JP2021197889A - Rotary electric machine control device - Google Patents

Abstract

To identify a fault location when one of switching elements constituting two inverters, each provided at both ends of an open winding, has an open fault.SOLUTION: In a first control state, it is determined which of a first failure pattern FP1 or a second failure pattern FP2 is a failure pattern FT. In a second control state, it is determined which of first and second lower-side failure patterns LF1 and LF2 is a lower-side failure pattern LF. On the basis of the determination result in the first control state and the determination result in the second control state, it is determined which of an upper side arm of a first inverter, a lower side arm of the first inverter, an upper side arm of a second inverter, and a lower side arm of the second inverter is a fault side arm.SELECTED DRAWING: Figure 15

Description

The present invention relates to a rotary electric machine control device that drives and controls a rotary electric machine having an open winding via two inverters.

A control device for driving and controlling a rotary electric machine by switching and controlling an inverter provided at each end of a three-phase open winding provided in a three-phase AC rotary electric machine is known. Japanese Unexamined Patent Publication No. 2014-192950 discloses a technique capable of continuing driving of a rotary electric machine even when a failure occurs in a switching element of an inverter for driving such a three-phase open winding. ing. According to this, when one of the switching elements of the two inverters fails, all the upper switching elements of the inverter including the failed switching element or all the lower switching elements are used. All are turned on, all the switching elements on the other side are turned off, the inverter is neutralized, and the rotary electric machine is driven by the other inverter that has not failed.

Japanese Unexamined Patent Publication No. 2014-192950

Here, it is possible to detect a failed switching element by arranging a sensor or the like for each switching element. However, it is costly to arrange sensors for failure detection in all switching elements. Therefore, it is conceivable to detect the failure by using the existing parameters used for control. That is, when a failure occurs in one switching element, the AC phase current, voltage, and the like change. Therefore, it is possible to detect the presence or absence of the failure based on each phase current, voltage, and the like. However, since two inverters are connected to the open winding, even if any of the inverters fails, it affects the current and interphase voltage flowing in the open winding, and simply fails the switching element. It is difficult to identify.

The above-mentioned literature does not mention a specific technique for identifying a failed switching element. Further, the failure of the switching element includes a short-circuit failure in which the switching element is always in a conductive state and an open failure in which the switching element is always in an open state, and the events caused by the failure are different from each other, and the identification method is also different. However, the above-mentioned literature does not mention specific techniques for distinguishing and specifying them.

In view of the above background, it is desired to provide a technique for identifying a failure location when one of the switching elements constituting the two inverters provided at both ends of the open winding causes an open failure.

In view of the above, the rotary electric machine control device for driving and controlling a rotary electric machine having a plurality of phases of open windings independent of each other via a first inverter and a second inverter is one embodiment of the first inverter. The multi-phase open winding is connected to one end side to convert power between DC and the multi-phase AC, and the second inverter is connected to the other end side of the multi-phase open winding. Power is converted between DC and multi-phase AC, and each of the first inverter and the second inverter has an arm for one AC phase composed of a series circuit of an upper switching element and a lower switching element. The first inverter and the second inverter can be controlled independently of each other, and one switching element is always open in either the first inverter or the second inverter. When an open failure occurs, the AC currents of a plurality of phases are integrated to calculate the integrated current value of each phase, and the occurrence of the open failure is detected based on the positive or negative of the integrated current value. At the same time, the location where the open failure has occurred is determined, and a plurality of inverters having different patterns in the first period, which is 1/2 cycle of the electric angle, are used for both the first inverter and the second inverter. When the occurrence of the open failure is detected while the pulse is output and controlled by the mixed pulse width modulation control controlled so that the ineffective state continues in the second period which is the remaining 1/2 cycle. In the failure side arm in which either the upper arm of the first inverter or the lower arm of the second inverter causes the open failure based on the positive or negative of the current integrated value in the first control state. Which of the first failure pattern and the second failure pattern in which either the lower arm of the first inverter or the upper arm of the second inverter is the failure side arm. Based on the current integrated value in each of the second control states different from the first control state, the first lower stage failure pattern in which the lower arm of the second inverter is the failure side arm, and It is determined which lower stage side failure pattern of the second lower stage side failure pattern in which the lower stage side arm of the first inverter is the failure side arm, and the determination result in the first control state and the second Based on the discrimination result in the control state, the first a. It is determined which of the upper arm of the inverter, the lower arm of the first inverter, the upper arm of the second inverter, and the lower arm of the second inverter is the failure side arm.

