Rotating motor control device

Abstract

Two inverters (10) provided at both ends of an open-circuit winding (8) can be appropriately controlled. As a control region (R) of a rotating electrical machine (80), a first speed region (VR1) and a second speed region (VR2) in which the rotation speed of the rotating electrical machine (80) is higher than that of the first speed region (VR1) under the same torque are set. In the second speed region (VR2), a rotating electrical machine control device (1) controls the first inverter (11) and the second inverter (12) by hybrid pulse width modulation control. The hybrid pulse width modulation control is controlled in such a manner that a plurality of pulses having different patterns are output in a first period (T1) that is a half cycle of an electrical angle, and an inactive state is maintained in a second period (T2) that is a half cycle.

Description

Technical Field

[0001] The present invention relates to a rotating electrical machine control device for driving and controlling a rotating electrical machine having an open-circuit winding by means of two inverters. Background Art

[0002] In the 2007 IEEE paper "Dual Inverter-Fed Traction Drive with DC Sources Power Balancing Based on Synchronized PWM," V. Oleschuk et al. disclose a control device that drives and controls a three-phase AC rotating electric machine by switching an inverter, one at each end of a three-phase open-circuit winding. Alternatively, there is a known method for driving and controlling the rotating electric machine by switching a single inverter, for example, located at the other end of a Y-shaped winding connected to one end of each of the three-phase windings. In a system using an open-circuit winding and two inverters, compared to a system using a Y-shaped winding and a single inverter, the line voltage of the AC voltage across the windings can be higher, providing the same DC voltage, thereby enabling the rotating electric machine to operate at a higher output.

[0003] The introduction to the paper by V. Oleschuk et al. states that by making the phases of the carrier signals used to generate pulses for switching control of the two inverters different from each other, the ripple of the current flowing in the winding can be reduced. V. Oleschuk et al. also point out that by generating pulses in a synchronous manner rather than an asynchronous manner using a carrier signal, control more suitable for medium / high output applications can be achieved. However, in both asynchronous and synchronous methods, the two inverters are always switched using the same control method.

[0004] Prior art literature

[0005] Non-patent literature

[0006] Non-patent literature 1: V.Oleschuk, R.Bojoi, G.Griva, F.Profumo, "Dual Inverter-FedTraction Drive with DC Sources Power Balancing Based on Synchronized PWM", Conference Paper / June 2007, 1-4244-0743-5 / 07, IEEE, p.260-265. Summary of the Invention

[0007] The switching control method is preferably determined based on various factors (operating conditions) such as the torque, rotational speed, and DC-side voltage required by the rotating electrical machine, to enable operation with higher system efficiency. While the technology of V. Oleschuk et al. is excellent, there is room for improvement in properly controlling the two inverters at each end of the open-circuit winding.

[0008] In view of the above background, it is desirable to provide a technology for appropriately controlling two inverters provided at both ends of an open winding.

[0009] In view of the above-mentioned rotating electrical machine control device as a mode, a rotating electrical machine having mutually independent multi-phase open-circuit windings is driven and controlled by a first inverter and a second inverter, wherein the first inverter is connected to one end side of the multi-phase open-circuit winding and converts power between direct current and multi-phase alternating current, and the second inverter is connected to the other end side of the multi-phase open-circuit winding and converts power between direct current and multi-phase alternating current, and the first inverter and the second inverter can be controlled by a plurality of control modes with different switching modes, and can be controlled by the control modes independently of each other, as the rotating electrical machine A control region is set with a first speed region and a second speed region in which the rotational speed of the rotating motor is higher than that of the first speed region under the same torque. The control method includes: pulse width modulation control, outputting multiple pulses with different patterns in one cycle of electrical angle; and hybrid pulse width modulation control, controlling to output multiple pulses with different patterns in a first period, which is 1 / 2 cycle of electrical angle, and maintaining an inactive state in the remaining second period, which is 1 / 2 cycle. In the second speed region, the first inverter and the second inverter are controlled by the hybrid pulse width modulation control.

[0010] Hybrid pulse width modulation control is a control method that combines a period of pulse width modulation with a period of no modulation (fixed state) for approximately half of each cycle of the electrical angle. That is, since the inverter does not perform switching during approximately 1 / 2 of the driving time, switching losses can be reduced, thereby reducing system losses. The second speed range in which hybrid pulse width modulation control is performed is set to the higher speed side than the first speed range at the same torque, and is a control range relative to the medium speed / high speed side. According to this structure, by reducing the system losses in the control range relative to the medium speed / high speed side in the entire operating range of the rotating electrical machine, the overall system losses in all operating ranges can be reduced. In this way, according to this structure, the two inverters provided at both ends of the open winding can be appropriately controlled.

[0011] In addition, in view of the above-mentioned rotating electrical machine control device as another embodiment, a rotating electrical machine having mutually independent multi-phase open windings is driven and controlled by a first inverter and a second inverter, wherein the first inverter is connected to one end side of the multi-phase open winding and converts power between direct current and multi-phase alternating current, and the second inverter is connected to the other end side of the multi-phase open winding and converts power between direct current and multi-phase alternating current, and in the first inverter and the second inverter, the arm of one phase of alternating current is respectively composed of a series circuit of an upper-side switching element and a lower-side switching element, The control methods for the first inverter and the second inverter include at least: pulse width modulation control, which outputs a plurality of pulses of different patterns in one cycle of electrical angle; and active short-circuit control, which sets the upper-side switching elements of all the arms of the multi-phase to the on state or sets the lower-side switching elements of all the arms of the multi-phase to the on state, and in the pulse width modulation control, the control methods include: continuous pulse width modulation control, which continuously performs pulse width modulation on all the arms of the multi-phase; and discontinuous pulse width modulation control. , pulse width modulation is performed on a portion of the arms of the multi-phase circuit, including a period in which the switching elements are fixed in an on state or an off state, the first inverter and the second inverter can be controlled independently of each other in the control method, and control regions of the rotating electrical machine are set as follows: a first speed region; a second speed region in which the rotational speed of the rotating electrical machine is higher than that in the first speed region under the same torque; and a third speed region in which the rotational speed of the rotating electrical machine is higher than that in the second speed region under the same torque. In the first speed region, one of the first and second inverters is controlled by the active short-circuit control, and the other inverter is controlled by the continuous pulse width modulation control. In the second speed region, one of the first and second inverters is controlled by the active short-circuit control, and the other inverter is controlled by the discontinuous pulse width modulation control. In the third speed region, target control is performed by controlling both the first and second inverters by the discontinuous pulse width modulation control.

[0012] With two inverters, as in this configuration, an AC voltage with a larger amplitude than the voltage on the DC side of each inverter can be generated. However, the rotating electrical machine control device does not need to always control both inverters to increase the AC voltage amplitude. For example, when the rotating electrical machine is rotating at a low speed, generating the AC voltage that can be generated by a single inverter may be sufficient. According to this configuration, in the first and second speed ranges, one of the two inverters is controlled using active short-circuit control. This short-circuits the open windings in this inverter, making the rotating electrical machine similar to a rotating electrical machine in which the stator coils have an electrical neutral point. In other words, the rotating electrical machine is essentially driven by only one of the two inverters. Since the inverter controlled by active short-circuit control does not perform switching operations, the rotating electrical machine can be driven while minimizing overall system losses. Furthermore, the maximum modulation rate of the discontinuous pulse width modulation control performed in the second speed range is greater than the maximum modulation rate of the continuous pulse width modulation control performed in the first speed range. The second speed range is a control range in which the rotational speed of the rotating electric machine is higher than that of the first speed range at the same torque. From the perspective of system efficiency, modulation is preferably performed at a higher modulation rate in the second speed range than in the first speed range. By performing continuous pulse width modulation control in the first speed range and discontinuous pulse width modulation control in the second speed range, the rotating electric machine can be appropriately driven by a single inverter in the control range that combines the first and second speed ranges. Furthermore, since two inverters are controlled by discontinuous pulse width modulation control in the third speed range, in which the rotational speed of the rotating electric machine is higher than that of the second speed range, a line voltage higher than that generated by a single DC power supply can be generated in the open winding to drive the rotating electric machine. Thus, according to this configuration, the two inverters, each at either end of the open winding, can be appropriately controlled.

[0013] Other features and advantages of the rotating electrical machine control device will become apparent from the following description of the embodiments explained with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is a schematic block diagram of a rotating electric machine drive system.

[0015] Figure 2 This is a simplified partial block diagram of a rotating electrical machine control device.

[0016] Figure 3 is a vector diagram of a rotating motor drive system using two inverters.

[0017] Figure 4 It is a schematic voltage vector diagram of a rotating motor in an orthogonal vector space.

[0018] Figure 5 This is a diagram showing an example of a control area of ​​a rotating electrical machine.

[0019] Figure 6 This is a diagram showing an example of a control area of ​​a rotating electrical machine.

[0020] Figure 7 This is a diagram showing an example of a control area of ​​a rotating electrical machine.

[0021] Figure 8 This is a waveform diagram showing an example of the voltage command and the switch control signal in the second speed range (low-speed side second speed range).

[0022] Figure 9 3 is a waveform diagram showing an example of a voltage command and a switch control signal in the second speed region on the high speed side.

[0023] Figure 10 4 is a waveform diagram showing another example of the voltage command and the switch control signal in the second speed range (low-speed side second speed range).

[0024] Figure 11 3 is a waveform diagram showing another example of the voltage command and the switch control signal in the second speed region on the high speed side.

[0025] Figure 12 This is a waveform diagram showing an example of a voltage command and a switch control signal in the first speed region (low-speed side first speed region).

[0026] Figure 13 3 is a waveform diagram showing an example of a voltage command and a switch control signal in a first speed region on the high speed side.

[0027] Figure 14 3 is a waveform diagram showing another example of the voltage command and the switch control signal in the third speed range.

[0028] Figure 15 3 is a waveform diagram showing another example of the voltage command and the switch control signal in the second speed region on the high speed side.

[0029] Figure 16 3 is a waveform diagram showing an example of the voltage command and the switch control signal in the first speed range in the noise reduction priority mode.

[0030] Figure 17 This is a diagram showing an example of a case where hybrid continuous pulse width modulation control is performed on both inverters of a dual inverter system in the first speed region.

[0031] Figure 18This is a diagram showing an example of a case where continuous pulse width modulation control is performed on both inverters of a dual inverter system in the first speed region.

[0032] Figure 19 1 is a diagram showing an example of a case where continuous pulse width modulation control is performed on a single inverter system in the first speed region.

[0033] Figure 20 This is a diagram showing an example of a control area of ​​a rotating electrical machine in a single inverter system.

[0034] Figure 21 1 and 2 are diagrams showing comparative examples of switching control signals and line voltages between a single inverter system and a dual inverter system, and comparative examples of switching control signals and line voltages between different control methods in a dual inverter system.

[0035] Figure 22 1 and 2 are diagrams showing a comparative example of phase currents between a single inverter system and a dual inverter system, and a comparative example of phase currents between different control methods in a dual inverter system.

[0036] Figure 23 The diagram shows a comparative example of FFT analysis results using the carrier frequency of the phase current of a single inverter system and a dual inverter system as the center frequency, and a comparative example of FFT analysis results using the carrier frequency of the phase current of different control methods in the dual inverter system as the center frequency.

[0037] Figure 24 This is a diagram showing a comparison example of the FFT analysis results with a frequency of twice the carrier frequency of the phase current of a single inverter system and a dual inverter system as the center frequency, and a comparison example of the FFT analysis results with a frequency of twice the carrier frequency of the phase current between different control methods in a dual inverter system as the center frequency.

[0038] Figure 25 The diagram shows a comparative example of FFT analysis results using the carrier frequency of the line voltage as the center frequency between a single inverter system and a dual inverter system, and a comparative example of FFT analysis results using the carrier frequency of the line voltage as the center frequency between different control methods in the dual inverter system.

[0039] Figure 26 This is a diagram showing a comparative example of the FFT analysis results with a frequency of twice the carrier frequency of the line voltage of a single inverter system and a dual inverter system as the center frequency, and a comparative example of the FFT analysis results with a frequency of twice the carrier frequency of the line voltage between different control methods in a dual inverter system as the center frequency.

[0040] Figure 27 This is a diagram showing an example of a control area of ​​a rotating electrical machine in a dual inverter system according to a comparative example.

[0041] Figure 28 These are diagrams showing waveform examples and FFT analysis result examples when discontinuous pulse width modulation control is performed in a single inverter system.

[0042] Figure 29 These are diagrams showing waveform examples and FFT analysis result examples when discontinuous pulse width modulation control is performed in a dual inverter system.

[0043] Figure 30 These are diagrams showing waveform examples and FFT analysis result examples when hybrid continuous pulse width modulation control is executed in a dual inverter system.

[0044] Figure 31 This is a diagram showing the relationship between the rotation speed of a rotating electrical machine and audible noise in a single inverter system.

[0045] Figure 32 Graph showing the relationship between the rotational speed of a rotating electrical machine and audible noise in a dual inverter system of a comparative example.

[0046] Figure 33 Graph showing the relationship between the rotational speed of a rotating electrical machine and audible noise in a dual inverter system.

[0047] Figure 34 This is a diagram showing an example of a control area of ​​a rotating electrical machine.

[0048] Figure 35 Yes Figure 20 as well as Figure 34 Graphs showing comparative examples of phase current waveforms and FFT analysis results of phase currents at the first operating point (Q1) of a single inverter system, a dual inverter system using conventional pulse width modulation control, and a dual inverter system using hybrid pulse width modulation control.

[0049] Figure 36 Graphs showing comparative examples of DC bus current waveforms and FFT analysis results of the DC bus current at the first operating point for a single inverter system, a dual inverter system using conventional pulse width modulation control, and a dual inverter system using hybrid pulse width modulation control.

[0050] Figure 37 Graphs showing comparative examples of battery current waveforms and FFT analysis results of the battery currents at the first operating point for a single inverter system, a dual inverter system using normal pulse width modulation control, and a dual inverter system using hybrid pulse width modulation control.

[0051] Figure 38Graphs showing comparative examples of capacitor current waveforms and FFT analysis results of capacitor currents at the first operating point for a single inverter system, a dual inverter system using normal pulse width modulation control, and a dual inverter system using hybrid pulse width modulation control.

[0052] Figure 39 This figure shows a comparative example of the DC bus voltage ripple waveforms and FFT analysis results of the DC bus voltage ripple at the first operating point for a single inverter system, a dual inverter system using conventional pulse width modulation control, and a dual inverter system using hybrid pulse width modulation control.

[0053] Figure 40 Yes Figure 20 as well as Figure 34 Graph showing a comparative example of phase currents and FFT analysis results of phase currents of a single inverter system, a dual inverter system using conventional pulse width modulation control, and a dual inverter system using hybrid pulse width modulation control at the second operating point (Q2).

[0054] Figure 41 Graphs showing comparative examples of DC bus current waveforms and FFT analysis results of the DC bus current at the second operating point for a single inverter system, a dual inverter system using conventional pulse width modulation control, and a dual inverter system using hybrid pulse width modulation control.

[0055] Figure 42 Graphs showing comparative examples of battery current waveforms and FFT analysis results of the battery currents at the second operating point for a single inverter system, a dual inverter system using normal pulse width modulation control, and a dual inverter system using hybrid pulse width modulation control.

[0056] Figure 43 Graphs showing comparative examples of capacitor current waveforms and FFT analysis results of capacitor currents at the second operating point for a single inverter system, a dual inverter system using normal pulse width modulation control, and a dual inverter system using hybrid pulse width modulation control.

[0057] Figure 44 This figure shows a comparative example of the DC bus voltage ripple waveforms and FFT analysis results of the DC bus voltage ripple at the second operating point for a single inverter system, a dual inverter system using conventional pulse width modulation control, and a dual inverter system using hybrid pulse width modulation control.

[0058] Figure 45 This is a flowchart showing an example of a procedure for selecting a control method when the ripple of the DC bus current flowing through the DC link capacitor is not taken into consideration.

[0059] Figure 46 This is a flowchart showing an example of a procedure for selecting a control method in consideration of ripples in the DC bus current flowing through the DC link capacitor.

[0060] Figure 47 This is a flowchart showing another example of the procedure for selecting a control method when the ripple of the DC bus current flowing through the DC link capacitor is taken into consideration.

[0061] Figure 48 This is a diagram showing an example of a control area of ​​the rotating electrical machine according to the second embodiment.

[0062] Figure 49 This is a diagram showing another example of the control area of ​​the rotating electrical machine according to the second embodiment.

[0063] Figure 50 This is a diagram showing an example of a control area of ​​a rotating electrical machine of a single inverter system for comparison with the second embodiment. DETAILED DESCRIPTION

[0064] Hereinafter, embodiments of a rotating electrical machine control device for driving and controlling a rotating electrical machine having multi-phase open windings independent of each other using two inverters will be described with reference to the drawings. Figure 1 This is a schematic block diagram of a rotating motor drive system including a rotating motor control device 1 (MG-CTRL). The rotating motor 80 is a component that serves as a driving force source for the wheels of a vehicle such as an electric vehicle or a hybrid vehicle. The rotating motor 80 is an open-circuit winding type rotating motor having mutually independent multi-phase (three-phase in this embodiment) stator coils 8 (open-circuit windings). An inverter 10 that is independently controlled to convert power between direct current and multi-phase (three-phase in this embodiment) alternating current is connected to each end of the stator coil 8. That is, a first inverter 11 (INV1) is connected to one end of the stator coil 8, and a second inverter 12 (INV2) is connected to the other end of the stator coil 8. In the following, when there is no need to distinguish between the first inverter 11 and the second inverter 12, they are simply referred to as the inverter 10 for explanation.

[0065] The inverter 10 includes a plurality of switching elements 3. The switching elements 3 use IGBTs (Insulated Gate Bipolar Transistors) and power MOSFETs (Metal Oxide Semiconductor Field Effect Transistors). Figure 1, an embodiment using IGBTs as switching elements 3 is illustrated. In this embodiment, the first inverter 11 and the second inverter 12 are inverters 10 having the same circuit configuration and using the same type of switching elements 3. However, the first inverter 11 and the second inverter 12 may also be configured to use different types of switching elements 3.

[0066] For example, as will be described later with reference to Tables 1 to 6, even in cases where two inverters 10 are controlled using different control methods (e.g., in the case of control in the first speed region VR1 described later), it is preferable to use different types of switching elements 3 to configure the first inverter 11 and the second inverter 12, depending on the characteristics of each control method. For example, in situations where the first inverter 11 is substantially short-circuited and not performing switching control, the second switching element 32 of the second inverter 12 preferably exhibits relatively lower switching losses during the transition between the off and on states than the first switching element 31 of the first inverter 11. For example, a Si-IGBT can be used as the first switching element 31 of the first inverter 11, and a SiC-MOSFET (Silicon Carbide-Metal Oxide Semiconductor FET) can be used as the second switching element 32 of the second inverter 12. In addition to the Si-IGBT, the first switching element 31 may also be a Si-MOSFET. In addition, the second switching element 32 may be a SiC-SIT (SiC-Static Induction Transistor), a GaN-MOSFET (Gallium Nitride-MOSFET), or the like, in addition to the SiC-MOSFET.

[0067] In both inverters 10, the AC single-phase arm 3A is composed of a series circuit consisting of an upper-side switching element 3H and a lower-side switching element 3L. Each switching element 3 has a freewheeling diode 35 connected in parallel, with the positive direction from the negative electrode FG toward the positive electrode P (from the lower side toward the upper side) being the positive direction. Furthermore, in this embodiment, the two inverters 10 are connected to independent DC power supplies 6. Specifically, the negative electrode FG of the first inverter 11, i.e., the first floating ground FG1, and the negative electrode FG of the second inverter 12, i.e., the second floating ground FG2, are independent of each other. Furthermore, a DC link capacitor 4 (smoothing capacitor) is provided between each inverter 10 and the DC power supply 6 to smooth the DC bus voltage.

[0068] Specifically, the AC single-phase arm 3A comprises a first inverter 11, which is comprised of a series circuit of a first upper-side switching element 31H and a first lower-side switching element 31L. A first DC link capacitor 41 (first smoothing capacitor) is connected to the DC side, and the DC side is connected to a first DC power supply 61. The AC side is connected to one end of the multi-phase stator coil 8, converting power between DC and multi-phase AC. The AC single-phase arm 3A comprises a second inverter 12, which is comprised of a series circuit of a second upper-side switching element 32H and a second lower-side switching element 32L. A second DC link capacitor 42 (second smoothing capacitor) is connected to the DC side, and the DC side is connected to a second DC power supply 62. The AC side is connected to the other end of the multi-phase stator coil 8, converting power between DC and multi-phase AC.

[0069] In this embodiment, the first DC power supply 61 and the second DC power supply 62 are DC power supplies with equal rated values ​​such as voltage, and the first DC link capacitor 41 and the second DC link capacitor are also capacitors with equal rated values ​​such as capacity. The rated voltage of the DC power supply 6 is approximately 48 volts to 400 volts. The DC power supply 6 is composed of, for example, a secondary battery (battery) such as a nickel-metal hydride battery or a lithium-ion battery, an electric double-layer capacitor, or the like. The rotating electric machine 80 can function as an electric motor or as a generator. The rotating electric machine 80 converts the electric power from the DC power supply 6 into power (power operation) via the inverter 10. Alternatively, the rotating electric machine 80 converts the rotational driving force transmitted from the wheels, etc. into electric power and charges the DC power supply 6 via the inverter 10 (regeneration).

[0070] like Figure 1 As shown, the inverter 10 is controlled by a rotating electrical machine control device 1. The rotating electrical machine control device 1 can control each of the first inverter 11 and the second inverter 12 independently of each other (the details of the control method will be described later). The rotating electrical machine control device 1 is constructed with a logic circuit such as a microcomputer as its core component. For example, the rotating electrical machine control device 1 controls the rotating electrical machine 80 via the inverter 10 by performing current feedback control using a vector control method based on the target torque (torque command) of the rotating electrical machine 80 provided by another control device such as a vehicle control device (not shown).

