination result in step S101 is positive, the control device 60 determines to execute short-circuit control (step S102). The processes in steps S101 and S102 correspond to the processes (abnormality detection process) performed by the abnormality detection units 67 and 78.

[0070] Then, the control device 60 sets the phase difference Δθ so as to increase the phase difference Δθ (step S103).The control device 60 then calculates a phase correction value θ1a for the phase θ1 of each phase voltage applied by the first inverter 20 and a phase correction value θ2a for the phase θ2 of each phase voltage applied by the second inverter 30 so as to achieve the set phase difference Δθ (step S104).The processing of steps S103 to S104 corresponds to the processing performed by the phase manipulation units 68 and 79.

[0071] The control device 60 shifts the phases of the operation signals of the switches SUHa to SWLa and SUHb to SWLb based on the calculated phase correction values ​​θ1a and θ2a (step S105). The process of step S105 corresponds to the process performed by the phase correction units 66a, 66b, 77a, and 77b.

[0072] Next, the control device 60 determines whether the phase difference Δθ has reached its maximum value (step S106). If the result of this determination is negative, the control device 60 determines whether a predetermined time has elapsed since the decision to execute short circuit control was made in step S101 (step S107). If the result of this determination is negative, the control device 60 again performs the process of step S103 and resets the phase difference Δθ so as to increase the phase difference Δθ. Then, the process from step S103 onward is similarly performed.

[0073] On the other hand, if the determination result in step S106 or step S107 is positive, the control device 60 performs short-circuit control (step S108), and then ends the ASC transition process. Step S108 corresponds to the process of the short-circuit control units 69 and 80.

[0074] The operation when the ASC transition process is performed will be described with reference to Figures 7 to 9. Figure 7 illustrates the operation when PWM control (current control) is performed. Figure 8 illustrates the operation when square wave control (phase control) is performed. Figure 9 illustrates the operation when overmodulation control (phase control) is performed.

[0075] The upper rows of Figures 7 to 9(a) show the U-phase voltage (hereinafter referred to as INV1_U) applied from the first inverter 20 and the U-phase voltage (hereinafter referred to as INV2_U) applied from the second inverter 30 before the short circuit control is determined, i.e., during normal operation. The lower rows of Figures 7 to 9(a) show the applied voltage (hereinafter referred to as applied voltage_U) applied to the U-phase winding 51U before the short circuit control is determined. The upper rows of Figures 7 to 8(b) show INV1_U and INV2_U when the short circuit control is determined (ASC transition) and the phase difference Δθ is 90 degrees. The lower rows of Figures 7 to 8(b) show applied voltage_U when the short circuit control is determined and the phase difference Δθ is 90 degrees. The upper rows of Figures 7 to 8(c) show INV1_U and INV2_U when the short circuit control is determined and the phase difference Δθ is 180 degrees. The lower rows of Figures 7 to 8(c) show the applied voltage_U when short circuit control is determined and the phase difference Δθ is 180 degrees. The upper row of Figure 9(b) shows INV1_U and INV2_U when short circuit control is determined and the phase difference Δθ is 30 degrees. The lower row of Figure 9(b) shows the applied voltage_U when short circuit control is determined and the phase difference Δθ is 30 degrees. Although Figures 7 to 9 show the U phase as an example, the same applies to the V phase and W phase.

[0076] As can be seen from a comparison of Figures 7(a) and 7(b), when PWM control is being performed, if short circuit control is selected and the phase difference Δθ increases to 90 degrees, the timing at which the switches of the first inverter 20 and the second inverter 30 are turned on differs, and the applied voltage _U decreases. Referring to Figure 7(c), if the phase difference Δθ further increases to 180 degrees, the applied voltage _U becomes zero. As a result, as shown in Figure 10, the phase current also gradually decreases. Therefore, even if short circuit control is subsequently performed, the applied voltage does not change abruptly, and overcurrent can be suppressed.

[0077] Furthermore, as can be seen by comparing Figures 8(a) and 8(b), when square wave control is performed, if short circuit control is determined and the phase difference Δθ increases to 90 degrees, the timing at which each switch is turned on in the first inverter 20 and the second inverter 30 differs, and the applied voltage _U decreases. Furthermore, referring to Figure 8(c), if the phase difference Δθ further increases to 180 degrees, the applied voltage _U becomes zero. As a result, the phase current also gradually decreases. Therefore, even if short circuit control is subsequently performed, the applied voltage does not change abruptly, and overcurrent can be suppressed.

[0078] 9(a) and 9(b), when overmodulation control is performed, if short-circuit control is determined and the phase difference Δθ increases to 30 degrees, the timing at which the switches of the first inverter 20 and the second inverter 30 are turned on differs, and the applied voltage _U decreases. Although not shown, the larger the phase difference Δθ, the smaller the applied voltage _U and the gradually smaller the phase current. Therefore, even if short-circuit control is subsequently performed, the applied voltage does not change suddenly, and overcurrent can be suppressed.