According to experiments and simulations by the inventors, it was confirmed that when an open failure of the switching element occurs in one of the two inverters, the three-phase current waveform becomes an asymmetric and distorted waveform. For example, the AC current waveform of a phase is largely deflected to the positive side, and the AC current waveform of a phase is largely deflected to the negative side. Then, when the alternating current is integrated over a predetermined time, this tendency of deflection becomes more remarkable. The direction of deflection depends on the position of the open failed switching element. Therefore, based on the positive and negative of the current integrated value, it is possible to determine whether the open failure has occurred and which of the inverter's upper arm and lower arm the open failure has occurred. Further, according to the experiments and simulations of the inventors, in the second control state, when an open failure occurs in the upper arm, it is difficult to detect the open failure itself, but the open failure in the lower arm is difficult. When is occurring, it is possible to detect an open failure and determine which inverter is the failure. In the first control state, it is possible to detect an open failure regardless of whether the upper arm or the lower arm has an open failure. However, in the first control state, it is possible to determine whether the failure pattern is the first failure pattern or the second failure pattern, but it is not possible to determine which inverter it is. According to this configuration, when an open failure occurs in the lower arm, the failed arm can be determined at least based on the determination result in the second control state. Further, regardless of whether the open failure occurs in the upper arm or the lower arm, both the discrimination result in the first control state and the discrimination result in the second control state Based on this, the faulty side arm can be determined. As described above, according to this configuration, when one of the switching elements constituting the two inverters provided at both ends of the open winding has an open failure, the failure location can be specified. ..

Further features and advantages of the rotary electric machine control device will be clarified from the following description of the embodiments described with reference to the drawings.

Schematic block diagram of rotary electric drive system Simple partial block diagram of rotary electric machine control device Schematic voltage vector diagram of rotating electric machine in orthogonal vector space The figure which shows an example of the control area of a rotary electric machine. Waveform diagram showing an example of voltage command and switching control signal of mixed continuous pulse width modulation (half cycle continuous pulse) Waveform diagram showing an example of voltage command and switching control signal of mixed discontinuous pulse width modulation (half-period discontinuous pulse) Waveform diagram showing other examples of voltage command and switching control signals for mixed continuous pulse width modulation (half cycle continuous pulse) Waveform diagram showing other examples of voltage command and switching control signals for mixed discontinuous pulse width modulation (half-period discontinuous pulse) Waveform diagram showing an example of voltage command and switching control signal of continuous pulse width modulation Waveform diagram showing an example of voltage command and switching control signal of discontinuous pulse width modulation Waveform diagram showing an example of a three-phase AC waveform when an open failure occurs during power running (low speed) Waveform diagram showing an example of a three-phase AC waveform when an open failure occurs during power running (high speed) Waveform diagram showing an example of a three-phase AC waveform when an open failure occurs during regeneration (low speed) Waveform diagram showing an example of a three-phase AC waveform when an open failure occurs during regeneration (high speed) Explanatory diagram of the principle for determining the open failure location Waveform diagram showing an example of a three-phase AC waveform when an open failure occurs in the first inverter during power running at an ultra-low rotation speed. Waveform diagram showing an example of a three-phase AC waveform when an open failure occurs in the second inverter during power running at an ultra-low rotation speed. The figure which shows the difference in the behavior of three-phase AC between the case where an open failure occurs at the time of power running at an ultra-low rotation speed and the case where an open failure occurs at the time of power running at a faster rotation speed. The figure which shows the operating point in the control area of a rotary electric machine. The figure which shows the relationship between the torque command of a rotary electric machine and the rotation speed at the time of discriminating the failure part. The figure which shows an example (pulse exchange) of a regenerative fail action for eliminating the distortion of a three-phase current waveform at the time of regeneration in the state where an open failure occurs in the lower stage side. The figure which shows the other example (pulse exchange and the inversion of the direction definition of an alternating current) for eliminating the distortion of a three-phase current waveform at the time of regeneration in the state where an open failure occurs in the lower stage side. The figure which shows the three-phase current waveform which distortion was eliminated by the switching control signal of FIG. 21 and FIG. A flowchart showing an example of a schematic procedure for determining the location of an open failure. A diagram showing an example of a three-phase AC waveform and integrated current that can identify the location of a failure. A diagram showing an example of a three-phase AC waveform and integrated current that can identify the location of a failure. A diagram showing an example of a three-phase AC waveform and integrated current that make it difficult to determine the location of a failure. The figure which shows an example of the integrated current before distortion elimination and the integrated current after distortion elimination of AC current. The figure which shows an example of the integrated current before distortion elimination and the integrated current after distortion elimination of AC current. The figure which shows an example of the integrated current which it is difficult to identify the failure location when an open failure occurs at the time of power running at an ultra-low rotation speed. The figure which shows an example of the integrated current which can identify the failure location when an open failure occurs at the time of power running at an ultra-low rotation speed. A flowchart showing an example of a procedure for determining the location of an open failure. Flow chart showing an example of the procedure of the first failure location determination process A flowchart showing an example of the procedure for determining the second failure location. A flowchart showing an example of the procedure for determining the third failure location. Waveform diagram showing an example of a three-phase AC waveform when an open failure occurs during power running (low speed) in the noise reduction priority mode. Waveform diagram showing an example of a three-phase AC waveform when an open failure occurs during power running (high speed) in the noise reduction priority mode. Waveform diagram showing an example of a three-phase AC waveform when an open failure occurs during regeneration (low speed) in the noise reduction priority mode. Waveform diagram showing an example of a three-phase AC waveform when an open failure occurs during regeneration (high speed) in the noise reduction priority mode. A flowchart showing an example of a procedure for determining the location of an open failure in the noise reduction priority mode. A flowchart showing another example of the procedure for determining the location of an open failure in the noise reduction priority mode. The figure which shows the behavior of a three-phase AC waveform in the case where an open failure occurs at the time of power running and the case where an open failure occurs at the time of regeneration in the noise reduction priority mode.