[0071] The actual current flowing through the stator coil 8 of each phase of the rotating electrical machine 80 is detected by a current sensor 15, and the magnetic pole position of the rotor of the rotating electrical machine 80 at each moment is detected by a rotation sensor 13, such as a resolver. The rotating electrical machine control device 1 uses the detection results from the current sensor 15 and the rotation sensor 13 to perform current feedback control. The rotating electrical machine control device 1 is configured to include various functional units for performing current feedback control, each of which is implemented through the collaboration of hardware, such as a microcomputer, and software (program).

[0072] Figure 2 The block diagram briefly illustrates some functional components of the rotating electrical machine control device 1. In the vector control method, feedback control is performed by coordinate conversion of the actual currents (U-phase current Iu, V-phase current Iv, and W-phase current Iw) flowing through the rotating electrical machine 80 into vector components (d-axis current Id and q-axis current Iq) that correspond to the d-axis, which is the direction of the magnetic field (magnetic flux) generated by the permanent magnets arranged in the rotor of the rotating electrical machine 80, and the q-axis, which is perpendicular to the d-axis (direction extending at an electrical angle of π / 2 relative to the direction of the magnetic field). The rotating electrical machine control device 1 performs coordinate conversion using the three-phase / two-phase coordinate conversion unit 55 based on the detection results (θ: magnetic pole position, electrical angle) of the rotation sensor 13.

[0073] The current feedback control unit 5 (FB) performs feedback control on the rotating electrical machine 80 based on the deviation between the current command (d-axis current command Id*, q-axis current command Iq*) based on the torque command for the rotating electrical machine 80 and the actual current (d-axis current Id, q-axis current Iq) in the dq-axis orthogonal vector coordinate system, thereby calculating voltage commands (d-axis voltage command Vd*, q-axis voltage command Vq*). The rotating electrical machine 80 is driven by two inverters 10: a first inverter 11 and a second inverter 12. Therefore, the d-axis voltage command Vd* and the q-axis voltage command Vq* are distributed by the distribution unit 53 (DIV) into a first d-axis voltage command Vd1* and a first q-axis voltage command Vq1* for the first inverter 11, and a second d-axis voltage command Vd2* and a second q-axis voltage command Vq2* for the second inverter 12, respectively.

[0074] As described above, the rotating electrical machine control device 1 is capable of controlling each of the first inverter 11 and the second inverter 12 in a mutually independent control manner, and has two voltage control units 7, wherein the voltage control unit 7 has a three-phase voltage command operation unit 73 and a modulation unit 74 (MOD). That is, the rotating electrical machine control device 1 has: a first voltage control unit 71 that generates switching control signals (Su1, Sv1, Sw1) for each of the U-phase, V-phase, and W-phase of the first inverter 11; and a second voltage control unit 72 that generates switching control signals (Su2, Sv2, Sw2) for each of the U-phase, V-phase, and W-phase of the second inverter 12. For details, please refer to Figures 9 and 10 As will be described later, the phase difference between the voltage commands (Vu1**, Vv1**, Vw**) for the first inverter 11 and the voltage commands (Vu2**, Vv2**, Vw2**) for the second inverter 12 is "π." Therefore, the second voltage control unit 72 receives input from the value obtained by subtracting "π" from the detection result (θ) of the rotation sensor 13.

[0075] As will be described later, modulation methods include synchronous modulation that is synchronized with the rotation of the rotating motor 80 and asynchronous modulation that is independent of the rotation of the rotating motor 80. Generally speaking, the module (or, in the case of software, the generation process) for generating a switching control signal based on synchronous modulation differs from the module (or, in the case of software, the generation process) for generating a switching control signal based on asynchronous modulation. The voltage control unit 7 described above generates a switching control signal based on a voltage command and a carrier wave that is asynchronous with the rotation of the rotating motor 80. However, in this embodiment, for simplicity of explanation, the voltage control unit 7 is also configured to generate a switching control signal based on synchronous modulation (e.g., a switching control signal in the case of rectangular wave control described later).

[0076] As described above, each arm 3A of the inverter 10 is composed of a series circuit of an upper-side switching element 3H and a lower-side switching element 3L. Figure 2 Although not differentiated, the switching control signals for each phase are output as two signals: an upper-side switching control signal and a lower-side switching control signal. For example, the first U-phase switching control signal Su1, which controls the switching of the U-phase of the first inverter 11, is output as two signals: a first U-phase upper-side switching control signal Su1+ with a "+" appended to the end, and a first U-phase lower-side switching control signal Su1- with a "-" appended to the end. Furthermore, if the upper-side switching element 3H and the lower-side switching element 3L constituting each arm 3A are simultaneously turned on, the arm 3A becomes short-circuited. To prevent this, a dead time is provided during which both the upper-side switching control signal and the lower-side switching control signal for each arm 3A become inactive. This dead time is also added to the voltage control unit 7.

[0077] like Figure 1 As shown, the control terminals (gate terminals in the case of IGBTs and FETs) of each switching element 3 constituting the inverter 10 are connected to the rotating electrical machine control device 1 via a drive circuit 2 (DRV), allowing each element to be independently switched. The operating voltages (power supply voltages) of the high-voltage system circuits (connected to the DC power supply 6) used to drive the rotating electrical machine 80, such as the inverter 10, and the low-voltage system circuits (operating voltages of approximately 3.3 to 5 volts), such as the rotating electrical machine control device 1, which utilize a microcomputer as its core, differ significantly. The drive circuit 2 relays the drive signal (switching control signal) by increasing the drive capability (e.g., voltage amplitude, output current, etc.) of each switching element 3. The first drive circuit 21 relays the switching control signal to the first inverter 11, and the second drive circuit 22 relays the switching control signal to the second inverter 12.

[0078] The rotating electrical machine control device 1 can implement two control methods, for example, pulse width modulation (PWM) control, which outputs multiple pulses of varying patterns per one electrical angle cycle, and rectangular wave control (1-pulse control), which outputs one pulse per one electrical angle cycle, as switching pattern methods (voltage waveform control methods) for the switching elements 3 constituting the first inverter 11 and the second inverter 12. Specifically, the rotating electrical machine control device 1 can implement both pulse width modulation control and rectangular wave control as control methods for the first inverter 11 and the second inverter 12. Furthermore, as described above, the rotating electrical machine control device 1 can control the first inverter 11 and the second inverter 12 independently of each other.

[0079] Pulse width modulation includes continuous pulse width modulation (CPWM) such as sinusoidal pulse width modulation (SPWM) and space vector pulse width modulation (SVPWM), and discontinuous pulse width modulation (DPWM). Therefore, the pulse width modulation control that can be executed by the rotating electrical machine control device 1 includes both continuous pulse width modulation control and discontinuous pulse width modulation control as control methods.

[0080] Continuous pulse width modulation (CPWM) is a modulation method that continuously performs PWM on all arms 3A of a multi-phase system. Discontinuous pulse width modulation (DPWM) is a modulation method that performs PWM on a portion of arms 3A of a multi-phase system, including periods in which the switching elements are fixed in either the on or off state. Specifically, in DPWM, for example, the signal levels of the inverter switching control signals corresponding to one of the three phases of AC power are sequentially fixed, while the signal levels of the switching control signals corresponding to the other two phases are varied. In continuous CPWM, all phases are modulated, rather than fixing the switching control signals corresponding to a single phase as described above. These modulation methods are determined based on the operating conditions required of the rotating electrical machine 80, such as the speed and torque, and the modulation ratio (the ratio of the effective value of the three-phase AC line voltage to the DC bus voltage) required to meet these operating conditions.

[0081] In pulse width modulation, pulses are generated based on the magnitude relationship between the amplitude of the AC waveform as a voltage command and the amplitude of the carrier wave (CA) in the form of a triangular wave (including a sawtooth wave). Figure 7 There are also cases where a PWM waveform is directly generated by digital calculation without comparison with a carrier wave. However, in this case, the amplitude of the AC waveform as the command value and the amplitude of the virtual carrier waveform are also correlated.

[0082] In pulse width modulation based on digital calculations, the carrier wave is determined based on the control cycle of the rotating electrical machine control device 1, such as the microcomputer's calculation cycle or the electronic circuit's operation cycle. That is, even when multi-phase AC power is used to drive the AC rotating electrical machine 80, the carrier wave has a cycle (an asynchronous cycle) that is not constrained by the rotational speed or rotational angle (electrical angle) of the rotating electrical machine 80. Therefore, neither the carrier wave nor the pulses generated based on the carrier wave are synchronized with the rotation of the rotating electrical machine 80. Therefore, modulation methods such as sinusoidal pulse width modulation and space vector pulse width modulation are sometimes referred to as asynchronous modulation. In contrast, modulation methods that generate pulses synchronously with the rotation of the rotating electrical machine 80 are referred to as synchronous modulation. For example, in rectangular wave control (rectangular wave modulation), one pulse is output during one cycle of the electrical angle of the rotating electrical machine 80, making rectangular wave modulation a synchronous modulation.

[0083] However, as an indicator of the conversion rate from DC bus voltage to AC voltage, there is a modulation rate that represents the ratio of the effective value of the line voltage of the multi-phase AC voltage to the DC bus voltage. Generally speaking, the maximum modulation rate of sinusoidal pulse width modulation is about 0.61 (≈0.612), and the maximum modulation rate of space vector pulse width modulation control is about 0.71 (≈0.707). A modulation method with a modulation rate exceeding about 0.71 is called "overmodulation pulse width modulation" as a modulation method with a higher modulation rate than the usual modulation rate. The maximum modulation rate of "overmodulation pulse width modulation" is about 0.78. This 0.78 is the physical (mathematical) limit value in the power conversion from DC to AC. In overmodulation pulse width modulation, when the modulation rate reaches 0.78, it becomes rectangular wave modulation (1 pulse modulation) that outputs one pulse in one cycle of electrical angle. In rectangular wave modulation, the modulation rate becomes fixed to the physical limit value, that is, about 0.78.

[0084] Overmodulation pulse width modulation with a modulation rate less than 0.78 can also be implemented using the principles of either synchronous modulation or asynchronous modulation. A representative modulation method for overmodulation pulse width modulation is discontinuous pulse width modulation. Discontinuous pulse width modulation can also be implemented using the principles of either synchronous modulation or asynchronous modulation. For example, when using synchronous modulation, rectangular wave modulation outputs one pulse per electrical angle cycle, but discontinuous pulse width modulation outputs multiple pulses per electrical angle cycle. If there are multiple pulses per electrical angle cycle, the effective period of the pulses is correspondingly reduced, thereby reducing the modulation rate. Therefore, the modulation rate is not limited to a fixed rate of approximately 0.78; any modulation rate less than 0.78 can be achieved using synchronous modulation. For example, multi-pulse modulation (multi-pulse modulation) such as 9-pulse modulation (9-pulses) that outputs 9 pulses per electrical angle cycle or 5-pulse modulation (5-pulses) that outputs 5 pulses can also be used.

[0085] In addition, the rotating electrical machine control device 1 can execute shutdown control (SDN) and active short-circuit control (ASC) as failsafe controls for situations where an abnormality is detected in the inverter 10 or the rotating electrical machine 80. Shutdown control is a control that deactivates the switching control signals of all the switching elements 3 constituting the inverter 10, thereby placing the inverter 10 in an off state. Active short-circuit control is a control that turns on either the upper-side switching elements 3H of all arms 3A of multiple phases or the lower-side switching elements 3L of all arms 3A of multiple phases, and turns off the other. Furthermore, the situation in which the upper-side switching elements 3H of all arms 3A of multiple phases are turned on and the lower-side switching elements 3L of all arms 3A of multiple phases are turned off is referred to as upper-side active short-circuit control. The following is referred to as lower-side active short-circuit control: turning on the lower-side switching elements 3L of all arms 3A of multiple phases and turning off the upper-side switching elements 3H of all arms 3A of multiple phases.

[0086] As in this embodiment, when inverters 10 are connected to both ends of the stator coil 8, if one inverter 10 is short-circuited through active short-circuit control, the multi-phase stator coils 8 are short-circuited in that one inverter 10. That is, that one inverter 10 becomes the neutral point, and the stator coils 8 are connected in a Y-connection. Therefore, the rotating electrical machine control device 1 can implement both a method of controlling an open-winding rotating electrical machine 80 using two inverters 10 and a method of controlling a Y-connected rotating electrical machine 80 using a single inverter 10 (the inverter 10 not undergoing active short-circuit control). Therefore, in this embodiment, the control method is not limited to failsafe control and also includes active short-circuit control as a control method selectable during normal control. That is, the rotating electrical machine control device 1 can also execute active short-circuit control as a control method for the first inverter 11 and the second inverter 12.

[0087] However, when vector control is performed on one inverter 10, eight space vectors can be defined based on the states of the three-phase arms 3A. Specifically, eight space vectors (2 3 =8). Furthermore, the signal levels of the three-phase switching control signals for lower-side switching element 3L are complementary to the switching control signals for upper-side switching element 3H. Therefore, a space vector can be defined by the signal levels of either the upper-side or lower-side switching control signals.

[0088] If the signal level of each switching control signal is high and is represented by "1" and low, respectively, and the signal levels of the switching control signals for the U-phase, V-phase, and W-phase are represented by (UVW), then the eight space vectors are (000), (001), (010), (011), (100), (101), (110), and (111). Of the eight space vectors, (000) and (111) are referred to as zero vectors or null vectors because the line voltage is zero and no voltage is applied to the rotating electrical machine 80. These vectors represent the same coordinates in the dq-axis vector coordinate system. In contrast, the other six space vectors are referred to as dynamic vectors and represent different coordinates in the dq-axis vector coordinate system.

[0089] like Figure 1 As shown, when two inverters 10 are vector controlled, 64 space vectors (2 (3·2) =2 6=64). Of these, 10 are null vectors. If (U1V1W1-U2V2W2) represents the signal levels of the U-phase (U1-phase), V-phase (V1-phase), and W-phase (W1-phase) of the first inverter 11 and the signal levels of the U-phase (U2-phase), V-phase (V2-phase), and W-phase (W2-phase) of the second inverter 12, then (000-000), (001-001), (010-010), (011-011), (100-100), (101-101), (110-110), (111-111), (000-111), and (111-000) are null vectors where the line voltage becomes zero. The remaining 54 are dynamic vectors that have valid magnitudes from the origin (the coordinates of the null vector) to 18 different coordinates in the dq-axis vector coordinate system.

[0090] exist Figure 3 In the figure, the coordinates of the null vector and the coordinates of the dynamic vectors at 18 locations are plotted. Z0 represents the coordinates of the null vector in the dq-axis vector coordinate system (all 10 vectors have the same coordinates). Z1 to Z6 represent the coordinates of the dynamic vectors substantially realized by one inverter 10 in the dq-axis vector coordinate system. Z7 to Z18 represent the coordinates corresponding to the dynamic vectors realized by two inverters 10 in the dq-axis vector coordinate system.

[0091] Z1 includes (000-011), (100-000), (100-111), (111-011), Z2 includes (000-001), (110-000), (110-111), (111-001), Z3 includes (000-101), (010-000), (010-111), (111-101), Z4 includes (000-100), (011-000), (011-111), (111-100), Z5 includes (000-110), (001-000), (001-111), (111-110), and Z6 includes (000-010), (101-000), (101-111), (111-010). These 24 space vectors are combinations where the space vector of one inverter 10 is a null vector and the space vector of another inverter 10 is a dynamic vector.

[0092] Furthermore, the 12 space vectors Z1: (101-001), (110-010), Z2: (010-011), (100-101), Z3: (011-001), (110-100), Z4: (001-101), (010-110), Z5: (011-010), (101-100), and Z6: (001-011), (100-110) also represent the coordinates of Z1 to Z6. However, these are not null vectors for one inverter 10; both inverters 10 are combinations of dynamic vectors.

[0093] Z7: (100-001), (110-011), Z8: (010-001), (110-101), Z9: (010-100), (011-101), Z10: (001-100), (011-110), Z11: (001-010), (101-110), Z12: (100-010), (101-011), corresponding to 12 space vectors. In addition, Z13: (100-011), Z14: (110-001), Z15: (010-101), Z16: (011-100), Z17: (001-110), Z18: (101-010), corresponding to 6 space vectors.

[0094] Figure 4 The vector diagram of an operating point in the dq axis vector coordinate system of the rotating motor 80 is illustrated. In the figure, "V1" is a first voltage vector representing the voltage based on the first inverter 11, and "V2" is a second voltage vector representing the voltage based on the second inverter 12. The voltage presented on the open winding, i.e., the stator coil 8, through the two inverters 10 is equivalent to the difference "V1-V2" between the first voltage vector V1 and the second voltage vector V2. "Va" in the figure represents the composite voltage vector presented on the stator coil 8. In addition, "Ia" represents the current flowing in the stator coil 8 of the rotating motor 80. As shown Figure 4 As shown, if the first inverter 11 and the second inverter 12 are controlled so that the directions of the first voltage vector V1 and the second voltage vector V2 differ by 180 degrees, the composite voltage vector Va is a vector obtained by adding the magnitude of the second voltage vector V2 to the direction of the first voltage vector V1.

[0095] When a rotating electrical machine 80 having independent multi-phase open-circuit windings is driven and controlled by two inverters 10, as in this embodiment, the two inverters 10 generally perform switching control using the same control method. However, the switching control method is preferably determined based on various factors (operating conditions) such as the torque, rotational speed, and DC side voltage required by the rotating electrical machine 80, to enable operation with higher system efficiency. Therefore, the rotating electrical machine control device 1 includes a control mode for controlling the first inverter 11 and the second inverter 12 using different control methods depending on the operating region (control region R) of the rotating electrical machine 80. The inventors' experiments and simulations have confirmed that by having a control mode for controlling the first inverter 11 and the second inverter 12 using different control methods depending on the operating conditions of the rotating electrical machine 80, system efficiency can be improved.

[0096] (First embodiment)

[0097] Hereinafter, an embodiment of the rotating electrical machine control device 1 having a control mode for controlling the first inverter 11 and the second inverter 12 in different control methods according to the operating conditions of the rotating electrical machine 80 will be described in detail.

[0098] In this embodiment (first embodiment), a plurality of control regions R (see Figure 5 The rotating electrical machine control device 1 controls the inverter 10 in a control manner corresponding to each control region R. Figure 5 FIG. 8 shows an example of the relationship between the rotation speed and torque of the rotating motor 80. For example, Figure 5 As shown, as the control region R of the rotary electric machine 80 , at least a first speed region VR1 and a second speed region VR2 where the rotation speed of the rotary electric machine 80 is higher than the first speed region VR1 at the same torque T are set.

[0099] As described above, the rotating electrical machine control device 1 can control each of the first inverter 11 and the second inverter 12 in a plurality of control modes with different switching patterns, and can control each of the first inverter 11 and the second inverter 12 in a mutually independent control mode. The control modes include: pulse width modulation control (PWM), which outputs a plurality of pulses with different patterns in one cycle of electrical angle; and hybrid pulse width modulation control (MX-PWM), which outputs a plurality of pulses with different patterns in one cycle of electrical angle, i.e., the first period T1 (see FIG. 1 ). Figure 8 etc.) outputs multiple pulses with different patterns, and in the remaining 1 / 2 cycle, that is, the second period T2 (refer to Figure 8 etc.) is controlled in a continuously inactive state (refer to Figures 8 to 11(Description will be made.) The rotating electrical machine control device 1 controls both the first inverter 11 and the second inverter 12 by hybrid pulse width modulation control in the second speed region VR2.

[0100] In hybrid pulse width modulation control, the switching control signal is also inactive during second period T2. This reduces losses in inverter 10 and reduces harmonic currents caused by switching operations, thereby reducing losses (iron losses) in rotating electric machine 80. In other words, hybrid pulse width modulation control can reduce system losses.

[0101] In the first speed region VR1, the rotating electrical machine control device 1 controls each of the first inverter 11 and the second inverter 12 using a control method different from hybrid pulse width modulation control. For example, as shown in Table 1 below, in the first speed region VR1, the rotating electrical machine control device 1 controls one of the first and second inverters 11, 12 (here, the first inverter 11) using active short circuit control (ASC) and controls the other inverter 10 (here, the second inverter 12) using pulse width modulation control (PWM). This type of control in the first speed region VR1 is referred to as target first speed region control.

[0102] [Table 1]

[0103] R INV1 INV2 VR1 ASC PWM VR2 MX-PWM MX-PWM

[0104] Table 1 illustrates the example of controlling the first inverter 11 through active short-circuit control in the first speed range VR1. However, the second inverter 12 can also be controlled through active short-circuit control. Furthermore, within the first speed range VR1, the control method for controlling the first inverter 11 and the control method for controlling the second inverter 12 can be alternately switched based on predetermined conditions. By switching the control method, it is possible to suppress energy consumption in only one of the first inverter 11 and the second inverter 12, or to prevent an increase in the discharge amount of only one of the first DC power supply 61 and the second DC power supply 62. The predetermined conditions are preferably, for example, a constant time or a constant discharge amount of the DC power supply 6.

[0105] In addition, if Figure 6As shown, the control region R may include a low-speed first speed region VR1-1 on the low-speed side within the first speed region VR1, and a high-speed first speed region VR1-2 on the high-speed side within the first speed region VR1, where the rotational speed of the rotating electrical machine 80 is higher than that in the low-speed first speed region VR1-1 at the same torque T. As shown in Table 2 below, the rotating electrical machine control device 1 controls one of the first inverter 11 and the second inverter 12 (herein, the first inverter 11) using active short-circuit control in the low-speed first speed region VR1-1 and controls the other inverter 10 (herein, the second inverter 12) using continuous pulse width modulation control. Furthermore, the rotating electrical machine control device 1 controls one of the first inverter 11 and the second inverter 12 (herein, the first inverter 11) using active short-circuit control in the high-speed first speed region VR1-2 and controls the other inverter 10 (herein, the second inverter 12) using discontinuous pulse width modulation control.

[0106] [Table 2]

[0107] R INV1 INV2 VR1-1(VR1) ASC CPWM(PWM) VR1-2(VR1) ASC DPWM(PWM) VR2 MX-PWM MX-PWM

[0108] In addition, when the first speed region VR1 is not divided into the low-speed side first speed region VR1-1 and the high-speed side first speed region VR1-2, that is, as shown in Table 1, it is preferable that the pulse width modulation control when only the first speed region VR1 is set is continuous pulse width modulation (CPWM).