[0079] According to the above embodiment, the following effects are achieved.

[0080] After the decision to implement short circuit control is made, but before the short circuit control is implemented, the phase manipulation units 68, 79 change the phase difference Δθ between the phase θ1 of the output phase voltage of each phase applied by the first inverter 20 and the phase θ2 of the output phase voltage of each phase applied by the second inverter 30 so as to increase it. This prevents a sudden change in voltage even when short circuit control is implemented, making it possible to suppress the occurrence of overcurrent, and thereby preventing element damage.

[0081] After the decision to implement short circuit control is made, but before the short circuit control is implemented, the phase manipulation units 68 and 79 gradually increase the phase difference Δθ so that the phase difference approaches 180 degrees. As the phase difference approaches 180 degrees, the applied voltage can be reduced, so that even if short circuit control is subsequently implemented, the voltage does not change suddenly. Furthermore, because the phase difference Δθ is gradually increased, sudden changes in the applied voltage can be prevented while the phase difference Δθ is being increased. This makes it possible to suppress the occurrence of overcurrent and prevent element damage.

[0082] In the above embodiment, the modulation factor of the first inverter 20 is the same as the modulation factor of the second inverter 30. Therefore, when the phase difference Δθ becomes 180 degrees, the applied voltage can be set to zero, as shown in Figures 7(c) and 8(c). Therefore, overcurrent can be more reliably suppressed.

[0083] (Modifications) Hereinafter, modifications in which the configuration of the above embodiment is partially changed will be described.

[0084] In the above embodiment, after the phase difference Δθ is increased, the phase difference Δθ does not have to be further increased over time. In other words, the phase difference Δθ may be increased once, and then the short-circuit control may be performed.

[0085] In the above embodiment, the modulation factor may be different between the first inverter 20 and the second inverter 30. Furthermore, the phase control and the current control may be different between the first inverter 20 and the second inverter 30. For example, when the modulation factor of the first inverter 20 is equal to or greater than a threshold value and the modulation factor of the second inverter 30 is less than the threshold value, phase control (overmodulation control or square wave control) may be performed on the first inverter 20, and current control (PWM control) may be performed on the second inverter 30. Similarly, when the modulation factor of the first inverter 20 is less than the threshold value and the modulation factor of the second inverter 30 is equal to or greater than the threshold value, current control (PWM control) may be performed on the first inverter 20, and phase control (overmodulation control or square wave control) may be performed on the second inverter 30.

[0086] Even when the control or modulation factor differs between the inverters 20 and 30, the phase difference Δθ may be increased after the decision to perform short circuit control is made and before the short circuit control is performed. An example of the case where the control or modulation factor differs will be described.

[0087] FIG. 11 shows an example in which PWM control is performed in the first inverter 20 and overmodulation control is performed in the second inverter 30. The upper part of FIG. 11(a) shows INV1_U and INV2_U during normal operation, and the lower part of FIG. 11(a) shows the applied voltage _U during normal operation. The upper part of FIG. 11(b) shows INV1_U and INV2_U when the phase difference Δθ is 30 degrees after short-circuit control is determined and before short-circuit control is performed. The lower part of FIG. 11(b) shows the applied voltage _U when the phase difference Δθ is 30 degrees after short-circuit control is determined and before short-circuit control is performed. Comparing FIG. 11(a) and FIG. 11(b) reveals that even when PWM control and overmodulation control are performed, the applied voltage _U decreases as the phase difference Δθ increases. As a result, the U-phase current also decreases, and overcurrent can be suppressed even when short-circuit control is performed.

[0088] FIG. 12 shows an example in which PWM control is performed in the first inverter 20 and square-wave control is performed in the second inverter 30. The upper part of FIG. 12(a) shows INV1_U and INV2_U during normal operation, and the lower part of FIG. 12(a) shows applied voltage_U during normal operation. The upper part of FIG. 12(b) shows INV1_U and INV2_U when the phase difference Δθ is 30 degrees after short-circuit control is determined and before short-circuit control is performed. The lower part of FIG. 12(b) shows applied voltage_U when the phase difference Δθ is 30 degrees after short-circuit control is determined and before short-circuit control is performed. Comparing FIG. 12(a) and FIG. 12(b) reveals that even when PWM control and square-wave control are performed, the applied voltage_U decreases as the phase difference Δθ increases. As a result, the U-phase current also decreases, suppressing overcurrent even when short-circuit control is performed.