[0109] In addition, while Table 2 illustrates the example of a method for controlling the first inverter 11 through active short-circuit control in the low-speed first speed region VR1-1 and the high-speed first speed region VR1-2, it is of course also possible to control the second inverter 12 through active short-circuit control. Alternatively, the first inverter 11 may be controlled through active short-circuit control in the low-speed first speed region VR1-1, while the second inverter 12 may be controlled through active short-circuit control in the high-speed first speed region VR1-2. Alternatively, the inverter 10 controlled by active short-circuit control may be different in the low-speed first speed region VR1-1 and the high-speed first speed region VR1-2 (including the opposite combination). Furthermore, as described above, in the low-speed first speed region VR1-1 and the high-speed first speed region VR1-2 (i.e., the first speed region VR1), the control method for controlling the first inverter 11 and the control method for controlling the second inverter 12 are alternately switched based on predetermined conditions.

[0110] In addition, if Figure 6As shown, as the control region R, a low-speed side second speed region VR2-1 on the low-speed side within the second speed region VR2 and a high-speed side second speed region VR2-2 on the high-speed side within the second speed region VR2 where the rotation speed of the rotating motor 80 is higher than the rotation speed of the low-speed side second speed region VR2-1 under the same torque T may also be set. In addition, the hybrid pulse width modulation control (MX-PWM) may also include a hybrid continuous pulse width modulation control (MX-CPWM) and a hybrid discontinuous pulse width modulation control (MX-DPWM). The details will be described later. In the hybrid continuous pulse width modulation control, control is performed in a continuously inactive state during the second period T2, and pulse width modulation is continuously performed on all arms 3A of the multi-phase during the first period T1 (to be referred to later). Figure 8 、 Figure 10 Similarly, as will be described in detail later, in the hybrid discontinuous pulse width modulation control, control is performed in a manner that the inactive state is continuously maintained during the second period T2, and pulse width modulation is performed on a portion of the arms 3A of the multi-phase in the first period T1, including a period in which the switching element 3 is fixed to the on state or the off state (to be referred to later). Figure 9 、 Figure 11 Describe it. ).

[0111] In this case, as shown in Table 3 below, the rotating electrical machine control device 1 controls both inverters 10, namely, the first inverter 11 and the second inverter 12, using hybrid continuous pulse width modulation control (MX-CPWM) in the low-speed second speed region VR2-1, and controls both inverters 10, namely, the first inverter 11 and the second inverter 12, using hybrid discontinuous pulse width modulation control (MX-DPWM) in the high-speed second speed region VR2-2. Furthermore, when the second speed region VR2 is not divided into the low-speed second speed region VR2-1 and the high-speed second speed region VR2-2, that is, when only the second speed region VR2 is set, as shown in Tables 1 and 2, the hybrid continuous pulse width modulation control (MX-CPWM) is preferably used.

[0112] [Table 3]

[0113] R INV1 INV2 VR1-1(VR1) ASC CPWM(PWM) VR1-2(VR1) ASC DPWM(PWM) VR2-1(VR2) MX-CPWM(MX-PWM) MX-CPWM(MX-PWM) VR2-2(VR2) MX-DPWM(MX-PWM) MX-DPWM(MX-PWM)

[0114] In addition, if Figure 7As shown, a third speed region VR3 may be set as the control region R, where the rotational speed of the rotating electrical machine 80 is higher than that of the second speed region VR2 under the same torque T. In this case, as shown in Table 4 below, the rotating electrical machine control device 1 preferably controls both inverters 10, the first inverter 11 and the second inverter 12, using the aforementioned rectangular wave control in the third speed region VR3. Table 4 also illustrates the allocation of control methods for the case where the first speed region VR1 and the second speed region VR2 are divided into two regions, the low speed side and the high speed side, respectively. Regarding the method for the case where the first speed region VR1 and the second speed region VR2 are not divided, the third speed region VR3 can be added to Table 1, and thus the table description is omitted.

[0115] [Table 4]

[0116] R INV1 INV2 VR1-1(VR1) ASC CPWM(PWM) VR1-2(VR1) ASC DPWM(PWM) VR2-1(VR2) MX-CPWM(MX-PWM) MX-CPWM(MX-PWM) VR2-2(VR2) MX-DPWM(MX-PWM) MX-DPWM(MX-PWM) VR3 1-Pulse 1-Pulse

[0117] Here, preferably, the boundaries of each control area R are set based on at least one of the ratio of the rotational speed of the rotating motor 80 corresponding to the torque of the rotating motor 80 and the effective value of the line voltage of the multi-phase AC voltage to the DC bus voltage (which can be a command value or a converted value from the output voltage).

[0118] like Figures 5 to 7 As illustrated, the operating conditions of the rotary electric machine 80 are often defined by the relationship between rotational speed and torque. The control region R can be set based on the rotational speed as a parameter. While the rotational speed defining the boundaries of the control region R can be set constant regardless of torque, it is more preferable to set the rotational speed defining the boundaries of the control region R to a value that varies depending on the torque. This allows the rotary electric machine 80 to be driven and controlled efficiently according to its operating conditions.

[0119] Furthermore, for example, if a high output (fast rotational speed, high torque) is required for the rotating electrical machine 80, this requirement can be achieved in a voltage-type inverter by increasing the DC bus voltage or by increasing the conversion ratio of the DC bus voltage to the AC voltage. If the DC bus voltage is constant, this requirement can be achieved by increasing the conversion ratio of the DC bus voltage to the AC voltage. This ratio can be expressed as the ratio of the effective value of the three-phase AC power to the DC bus power (in the case of a voltage-type inverter, it is equivalent to the ratio of the effective value of the line voltage of the three-phase AC voltage to the DC bus voltage). As described above, various control methods exist for controlling the inverter 10, ranging from low to high.

[0120] If the control region R is set based on the ratio (modulation factor) of the effective value of the line voltage of the three-phase AC voltage to the DC bus voltage determined based on the requirements for the rotating electric machine 80, the rotating electric machine 80 can be driven and controlled with high efficiency according to the operating conditions of the rotating electric machine 80. Table 5, shown below, corresponds to Table 4 above and illustrates the modulation factors corresponding to each control region R. Details will be described later, but in the table, "Mi_inv1" represents the modulation factor of the first inverter 11, "Mi_inv2" represents the modulation factor of the second inverter 12, and "Mi_sys" represents the modulation factor of the entire system.

[0121] [Table 5]

[0122] R Mi_sys INV1 Mi_inv1 INV2 Mi_inv2 VR1-1 M<a ASC M＝0 CPWM M<2a VR1-2 a≤M<X ASC M＝0 DPWM 2a≤M<2X VR2-1 X≤M<b MX-CPWM X≤M<b MX-CPWM X≤M<b VR2-2 b≤M<0.78 MX-DPWM b≤M<0.78 MX-DPWM b≤M<0.78 VR3 M＝0.78 1-Pulse M＝0.78 1-Pulse M＝0.78

[0123] In this embodiment, the inter-terminal voltage "E1" of the first DC power supply 61 and the inter-terminal voltage "E2" of the second DC power supply 62 are the same (both are voltage "E"). If the effective value on the AC side of the first inverter 11 is "Va_inv1" and the effective value on the AC side of the second inverter 12 is "Va_inv2," the modulation rate "Mi_inv1" of the first inverter 11 and the modulation rate "Mi_inv2" of the second inverter 12 are expressed as follows: Equations (1) and (2). Furthermore, the modulation rate "Mi_sys" of the entire system is expressed as follows: Equation (3).

[0124] Mi_inv1=Va_inv1 / E1=Va_inv1 / E···(1)

[0125] Mi_inv2=Va_inv2 / E2=Va_inv2 / E···(2)

[0126] Mi_sys=(Va_inv1+Va_inv2) / (E1+E2)

[0127] =(Va_inv1+Va_inv2) / 2E···(3)

[0128] Regarding the instantaneous value of the voltage, the instantaneous vector must be considered. However, if only the modulation rate is considered, the modulation rate "Mi_sys" for the entire system is "(Mi_inv1 + Mi_inv2) / 2" as shown in Equations (1) to (3). Furthermore, Table 5 shows the modulation rates corresponding to each control region R as rated values. Therefore, during actual control, considering fluctuations caused by changes in the control method within the control region R, a range of modulation rates that overlap with each control region R may be included.

[0129] The modulation rate "X" is set based on the theoretical upper limit of the modulation rate for continuous pulse width modulation (space vector pulse width modulation) (approximately 0.707), taking into account the dead time. As shown in Tables 1 to 5, in the first speed range VR1, modulation may be performed by only one inverter 10. Therefore, in the first speed range VR1, the maximum modulation rate "2X" of one inverter 10 (here, the second inverter 12) is set to approximately 0.5 to 0.6, for example, based on the theoretical upper limit of the modulation rate for continuous pulse width modulation control (approximately 0.707 for space vector pulse width modulation), taking into account the dead time. Therefore, the modulation rate "X" is set to a value of approximately 0.25 to 0.3, for example. The modulation rates "a" and "b" are appropriately set based on experiments, simulations, and the like.

[0130] In the first speed region VR1, one of the two inverters 10 (e.g., the first inverter 11) is controlled through active short-circuit control. That is, the rotating electric machine 80 is essentially driven by only one of the two inverters 10 (e.g., the second inverter 12). Since one inverter 10 does not perform switching, the corresponding switching losses can be reduced. As a result, the rotating electric machine 80 can be driven while suppressing losses in the entire system.

[0131] With two inverters 10, as in this configuration, it is possible to generate an AC voltage with a larger amplitude than the voltage on the DC side of each inverter 10. However, the rotating electrical machine control device 1 does not necessarily need to constantly control both inverters 10 to increase the AC amplitude. For example, when the rotating electrical machine 80 is rotating at a low speed, generating the AC voltage that can be generated by a single inverter 10 may be sufficient. If one of the two inverters 10 is controlled using active short-circuit control, the three-phase stator coils 8 are short-circuited in that inverter 10. In this case, the other inverter 10 drives and controls the rotating electrical machine 80, which has stator coils 8 connected to a neutral point.

[0132] As mentioned above, with respect to the modulation rate based on continuous pulse width modulation, space vector pulse width modulation has a higher modulation rate than sine wave pulse width modulation, while discontinuous pulse width modulation has a higher modulation rate than space vector pulse width modulation. When the first speed range VR1 is divided, the high-speed first speed range VR1-2 is a control range in which the rotational speed of the rotating electrical machine 80 is higher than that of the low-speed first speed range VR1-1. A higher modulation rate is required in the high-speed first speed range VR1-2 than in the low-speed first speed range VR1-1. By performing continuous pulse width modulation control in the low-speed first speed range VR1-1 and discontinuous pulse width modulation control in the high-speed first speed range VR1-2, the control method can be appropriately switched according to the load throughout the first speed range VR1, thereby driving the rotating electrical machine 80 while minimizing losses in the entire system.

[0133] Furthermore, under the same torque T, the highest modulation rate is obtained in the third speed range VR3 on the highest speed side. In the third speed range VR3, both inverters 10, the first inverter 11 and the second inverter 12, are controlled using rectangular wave control, which physically maximizes the modulation rate. This allows the rotating electric machine 80 to be appropriately driven even when a high load is required of the rotating electric machine 80.

[0134] The second speed region VR2 is located between the first speed region VR1 and the third speed region VR3 and can be referred to as a control region corresponding to the so-called intermediate to high speed region, or the intermediate to high modulation rate region. In this region (second speed region VR2), it is considered possible to control both the first inverter 11 and the second inverter 12 using either continuous pulse width modulation control or discontinuous pulse width modulation control. In this embodiment, since both the first inverter 11 and the second inverter 12 are controlled using hybrid pulse width modulation control in the second speed region VR2, switching losses in the inverter 10 can be further reduced compared to control using continuous pulse width modulation control or discontinuous pulse width modulation control.

[0135] The inventors' experiments and simulations have confirmed that the application of hybrid pulse-width modulation control is particularly effective in the second, low-speed range VR2-1. Specifically, at least in the second, low-speed range VR2-1, implementing hybrid continuous pulse-width modulation control can reduce system losses. As shown in Table 6 below, the rotating electrical machine control device 1 can also control both inverters 10, the first inverter 11 and the second inverter 12, using discontinuous pulse-width modulation control in the second, high-speed range VR2-2, instead of hybrid discontinuous pulse-width modulation control.

[0136] [Table 6]

[0137] R Mi_sys INV1 Mi_inv1 INV2 Mi_inv2 VR1-1 M<a ASC M＝0 CPWM M<2a VR1-2 a≤M<X ASC M＝0 DPWM 2a≤M<2X VR2-1 X≤M<b MX-CPWM X≤M<b MX-CPWM X≤M<b VR2-2 b≤M<0.78 DPWM b≤M<0.78 DPWM b≤M<0.78 VR3 M＝0.78 1-Pulse M＝0.78 1-Pulse M＝0.78

[0138] The following describes the control method in each control region R with reference to waveform examples of the U-phase voltage commands (Vu1**, Vu2**) and the U-phase upstream-side switch control signals (Su1+, Su2+). Illustration of the second U-phase downstream-side switch control signal Su2- and the V and W phases is omitted.

[0139] First, refer to Figures 8 to 11 The hybrid pulse width modulation control (MX-PWM) which is the most characteristic of the present embodiment and is executed in the second speed region VR2 will be described. Figure 8 as well as Figure 10 shows the hybrid continuous pulse width modulation control (MX-CPWM), Figure 9 as well as Figure 11 A hybrid discontinuous pulse width modulation control (MX-DPWM) is shown.

[0140] exist Figure 8 and Figure 9 , an example of the carrier CA of the first inverter 11, i.e., the first carrier CA1, the carrier CA of the second inverter 12, i.e., the second carrier CA2, the U-phase voltage command shared by the first inverter 11 and the second inverter 12, i.e., the common U-phase voltage command Vu**, the first U-phase upstream-side switch control signal Sul+, and the second U-phase upstream-side switch control signal Su2+ is shown. The first U-phase downstream-side switch control signal Su1-, the second U-phase downstream-side switch control signal Su2-, and the V and W phases are not shown (the same applies to other control methods).

[0141] For example, the first carrier CA1 can vary between "0.5 < CA1 < 1," the second carrier CA2 can vary between "0 < CA2 < 0.5," and the voltage command (V**) can vary between "0 ≤ V** ≤ 1." By comparing the carrier CA (first carrier CA1 and second carrier VA2) with the voltage command (V**), the switch control signal becomes "1" when the voltage command is greater than the carrier CA, and "0" when the voltage command is less than the carrier CA. The comparison logic between the carrier CA and the voltage command (V**) remains the same throughout the following description.

[0142] like Figure 8 and Figure 9As shown, the amplitudes of the first carrier wave CA1 and the second carrier wave CA2 are half the amplitude allowed by the voltage command (V**). In conventional pulse width modulation, the amplitude of the carrier wave CA is equal to the amplitude allowed by the voltage command. The carrier wave CA in hybrid pulse width modulation can be referred to as a half-carrier wave. By using this half-carrier wave, during the first period T1, which is half a cycle in electrical angle, the half-carrier wave intersects with the voltage command (V**), resulting in the output of multiple pulses with different patterns as switching control signals. During the remaining half cycle, during the second period T2, the half-carrier wave does not intersect with the voltage command (V**), resulting in the output of the switching control signal remaining in an inactive state.

[0143] In addition, if Figure 9 As shown in FIG, in the hybrid discontinuous pulse width modulation control, in the second period T2, a pulse that partially becomes active is also output as a switch control signal. This is because the modulation rate of the discontinuous pulse width modulation as the basis is larger than that of the continuous pulse width modulation. The pulse that becomes active in the second period T2 is output near the amplitude center of the voltage command (V**), near the inflection point of the voltage command (V**). Figure 9 As shown, even in hybrid discontinuous pulse width modulation control, it can be said that the inactive state is continuously output during the second period T2. Furthermore, if the second period T2 is set to be only the period during which the switch control signal is in the inactive state (a period less than 1 / 2 cycle), and the period in one cycle is set to be other than the second period T2 (a period longer than 1 / 2 cycle), hybrid pulse width modulation can also be defined as follows. Alternatively, hybrid pulse width modulation control can be said to output multiple pulses with different patterns during the first period T1, which is longer than 1 / 2 cycle in electrical angle, and to maintain the inactive state during the remaining period of one electrical angle cycle, which is the second period T2.

[0144] Figure 10 as well as Figure 11 Illustrated with Figure 8 as well as Figure 9 Different hybrid continuous pulse width modulation control and hybrid discontinuous pulse width modulation control methods. The generated switch control signals are the same. Figure 10 as well as Figure 11, which shows an example of the carrier CA of the first inverter 11, i.e., the first carrier CA1; the carrier CA of the second inverter 12, i.e., the second carrier CA2; the U-phase voltage instruction of the first inverter 11, i.e., the first U-phase voltage instruction Vu1**; the U-phase voltage instruction of the second inverter 12, i.e., the second U-phase voltage instruction Vu2**; the first U-phase upstream side switch control signal Su1+; and the second U-phase upstream side switch control signal Su2+. For example, the first carrier CA1 and the second carrier CA2 can vary between "0.5<CA1<1", and the voltage instruction (V**) can vary between "0≤V**≤1". The phase difference between the first carrier CA1 and the second carrier CA2 is 180 degrees (π). In addition, the phase difference between the first U-phase voltage instruction Vu1** and the second U-phase voltage instruction Vu2** is also 180 degrees (π).

[0145] like Figure 10 as well as Figure 11 As shown in FIG, the amplitude of the first carrier CA1 and the second carrier CA2 is half of the amplitude allowed by the voltage command (V**). Figure 10 as well as Figure 11 The carrier CA in the illustrated embodiment is also a half-carrier. By using this half-carrier, during the first period T1, which is half a cycle (or longer) of electrical angle, the half-carrier intersects with the voltage command (V**), resulting in the output of multiple pulses with different patterns as the switching control signal. During the remaining period of the cycle, the second period T2, the half-carrier does not intersect with the voltage command (V**), resulting in the switching control signal being output in a continuously inactive state.

[0146] Figure 8 and Figure 9 The illustrated method is a method of using two half-carriers and a voltage command (V**) as a common reference for modulation, which can be called a dual half-carrier single reference method. Figure 10 and Figure 11 The illustrated method is a method of using two half-carriers and two voltage commands (V**) for modulation, which can be called a dual-half-carrier dual-reference method.

[0147] As reference Figures 8 to 11 As described above, hybrid pulse width modulation control generates multiple pulses based on a carrier CA having a wave height of half the range of the command value (voltage command, in the above example, the U-phase voltage command (Vu** (Vu** = Vu1** = Vu2**), Vu1**, Vu2**)) and the command value (first carrier CA1, second carrier CA2). Furthermore, in this embodiment, two hybrid pulse width modulation control methods are exemplified: a dual half-carrier single-reference method and a dual half-carrier dual-reference method.

[0148] As reference Figure 8 as well as Figure 9 As described above, in the dual half-carrier single reference method, pulses for the first inverter 11 are generated based on a first half-carrier (first carrier CA1) set as a half-carrier at one of the higher voltage side and the lower voltage side (here, the higher voltage side) relative to the amplitude center of the command value (common U-phase voltage command Vu**) and a command value (common U-phase voltage command Vu**) common to the first inverter 11 and the second inverter 12. Furthermore, in this method, pulses for the second inverter 12 are generated based on a second half-carrier (second carrier CA2) having the same phase as the first half-carrier (first carrier CA1) and set at the other of the higher voltage side and the lower voltage side (here, the lower voltage side) relative to the amplitude center of the command value (common U-phase voltage command Vu**) and the command value (common U-phase voltage command Vu**).

[0149] As reference Figure 10 as well as Figure 11 As described above, in the dual half-carrier dual-reference method, pulses for the first inverter 11 are generated based on a first half-carrier (first carrier CA1) set as a half-carrier on one of the higher voltage side and the lower voltage side (here, the higher voltage side) relative to the amplitude center of the command values ​​(first U-phase voltage command Vu1**, second U-phase voltage command Vu2**), and a first command value (first U-phase voltage command Vu1**) for the first inverter 11. Furthermore, in this method, pulses for the second inverter 12 are generated based on a second half-carrier (second carrier CA2) having a phase 180 degrees different from that of the first half-carrier (first carrier CA1) and set on the same side (the higher voltage side) as the first half-carrier (first carrier CA1), and a second command value (second U-phase voltage command Vu2**) for the second inverter 12 having a phase 180 degrees different from that of the first command value (first U-phase voltage command Vu1**).

[0150] Although not shown in the figure, pulses can also be generated using a single half-carrier / dual reference method, in which pulses are generated based on a common half-carrier and command values ​​that are 180 degrees out of phase with each other. Specifically, in this method, a common half-carrier (carrier CA) is set closer to either the high-voltage side or the low-voltage side (e.g., the high-voltage side) than the amplitude center of the command values ​​(first U-phase voltage command Vu1**, second U-phase voltage command Vu2**). Pulses for the first inverter 11 are generated based on this half-carrier (carrier CA) and the first command value (first U-phase voltage command Vu1**) for the first inverter 11. Furthermore, in this method, pulses for the second inverter 12 are generated based on a second command value (second U-phase voltage command Vu2**) for the second inverter 12 that is 180 degrees out of phase with the first command value (first U-phase voltage command Vu1**) and the half-carrier (carrier CA).

[0151] However, the inventors' experiments and simulations have confirmed that, compared to the single half-carrier / dual reference method, the dual half-carrier single reference method and the dual half-carrier dual reference method can suppress harmonic components in the frequency of carrier CA. Therefore, hybrid pulse width modulation control is preferably performed using the dual half-carrier single reference method or the dual half-carrier dual reference method.

[0152] Figure 12 The waveform diagram shows an example of the U-phase voltage command (i.e., first U-phase voltage command Vu1**) for the first inverter 11, the U-phase voltage command (i.e., second U-phase voltage command Vu2**) for the second inverter 12, the carrier CA, the first U-phase upstream-side switch control signal Su1+, and the second U-phase upstream-side switch control signal Su2+ in the low-speed first speed region VR1-1. For example, the carrier CA varies within the range of "0 < CA < 1," and the voltage command (V**) varies within the range of "0 ≤ V** ≤ 1." The same applies to the range of variation of the carrier CA and the voltage command (V**) in the following description.

[0153] In the low-speed side first speed region VR1-1, the second inverter 12 is controlled by continuous pulse width modulation control. Figure 12 As shown, a pulse-shaped second U-phase upper-side switch control signal Su2+ is generated based on the carrier CA and the second U-phase voltage command Vu2**.

[0154] As described above, since the first inverter 11 is controlled by active short-circuit control in the first speed region VR1-1 on the low-speed side, the first U-phase voltage command Vu1** is fixed to "0", for example, and the first U-phase upper-side switch control signal Su1+ is always "0". Although not shown in the figure, the first U-phase lower-side switch control signal Su1- is always "1". As a result, the upper-side switching element 3H (31H) of the U-phase arm 3A of the first inverter 11 is controlled to be in the disconnected state, and the lower-side switching element 3L (31L) is controlled to be in the connected state. The same is true for the V-phase and W-phase, and thus, the first inverter 11 is controlled by active short-circuit control on the lower side. In addition, the first U-phase voltage command Vu1** may be set to a fixed value without setting the first U-phase switch control signal Su1.

[0155] Figure 13 The waveform diagram shows an example of the first U-phase voltage command Vu1**, the second U-phase voltage command Vu2**, the carrier CA, the first U-phase upstream side switch control signal Su1+, and the second U-phase upstream side switch control signal Su2+ in the high-speed side first speed region VR1-2. Similar to the low-speed side first speed region VR1-1, since the first inverter 11 is controlled by active short-circuit control in the high-speed side first speed region VR1-2, the first U-phase voltage command Vu1** is a fixed value. In the high-speed side first speed region VR1-2, the second inverter 12 is controlled by discontinuous pulse width modulation control. In the interval where the second U-phase voltage command Vu2** is "0" or "1", the first U-phase upstream side switch control signal Su1+ is a fixed value, and the switching element 3 (32) is fixed to the on state or the off state.

[0156] Figure 14 The waveform diagram shows an example of the first U-phase voltage command Vu1**, the second U-phase voltage command Vu2**, the carrier CA, the first U-phase upstream-side switch control signal Su1+, and the second U-phase upstream-side switch control signal Su2+ in the third speed region VR3. As described above, in the third speed region VR3, both the first inverter 11 and the second inverter 12 are controlled using rectangular wave control. Furthermore, when the inverter 10 is controlled using rectangular wave modulation control, while the carrier CA is not required, it is also shown for ease of comparison with other control methods.

[0157] As described with reference to Table 6, Figure 15The waveform diagram shows an example of the first U-phase voltage command Vu1**, the second U-phase voltage command Vu2**, the carrier CA, the first U-phase upper side switch control signal Su1+, and the second U-phase upper side switch control signal Su2+ when the two inverters 10 are controlled by discontinuous pulse width modulation control in the second speed region VR2-2 on the high speed side.

[0158] like Figures 8 to 11 、 Figure 14 as well as Figure 15 As shown, when both the first inverter 11 and the second inverter 12 are switched, the first U-phase voltage command Vu1** and the second U-phase voltage command Vu2** are approximately 180 degrees out of phase. For example, the maximum amplitude of the U-phase voltage is "(4 / 3)E", and the maximum amplitude of the line voltage is "2E" (see also Figure 3 as well as Figure 4 Vector diagram. Furthermore, the first DC power supply 61 and the second DC power supply 62 are independent of each other, and the first DC bus voltage E1 of the first DC power supply 61 and the second DC bus voltage E2 of the second DC power supply 62 may have different values. For example, to be precise, the maximum amplitude of the U-phase voltage is "((2 / 3)E1) + (2 / 3)E2", but for ease of understanding, it is assumed in this specification that "E1 = E2 = E".

[0159] As described above, in the first speed range VR1, where the modulation rate and rotational speed are relatively low, and the power is relatively low, all power is supplied from a single inverter 10. At this time, a voltage command (V**) is provided to one inverter 10 to perform active short-circuit control, while a normal voltage command (V**) is provided to the other inverter 10. In the second and third speed ranges VR2 and VR3, where the modulation rate and rotational speed are higher than in the first speed range VR1 and the power is higher than in the first speed range VR1, equal power is supplied from both inverters 10. At this time, the same voltage command (V**) is provided to both inverters 10, with a phase difference of 180 degrees (π).

[0160] However, when switching inverter 10, a pulsating component superimposed on the fundamental wave of the AC current may generate noise in the audible band. When two inverters 10 are controlled using different control methods, pulsations corresponding to each control method are generated, which may increase noise in the audible band. Especially when the rotating motor 80 is rotating at a low speed, the frequency of the pulsating component (or its sideband frequency) is more likely to be included in the audible band. The control method for the rotating motor 80, i.e., the control method for the inverter 10, is preferably appropriately set according to the operating conditions to achieve operation with high system efficiency and reduce audible noise.

[0161] The rotating electrical machine control device 1 of this embodiment has a loss reduction priority mode and a noise reduction priority mode as control modes for the rotating electrical machine 80, and is capable of switching between the loss reduction priority mode and the noise reduction priority mode. As described above, the rotating electrical machine control device 1 performs target first speed range control in the first speed range VR1 in the loss reduction priority mode, and performs alternative first speed range control in place of the target first speed range control in the noise reduction priority mode. Specifically, as shown in Table 7 below, the rotating electrical machine control device 1 performs alternative first speed range control in place of the target first speed range control in the noise reduction priority mode, controlling both inverters 10, the first inverter 11 and the second inverter 12, using pulse width modulation control (continuous pulse width modulation control) in the first speed range VR1.

[0162] [Table 7]

[0163] R Mi_sys INV1 Mi_inv1 INV2 Mi_inv2 VR1 M<X CPWM M<X CPWM M<X VR2-1 X≤M<b MX-CPWM X≤M<b MX-CPWM X≤M<b VR2-2 b≤M<0.78 MX-DPWM b≤M<0.78 MX-DPWM b≤M<0.78 VR3 M＝0.78 1-Pulse M＝0.78 1-Pulse M＝0.78

[0164] When the inverter 10 is switched, a pulsating component superimposed on the fundamental wave of the AC current may generate noise in the audible band. Especially when the rotating electrical machine 80 is rotating at a low speed, the frequency of the pulsating component (or its sideband frequencies) is more likely to fall within the audible band. For example, when two inverters 10 are controlled using different control methods, pulsations corresponding to each control method are generated, potentially increasing noise in the audible band. In the loss reduction priority mode, since only one inverter 10 is driven in the first speed range VR1 and the second speed range VR2, where the rotating electrical machine 80 rotates at relatively low speeds, noise in different frequency bands is not generated in the two inverters 10. However, since the output of the driven inverter 10 is higher, the energy of the noise increases. Furthermore, in the first speed range VR1 and the second speed range VR2, the sound associated with vehicle movement (such as the sound of wheels contacting the road) is also relatively low. Therefore, if the noise output from the driven inverter 10 falls within the audible band, the user may easily hear the noise.

[0165] For example, when the vehicle is starting or slowing down to a stop, the noise reduction mode is selected to prioritize audible noise, considering that the user is more likely to hear it. When the vehicle is in steady operation, the loss reduction mode is preferably selected. These modes can also be selected by user operation (including input from a setting switch (touch panel, etc.)).

[0166] In the noise reduction priority mode, the first inverter 11 and the second inverter 12 are controlled in the same manner in the first speed range VR1 and the second speed range VR2, where the rotational speed of the rotating electrical machine 80 is relatively low. Furthermore, the currents flowing through the stator coils 8 in the two inverters 10 are controlled with a phase difference of approximately 180 degrees. When the two inverters 10 are controlled in the same manner, the phase difference of the currents, including the pulsating components, is approximately 180 degrees. This allows the pulsating components to at least partially cancel each other out, reducing noise in the audible band.

[0167] Figure 16 The waveform diagram shows an example of the first U-phase voltage command Vu1**, the second U-phase voltage command Vu2**, the carrier CA, the first U-phase upstream-side switch control signal Su1+, and the second U-phase upstream-side switch control signal Su2+ in the first speed range VR1 in noise reduction priority mode. As shown in Table 7, in noise reduction priority mode, in the first speed range VR1, both the first inverter 11 and the second inverter 12 are controlled using continuous pulse width modulation control.

[0168] However, in the above description, in the loss reduction priority mode, as described with reference to Tables 1 to 6, hybrid continuous pulse width modulation (MX-CPWM) control is implemented in the second speed region VR2 (or, if divided, the lower-speed second speed region VR2-1). However, as shown in Table 8 below, similarly to the second speed region VR2 (low-speed second speed region VR2-1), hybrid continuous pulse width modulation (MX-CPWM) control can also be implemented for both the first inverter 11 and the second inverter 12 in the first speed region VR1. In other words, as the target first speed region control, both the first inverter 11 and the second inverter 12 can also be controlled using hybrid continuous pulse width modulation (MX-CPWM).

[0169] [Table 8]

[0170] R Mi_sys INV1 Mi_inv1 INV2 Mi_inv2 VR1 M<X MX-CPWM M<X MX-CPWM M<X VR2-1 X≤M<b MX-CPWM X≤M<b MX-CPWM X≤M<b VR2-2 b≤M<0.78 MX-DPWM b≤M<0.78 MX-DPWM b≤M<0.78 VR3 M＝0.78 1-Pulse M＝0.78 1-Pulse M＝0.78

[0171] Specifically, in the loss reduction priority mode, the target first speed region control executed in the first speed region VR1 includes two methods: the method described in Tables 1 to 6 (a method in which one inverter 10 is controlled using active short circuit control (ASC) (ASC / PWM)) and the method described in Table 8 (a method in which both inverters 10 are controlled using hybrid continuous pulse width modulation (MX-CPWM) (MX-CPWM / MX-CPWM)). Furthermore, as described in Table 7, in the noise reduction priority mode, an alternative first speed region control is executed in the first speed region VR1 instead of the target first speed region control. As described above, the alternative first speed region control is a method in which both inverters 10 are controlled using continuous pulse width modulation (CPWM) (CPWM / CPWM). Specifically, the control methods executed in the first speed region VR1 include three control methods: "ASC / PWM," "MX-CPWM / MX-CPWM," and "CPWM / CPWM."

[0172] When two inverters 10 are provided, as in this embodiment, an AC voltage with a larger amplitude than the voltage on the DC side of each inverter 10 can be generated. However, the rotating electrical machine control device 1 does not necessarily need to constantly control both inverters 10 to increase the AC voltage amplitude. For example, when the rotating electrical machine 80 is rotating at a low speed, generating the AC voltage that can be generated by a single inverter 10 may be sufficient. Therefore, the above-described embodiment described with reference to Tables 1 to 6 illustrates an embodiment in which one of the two inverters 10 is controlled using active short-circuit control as the target first speed range control. In this embodiment, the stator coils 8 are short-circuited in one inverter 10, and the rotating electrical machine 80 is similar to a rotating electrical machine having stator coils at an electrically neutral point. In other words, the rotating electrical machine 80 is essentially driven by only one of the two inverters 10. Since the inverter 10 controlled by active short-circuit control does not perform switching operations, it is possible to drive the rotating electrical machine 80 while minimizing losses in the entire system.

[0173] In the method illustrated in Table 8, hybrid pulse width modulation control is performed as the target first speed range control. As described above, hybrid pulse width modulation control is a control method that combines a period of pulse width modulation and a period of no modulation (fixed state) for approximately half a period within each cycle of the electrical angle. Therefore, for each 1 / 2 period, the rotating electrical machine 80 is essentially driven by only one of the two inverters 10. Since the inverter 10 does not perform switching during approximately 1 / 2 of the driving time, switching losses can be reduced, thereby reducing system losses. The inventors' experiments and simulations have confirmed that even when either "ASC / PWM" or "MX-CPWM / MX-CPWM" is performed as the target first speed range control, the loss improvement is roughly the same as that achieved by a single inverter system.

[0174] Figures 17 to 19 The waveforms and frequency characteristics (analysis results of the three-phase current based on Fast Fourier Transform (FFT)) of the three-phase current (U-phase current Iu, V-phase current Iv, W-phase current Iw) flowing in the stator coil 8 under different control methods are shown. Figure 17 The current and frequency characteristics under the "MX-CPWM / MX-CPWM" control mode are shown. Figure 18 The current and frequency characteristics under the "CPWM / CPWM" control mode are shown. Figure 19 The current and frequency characteristics of a single inverter system are shown as a comparative example. Note that the frequency characteristics of "ASC / PWM" ("ASC / CPWM") have been omitted from the illustration because they tend to be roughly the same as those of "MX-CPWM / MX-CPWM." The example shown here illustrates a case where the frequency "f" of the carrier CA is 5 kHz.

[0175] By comparison Figure 17 and Figure 19 It can be seen that when a dual inverter system is used to drive the rotating electrical machine 80 via two inverters 10 in order to reduce losses, when "MX-CPWM / MX-CPWM" is used as the control method, the harmonic components around 5 [kHz] (harmonic components of the sideband frequencies "f±3fm" of the frequency "f" of the carrier CA) slightly increase compared to the single inverter system ("fm" is the rotation speed of the rotating electrical machine 80, the same applies hereinafter). On the other hand, by comparing Figure 18 and Figure 19 It can be seen that even in the case of a dual inverter system, when "CPWM / CPWM" is used as the control method, for a single inverter system, the harmonic components near 5 [kHz] (the harmonic components with the sideband frequency "f" of the carrier CA frequency "f" being "f±3fm") are reduced and can hardly be observed.

[0176] While the human audible frequency range is generally around 20 Hz to 15 kHz, frequencies above 10 kHz are generally inaudible, and frequencies around 5 kHz are easily perceived as noise. In "MX-CPWM / MX-CPWM" or "ASC / PWM" operating in loss reduction priority mode, harmonic components around 5 kHz are slightly increased compared to single-inverter systems. In contrast, in "CPWM / CPWM" operating in noise reduction priority mode, harmonic components around 5 kHz are significantly reduced compared to single-inverter systems.

[0177] Therefore, for example, when the vehicle is starting or slowing to a stop, the noise reduction priority mode is preferably selected, considering that the user is more likely to hear noise in the audible frequency band. On the other hand, when the vehicle is in steady operation, the user is less likely to hear noise in the audible frequency band due to the driving sound, etc., and since steady operation takes much longer than starting, etc., the loss reduction priority mode is preferably selected during steady operation.

[0178] Although not shown in the figure, the magnitude of harmonic components in the audible frequency band (primarily harmonic components of the sideband frequencies "f ± 3fm" of the frequency "f" of the carrier CA) is generally in the relationship "CPWM / CPWM" < "ASC / PWM" ("ASC / CPWM") ≈ "MX-CPWM / MX-CPWM." For example, if it is predicted that transitions between the first speed range VR1 and the second speed range VR2 will occur frequently, selecting "MX-CPWM / MX-CPWM" in the first speed range VR1 allows the same control method to be maintained even if transitions between the first speed range VR1 and the second speed range VR2 occur frequently, thereby improving controllability. On the other hand, if it is predicted that transitions between the first speed range VR1 and the second speed range VR2 will not occur frequently, it is preferable to select "ASC / PWM" ("ASC / CPWM") in the first speed range VR1.

[0179] The control method in the first speed region VR1 in the loss reduction priority mode can be selected, for example, based on whether the road the vehicle is traveling on is a highway or a regular road (in the case of a regular road, it is predicted that there will be more acceleration and deceleration, so "MX-CPWM / MX-CPWM" is selected, etc.). Alternatively, the control method can be selected based on the average speed of the preceding vehicle (in the case of a lower average speed, it is predicted that there will be more acceleration and deceleration and a decrease in the average speed, so "MX-CPWM / MX-CPWM" is selected). Alternatively, the selection can be made by user operation (setting switch (including input from a touch panel, etc.)).

[0180] Figure 20 An example of the control range of a rotating electrical machine in a single inverter system, in which three-phase stator coils 8 are connected via a neutral point, is shown as a comparative example. As shown in Table 9 below, this inverter is controlled using continuous pulse width modulation (CPWM) in the first region VR11, discontinuous pulse width modulation (DPWM) in the second region VR12, and rectangular wave (1-Pulse) control in the third region VR13.

[0181] [Table 9]

[0182] R Mi_sys INV1 Mi_inv VR11 M<Y,where Y>X CPWM M<Y,where Y>X VR12 Y≤M<0.78 DPWM Y≤M<0.78 VR13 M＝0.78 1-Pulse M＝0.78

[0183] The modulation rate "Y" is a value greater than the modulation rate "X" illustrated in Tables 5 to 8. It is set to, for example, approximately 0.5 to 0.6 based on the theoretical upper limit of the modulation rate based on continuous pulse width modulation (space vector pulse width modulation) (approximately 0.707) and taking into account the dead time.

[0184] As described above, in this embodiment, in a single-inverter system, the second speed region VR2 is set in a region corresponding to the second region VR12 for discontinuous pulse width modulation (DPWM), and characteristic hybrid pulse width modulation control (MX-PWM) is implemented. Hybrid pulse width modulation control reduces losses in inverter 10 and also reduces harmonic currents caused by switching, thereby reducing losses (iron losses) in rotating electric machine 80. In other words, hybrid pulse width modulation control can reduce system losses. Furthermore, by setting the first speed region VR1 in a region corresponding to the first region VR11, overall system losses can be reduced in loss reduction priority mode, and both losses and noise can be reduced in noise reduction priority mode.

[0185] Figures 21 to 33 A comparative example of a single inverter system and a dual inverter system and a comparative example of control methods in the dual inverter system are shown. Figures 21 to 26 A comparative example in a relatively low speed region (eg, first region VR11 , first speed region VR1 ) is shown. Figures 28 to 33 Comparative examples in higher high-speed regions (eg, second region VR12 , second speed region VR2 ) are shown. Figure 27 FIG. 1 shows an example of a control region R of the rotary electric machine 80 of a dual inverter system of a comparative example in which discontinuous pulse width modulation control is performed on two inverters 10 in the second speed region VR2. Figures 28 to 33, in the second speed region VR2 of the dual inverter system, a comparison is also made between the case where discontinuous pulse width modulation control is performed on the two inverters 10 (the case where control is performed in the "DPWM / DPWM" method) and the case where hybrid continuous pulse width modulation control is performed on the two inverters 10 (the case where control is performed in the "MX-CPWM / MX-CPWM" method).

[0186] Figure 21 A comparative example of the switching control signals (Su, Su1, Su2) and the line voltage (Vuv) is shown. The column on the left represents a waveform example of a single inverter system, and the other columns represent waveform examples of a dual inverter system. The waveform examples of the dual inverter system, from left to right, represent a waveform example of a case where both inverters 10 are controlled by continuous pulse width modulation control (CPWM) (CPWM / CPWM), a waveform example of a case where the first inverter 11 is controlled by active short circuit control (ASC) and the second inverter 12 is controlled by continuous pulse width modulation control (CPWM) (ASC / CPWM), and a case where both inverters 10 are controlled by hybrid continuous pulse width modulation control (MX-CPWM) (MX-CPWM / MX-CPWM). For a single inverter system, a waveform example of a case where it is controlled by continuous pulse width modulation control (CPWM) is shown.

[0187] The first layer from the top shows an example waveform of the switching control signal Su1 for the U-phase arm 3A of the first inverter 11 (in the case of a single inverter system, this is the switching control signal Su for the U-phase arm of the inverter). The second layer from the top shows an example waveform of the switching control signal Su2 for the U-phase arm 3A of the second inverter 12 (this signal is not present in the case of a single inverter system). The third layer from the top shows an example waveform of the line voltage between the U-phase and V-phases of the stator coil 8 (UV line voltage Vuv).

[0188] Figure 22 A comparative example of three-phase currents (U-phase current Iu, V-phase current Iv, W-phase current Iw) is shown. Figure 23 The analysis results based on fast Fourier transform (FFT) of the U-phase current Iu centered on the frequency "f" of the carrier CA (for example, 5 [kHz] here) are shown, and the sizes of the sideband frequencies "f±3fm" of the frequency "f" of the carrier CA are compared ("fm" is the rotational speed of the rotating motor 80, and the same applies below). Figure 24 The analysis results based on fast Fourier transform (FFT) of the U-phase current Iu centered at a frequency "2f" (here, for example, 10 [kHz]) twice the frequency of the carrier CA are shown, and the sizes of the sideband frequencies "2f±fm" of "2f" are compared. Figure 25The analysis results of the UV line voltage Vuv based on the fast Fourier transform (FFT) centered on the frequency "f" of the carrier CA are shown, and the magnitudes of the sideband frequencies "f±3fm" of the frequency "f" of the carrier CA are compared. Figure 26 The results of analysis based on Fast Fourier Transform (FFT) of the UV line voltage Vuv centered around a frequency "2f" twice the frequency of the carrier CA are shown, and the magnitudes of the sideband frequencies "2f±fm" of "2f" are compared.

[0189] like Figure 24 and Figure 26 As shown, the harmonic components of the sideband frequency "2f±fm" of the frequency "2f" twice the frequency of the carrier CA in the U-phase current Iu and the UV line voltage Vuv are smaller in the "ASC / CPWM" mode and the "MX-CPWM / MX-CPWM" mode in the dual inverter system than in the "CPWM / CPWM" mode in the single inverter system and the dual inverter system. Therefore, since the iron loss can be suppressed and the switching loss is reduced by not performing a switching operation in the "ASC / CPWM" mode by one inverter 10, the overall system loss can be appropriately reduced. In addition, as shown in FIG. Figures 8 to 11 As described above, even in the "MX-CPWM / MX-CPWM" mode, since only one inverter 10 switches approximately every half cycle, switching losses can be reduced, thereby appropriately reducing overall system losses. Therefore, as described above, when prioritizing system loss reduction (in the loss reduction priority mode), it is preferable to select the "ASC / CPWM" mode or the "MX-CPWM / MX-CPWM" mode in the first speed range VR1.