[0089] FIG. 13 shows an example in which overmodulation control is performed in the first inverter 20 and square wave control is performed in the second inverter 30. The upper part of FIG. 13(a) shows INV1_U and INV2_U during normal operation, and the lower part of FIG. 13(a) shows applied voltage_U during normal operation. The upper part of FIG. 13(b) shows INV1_U and INV2_U when the phase difference Δθ is 30 degrees after short circuit control is determined and before short circuit control is performed. The lower part of FIG. 13(b) shows applied voltage_U when the phase difference Δθ is 30 degrees after short circuit control is determined and before short circuit control is performed. Comparing FIG. 13(a) and FIG. 13(b) reveals that even when PWM control and square wave control are performed, the applied voltage_U decreases as the phase difference Δθ increases. As a result, the U-phase current also decreases, suppressing overcurrent even when short circuit control is performed.

[0090] In addition, when the control and modulation factor of each inverter 20, 30 are different, if it is determined to implement short circuit control, it is desirable for the control device 60 to align the modulation factors and increase the phase difference Δθ. By aligning the modulation factors, the applied voltage can be reduced to zero when the phase difference Δθ is set to 180 degrees, as shown in Figures 7(c) and 8(c). When it is determined to implement short circuit control, a modulation factor adjustment unit 90 that adjusts the modulation factor of each inverter 20, 30 so that the modulation factor of the first inverter 20 and the modulation factor of the second inverter 30 are the same may be provided as a function of the control device 60, as shown in Figure 14. The modulation factor adjustment unit 90 may be implemented by hardware or software. For example, it may be implemented by the arithmetic processing device 60a executing a control program. Furthermore, the modulation units 65, 76 may be provided with the function of adjusting the modulation factor of each inverter 20, 30.

[0091] In the above embodiment, the modulation factor is assumed to be a value obtained by dividing the amplitude of each phase voltage command value Vu*, Vv*, Vw* by "system voltage Vsys / 2." However, the modulation factor may be a value obtained by dividing the amplitude of the fundamental wave component of the voltage applied to each phase (output phase voltage) by each inverter 20, 30 by "voltage of battery 10 (or system voltage Vsys) / 2." Note that the modulation factor may be calculated for each inverter 20, 30.

[0092] In the above embodiment, the Y drive state and the H drive state can be selected, but it may be configured so that only the H drive state can be implemented. In this case, the changeover switch 13 is not necessary.

[0093] In the above embodiment, the phase difference Δθ is gradually increased per unit time, but the manner in which the phase difference Δθ is increased may be changed as desired. For example, the phase difference Δθ may be increased exponentially as shown in Fig. 15 or logarithmically as shown in Fig. 16.

[0094] In the above embodiment, the speed at which the phase difference Δθ is increased may be varied depending on the magnitude or rate of change of the system voltage Vsys. When the magnitude or rate of change of the system voltage Vsys is large, the phase difference Δθ may be increased logarithmically as shown in Fig. 16. On the other hand, when the magnitude or rate of change of the system voltage Vsys is small, the phase difference Δθ may be increased exponentially as shown in Fig. 15.

[0095] The controller and methods described herein may be implemented by a special-purpose computer configured with a processor and memory programmed to perform one or more functions embodied in a computer program. Alternatively, the controller and methods described herein may be implemented by a special-purpose computer configured with a processor configured with one or more dedicated hardware logic circuits. Alternatively, the controller and methods described herein may be implemented by one or more special-purpose computers configured with a processor and memory programmed to perform one or more functions in combination with a processor configured with one or more hardware logic circuits. Furthermore, the computer program may be stored as instructions executed by a computer on a computer-readable non-transitory storage medium.

[0096] The following describes characteristic configurations extracted from the above-described embodiments.

[0097] [Configuration 1] A rotating electric machine (40) having a multi-phase armature winding (51U, 51V, 51W); a first inverter (20) having first upper arm switches (SUHa to SWHa) and first lower arm switches (SULa to SWLa) connected in series for the number of phases, and a series connection of the first upper arm switches and the first lower arm switches connected in parallel to a DC power source (10); a second inverter (30) having second upper arm switches (SUHb to SWHb) and second lower arm switches (SULb to SWLb) connected in series for the number of phases; a positive side bus (11) electrically connecting a high potential side terminal of the first upper arm switch and a high potential side terminal of the second upper arm switch in each phase; and a negative side bus (12) electrically connecting a low potential side terminal of the first lower arm switch and a low potential side terminal of the second lower arm switch in each phase. A control device (60) for a rotating electric machine applied to a system (100) comprising: a phase operation unit (68, 79) that, when it is decided to implement short-circuit control in which all of the first upper arm switches and the second upper arm switches are turned on and all of the first lower arm switches and the second lower arm switches are turned off, or all of the first upper arm switches and the second upper arm switches are turned off and all of the first lower arm switches and the second lower arm switches are turned on, changes the phase difference (Δθ) between the phase (θ1) of each phase voltage applied by the first inverter and the phase (θ2) of each phase voltage applied by the second inverter so as to increase it.