[0190] like Figure 23 and Figure 25As shown, the harmonic components of the sideband frequencies "f ± 3fm" of the carrier CA frequency "f" in the U-phase current Iu and the UV line voltage Vuv are minimized in the dual-inverter system using the CPWM / CPWM method. Even when comparing dual-inverter systems, the harmonic components of the sideband frequencies "f ± 3fm" of the carrier CA frequency "f" are smaller in the CPWM / CPWM method than in the ASC / CPWM method and the MX-CPWM / MX-CPWM method. While the human audible frequency range is generally around 20 Hz to 15 kHz, frequencies above 10 kHz are generally difficult to hear, and frequencies around 5 kHz are easily perceived as noise. In other words, the harmonic components of the carrier CA frequency "f" with sideband frequencies "f ± 3fm" around 5 kHz are more likely to become audible noise than the harmonic components of the sideband frequencies "2f" (2f ± fm), or around 10 kHz. Therefore, as shown in this example, when the frequency "f" of the carrier CA is 5 [kHz] and the harmonic components of the sideband frequencies "f±3fm" are preferentially suppressed from becoming audible noise (in the case of noise reduction priority mode), it is preferable to select the "CPWM / CPWM" method in the first speed region VR1.

[0191] In addition, if Figure 24 and Figure 26 As shown, in the "CPWM" method in a single inverter system and the "CPWM / CPWM" method in a dual inverter system, the harmonic components of the sideband frequencies "2f±fm" at a frequency "2f" twice the frequency of the carrier CA in the U-phase current Iu and the UV line voltage Vuv are approximately equal. Therefore, in the range where the rotation speed is relatively low and audible noise is easily noticeable, it is preferable to select the noise reduction priority mode and perform control using the "CPWM / CPWM" method.

[0192] However, as in this embodiment, a dual inverter system may be constructed without hybrid pulse width modulation. In this case, in order to further reduce system loss than a single inverter system, Figure 27 Consider setting the control method as shown in Tables 10 and 11 below for the control region R shown. This dual-inverter system is referred to as a comparative dual-inverter system. The control region R is the same as that described with reference to Tables 1 to 8. As described with reference to Tables 1 to 6, Table 10 shows the relationship between the control region and the control method in the loss reduction priority mode. As described with reference to Tables 7 and 8, Table 11 shows the relationship between the control region and the control method in the noise reduction priority mode.

[0193] [Table 10]

[0194] R Mi_sys INV1 Mi_inv1 iNV2 Mi_mv2 VR1-1 M<a ASC M＝0 CPWM M<2a VR1-2 a≤M<X ASC M＝0 DPWM 2a≤M<2X VR2 X≤M<0.78 DPWM X≤M<0.78 DPWM X≤M<0.78 VR3 M＝0.78 1-Pulse M＝0.78 1-Pulse M＝0.78

[0195] [Table 11]

[0196] R Mi_sys INV1 Mi_inv1 INV2 Mi_inv2 VR1-1 M<a CPWM M=a CPWM M<a VR1-2 a≤M<X DPWM a≤M<X DPWM a≤M<X VR2 X≤M<0.78 DPWM X≤M<0.78 DPWM X≤M<0.78 VR3 M＝0.78 1-Pulse M＝0.78 1-Pulse M＝0.78

[0197] As shown in Table 10, in the loss reduction priority mode, in the dual-inverter system of the comparative example, the rotating electrical machine control device 1 controls one of the first inverter 11 and the second inverter 12 using active short-circuit control (ASC) in the low-speed first speed region VR1-1, and controls the other inverter 10 using continuous pulse width modulation control (CPWM). Furthermore, in the high-speed first speed region VR1-2, the rotating electrical machine control device 1 controls one of the first inverter 11 and the second inverter 12 using active short-circuit control, and controls the other inverter 10 using discontinuous pulse width modulation control (DPWM). Furthermore, in the second speed region VR2, the rotating electrical machine control device 1 controls both inverters 10, the first inverter 11 and the second inverter 12, using discontinuous pulse width modulation control. Furthermore, the rotating electrical machine control device 1 controls the two inverters 10 , namely the first inverter 11 and the second inverter 12 , by rectangular wave control (1-pulse) in the third speed region VR3 .

[0198] As shown in Table 11, in the noise reduction priority mode, in the dual-inverter system of the comparative example, the rotating electrical machine control device 1 controls both inverters 10, namely the first inverter 11 and the second inverter 12, using continuous pulse width modulation (CPWM) control in the low-speed first speed region VR1-1. Furthermore, in the high-speed first speed region VR1-2, the rotating electrical machine control device 1 controls both inverters 10, namely the first inverter 11 and the second inverter 12, using discontinuous pulse width modulation (DPWM) control. In the second speed region VR2 and the third speed region, the same control mode as in the loss reduction priority mode is used.

[0199] As reference Figure 7 , Table 4 to Table 6, etc., in this embodiment of performing hybrid pulse width modulation, Figure 27 , In the dual inverter system of the comparative example shown in Table 10 and Table 11, in at least a portion of the second speed region VR2 controlled by the "DPWM / DPWM" method (for example, Figure 7 as well as Figure 27 In the low-speed side second speed region VR2-1 and the high-speed side first speed region VR1-2 shown, both inverters 10 are controlled by hybrid continuous pulse width modulation rectangular wave control ("MX-CPWM / MX-CPWM" method).

[0200] Below, refer to Figures 28 to 33, to compare and illustrate the case where discontinuous pulse width modulation control is performed on the two inverters 10 (the case where control is performed in the "DPWM / DPWM" method), the case where mixed continuous pulse width modulation control is performed on the two inverters 10 (the case where control is performed in the "MX-CPWM / MX-CPWM" method), and the case where the inverters are controlled by discontinuous pulse width modulation (DPWM) in a single inverter system.

[0201] As shown in Table 9 and Figure 20 As stated, Figure 28 This figure shows waveform examples and FFT analysis results for the case of discontinuous pulse width modulation control executed in a single inverter system within the second region VR12, which includes the region corresponding to the low-speed second speed region VR2-1. The top row shows the carrier CA, the U-phase voltage command "Vu**," and the U-phase switching control signal "Su." The second row from the top shows the UV line voltage Vuv, and the third row from the top shows the three-phase currents (U-phase current Iu, V-phase current Iv, and W-phase current Iw). The bottom row shows the results of a Fast Fourier Transform (FFT) analysis of the U-phase current Iu.

[0202] For example, refer to Table 10, Table 11, Figure 27 As stated, Figure 29 The following diagram shows waveform examples and FFT analysis results when discontinuous pulse width modulation control is performed on the two inverters 10 in the dual inverter system (when the "DPWM / DPWM" method of control is performed) in the second speed range VR2 including the low-speed second speed range VR2-1. The top layer shows the carrier CA, the U-phase voltage instructions "Vu1**, Vu2**" of each of the two inverters 10, and the switching control signals "Su1+, Su2+" of the two inverters 10. The second layer and the following layers are the same as the Figure 28 same.

[0203] As shown in Tables 3 to 6, Figure 7 As mentioned above, Figure 30 The following shows waveform examples and FFT analysis results when hybrid continuous pulse width modulation control is performed on the two inverters 10 in the dual inverter system (when the "MX-CPWM / MX-CPWM" method control is performed) in the low-speed second speed region VR2-1 included in the second speed region VR2. The signals shown in the waveform examples are Figure 29 same.

[0204] Figure 31 The relationship between the rotational speed and the audible noise in the single inverter system described with reference to Table 9 is shown. Figure 32The relationship between the rotation speed of the rotating electric machine 80 and the audible noise in the dual inverter system of the comparative example described with reference to Table 11 and the like is shown. Figure 33 The relationship between the rotation speed of the rotating electrical machine 80 and the audible noise in the dual inverter system of this embodiment described with reference to Table 7 and the like is shown. Figure 31 In the single inverter system, according to the modulation rate and the speed of the rotating motor 80, as shown in FIG. Figure 20 As shown in Table 9, the control area changes from the first area VR11 to the second area VR12, and the control mode switches from continuous pulse width modulation control (CPWM) to discontinuous pulse width modulation control (DPWM). Figure 32 In the dual inverter system of the comparative example, according to the modulation rate and the speed of the rotating motor 80, as shown in FIG. Figures 5 to 7 As shown in Table 11, the control area changes from the low-speed side first speed area VR1-1 to the high-speed side first speed area VR1-2, and the control method changes from the "CPWM / CPWM" method to the "DPWM / DPWM" method. Figure 33 In the dual inverter system of this embodiment, according to the modulation rate and the rotation speed of the rotating motor 80, as shown in FIG. Figures 5 to 7 As described in Table 7, the control region changes from the low-speed side first speed region VR1-1 to the high-speed side first speed region VR1-2, and the control mode switches from the "CPWM / CPWM" mode to the "MX-CPWM / MX-CPWM" mode.

[0205] from Figure 28 and Figure 29 Comparison and Figure 28 and Figure 30 A comparison shows that when using DPWM control in a single inverter system, more ripple is superimposed on the three-phase currents compared to when using the DPWM / DPWM or MX-CPWM / MX-CPWM control methods in a dual inverter system. Therefore, as shown by the FFT analysis results, more harmonic components at the sideband frequencies "f±3fm" of the carrier frequency "f" are generated in the single inverter system compared to the dual inverter system. These sideband harmonic components at the frequencies "f±3fm" sometimes overlap with lower-order harmonic components (11th and 13th).

[0206] like Figure 31 As shown in FIG. 1 , in a single inverter system, the noise of the rotating electric machine 80 generated according to the speed of the rotating electric machine 80 (the audible noise of "12fm" when the frequency of the rotation speed is set to "fm") and the audible noise of the sideband frequency "f±3fm" overlap in the portion surrounded by the dotted circle, so the audible noise becomes very large. On the other hand, as Figure 32 as well as Figure 33As shown, in a dual-inverter system, audible noise at the sideband frequencies "f ± 3 fm" of the frequency "f" of the carrier CA is almost nonexistent. Therefore, the audible noise (12 fm) of the rotating electric machine 80, which is generated depending on the speed of the rotating electric machine 80, does not overlap with the audible noise at the sideband frequencies "f ± 3 fm." Therefore, a dual-inverter system can be constructed with higher noise levels than a single-inverter system.

[0207] In addition, from the comparison Figure 29 and Figure 30 It can be seen that the number of switching times of the inverter 10 in the "MX-CPWM / MX-CPWM" method is reduced compared to the "DPWM / DPWM" method. Figure 30 The "MX-CPWM / MX-CPWM" method shown is the same as Figure 29 Compared to the DPWM / DPWM method shown above, switching losses are reduced, thereby reducing system losses. As mentioned above, the DPWM / DPWM method and the MX-CPWM / MX-CPWM method are equivalent in terms of audible noise. Therefore, by adopting the MX-CPWM / MX-CPWM method in the second speed range VR2 (low-speed second speed range VR2-1) of the dual inverter system, high quietness can be achieved and system losses can be reduced.

[0208] However, as described in Table 8, when both the first inverter 11 and the second inverter 12 are driven using hybrid pulse-width modulation control, the ripple of the DC bus current flowing through the DC power supply 6 or the DC link capacitor 4 (particularly the third harmonic component of the frequency of the rotational speed of the rotating electrical machine 80) may increase in the high-torque operating range. This harmonic current ripple can shorten the life of the DC power supply 6 or the DC link capacitor 4 and may also cause failure of the rotating electrical machine control device 1. Increasing the capacitance of the DC link capacitor 4 can reduce the ripple, but it may also increase the size of the DC link capacitor 4 and increase its cost. The following describes how to address this ripple.

[0209] Figure 34 An example of the control area of ​​the rotating motor 80 is shown. In the first speed area VR1 and the second speed area VR2, the area where the torque is above the specified torque Tref is called the high torque area VRH, and the area where the torque is less than the specified torque is called the low torque area VRL. The first action point Q1 is the action point belonging to the high torque area VRH, and the second action point Q2 is the action point belonging to the low torque area VRL. The following illustrates the simulation waveforms and FFT analysis results of the two action points, and compares and explains a single inverter system, a dual inverter system using conventional pulse width modulation control, and a dual inverter system using hybrid pulse width modulation control. In addition, for reference, in Figure 20 shows the first operating point Q1 and the second operating point Q2 in the single inverter system. Furthermore, although specific numerical values ​​are not shown in the waveform examples, in order to be equal to the output of the rotating electrical machine 80, the rated value of the DC side voltage (rated value of the DC link voltage Vdc) in the single inverter system is twice the rated value of the DC link voltage Vdc in the dual inverter system.

[0210] Figures 35 to 39 Shown Figure 20 and Figure 34 Comparative example of waveform examples of a single inverter system at the first operating point Q1, a dual inverter system using conventional pulse width modulation control, and a dual inverter system using hybrid pulse width modulation control, as well as a comparative example of FFT analysis results. Figures 40 to 44 Shown Figure 20 and Figure 34 Comparison of waveforms of a single inverter system at the second operating point Q2, a dual inverter system using conventional pulse width modulation control, and a dual inverter system using hybrid pulse width modulation control, as well as comparison of FFT analysis results. Figures 35 to 44 In all the figures, from left to right, a single inverter system, a dual inverter system using conventional pulse width modulation control, and a dual inverter system using hybrid pulse width modulation control are shown. Figures 35 to 44 In all figures, the upper side shows waveform examples, and the lower side shows FFT analysis results.

[0211] Furthermore, the simulation was performed by driving the inverter 10 by discontinuous pulse width modulation control (DPWM) in a single inverter system, driving the two inverters 10 by discontinuous pulse width modulation control (DPWM / DPWM) in a dual inverter system using conventional pulse width modulation control, and driving the two inverters 10 by hybrid continuous pulse width modulation control (MX-CPWM / MX-CPWM) in a dual inverter system using hybrid pulse width modulation control. Figures 35 to 44 In FIG. 1 , “fm” represents the frequency of the rotational speed of the rotating electrical machine 80 (rotational frequency), and “f” represents the switching frequency (frequency of the carrier CA) of the inverter 10. As described above, the simulation was performed here with the switching frequency “f” set to 5 [kHz].

[0212] Figure 35 as well as Figure 40 The waveforms of the three-phase AC phase currents (Iu, Iv, Iw) and the FFT analysis results of the phase currents (for example, U-phase current Iu is used as a representative example) are shown. Figure 36 as well as Figure 41The waveform of the DC bus current Idc and the FFT analysis results of the DC bus current Idc are shown. In addition, regarding the dual inverter system, the current waveform on the DC side of the first inverter 11 is shown as a representative. Figure 37 as well as Figure 42 The waveform of the battery current Ib flowing through the DC power supply 6 and the result of FFT analysis of the battery current Ib are shown. As a representative example of the dual inverter system, the waveform of the current flowing through the first DC power supply 61 on the first inverter 11 side is shown. Figure 38 as well as Figure 43 The waveform of the capacitor current Ic flowing through the DC link capacitor 4 and the FFT analysis results of the capacitor current Ic are shown. As a representative example of the dual inverter system, the waveform of the current flowing through the first DC link capacitor 41 on the first inverter 11 side is shown.

[0213] Figure 39 as well as Figure 44 The waveform of the DC link voltage Vdc is shown, especially the waveform of the DC bus voltage ripple on the DC link voltage Vdc and the FFT analysis results of the DC bus voltage ripple. Since the DC bus voltage ripple height is smaller than the DC link voltage Vdc (100-200 [V] in the dual inverter system and 200-400 [V] in the single inverter system), it is only about 10 [V] lower. Figure 39 as well as Figure 44 The waveform of the AC component near the rated value of the DC is shown in . In addition, regarding the dual inverter system, the waveform of the DC link voltage Vdc of the first inverter 11 is shown as a representative.

[0214] like Figure 35 as well as Figure 40 As shown, in a single-inverter system, high noise components are generated near the switching frequency "f". However, in a dual-inverter system, the first inverter 11 and the second inverter 12 cancel each other out the noise caused by the switching frequency "f", thereby significantly suppressing the noise components near the switching frequency "f".

[0215] like Figure 36 as well as Figure 41 As shown in FIG, since the DC bus current Idc flows through each inverter 10 even in the dual inverter system, the current ripple caused by the switching frequency "f" cannot be offset, and the same noise component as the single inverter system is observed. In particular, since the control method of the single inverter system and the dual inverter system using conventional pulse width modulation control is discontinuous pulse width modulation control (DPWM), the FFT analysis results are almost the same. On the other hand, as shown in FIG. Figure 8As described above, in a dual inverter system using hybrid continuous pulse width modulation control (MX-CPWM), since the pulses become asymmetric in one cycle of electrical angle, the ripple of the third harmonic component "3fm" of the rotation frequency "fm" is observed to be high.

[0216] exist Figure 37 as well as Figure 42 The battery current Ib shown in FIG. 1 shows the same trend as that of the DC bus current Idc. Figure 37 As shown in FIG. 1 , the ripple component of the battery current Ib at the first operating point Q1 has a very high wave height of approximately 30 [A] in the single inverter system, approximately 50 [A] in the dual inverter system using conventional discontinuous pulse width modulation control, and approximately 130 [A] in the dual inverter system using hybrid discontinuous pulse width modulation control. On the other hand, Figure 42 As shown, the ripple component height in the battery current Ib at the second operating point Q2 is less than 20 [V] in the single inverter system and the dual inverter system using conventional discontinuous pulse width modulation control, and less than 50 [A] even in the dual inverter system using hybrid discontinuous pulse width modulation control. In other words, even in the dual inverter system using hybrid discontinuous pulse width modulation control, the ripple component height in the battery current Ib at the second operating point Q2, where torque is relatively low, is suppressed to be smaller than the height (approximately 50 [A]) in the dual inverter system using conventional discontinuous pulse width modulation control at the first operating point Q1, where torque is relatively high.

[0217] The capacitor current Ic is "battery current Ib - DC bus current Idc". Therefore, if Figure 38 as well as Figure 43 As shown, the same trend is observed for battery current Ib and DC bus current Idc. Specifically, in the dual inverter system using hybrid discontinuous pulse width modulation control, while a ripple component, the third harmonic component "3fm" of the rotation frequency "fm," is observed, the height of the ripple component of capacitor current Ic is suppressed at the second operating point Q2 compared to the first operating point Q1, reaching a level comparable to that of a dual inverter system using conventional discontinuous pulse width modulation control.

[0218] like Figure 39 as well as Figure 44As shown, a similar trend is observed in the DC link voltage Vdc. Specifically, in the dual inverter system using hybrid discontinuous pulse width modulation control, a ripple component, "3fm," the third harmonic component of the rotation frequency "fm," is observed. At the first operating point Q1, a ripple voltage with a height of approximately 15 V is observed, compared to the ripple voltage of approximately 10 V in other systems. However, at the second operating point Q2, the ripple voltage height is suppressed compared to the first operating point Q1. The ripple voltage, which is approximately 3 V in a dual inverter system using conventional discontinuous pulse width modulation control, is reduced to a ripple voltage of approximately 5 V, achieving a level of suppression comparable to that of a dual inverter system using conventional discontinuous pulse width modulation control.

[0219] If the ripple of battery current Ib increases, the loss of DC power supply 6 increases. Since this loss is converted into heat, the heat generated by DC power supply 6 increases, potentially shortening the life of DC power supply 6. To reduce the ripple of the third harmonic component of the rotation frequency "fm" as described above, increasing the capacitance of DC link capacitor 4 is a conceivable option. However, this would increase the size of DC link capacitor 4, potentially increasing costs due to increased component unit prices and increased storage space.

[0220] As reference Figures 35 to 44 As described above, at the second operating point Q2, where torque is relatively low, the ripple of the third harmonic component of the rotation frequency "fm" can be suppressed compared to the first operating point Q1, where torque is relatively high. Therefore, preferably, the two inverters 10 are driven using hybrid pulse width modulation control in the control region (low torque region VRL) including the second operating point Q2, and are driven using normal pulse width modulation in the control region (high torque region (VRH)) including the first operating point Q1. Specifically, the rotating electrical machine control device 1 preferably controls both the first inverter 11 and the second inverter 10 using pulse width modulation control in the high torque region VRH, where torque is greater than or equal to a predetermined torque Tref, in the first speed region VR1 and the second speed region VR2, and controls both the first inverter 11 and the second inverter 10 using hybrid pulse width modulation control in the low torque region VRL, where torque is less than the predetermined torque Tref. For example, the rotating electrical machine control device 1 preferably drives the inverters 10 as shown in Table 12 below.

[0221] [Table 12]

[0222]

[0223] Here, when corresponding to the control area described in reference table 8, it is as shown in the following table 13. Figure 34In Table 13, the control region R and the control method corresponding to the method are exemplified. In addition, as shown in Table 8 or Table 12, Mi_sis, Mi_inv1, and Mi_inv2 are the same, so Mi_inv1 and Mi_inv2 are omitted in Table 13.

[0224] [Table 13]

[0225]

[0226] That is, as shown in Table 13, the rotating electrical machine control device 1 controls both the first inverter 11 and the second inverter 12 using hybrid continuous pulse width modulation control (MX-CPWM) in the low torque region VRL less than the predetermined torque Tref in the first speed region VR1 and the low-speed second speed region VR2-1. In the low torque region VRL less than the predetermined torque Tref in the high-speed second speed region VR2-2, the rotating electrical machine control device 1 controls both the first inverter 11 and the second inverter 12 using hybrid discontinuous pulse width modulation control (MX-DPWM). Furthermore, the rotating electrical machine control device 1 controls both the first inverter 11 and the second inverter 12 using continuous pulse width modulation control (CPWM) in the high torque region VRH in the first speed region VR1, and controls both the first inverter 11 and the second inverter 12 using discontinuous pulse width modulation control (DPWM) in the high torque region VRH in the second speed region VR2.

[0227] Furthermore, the actual DC power supply 6 has a resistance component (battery resistance Rb) and an inductance component (battery inductance Lb). In simulations conducted by the inventors, the battery resistance Rb and battery inductance Lb of an existing DC power supply 6 were used to calculate the battery current Ib and DC link voltage Vdc based on the DC bus current Idc. It was also confirmed that the calculated values ​​of the battery current Ib and DC link voltage Vdc matched the frequency characteristics of the current gain based on the switching frequency "f." Furthermore, since the frequency characteristics shift toward decreasing current gain as the battery resistance Rb and battery inductance Lb increase, current ripple can be further reduced.

[0228] See also below Figure 45 as well as Figure 46 The flowchart is described. Figure 45 The flowchart of is a flowchart showing an example of a selection of a control method when the ripple of the DC bus current flowing in the DC link capacitor 4 is not considered. Specifically, Figure 45 An example of the determination sequence when the control methods shown in Table 8 and Table 11 are selected is shown. Figures 34 to 44 As stated, Figure 46 4 is a flowchart showing an example of a selection of a control method when the DC bus current flowing in the DC link capacitor 4 is taken into consideration. Specifically, Figure 46 An example of the determination sequence when the control method shown in Table 13 above is selected is shown. Figure 45 as well as Figure 46 In the figure, “M”, “X1” and “X2” represent modulation rates, “S” and “S1 to S7” represent the rotation speed of the rotary electric machine 80 , “T” represents the torque of the rotary electric machine 80 , and “Tref” represents a predetermined torque.

[0229] like Figure 45 As shown, first select the operation mode (Drive mode) (#1). Here, when the noise reduction priority mode (Noise priority mode: Noise priority mode) is selected, select the control method (#3: PWM pattern Selection) according to the conditions of Table 11, thereby determining the various control methods shown in step #4. In addition, "X1" in step #3 corresponds to "a" in Table 11. Figure 45 As shown in Table 11, when the modulation rate "M" is less than "X1(a)" and the speed "S" is less than "S1", continuous pulse width modulation control (CPWM) is selected as the control method for the two inverters 10 (#31→#41). When the modulation rate "M" is greater than "X1(a)" and less than "0.78", and the speed "S" is greater than "S1" and less than "S2", discontinuous pulse width modulation control (DPWM) is selected as the control method for the two inverters 10 (#32→#42). When the modulation rate "M" is "0.78" and the speed "S" is greater than "S2" and less than "S3", rectangular wave control (1-Pulse) is selected as the control method for the two inverters 10 (#33→#43).

[0230] In step #1, when the loss reduction priority mode (efficiency priority mode) is selected, the control method (#5: PWM pattern Selection) is selected according to the conditions in Table 8, thereby determining the various control methods shown in step #6. In addition, "X2" in step #5 corresponds to "b" in Table 8. Figure 45As shown in Table 8, when the modulation rate "M" is less than "X2(b)" and the speed "S" is less than "S4", hybrid continuous pulse width modulation control (MX-CPWM) is selected as the control method for the two inverters 10 (#51→#61). When the modulation rate "M" is greater than "X2(b)" and less than "0.78", and the speed "S" is greater than "S4" and less than "S5", hybrid discontinuous pulse width modulation control (MX-DPWM) is selected as the control method for the two inverters 10 (#52→#62). When the modulation rate "M" is "0.78" and the speed "S" is greater than "S5" and less than "S6", rectangular wave control (1-Pulse) is selected as the control method for the two inverters 10 (#53→#63).

[0231] Even in the case of considering the DC bus current flowing in the DC link capacitor 4, similarly, as Figure 46 As shown, first, the operation mode (#1) is selected. Here, when the loss reduction priority mode (Efficiency priority mode) is selected, it is next determined whether the torque of the rotating motor 80 exceeds the specified torque Tref (#2: Torque check). When the torque of the rotating motor 80 is less than the specified torque Tref, the control method is selected (#5) and determined (#6) according to the conditions on the upper side of Table 13. Since steps #5 and #6 are the same as Figure 45 The same as above, so the detailed description is omitted. In addition, "X2" in step #3 corresponds to "b" in Table 13.

[0232] When the noise reduction priority mode (Noise priority mode) is selected in step #1, or when the loss reduction priority mode (Efficiency priority mode) is selected in step #1, and it is determined in step #2 "Torque determination" that the torque of the rotary electric machine 80 is greater than the specified torque Tref, the control method is selected (#3) and determined (#4) according to the conditions on the lower side of Table 13. Since steps #3 and #4 are related to Figure 45 The same as above, so the detailed description is omitted. In addition, "X1" in step #3 is equivalent to "X" in Table 13.

[0233] In reference Figure 46 In the above method, the method of performing "torque determination" in step #2 is exemplified. However, if Figure 47As shown, in step #2, it can also be determined whether both the torque and the speed meet the benchmark. Specifically, the operation mode (#1) is first selected. Here, when the loss reduction priority mode (Efficiency priority mode) is selected, it is then determined whether the torque "T" of the rotating motor 80 exceeds the specified torque Tref and exceeds the specified speed Sref (#2). When the torque "T" of the rotating motor 80 is below the specified torque Tref, or when the speed "S" of the rotating motor 80 is below the specified speed Sref, or when the torque "T" of the rotating motor 80 is below the specified torque Tref and the speed "S" of the rotating motor 80 is below the specified speed Sref, the same as the conditions on the upper side of Table 13, select (#5) and determine (#6) the control method. Since steps #5 and #6 are the same as Figure 45 as well as Figure 46 The same, so the detailed description is omitted.

[0234] When the noise reduction priority mode (Noise priority mode) is selected in step #1, or when the loss reduction priority mode (Efficiency priority mode) is selected in step #1, and then in step #2 it is determined that the torque "T" of the rotary motor 80 exceeds the specified torque Tref and the speed "S" of the rotary motor 80 exceeds the specified speed Sref, the control method is selected (#3) and determined (#4) in the same manner as the conditions on the lower side of Table 13. Since steps #3 and #4 are similar to the Figure 45 as well as Figure 46 The same, so the detailed description is omitted.

[0235] That is, in Figure 46 exemplifies a method of driving the rotating electric machine 80 in a loss reduction priority mode (Efficiency priority mode) prioritizing efficiency in a relatively high torque range, and in a noise reduction priority mode (Noise priority mode) in a relatively low torque range. Figure 47 , there is illustrated an example of driving the rotating electric machine 80 in a loss reduction priority mode (Efficiency priority mode) that prioritizes efficiency in a relatively high torque and high speed range, and driving the rotating electric machine 80 in a noise reduction priority mode (Noise priority mode) in a relatively low torque and low speed range.

[0236] (Second embodiment)

[0237] A second embodiment of a rotating electrical machine control device 1 having a control mode for controlling the first inverter 11 and the second inverter 12 using different control methods depending on the operating conditions of the rotating electrical machine 80 will be described in detail below. Matters identical to those of the first embodiment described above will be described with reference to the drawings referenced in the description of the first embodiment. Furthermore, even in the description of the second embodiment, which refers to drawings different from those of the first embodiment, matters identical to those of the first embodiment will be described using the same reference numerals.

[0238] In this embodiment (second embodiment), a plurality of control regions R (see FIG. 1 ) corresponding to the operating conditions of the rotary electric machine 80 are set. Figure 48 The rotating electrical machine control device 1 controls the inverter 10 in a control manner corresponding to each control region R. Figure 48 FIG. 8 shows an example of the relationship between the rotation speed and torque of the rotating motor 80. For example, Figure 48 As shown, as the control area R of the rotating motor 80, a first speed area VR1, a second speed area VR2 in which the rotation speed of the rotating motor 80 is higher than that of the first speed area VR1 under the same torque T, and a third speed area VR3 in which the rotation speed of the rotating motor 80 is higher than that of the second speed area VR2 under the same torque T are set.

[0239] For example, as shown in Table 14 below, in the first speed region VR1, the rotating electrical machine control device 1 controls one of the first inverter 11 and the second inverter 12 using active short-circuit control (ASC) and controls the other inverter 10 using continuous pulse width modulation control (CPWM). Furthermore, in the second speed region VR2, the rotating electrical machine control device 1 controls one of the first inverter 11 and the second inverter 12 using active short-circuit control and controls the other inverter 10 using discontinuous pulse width modulation control (DPWM). Furthermore, in the third speed region VR3, the rotating electrical machine control device 1 controls both inverters 10, the first inverter 11 and the second inverter 12, using discontinuous pulse width modulation control. Hereinafter, such control in the first speed region VR1, the second speed region VR2, and the third speed region VR3 will be referred to as target control.

[0240] [Table 14]

[0241] R INV1 INV2 VR1 ASC CPWM VR2 ASC DPWM VR3 DPWM DPWM

[0242] In addition, although Table 1 illustrates a method of controlling the first inverter 11 by active short-circuit control in the first speed region VR1 and the second speed region VR2, it is of course also possible to control the second inverter 12 by active short-circuit control. Alternatively, the first inverter 11 may be controlled by active short-circuit control in the first speed region VR1, and the second inverter 12 may be controlled by active short-circuit control in the second speed region VR2. Alternatively, the inverter 10 to be controlled by active short-circuit control may be different in the first speed region VR1 and the second speed region VR2 (including the opposite combination).

[0243] Furthermore, in the first speed range VR1 and the second speed range VR2, the control method for controlling the first inverter 11 and the control method for controlling the second inverter 12 may be alternately switched based on predetermined conditions. By switching the control methods, it is possible to suppress a situation where only one of the first inverter 11 and the second inverter 12 consumes power, or a situation where only the discharge amount of the first DC power supply 61 and the second DC power supply 62 increases. The predetermined conditions are preferably, for example, a constant time or a discharge amount of the DC power supply 6.

[0244] In the first speed range VR1 and the second speed range VR2, one of the two inverters 10 (e.g., the first inverter 11) is controlled using active short-circuit control. In other words, essentially only one of the two inverters 10 (e.g., the second inverter 12) drives the rotating electric machine 80. Since one inverter 10 does not perform switching, the corresponding switching losses are reduced. Consequently, the rotating electric machine 80 can be driven while suppressing overall system losses.

[0245] With two inverters 10, as in this configuration, it is possible to generate an AC voltage with a larger amplitude than the voltage on the DC side of each inverter 10. However, the rotating electrical machine control device 1 does not necessarily need to constantly control both inverters 10 to increase the AC amplitude. For example, when the rotating electrical machine 80 is rotating at a low speed, generating the AC voltage that can be generated by a single inverter 10 may be sufficient. If one of the two inverters 10 is controlled using active short-circuit control, the three-phase stator coils 8 are short-circuited in that inverter 10. In this case, the other inverter 10 drives and controls the rotating electrical machine 80, which has stator coils 8 connected to a neutral point.

[0246] As mentioned above, the modulation rate based on continuous pulse width modulation is higher in space vector pulse width modulation than in sinusoidal pulse width modulation, and higher in discontinuous pulse width modulation than in space vector pulse width modulation. The second speed range VR2 is a control range in which the rotational speed of the rotating electrical machine 80 is higher than in the first speed range VR1. A higher modulation rate is required in the second speed range VR2 than in the first speed range VR1. By performing continuous pulse width modulation control in the first speed range VR1 and discontinuous pulse width modulation control in the second speed range VR2, the rotating electrical machine 80 can be driven by a single inverter 10 in the control range that combines the first and second speed ranges VR1 and VR2. Specifically, in the wide control range that combines the first and second speed ranges VR1 and VR2, one of the two inverters 10 does not perform switching operations, thereby enabling the rotating electrical machine 80 to be driven while minimizing losses in the entire system.

[0247] In this way, preferably, the boundaries of each control area R (the boundaries of the first speed area VR1, the second speed area VR2 and the third speed area VR3) are set according to at least one of the ratio of the rotational speed of the rotating motor 80 corresponding to the torque of the rotating motor 80 and the effective value of the line voltage of the multi-phase AC voltage (which can be an instruction value or a converted value from the output voltage) to the DC voltage.

[0248] like Figure 48 As shown, the operating conditions of the rotating electric machine 80 are generally defined based on the relationship between rotational speed and torque. The control region R can also be set based on the rotational speed as a parameter. While the rotational speed defining the boundaries of the control region R can be set constant regardless of torque, it is more preferable to set the rotational speed defining the boundaries of the control region R to a value that varies depending on the torque. This allows the rotating electric machine 80 to be driven and controlled efficiently according to its operating conditions.

[0249] Furthermore, for example, when the rotating electrical machine 80 requires a high output (fast rotation speed, high torque), in a voltage-type inverter, this requirement can be achieved by increasing the DC voltage or increasing the ratio of DC voltage to AC voltage. When the DC voltage is constant, this requirement can be achieved by increasing the ratio of DC voltage to AC voltage. This ratio can be expressed as the ratio of the effective value of the three-phase AC power to the DC power (in the case of a voltage-type inverter, it is equivalent to the ratio of the effective value of the three-phase AC voltage to the DC voltage). As described above, in the control method of controlling the inverter (10), there are various methods of this ratio, ranging from low to high.

[0250] As shown in Table 15 below, if the control region R is set based on the ratio (modulation factor) of the effective value of the three-phase AC power to the DC power determined based on the demand on the rotating electric machine 80, the rotating electric machine 80 can be driven and controlled with high efficiency according to the operating conditions of the rotating electric machine 80. In the table, "Mi_inv1" represents the modulation factor of the first inverter 11, "Mi_inv2" represents the modulation factor of the second inverter 12, and "Mi_sys" represents the modulation factor of the entire system.

[0251] [Table 15]

[0252] R Mi_sys INV1 Mi_inv1 INV2 Mi_inv2 VR1 M<a ASC M＝0 CPWM M<2a VR2 a≤M<X ASC M＝0 DPWM 2a≤M<2X VR3 X≤M<0.78 DPWM X≤M<0.78 DPWM X≤M<0.78

[0253] In addition, if Figure 49 As shown in Table 16 below, a fourth speed region VR4 may be set in which the rotation speed of the rotating electrical machine 80 is higher than the third speed region VR3 at the same torque. In this case, the rotating electrical machine control device 1 controls the two inverters 10, namely, the first inverter 11 and the second inverter 12, by rectangular wave control in the fourth speed region VR4 (see Figure 14 ). As described above, the modulation rate in rectangular wave control is 0.78.

[0254] [Table 16]

[0255] R Mi_sys INV1 Mi_inv1 INV2 Mi_inv2 VR1 M<a ASC M＝0 CPWM M<2a VR2 a≤M<X ASC M＝0 DPWM 2a≤M<2X VR3 X≤M<0.78 DPWM X≤M<0.78 DPWM X≤M<0.78 VR4 M＝0.78 1-Pulse M＝0.78 1-Pulse M＝0.78

[0256] Tables 15 and 16 above illustrate the modulation rates corresponding to the respective control regions R. In this embodiment, the inter-terminal voltage "E1" of the first DC power supply 61 and the inter-terminal voltage "E2" of the second DC power supply 62 are the same (both are voltage "E"). Assuming the effective value of the AC side of the first inverter 11 is "Va_inv1" and the effective value of the AC side of the second inverter 12 is "Va_inv2", the modulation rate "Mi_inv1" of the first inverter 11 and the modulation rate "Mi_inv2" of the second inverter 12 are as shown in equations (1) and (2) shown in the description of the first embodiment (described again below). Furthermore, the modulation rate "Mi_sys" of the entire system is as shown in equation (3) (described again below).

[0257] Mi_inv1=Va_inv1 / E1=Va_inv1 / E···(1)

[0258] Mi_inv2=Va_inv2 / E2=Va_inv2 / E···(2)

[0259] Mi_sys=(Va_inv1+Va_inv2) / (E1+E2)

[0260] =(Va_inv1+Va_inv2) / 2E···(3)

[0261] Regarding the instantaneous value of the voltage, the instantaneous vector must be considered. However, if only the modulation rate is considered, the modulation rate of the entire system, "Mi_sys," is "(Mi_inv1 + Mi_inv2) / 2," as shown in equations (1) to (3). Furthermore, Tables 15 and 16 show the modulation rates corresponding to the various control regions R as rated values. Therefore, during actual control, the modulation rates corresponding to the various control regions R may include overlapping ranges, taking into account fluctuations caused by changes in the control method within the control region R.

[0262] The modulation rate "X" is set based on the theoretical upper limit of the modulation rate for continuous pulse width modulation (space vector pulse width modulation) (approximately 0.707), taking into account the dead time. As shown in Tables 15 and 16, modulation may be performed by only one inverter 10 in the first speed range VR1 and the second speed range VR2. Therefore, in the first speed range VR1 and the second speed range VR2, the maximum modulation rate "2X" of one inverter 10 (here, the second inverter 12) is set to approximately 0.5 to 0.6, for example, based on the theoretical upper limit of the modulation rate for continuous pulse width modulation control (approximately 0.707 for space vector pulse width modulation), taking into account the dead time. Therefore, the modulation rate "X" is set to a value of approximately 0.25 to 0.3, for example. The modulation rate "a" is appropriately set based on experiments, simulations, and the like.

[0263] Regarding the waveform examples of the U-phase voltage command (Vu1**, Vu2**) and the U-phase upstream side switch control signal (Su1+, Su2+) in the control mode in each control region R in the modes illustrated in Tables 15 and 16, since the waveforms are similar to those in the first embodiment, Figures 12 to 16 The descriptions are the same, so detailed descriptions are omitted.

[0264] As described above, in the first speed range VR1 and the second speed range VR2, where the modulation rate and rotational speed are relatively low, and the power is relatively low, all power is supplied from a single inverter 10. In this case, a voltage command (V**) is provided to one inverter 10 for active short-circuit control, while a normal voltage command (V**) is provided to the other inverter 10. In the third speed range VR3 and the fourth speed range VR4, where the modulation rate and rotational speed are relatively high, and the power is relatively high, equal power is supplied from both inverters 10. In this case, the same voltage command (V**) is provided to both inverters 10, with a phase difference of 180 degrees (π).

[0265] However, when switching inverter 10, a pulsating component superimposed on the fundamental wave of the AC current may generate noise in the audible band. When two inverters 10 are controlled using different control methods, pulsations corresponding to each control method are generated, potentially increasing noise in the audible band. Especially when the rotating electrical machine 80 rotates at a low speed, the frequency of the pulsating component (or its sideband frequencies) is more likely to fall within the audible band. The control method for rotating electrical machine 80, i.e., the control method for inverter 10, is appropriately set according to operating conditions to achieve high system efficiency and reduced audible noise.

[0266] The rotating electrical machine control device 1 of this embodiment has two control modes for the rotating electrical machine 80: a loss reduction priority mode and a noise reduction priority mode, and is capable of switching between the loss reduction priority mode and the noise reduction priority mode. As described above, the rotating electrical machine control device 1 performs target control in the loss reduction priority mode and performs alternative control in place of target control in the noise reduction priority mode. Specifically, as shown in Table 17 below, in the noise reduction priority mode, the rotating electrical machine control device 1 controls the two inverters 10 (the first inverter 11 and the second inverter 12) using continuous pulse width modulation control in the first speed range VR1, controls the two inverters 10 using discontinuous pulse width modulation control in the second speed range VR2, and performs alternative control in place of target control in the third speed range VR3.

[0267] [Table 17]

[0268] R Mi_sys INV1 Mi_inv1 INV2 Mi_inv2 VR1 M<a CPWM M<a CPWM M<a VR2 a≤M<X DPWM a≤M<X DPWM a≤M<X VR3 X≤M<0.78 DPWM X≤M<0.78 DPWM X≤M<0.78

[0269] When the fourth speed region VR4 is set, the rotating electrical machine control device 1 similarly executes target control in the loss reduction priority mode and executes alternative control in place of the target control in the noise reduction priority mode, as shown in Table 18 below. Specifically, in the noise reduction priority mode, the rotating electrical machine control device 1 executes alternative control in the fourth speed region VR4, controlling both inverters 10, namely, the first inverter 11 and the second inverter 12, using rectangular wave control, in place of the target control.

[0270] [Table 18]

[0271] R Mi_sys INV1 Mi_inv1 INV2 Mi_inv2 VR1 M<a CPWM M<a CPWM M<a VR2 a≤M<X DPWM a≤M<X DPWM a≤M<X VR3 <![CDATA[X≤M x 0.78]]> DPWM X≤M<0.78 DPWM X≤M<0.78 VR4 M＝0.78 1-Pulse M＝0.78 1-Pulse M＝0.78

[0272] When the inverter 10 is switched, a pulsating component superimposed on the fundamental wave of the AC current may generate noise in the audible band. Especially when the rotating electrical machine 80 is rotating at a low speed, the frequency of the pulsating component (or its sideband frequencies) is more likely to fall within the audible band. For example, when two inverters 10 are controlled using different control methods, pulsations corresponding to each control method are generated, potentially increasing noise in the audible band. In the loss reduction priority mode, since only one inverter 10 is driven in the first speed range VR1 and the second speed range VR2, where the rotating electrical machine 80 rotates at relatively low speeds, noise in different frequency bands is not generated in the two inverters 10. However, since the output of the driven inverter 10 is higher, the energy of the noise increases. Furthermore, in the first speed range VR1 and the second speed range VR2, the sound associated with vehicle travel (such as the sound of wheels contacting the road) is also relatively low. Therefore, if the noise output from the driven inverter 10 falls within the audible band, it may be easily heard by the user.

[0273] For example, when the vehicle is starting or slowing down to a stop, the noise reduction mode is selected to prioritize the user's audible noise, while the loss reduction mode is selected during steady-state operation. These modes can also be selected by user operation (including input from a setting switch (touch panel, etc.)).

[0274] In the noise reduction priority mode, the first inverter 11 and the second inverter 12 are controlled using the same control method in the first speed range VR1 and the second speed range VR2, where the rotational speed of the rotating electrical machine 80 is relatively low. Furthermore, the currents of the two inverters 10 flowing through the stator coil 8 are controlled with a phase difference of approximately 180 degrees. When the two inverters 10 are controlled using the same control method, the phase difference of the currents, including the pulsating components, is approximately 180 degrees. This allows the pulsating components to at least partially cancel each other out, reducing noise in the audible band.

[0275] As shown in Table 17, in the noise reduction priority mode, in the first speed region VR1, both the first inverter 11 and the second inverter 12 are controlled by continuous pulse width modulation control (see Figure 16 ). In addition, in the second speed region VR2, similarly to the third speed region VR3, both the first inverter 11 and the second inverter 12 are controlled by discontinuous pulse width modulation control (see Figure 15 ).

[0276] Figure 50As a comparative example, an example of a control region for a rotating electrical machine in a single inverter system in which three-phase stator coils 8 are connected via a neutral point is shown. As shown in Table 19 below, the inverter is controlled by continuous pulse width modulation control in a first comparative region VR11, by discontinuous pulse width modulation control in a second comparative region VR13, and by rectangular wave control in a third comparative region VR14. Figure 20 As can be seen from the description of the first embodiment, the first comparison area VR11 in the second embodiment roughly corresponds to the first area VR11 of the first embodiment, the second comparison area VR13 in the second embodiment roughly corresponds to the second area VR12 of the first embodiment, and the third comparison area VR14 in the second embodiment roughly corresponds to the third area VR13 of the first embodiment.