[0098] [Configuration 2] The control device for a rotating electric machine according to Configuration 1, further comprising: a modulation factor adjustment unit (90) that adjusts the modulation factor of each of the inverters so that the modulation factor of the first inverter and the modulation factor of the second inverter are the same when it is determined to perform the short circuit control.

[0099] [Configuration 3] The control device for a rotating electric machine according to configuration 1 or 2, wherein the phase operation unit gradually increases the phase difference so that the phase difference approaches 180 degrees.

[0100] [Configuration 4] A rotating electric machine (40) having a multi-phase armature winding (51U, 51V, 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 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 program for a rotating electric machine executed by a control device (60) for a rotating electric machine applied to a system (100) comprising the above, wherein when it is determined to implement short-circuit control in which all of the first upper arm switches and the second upper arm switches are turned on and all of the first lower arm switches and the second lower arm switches are turned off, or all of the first upper arm switches and the second upper arm switches are turned off and all of the first lower arm switches and the second lower arm switches are turned on, the control program for a rotating electric machine executes a phase operation process in which a phase difference (Δθ) between a phase (θ1) of each phase voltage applied by the first inverter and a phase (θ2) of each phase voltage applied by the second inverter is changed so as to increase the phase difference (Δθ).

[0101] [Configuration 5] A rotating electric machine (40) having a multi-phase armature winding (51U, 51V, 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 bus (11) electrically connecting a high potential side terminal of the first upper arm switch and a high potential side terminal of the second upper arm switch in each phase; and a negative bus (12) electrically connecting a low potential side terminal of the first lower arm switch and a low potential side terminal of the second lower arm switch in each phase. A control method for a rotating electric machine implemented by a control device (60) for a rotating electric machine applied to a system (100) comprising the above, the control method for a rotating electric machine including, when it is determined to implement short-circuit control in which all of the first upper arm switches and the second upper arm switches are turned on and all of the first lower arm switches and the second lower arm switches are turned off, or all of the first upper arm switches and the second upper arm switches are turned off and all of the first lower arm switches and the second lower arm switches are turned on, a phase operation process for changing so as to increase the phase difference (Δθ) between the phase (θ1) of each phase voltage applied by the first inverter and the phase (θ2) of each phase voltage applied by the second inverter.

[0102] 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 control device (60) for a rotating electrical machine applied to a system (100) comprising: a rotating electrical machine (40) having a multi-phase armature winding (51U, 51V, 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 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. When it is determined to perform short-circuit control in which all of the first upper arm switches and the second upper arm switches are turned on and all of the first lower arm switches and the second lower arm switches are turned off, or all of the first upper arm switches and the second upper arm switches are turned off and all of the first lower arm switches and the second lower arm switches are turned on, the control device for a rotating electrical machine comprises a phase operation unit (68, 79) that changes so as to increase a phase difference (Δθ) between a phase (θ1) of each phase voltage applied by the first inverter and a phase (θ2) of each phase voltage applied by the second inverter.

2. The control device for a rotating electrical machine according to claim 1, further comprising a modulation ratio adjustment unit (90) that adjusts the modulation ratio of each inverter so that the modulation ratio of the first inverter and the modulation ratio of the second inverter are the same when it is determined to perform the short-circuit control.

3. The control device for a rotating electrical machine according to claim 1 or 2, wherein the phase operation unit gradually increases the phase difference so that the phase difference approaches 180 degrees.

4. A control program for a rotating electrical machine implemented by a control device (60) of a rotating electrical machine applied to a system (100) comprising: a rotating electrical machine (40) having a multi-phase armature winding (51U, 51V, 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) equal 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) equal 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. When it is determined to perform short-circuit control in which all of the first upper arm switches and the second upper arm switches are turned on and all of the first lower arm switches and the second lower arm switches are turned off, or all of the first upper arm switches and the second upper arm switches are turned off and all of the first lower arm switches and the second lower arm switches are turned on, a phase operation process is performed to change the phase difference (Δθ) between the phase (θ1) of each phase voltage applied by the first inverter and the phase (θ2) of each phase voltage applied by the second inverter so as to expand it.

5. A rotating electrical machine (40) having a multi-phase armature winding (51U, 51V, 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 the series-connected body 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 method of a rotating electrical machine implemented by a control device (60) of the rotating electrical machine applied to a system (100), when it is determined to perform short-circuit control in which all of the first upper arm switches and the second upper arm switches are turned on and all of the first lower arm switches and the second lower arm switches are turned off, or all of the first upper arm switches and the second upper arm switches are turned off and all of the first lower arm switches and the second lower arm switches are turned on, a phase operation process of changing so as to expand a phase difference (Δθ) between a phase (θ1) of each phase voltage applied by the first inverter and a phase (θ2) of each phase voltage applied by the second inverter is included.

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