[0277] [Table 19]

[0278] R Mi_sys INV1 Mi_inv VR11 M<Y,where Y>X CPWM M<Y,where Y>X VR13 Y≤M<0.78 DPWM Y≤M<0.78 VR14 M＝0.78 1-Pulse M＝0.78

[0279] Here, the modulation rate "Y" is a value greater than the modulation rate "X" exemplified in Tables 15 to 18. It is set to, for example, approximately 0.5 to 0.6 based on the theoretical upper limit of the modulation rate for continuous pulse width modulation (space vector pulse width modulation) (approximately 0.707), and further taking into account the dead time. As described above, in this embodiment, by setting the first speed region VR1 and the second speed region VR2 in a region corresponding to the comparative first region VR11, it is possible to reduce overall system loss in the loss reduction priority mode, and to reduce both loss and noise in the noise reduction priority mode.

[0280] In addition, from Figure 49 and Figure 50 Comparisons of Table 19 with Table 15, and Table 19 with Table 16 show that within the region corresponding to the first comparative region VR11, not only the first speed region VR1 and the second speed region VR2 can be set, but also a portion of the third speed region VR3 can be set. In other words, a portion of the third speed region VR3 can be set within the higher-speed side of the first comparative region VR11. This expands the area within the lower-speed control region where discontinuous pulse width modulation control is performed, reducing current ripple and switching losses, thereby reducing system losses. In other words, by expanding the control region with high system efficiency to the lower-speed side, overall system efficiency can be improved.

[0281] Hereinafter, reference will be made to the description of the first embodiment. Figures 21 to 26 、 Figure 28 、 Figure 29 、 Figure 31 、 Figure 32(Comparative example of a single inverter system and a dual inverter system, and comparative example of control methods in a dual inverter system) will be described. Figures 21 to 26 A comparative example in a relatively low speed region (for example, a comparative first region VR11 , a first speed region VR1 ) is shown. Figure 28 、 Figure 29 、 Figure 31 、 Figure 32 Comparative examples are shown in higher speed ranges (e.g., the comparative second range VR13 and the third speed range VR3). These figures also show waveform examples related to the hybrid continuous pulse width modulation control (MX-CPWM) employed in the first embodiment. However, since hybrid continuous pulse width modulation control (MX-CPWM) is not employed in the second embodiment, these waveforms are omitted from the description.

[0282] like Figure 24 as well as Figure 26 As shown, the harmonic components of the sideband frequencies "2f±fm" at a frequency "2f" twice the frequency of the carrier CA in the U-phase current Iu and the UV line voltage Vuv are smaller in the "ASC / CPWM" mode in the dual-inverter system than in the "CPWM / CPWM" mode in the single-inverter system and the dual-inverter system. Therefore, iron losses can be suppressed, and in the "ASC / CPWM" mode, since one inverter 10 does not perform switching, switching losses can be reduced, thereby appropriately reducing overall system losses. Therefore, as described above, when prioritizing system loss reduction (in the loss reduction priority mode), it is preferable to select the "ASC / CPWM" mode in the first speed range VR1.

[0283] On the other hand, Figure 23 as well as Figure 25 As shown, the harmonic components of the sideband frequencies "f ± 3fm" of the carrier CA frequency "f" in the U-phase current Iu and the UV line voltage Vuv are minimized in the "CPWM / CPWM" method in the dual inverter system. While the human audible frequency range is generally around 20 Hz to 15 kHz, frequencies above 10 kHz are generally difficult to hear, and frequencies around 5 kHz are easily perceived as noise. In other words, the sideband frequencies of the carrier CA frequency "f" are "f ± 3fm," and harmonic components around 5 kHz are more likely to become audible noise than harmonic components around the sideband frequencies of "2f" (2f ± fm), or 10 kHz. Therefore, as in this example, when the carrier CA frequency "f" is 5 kHz and priority is given to suppressing the harmonic components of the sideband frequencies "f ± 3fm" from becoming audible noise (in the noise reduction priority mode), it is preferable to select the "CPWM / CPWM" method in the first speed range VR1.

[0284] In addition, if Figure 24 as well as Figure 26 As shown, in the "CPWM" method in a single inverter system and the "CPWM / CPWM" method in a dual inverter system, the harmonic components of the sideband frequencies "2f±fm" at a frequency "2f" twice the frequency of the carrier CA in the U-phase current Iu and the UV line voltage Vuv are approximately equal. Therefore, in the range where the rotation speed is relatively low and audible noise is easily noticeable, it is preferable to select the noise reduction priority mode and perform control using the "CPWM / CPWM" method.

[0285] Figure 28 As shown in Table 19 and Figure 50 Waveform examples and FFT analysis results when discontinuous pulse width modulation control is performed in a single inverter system in the second comparative region VR13. Figure 28 The same as the description in the first embodiment.

[0286] Figure 29 As shown in Tables 14 to 18, Figure 48 、 Figure 49 Waveform examples and FFT analysis results when discontinuous pulse width modulation control is performed on two inverters 10 in a dual inverter system (when "DPWM / DPWM" control is performed). Figure 29 The same as the description in the first embodiment.

[0287] Figure 31 The relationship between the rotation speed of the rotating electric machine 80 and the audible noise in the single inverter system described with reference to Table 19 is shown. Figure 32 The relationship between the rotation speed of the rotating electrical machine 80 and the audible noise in the dual inverter system of the present embodiment (second embodiment) described with reference to Tables 17 and 18 is shown. Figure 31 In the single inverter system, according to the modulation rate and the speed of the rotating motor 80, as shown in FIG. Figure 50 As shown in Table 19, the control area is changed from the first comparison area VR11 to the second comparison area VR13, and the control method is switched from continuous pulse width modulation control (CPWM) to discontinuous pulse width modulation control (DPWM). Figure 32 In the dual inverter system, according to the modulation rate and the speed of the rotating motor 80, as shown in FIG. Figure 48 、 Figure 49 As shown in Table 17 and Table 18, the control region changes from the first speed region VR1 to the second speed region VR2, and the control mode switches from the "CPWM / CPWM" mode to the "DPWM / DPWM" mode.

[0288] From comparison Figure 28 and Figure 29 It can be seen that when "DPWM" control is implemented in a single inverter system, more ripple is superimposed on the three-phase currents than when "DPWM / DPWM" control is implemented in a dual inverter system. Therefore, as shown by the FFT analysis results, more harmonic components of the sideband frequencies "f±3fm" of the carrier frequency "f" are generated in the single inverter system compared to the dual inverter system. These sideband frequencies "f±3fm" harmonic components sometimes overlap with lower-order harmonic components (11th and 13th).

[0289] In addition, from the comparison Figure 31 and Figure 32 It can be seen that in a single inverter system, if Figure 31 As shown in FIG. 1 , the noise of the rotating motor 80 generated according to the speed of the rotating motor 80 (the audible noise of "12fm" when the frequency of the rotation speed is "fm") and the audible noise of the sideband frequency "f±3fm" overlap in the portion surrounded by the dotted circle, so the audible noise becomes very large. On the other hand, as Figure 32 As shown, in a dual-inverter system, audible noise at the sideband frequencies "f ± 3 fm" of the frequency "f" of the carrier CA is almost nonexistent. Therefore, the audible noise (12 fm) of the rotating electric machine 80, which is generated depending on the speed of the rotating electric machine 80, does not overlap with the audible noise at the sideband frequencies "f ± 3 fm." Therefore, a dual-inverter system can be constructed with higher noise levels than a single-inverter system.

[0290] (Overview of Embodiments)

[0291] Hereinafter, the outline of the rotating electrical machine control device (1) described above will be briefly described.

[0292] A rotating electrical machine control device (1) as a mode drives and controls a rotating electrical machine (80) having mutually independent multi-phase open-circuit windings (8) through a first inverter (11) and a second inverter (12), wherein the first inverter (11) is connected to one end of the multi-phase open-circuit winding (8) and converts power between direct current and multi-phase alternating current, and the second inverter (12) is connected to the other end of the multi-phase open-circuit winding (8) and converts power between direct current and multi-phase alternating current, and the first inverter (11) and the second inverter (12) can be controlled in a plurality of control modes having different switching modes and can be controlled in the control modes independently of each other, as a control region (R) of the rotating electrical machine (80). ), a first speed region (VR1) and a second speed region (VR2) in which the rotational speed of the rotating motor (80) is higher than that of the first speed region (VR1) at the same torque (T) are set, and the control method includes: pulse width modulation control, outputting multiple pulses with different modes in one cycle of electrical angle; and mixed pulse width modulation control, controlling to output multiple pulses with different modes in a 1 / 2 cycle of electrical angle, i.e., a first period (T1), and continuing an inactive state in the remaining 1 / 2 cycle, i.e., a second period (T2), and in the second speed region (VR2), the first inverter (11) and the second inverter (12) are controlled by the mixed pulse width modulation control.

[0293] Hybrid pulse width modulation control is a control method that combines a period of pulse width modulation and a period of no modulation (fixed state) for approximately half a period of each cycle of the electrical angle. That is, since the inverter (10) does not perform switching during approximately 1 / 2 of the driving time, switching loss can be reduced, thereby reducing system loss. The second speed region (VR2) in which the hybrid pulse width modulation control is performed is set to a higher speed side than the first speed region (VR1) under the same torque (T), and is a control region relative to the medium speed / high speed side. According to this structure, in the entire operating range of the rotating electrical machine (80), by reducing the system loss in the control region relative to the medium speed / high speed side, the overall system loss in all operating ranges can be reduced. In this way, according to this structure, the two inverters provided at both ends of the open winding can be appropriately controlled.

[0294] In addition, preferably, the pulse width modulation control is a control for generating a plurality of pulses based on an instruction value and a carrier, and the hybrid pulse width modulation control is a control for generating a plurality of pulses based on the carrier having a wave height of 1 / 2 of the variation range of the instruction value, i.e., a half-carrier and the instruction value, and the hybrid pulse width modulation control generates a plurality of pulses by the following method: a double half-carrier single reference method, wherein pulses for the first inverter (11) are generated based on a first half-carrier (CA1) as the half-carrier set at one of the high voltage side and the low voltage side relative to the amplitude center of the instruction value and the instruction value (Vu**) shared by the first inverter (11) and the second inverter (12), and a pulse having the same phase as the first half-carrier (CA1) and set at one of the high voltage side and the low voltage side relative to the amplitude center of the instruction value. The invention relates to a method for generating a pulse for the second inverter (12) based on a second half carrier (CA2) on the other side of the half carrier and the command value (Vu**); or a dual half carrier dual reference method, wherein a pulse for the first inverter (11) is generated based on a first half carrier (CA1) set as the half carrier at one of the high voltage side and the low voltage side relative to the amplitude center of the command value and a first command value (Vu1**) for the first inverter (11); and a pulse for the second inverter (12) is generated based on a second half carrier (CA2) having a phase 180 degrees different from that of the first half carrier (CA1) and set at the same side as the first half carrier (CA1) and a second command value (Vu2**) for the second inverter (12) having a phase 180 degrees different from that of the first half carrier (CA1).

[0295] In hybrid pulse width modulation control, in addition to the aforementioned dual half-carrier single reference method and dual half-carrier dual reference method, a single half-carrier dual reference method can also be employed. The single half-carrier dual reference method generates pulses based on a shared half-carrier and two command values ​​with a phase difference of 180 degrees. Simulations and experiments conducted by the inventors have confirmed that the dual half-carrier single reference method and the dual half-carrier dual reference method are more effective in suppressing harmonic noise in the carrier (CA) frequency than the single half-carrier dual reference method. Therefore, hybrid pulse width modulation control is preferably performed using the dual half-carrier single reference method or the dual half-carrier dual reference method.

[0296] In addition, preferably, in the first inverter (11) and the second inverter (12), the arm (3A) of the AC 1 phase is respectively composed of a series circuit of an upper side switching element (3H) and a lower side switching element (3L), and the control method also includes active short-circuit control, in which the upper side switching elements (3H) of all the arms (3A) of the multi-phase are set to the on state or the lower side switching elements (3L) of all the arms (3A) of the multi-phase are set to the on state, and the rotating motor control device (1) performs the object first speed region control in the first speed region (VR1) by controlling one of the first inverter (11) and the second inverter (12) by the active short-circuit control and controlling the other inverter (10) by the pulse width modulation control.

[0297] In the case of two inverters (10) as in this configuration, an AC voltage with an amplitude greater than the voltage on the DC side of each inverter (10) can be generated. However, the rotating electrical machine control device (1) does not need to always control the two inverters (10) in such a manner that the AC amplitude becomes larger. For example, when the rotation speed of the rotating electrical machine (80) is low, there is a case where it is sufficient to generate an AC voltage that can be generated by only one inverter (10). According to this configuration, in a first speed region (VR1) that is lower than the second speed region (VR2) at the same torque, one of the two inverters (10) is controlled by active short-circuit control. As a result, the open-circuit windings (8) are short-circuited in the one inverter (10), and the rotating electrical machine (80) is the same as a rotating electrical machine having an electrical neutral point in the stator coil. That is, the rotating electrical machine (80) is essentially driven by only one of the two inverters (10). Since the inverter (10) controlled by active short-circuit control does not perform a switching operation, the overall loss of the system can be suppressed and the rotating electric machine (80) can be driven.

[0298] In addition, preferably, the rotating electrical machine control device (1) alternately switches the control mode for controlling the first inverter (11) and the control mode for controlling the second inverter (12) in the first speed region (VR1) according to predetermined conditions.

[0299] By switching the control mode, it is possible to suppress the situation where only one of the first inverter (11) and the second inverter (12) consumes power. In addition, when the first inverter (11) and the second inverter (12) are respectively connected to independent DC power supplies (6), it is possible to suppress the situation where only one of the DC power supply (61) connected to the first inverter (11) and the DC power supply (62) connected to the second inverter (12) consumes more power. Here, the predetermined condition preferably refers to, for example, a constant time or the power consumption of the DC power supply (6).

[0300] In addition, preferably, in the pulse width modulation control, the control method includes: continuous pulse width modulation control, which continuously performs pulse width modulation on all the arms (3A) of the multi-phase; and discontinuous pulse width modulation control, which performs pulse width modulation on a part of the arms (3A) of the multi-phase, including a period in which the switching element (3) is fixed to an on state or an off state, and the rotating electrical machine control device (1) is in a low-speed side first speed region (VR1-1) on the low-speed side within the first speed region (VR1), through the active short-circuit control to control one of the first inverter (11) and the second inverter (12) by the active short-circuit control, and to control the other of the inverters (10) by the continuous pulse width modulation control; and in a high-speed side first speed region (VR2-2) on the high-speed side within the first speed region (VR1), to control one of the first inverter (11) and the second inverter (12) by the active short-circuit control, and to control the other of the inverters (10) by the discontinuous pulse width modulation control.

[0301] The maximum modulation rate of the discontinuous pulse width modulation control performed in the high-speed first speed region (VR1-2) is greater than the maximum modulation rate of the continuous pulse width modulation control performed in the low-speed first speed region (VR1-1). The high-speed first speed region (VR1-2) is a control region (R) in which the rotation speed of the rotating electric machine (80) is higher than that in the low-speed first speed region (VR1-1) under the same torque (T). From the perspective of system efficiency, it is preferable to perform modulation at a higher modulation rate in the high-speed first speed region (VR1-2) than in the low-speed first speed region (VR1-1). By performing continuous pulse width modulation control in the low-speed first speed region (VR1-1) and discontinuous pulse width modulation control in the high-speed first speed region (VR1-2), the rotating electric machine (80) can be appropriately driven by a single inverter (10) throughout the entire first speed region (VR1).

[0302] Furthermore, preferably, in the first speed region (VR1), target first speed region control is performed to control the two inverters (10), namely the first inverter (11) and the second inverter (12), by the hybrid pulse width modulation control.

[0303] Even when there are two inverters (10), for example, when the rotation speed of the rotating motor (80) is low, there are cases where it is sufficient to generate an AC voltage that can be generated by only one inverter (10). Hybrid pulse width modulation control is a control method that combines a period of pulse width modulation and a period of no modulation (fixed state) for approximately half a cycle within each cycle of the electrical angle. That is, for each 1 / 2 cycle, only one of the two inverters (10) actually drives the rotating motor (80). Since the inverter (10) does not perform a switching operation during approximately 1 / 2 of the driving time, switching loss can be reduced, thereby reducing system loss.

[0304] Preferably, in the rotating electric machine control device (1), as a control mode of the rotating electric machine (80), there is a loss reduction priority mode and a noise reduction priority mode, and the loss reduction priority mode and the noise reduction priority mode can be switched, in which, in the loss reduction priority mode, in the first speed region (VR1), the object first speed region control is performed, and in the noise reduction priority mode, in the first speed region (VR1), an alternative first speed region control of the two inverters (10) of the first inverter (11) and the second inverter (12) is performed by the pulse width modulation control to replace the object first speed region control.

[0305] When the inverter (10) is switched, a pulsating component superimposed on the fundamental wave of the alternating current may generate noise in the audible frequency band. In particular, when the rotation speed of the rotating electrical machine (80) is low, the frequency of the pulsating component (or its sideband frequency) is more likely to be included in the audible frequency band. In object control, when one inverter (10) is controlled by active short-circuit control, the output of the inverter (10) controlled by pulse width modulation control becomes larger than when two inverters (10) are used. That is, the energy of the noise also becomes higher. Compared with the case of using one inverter (10), when two inverters (10) are used, the energy of the noise can be reduced, and the two inverters (10) can be controlled so that the noise components cancel each other out. In the noise reduction priority mode, since the first inverter (11) and the second inverter (12) are controlled in the same control method, it is easy to perform control such that the noise components are canceled out. According to this structure, as the control mode of the rotating motor (80), there are a loss reduction priority mode and a noise reduction priority mode, and the loss reduction priority mode and the noise reduction priority mode can be switched, thereby making it possible to appropriately control the two inverters (10) according to the operating conditions, thereby achieving both high system efficiency operation and noise reduction.

[0306] In addition, preferably, in the first inverter (11) and the second inverter (12), the arm (3A) of the AC 1 phase is respectively composed of a series circuit of an upper side switching element (3H) and a lower side switching element (3L), and the hybrid pulse width modulation control includes: a hybrid continuous pulse width modulation control, which controls in a continuous non-effective state during the second period (T2), and continuously performs pulse width modulation on all the arms (3A) of the multi-phase during the first period (T1); and a hybrid discontinuous pulse width modulation control, which controls in a continuous non-effective state during the second period (T2), and continuously performs pulse width modulation on a part of the multi-phase arms (3A) during the first period (T1). An arm (3A) includes pulse width modulation during a period in which a switching element is fixed in an on state or an off state, wherein the rotating electrical machine control device (1) controls the first inverter (11) and the second inverter (12) by the hybrid continuous pulse width modulation control in a low-speed side second speed region (VR2-1) on the low-speed side within the second speed region (VR2), and controls the first inverter (11) and the second inverter (12) by the hybrid discontinuous pulse width modulation control in a high-speed side second speed region (VR2-2) on the high-speed side within the second speed region (VR2).

[0307] Hybrid pulse width modulation control is a control method that combines a period of pulse width modulation and a period of no modulation (fixed state) for approximately half a period within each cycle of an electrical angle. In hybrid continuous pulse width modulation control, continuous pulse width modulation is performed as a pulse width modulation method, and in hybrid discontinuous pulse width modulation control, discontinuous pulse width modulation is performed as a pulse width modulation method. The maximum modulation rate of discontinuous pulse width modulation control is greater than the maximum modulation rate of continuous pulse width modulation control. The high-speed side second speed region (VR2-2) is a control region (R) in which the rotation speed of the rotating motor (80) is higher than that of the low-speed side second speed region (VR2-1) under the same torque (T). From the perspective of system efficiency, it is preferable to perform modulation at a higher modulation rate in the high-speed side second speed region (VR2-2) than in the low-speed side second speed region (VR2-1). By performing hybrid continuous pulse width modulation control combined with continuous pulse width modulation control in a low-speed side second speed region (VR2-1), and performing hybrid discontinuous pulse width modulation control combined with discontinuous pulse width modulation control in a high-speed side second speed region (VR2-2), the rotary electric machine (80) can be appropriately driven throughout the entire second speed region (VR2).

[0308] In addition, the control method may also include discontinuous pulse width modulation control, in which pulse width modulation is performed on a part of the arms (3A) of the multi-phase, including a period in which the switching element is fixed in an on state or an off state. The rotating electrical machine control device (1) may also control the two inverters (10), namely the first inverter (11) and the second inverter (12), by the discontinuous pulse width modulation control in the second speed region (VR2-2) on the high speed side, instead of the mixed discontinuous pulse width modulation control.

[0309] The high-speed side second speed region (VR2-2) is set at a relatively high high speed side in the control region (R) of the rotating electric machine (80), and therefore there is a high possibility that a relatively high modulation rate is required. Hybrid pulse width modulation control is a control method that combines a period of pulse width modulation and a period of no modulation (fixed state) for approximately half a cycle within each cycle of the electrical angle. That is, since the hybrid pulse width modulation control includes a period of no modulation, the maximum modulation rate becomes lower than when pulse width modulation is performed throughout the entire cycle. Therefore, when a higher modulation rate is required, in the high-speed side second speed region (VR2-2), the two inverters (10) are controlled by discontinuous pulse width modulation control instead of hybrid discontinuous pulse width modulation, thereby enabling the rotating electric machine (80) to be appropriately driven.

[0310] In addition, preferably, the rotating electrical machine control device (1) performs the target first speed region control in which the first inverter (11) and the second inverter (12) are controlled by the hybrid pulse width modulation control in the first speed region (VR1) and the second speed region (VR2). In a high torque region (VRH) greater than a predetermined torque (Tref) which is a predetermined torque, the first inverter (11) and the second inverter (12) are controlled by the pulse width modulation control, and in a low torque region (VRL) less than the predetermined torque (Tref), the first inverter (11) and the second inverter (12) are controlled by the hybrid pulse width modulation control.

[0311] When the object first speed region control is executed, in the first speed region (VR1) and the second speed region (VR2), two inverters (10), namely the first inverter (11) and the second inverter (12), are controlled by hybrid pulse width modulation control. According to the inventor's experiments or simulations, it can be confirmed that in the high torque region (VRH) in the first speed region (VR1) and the second speed region (VR2), a ripple component corresponding to the harmonic component of the frequency of the rotation speed of the rotating electric machine (80) appears on the DC bus current (Idc). Generally, a DC link capacitor (4) (smoothing capacitor) for smoothing the DC power supply (6) or the DC bus voltage (DC link voltage (Vdc)) is provided on the DC side of the inverter (10). The ripple component of the DC bus current (Idc) may shorten the life of the DC power supply (6) or the DC link capacitor (4). By increasing the capacity of the DC link capacitor (4), although the ripple can be reduced, it may lead to an increase in the size of the DC link capacitor (4) or an increase in cost. Therefore, it is preferable to reduce the ripple of the DC bus current (Idc). According to this structure, in such a high torque region (VRH) where the ripple increases, hybrid pulse width modulation control is not performed, but pulse width modulation control is performed. According to the inventor's experiments and simulations, it can be confirmed that even in the high torque region (VRH), the ripple of the DC bus current (Idc) is reduced by controlling the two inverters (10) of the first inverter (11) and the second inverter (12) by pulse width modulation control. That is, according to this structure, in the first speed region (VR1) and the second speed region (VR2), even when the two inverters (10) are controlled by hybrid pulse width modulation control, the ripple of the DC bus current (Idc) can be appropriately reduced.

[0312] Furthermore, as described above, preferably, in the rotating electrical machine control device (1), in a high torque region (VRH), the first inverter (11) and the second inverter (12) are controlled by the pulse width modulation control, and in a low torque region (VRL) less than the specified torque (Tref), the first inverter (11) and the second inverter (12) are controlled by the hybrid pulse width modulation control. In the case where each AC 1-phase arm (3A) of the first inverter (11) and the second inverter (12) is composed of an upper-side switching element (3H) and a lower-side switching element (3H), the arm (3A) of each AC 1-phase arm (3A) is composed of an upper-side switching element (3H) and a lower-side switching element (3H). L), in the pulse width modulation control, the control method includes: continuous pulse width modulation control, which continuously performs pulse width modulation on all the arms (3A) of the multi-phase; and discontinuous pulse width modulation control, which performs pulse width modulation on a part of the arms (3A) of the multi-phase, including a period in which the switching element (3) is fixed to an on state or an off state, and the mixed pulse width modulation control includes: mixed continuous pulse width modulation control, which controls in a manner of continuously performing an inactive state during the second period (T2) and continuously performs pulse width modulation on all the arms (3A) of the multi-phase during the first period (T1);and hybrid discontinuous pulse width modulation control, wherein control is performed in a manner that the second period (T2) is continuously in an inactive state, and in the first period (T1), pulse width modulation is performed on a portion of the arms (3A) of the multiphase, including a period in which the switching element (3) is fixed to an on state or an off state, the low-speed side region within the second speed region (VR2) is set as a low-speed side second speed region (VR2-1), and the high-speed side region within the second speed region (VR2) is set as a high-speed side second speed region (VR2-2), and the rotating electrical machine control device (1) controls the first inverter (11) by the hybrid continuous pulse width modulation control in the low torque region (VRL) in the first speed region (VR1) and the low-speed side second speed region (VR2-1). The first inverter (11) and the second inverter (12) are controlled by the hybrid discontinuous pulse width modulation control in the low torque region (VRL) in the high speed side second speed region (VR2-2). The first inverter (11) and the second inverter (12) are controlled by the continuous pulse width modulation control in the high torque region (VRH) in the first speed region (VR1). The first inverter (11) and the second inverter (12) are controlled by the discontinuous pulse width modulation control in the high torque region (VRH) in the second speed region (VR2).

[0313] The control region (R) suitable for hybrid continuous PWM control does not completely coincide with the control region (R) suitable for continuous PWM control, nor does the control region (R) suitable for hybrid discontinuous PWM control completely coincide with the control region (R) suitable for discontinuous PWM control. Therefore, for example, when hybrid PWM control is executed in the low torque region (VRL) and PWM control is executed in the high torque region (VRH), the control mode is not limited to simply switching between hybrid continuous PWM control and continuous PWM control; it is sufficient to switch between hybrid discontinuous PWM control and discontinuous PWM control. According to the inventor's experiments and simulations, it can be confirmed that, as described above, preferably, in the first speed region (VR1) and the low torque region (VRL) in the low speed side second speed region (VR2-1), the first inverter (11) and the second inverter (12) are controlled by mixed continuous pulse width modulation control, in the low torque region (VRL) in the high speed side second speed region (VR2-2), the first inverter (11) and the second inverter (12) are controlled by mixed discontinuous pulse width modulation control, in the high torque region (VRH) in the first speed region (VR1), the first inverter (11) and the second inverter (12) are controlled by continuous pulse width modulation control, and in the high torque region (VRH) in the second speed region (VR2), the first inverter (11) and the second inverter (12) are controlled by discontinuous pulse width modulation control. According to this configuration, the rotary electric machine (80) can be appropriately driven in all of the first speed range (VR1) and the second speed range (VR2).

[0314] In addition, preferably, the boundaries of each control area (R) are set based on at least one of the rotation speed of the rotating motor (80) corresponding to the torque of the rotating motor (80) and the ratio of the effective value of the line voltage of the multi-phase AC voltage to the DC bus voltage.

[0315] The operating conditions of a rotating electric machine (80) are generally defined by the relationship between the rotational speed and the torque. If the rotating electric machine control device (1) changes the control method for controlling the first inverter (11) and the second inverter (12) based on a parameter, namely the rotational speed, the rotating electric machine (80) can be driven and controlled with high efficiency according to the operating conditions of the rotating electric machine (80). In addition, for example, when the rotating electric machine (80) requires a high output (fast rotational speed, high torque), in a voltage-type inverter, this requirement is achieved by increasing the DC bus voltage or increasing the ratio of the DC bus voltage to the AC voltage. When the DC bus voltage is constant, this requirement can be achieved by increasing the ratio of the DC bus voltage to the AC voltage. This ratio can be expressed as the ratio of the effective value of the three-phase AC power to the DC power (in the case of a voltage-type inverter, it is equivalent to the ratio of the effective value of the line voltage of the three-phase AC voltage to the DC bus voltage). In the control method of controlling the inverter (10), there are various methods of this ratio, ranging from low to high. By changing the control method based on the effective value, the rotating motor (80) can be driven and controlled with high efficiency according to the operating conditions of the rotating motor (80).

[0316] In addition, preferably, as the control method, there is also a rectangular wave control that outputs one pulse in one cycle of electrical angle, and a third speed region (VR3) is set in which the rotation speed of the rotating motor (80) is higher than the second speed region (VR2) under the same torque (T). In the third speed region (VR3), the rotating motor control device (1) controls the two inverters (10), namely the first inverter (11) and the second inverter (12), by the rectangular wave control.

[0317] Pulse width modulation control is superior to rectangular wave control in terms of smoothness of rotation, but rectangular wave control can physically (mathematically) drive the rotating motor (80) with the highest modulation rate. As a control method, if rectangular wave control can be performed in addition to pulse width modulation control, the flexibility of control can be improved, thereby making it possible to drive and control the rotating motor (80) with high efficiency according to the operating conditions of the rotating motor (80).

[0318] In addition, as another mode of the rotary electric machine control device (1), a rotary electric machine (80) having mutually independent multi-phase open-circuit windings (8) is driven and controlled by a first inverter (11) and a second inverter (12), wherein the first inverter (11) is connected to one end of the multi-phase open-circuit winding (8) to convert power between direct current and multi-phase alternating current, and the second inverter (12) is connected to the other end of the multi-phase open-circuit winding (8) to convert power between direct current and multi-phase alternating current, and in the first inverter (11) and the second inverter (12), an arm (3A) of one phase of alternating current is respectively composed of a series circuit of an upper-side switching element (3H) and a lower-side switching element (3L), as The control methods of the first inverter (11) and the second inverter (12) include at least: pulse width modulation control, which outputs a plurality of pulses of different modes in one cycle of electrical angle; and active short-circuit control, which sets the upper-side switching elements (3H) of all the arms (3A) of the multi-phase to the on state or sets the lower-side switching elements (3L) of all the arms (3A) of the multi-phase to the on state, and in the pulse width modulation control, the control methods include: continuous pulse width modulation control, which continuously performs pulse width modulation on all the arms (3A) of the multi-phase; and discontinuous pulse width modulation control, which includes setting the lower-side switching elements (3L) of all the arms (3A) of the multi-phase to the on state. The switching element (3) is fixed in an on state or an off state during pulse width modulation, the first inverter (11) and the second inverter (12) can be controlled in the control mode independently of each other, and the control region (R) of the rotating motor (80) is set as follows: a first speed region (VR1); a second speed region (VR2), the rotation speed of the rotating motor (80) is higher than the first speed region (VR1) under the same torque; and a third speed region (VR3), the rotation speed of the rotating motor (80) is higher than the second speed region (VR2) under the same torque, in the first speed region (VR1), the active short-circuit control is used to control the third speed region (VR3). The invention relates to a method for controlling the first inverter (11) and the second inverter (12) by controlling one of the first inverter (11) and the second inverter (12) and controlling the other of the first inverter (10) by continuous pulse width modulation control. In the second speed region (VR2), the active short-circuit control is used to control one of the first inverter (11) and the second inverter (12) and the other of the first inverter (10) and the second inverter (12) and the discontinuous pulse width modulation control is used to control the first inverter (11) and the second inverter (12) and the second inverter (10). In the third speed region (VR3), object control is performed to control the first inverter (11) and the second inverter (12) by discontinuous pulse width modulation control.

[0319] In the case of two inverters (10) as in this structure, an AC voltage with a larger amplitude than the voltage on the DC side of each inverter (10) can be generated. However, the rotating electrical machine control device (1) does not need to always control the two inverters (10) in such a way that the AC amplitude becomes larger. For example, when the rotation speed of the rotating electrical machine (80) is low, there are cases where it is sufficient to generate an AC voltage that can be generated by only one inverter (10). According to this structure, in the first speed range (VR1) and the second speed range (VR2), one of the two inverters (10) is controlled by active short-circuit control. As a result, the open-circuit windings (8) are short-circuited in the one inverter (10), and the rotating electrical machine (80) is the same as a rotating electrical machine having an electrical neutral point in the stator coil. That is, the rotating electrical machine (80) is essentially driven by only one of the two inverters (10). Since the inverter (10) controlled by active short-circuit control does not perform switching operations, it is possible to drive the rotating motor (80) while suppressing the overall system loss. In addition, the maximum modulation rate of the discontinuous pulse width modulation control performed in the second speed region (VR2) is greater than the maximum modulation rate of the continuous pulse width modulation control performed in the first speed region (VR1). The second speed region (VR2) is a control region in which the rotation speed of the rotating motor (80) is higher than that of the first speed region (VR1) under the same torque (T). From the perspective of system efficiency, it is preferable to perform modulation at a higher modulation rate in the second speed region (VR2) than in the first speed region (VR1). By performing continuous pulse width modulation control in the first speed region (VR1) and discontinuous pulse width modulation control in the second speed region (VR2), the rotating motor (80) can be appropriately driven by a single inverter (10) in a control region that combines the first speed region (VR1) and the second speed region (VR2). Furthermore, since the two inverters (10) are controlled by discontinuous pulse width modulation control in a third speed range (VR3) where the rotation speed of the rotating electric machine (80) is higher than that of the second speed range (VR2), a line voltage higher than that which can be generated by a single DC power supply (6) can be generated in the open winding (8) to drive the rotating electric machine (80). Thus, according to this structure, the two inverters provided at both ends of the open winding can be appropriately controlled.

[0320] Description of reference numerals:

[0321] 1: Rotating electrical machine control device, 3: Switching element, 3A: Arm, 3H: Upper-side switching element, 3L: Lower-side switching element, 8: Stator coil (open winding), 10: Inverter, 11: First inverter, 12: Second inverter, 80: Rotating electrical machine, R: Control region, T: Torque, T1: First period, T2: Second period, VR1: First speed region, VR1-1: First speed region on the low-speed side, VR1-2: First speed region on the high-speed side, VR2: Second speed region, VR2-1: Second speed region on the low-speed side, VR2-2: Second speed region on the high-speed side, VR3: Third speed region, VR4: Fourth speed region, VRH: High torque region, VRL: Low torque region.

Claims

1. A rotating electrical machine control device, which drives and controls a rotating electrical machine having mutually independent multi-phase open-circuit windings by means of a first inverter and a second inverter, wherein: The first inverter is connected to one end of the multi-phase open winding and converts power between direct current and multi-phase alternating current. The second inverter is connected to the other end of the multi-phase open winding and converts power between direct current and multi-phase alternating current. The first inverter and the second inverter can be controlled by a plurality of control methods with different switching modes, and can be controlled in the control methods independently of each other. As the control region of the rotating electrical machine, a first speed region and a second speed region in which the rotation speed of the rotating electrical machine is higher than the first speed region at the same torque are set. The control method includes: pulse width modulation control, which outputs multiple pulses with different patterns in one cycle of electrical angle; and mixed pulse width modulation control, which controls to output multiple pulses with different patterns in a first period, which is 1 / 2 cycle of electrical angle, and maintains an inactive state in the remaining second period, which is 1 / 2 cycle. In the second speed range, both the first inverter and the second inverter are controlled by the hybrid pulse width modulation control.

2. The rotating electrical machine control device according to claim 1, wherein: The pulse width modulation control is a control that generates a plurality of pulses based on a command value and a carrier wave. The hybrid pulse width modulation control is a control for generating a plurality of pulses based on the carrier wave having a wave height of 1 / 2 of the variation range of the command value, that is, the half carrier wave and the command value. The hybrid pulse width modulation control generates multiple pulses by: A dual half-carrier single reference method, wherein a pulse for the first inverter is generated based on a first half-carrier as the half-carrier set at one of the higher voltage side and the lower voltage side relative to the amplitude center of the command value and the command value common to the first and second inverters, and a pulse for the second inverter is generated based on a second half-carrier having the same phase as the first half-carrier and set at the other of the higher voltage side and the lower voltage side relative to the amplitude center of the command value and the command value; or The dual half-carrier dual-reference method generates pulses for the first inverter based on a first half-carrier that is set as the half-carrier at one of the higher voltage side and the lower voltage side relative to the amplitude center of the command value and a first command value for the first inverter, and generates pulses for the second inverter based on a second half-carrier that has a phase 180 degrees different from that of the first half-carrier and is set on the same side as the first half-carrier and a second command value for the second inverter that has a phase 180 degrees different from that of the first half-carrier.

3. The rotating electrical machine control device according to claim 1 or 2, wherein: In the first inverter and the second inverter, each AC single-phase arm is composed of a series circuit of an upper-side switching element and a lower-side switching element. The control method also includes active short-circuit control, in which the upper-side switching elements of all the arms of the multi-phase are set to the on state or the lower-side switching elements of all the arms of the multi-phase are set to the on state, In the first speed range, target first speed range control is performed in which one of the first inverter and the second inverter is controlled by the active short-circuit control and the other inverter is controlled by the pulse width modulation control.

4. The rotating electrical machine control device according to claim 3, wherein: In the first speed range, the control method for controlling the first inverter and the control method for controlling the second inverter are alternately switched according to predetermined conditions.

5. The rotating electrical machine control device according to claim 3 or 4, wherein: In the pulse width modulation control, the control method includes: continuous pulse width modulation control, which continuously performs pulse width modulation on all the arms of multiple phases; and discontinuous pulse width modulation control, wherein pulse width modulation is performed on a portion of the arms of the multi-phase, including a period in which the switching element is fixed in an on state or an off state, In a low-speed first speed range on a low-speed side within the first speed range, one of the first inverter and the second inverter is controlled by the active short-circuit control, and the other inverter is controlled by the continuous pulse width modulation control. In a high-speed first speed region on the high-speed side within the first speed region, one of the first and second inverters is controlled by the active short-circuit control, and the other inverter is controlled by the discontinuous pulse width modulation control.

6. The rotating electrical machine control device according to claim 1 or 2, wherein: In the first speed range, target first speed range control is executed in which both the first inverter and the second inverter are controlled by the hybrid pulse width modulation control.

7. The rotating electrical machine control device according to any one of claims 3 to 6, wherein: As the control mode of the rotating electrical machine, there are a loss reduction priority mode and a noise reduction priority mode, and the loss reduction priority mode and the noise reduction priority mode can be switched. In the loss reduction priority mode, in the first speed range, the object first speed range control is executed, In the noise reduction priority mode, in the first speed range, alternative first speed range control is executed to control both the first inverter and the second inverter by the pulse width modulation control instead of the target first speed range control.

8. The rotating electrical machine control device according to any one of claims 1 to 7, wherein: In the first inverter and the second inverter, each AC single-phase arm is composed of a series circuit of an upper-side switching element and a lower-side switching element. The hybrid pulse width modulation control includes: hybrid continuous pulse width modulation control, in which the second period is controlled so as to be continuously in an inactive state, and in which the pulse width modulation is continuously performed on all the arms of the multi-phase in the first period; and hybrid discontinuous pulse width modulation control, in which the second period is controlled so as to be continuously in an inactive state, and in which the pulse width modulation is performed on some of the arms of the multi-phase in the first period, including a period in which the switching element is fixed in the on state or the off state. In a second speed range on a lower speed side within the second speed range, both the first inverter and the second inverter are controlled by the hybrid continuous pulse width modulation control. In a second speed range on a higher speed side within the second speed range, both the first inverter and the second inverter are controlled by the hybrid discontinuous pulse width modulation control.

9. The rotating electrical machine control device according to claim 8, wherein: The control method includes discontinuous pulse width modulation control, in which pulse width modulation is performed on a portion of the arms of the multi-phase, including a period in which a switching element is fixed in an on state or an off state. In the high-speed side second speed region, both the first inverter and the second inverter are controlled by the discontinuous pulse width modulation control instead of the hybrid discontinuous pulse width modulation control.

10. The rotating electrical machine control device according to claim 6, wherein: In the first speed range and the second speed range, in a high torque range greater than a predetermined torque, which is a predetermined torque, the first inverter and the second inverter are controlled by the pulse width modulation control, and in a low torque range less than the predetermined torque, the first inverter and the second inverter are controlled by the hybrid pulse width modulation control.

11. The rotating electrical machine control device according to claim 10, wherein: In the first inverter and the second inverter, each AC single-phase arm is composed of a series circuit of an upper-side switching element and a lower-side switching element. In the pulse width modulation control, the control method includes: continuous pulse width modulation control, which continuously performs pulse width modulation on all the arms of multiple phases; and discontinuous pulse width modulation control, wherein pulse width modulation is performed on a portion of the arms of the multi-phase, including a period in which the switching element is fixed in an on state or an off state, The hybrid pulse width modulation control includes: hybrid continuous pulse width modulation control, wherein control is performed in a manner of continuously being in an inactive state during the second period, and pulse width modulation is continuously performed on all the arms of the multi-phase during the first period; and hybrid discontinuous pulse width modulation control, wherein control is performed so as to continue the inactive state during the second period, and pulse width modulation is performed on some of the arms of the multi-phase in the first period, including a period in which the switching element is fixed in the on state or the off state. The low-speed side region within the second speed region is set as the low-speed side second speed region, and the high-speed side region within the second speed region is set as the high-speed side second speed region. In the low torque range of the first speed range and the low speed side second speed range, both the first inverter and the second inverter are controlled by the hybrid continuous pulse width modulation control. In the low torque region in the high-speed side second speed region, both the first inverter and the second inverter are controlled by the hybrid discontinuous pulse width modulation control. In the high torque range in the first speed range, both the first inverter and the second inverter are controlled by the continuous pulse width modulation control. In the high torque region in the second speed region, both the first inverter and the second inverter are controlled by the discontinuous pulse width modulation control.

12. The rotating electrical machine control device according to any one of claims 1 to 11, wherein: The boundaries of each control area are set based on at least one of the rotation speed of the rotating electric machine corresponding to the torque of the rotating electric machine and the ratio of the effective value of the line voltage of the multi-phase AC voltage to the DC bus voltage.

13. The rotating electrical machine control device according to any one of claims 1 to 12, wherein: As the control method, there is also a rectangular wave control that outputs one pulse in one cycle of electrical angle. A third speed range is set in which the rotation speed of the rotating electric machine is higher than the second speed range at the same torque. In the third speed range, both the first inverter and the second inverter are controlled by the rectangular wave control.

14. A rotating electrical machine control device, which drives and controls a rotating electrical machine having mutually independent multi-phase open-circuit windings by means of a first inverter and a second inverter, wherein: The first inverter is connected to one end of the multi-phase open winding and converts power between direct current and multi-phase alternating current. The second inverter is connected to the other end of the multi-phase open winding and converts power between direct current and multi-phase alternating current. In the first inverter and the second inverter, each AC single-phase arm is composed of a series circuit of an upper-side switching element and a lower-side switching element. The control method of the first inverter and the second inverter includes at least: pulse width modulation control to output a plurality of pulses of different patterns in one cycle of electrical angle; and active short-circuit control, setting the upper-side switching elements of all the arms of the multi-phase to an on-state or setting the lower-side switching elements of all the arms of the multi-phase to an on-state, and wherein the pulse width modulation control includes, as the control method, continuous pulse width modulation control, continuously performing pulse width modulation on all the arms of the multi-phase; and discontinuous pulse width modulation control, wherein pulse width modulation is performed on a portion of the arms of the multi-phase, including a period in which the switching element is fixed in an on state or an off state, The first inverter and the second inverter can be controlled in the control mode independently of each other. The control areas set as the rotating electrical machine include: a first speed area; a second speed region, wherein the rotational speed of the rotating electrical machine is higher than that of the first speed region at the same torque; and a third speed region, in which the rotational speed of the rotating electrical machine is higher than that of the second speed region at the same torque, In the first speed range, one of the first inverter and the second inverter is controlled by the active short-circuit control, and the other inverter is controlled by the continuous pulse width modulation control. In the second speed range, one of the first inverter and the second inverter is controlled by the active short-circuit control, and the other inverter is controlled by the discontinuous pulse width modulation control. In the third speed region, target control is performed to control both the first inverter and the second inverter by the discontinuous pulse width modulation control.

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