Hereinafter, an embodiment of a rotary electric machine control device for driving and controlling a rotary electric machine having a plurality of phases of open windings independent of each other via two inverters will be described with reference to the drawings. FIG. 1 is a schematic block diagram of a rotary electric machine drive system including a rotary electric machine control device 1 (MG-CTRL). The rotary electric machine 80 is a driving force source for wheels in a vehicle such as an electric vehicle or a hybrid vehicle. The rotary electric machine 80 is an open winding type rotary electric machine having a plurality of phases (three phases in this embodiment) of stator coils 8 (open windings) that are independent of each other. One inverter 10 is connected to both ends of the stator coil 8 to convert electric power between direct current and alternating current having a plurality of phases (here, three phases), which are independently controlled. That is, the first inverter 11 (INV1) is connected to one end side of the stator coil 8, and the second inverter 12 (INV2) is connected to the other end side of the stator coil 8. Hereinafter, when it is not necessary to distinguish between the first inverter 11 and the second inverter 12, it will be simply referred to as an inverter 10.

The inverter 10 includes a plurality of switching elements 3. An IGBT (Insulated Gate Bipolar Transistor) or a power MOSFET (Metal Oxide Semiconductor Field Effect Transistor) is used for the switching element 3. FIG. 1 illustrates a mode in which an IGBT is used as the switching element 3. In the present embodiment, the first inverter 11 and the second inverter 12 are inverters 10 having the same circuit configuration using the same type of switching element 3.

In each of the two inverters 10, the arm 3A for one AC phase is composed of a series circuit of the upper switching element 3H and the lower switching element 3L. Each switching element 3 is provided with a freewheel diode 35 in parallel with the direction from the negative electrode FG toward the positive electrode P (the direction from the lower side to the upper side) as the forward direction. In the multi-phase arm 3A, the side including the upper switching element 3H is referred to as an upper arm, and the side including the lower switching element 3L is referred to as a lower arm.

Further, in the present embodiment, the two inverters 10 are connected to independent DC power supplies 6. That is, the first floating ground FG1 which is the negative electrode FG of the first inverter 11 and the second floating ground FG2 which is the negative electrode FG of the second inverter 12 are independent of each other. Further, a DC link capacitor 4 (smoothing capacitor) for smoothing the DC voltage is provided between the inverter 10 and the DC power supply 6.

Specifically, the first inverter 11 in which the arm 3A for one AC phase is composed of a series circuit of the first upper stage side switching element 31H and the first lower stage side switching element 31L is a first DC link capacitor on the DC side. 41 (first smoothing capacitor) is connected, the DC side is connected to the first DC power supply 61, and the AC side is connected to one end side of the multi-phase stator coil 8 between the DC and the multi-phase AC. Convert power. The second inverter 12 in which the arm 3A for one AC phase is composed of a series circuit of the second upper stage side switching element 32H and the second lower stage side switching element 32L has a second DC link capacitor 42 (second smoothing) on the DC side. A capacitor) is connected, the DC side is connected to the second DC power supply 62, and the AC side is connected to the other end side of the multi-phase stator coil 8 to convert power between the DC and the multi-phase AC. ..

In the present embodiment, the first DC power supply 61 and the second DC power supply 62 are DC power supplies having the same rating such as voltage, and the first DC link capacitor 41 and the second DC link capacitor also have the same rating such as capacity. It is a capacitor of. The rated voltage of the DC power supply 6 is about 48 to 400 volts. The DC power supply 6 is composed of, for example, a secondary battery (battery) such as a nickel hydrogen battery or a lithium ion battery, or a power storage element such as an electric double layer capacitor. The rotary electric machine 80 can function as both an electric machine and a generator. The rotary electric machine 80 converts the electric power from the DC power source 6 into power via the inverter 10 (power running). Alternatively, the rotary electric machine 80 converts the rotational driving force transmitted from the wheels or the like into electric power, and charges the DC power supply 6 via the inverter 10 (regeneration).

As shown in FIG. 1, the inverter 10 is controlled by the rotary electric machine control device 1. The rotary electric machine control device 1 can control each of the first inverter 11 and the second inverter 12 by a control method independent of each other (details of the control method will be described later). The rotary electric machine control device 1 is constructed with a logic circuit such as a microcomputer as a core member. For example, the rotary electric machine control device 1 performs current feedback control using a vector control method based on a target torque (torque command) of the rotary electric machine 80 provided from another control device such as a vehicle control device (not shown). Then, the rotary electric machine 80 is controlled via the inverter 10.

The actual current flowing through the stator coil 8 of each phase of the rotary electric machine 80 is detected by the current sensor 15, and the magnetic pole position of the rotor of the rotary electric machine 80 at each time point is detected by the rotation sensor 13 such as a resolver. The rotary electric machine control device 1 executes current feedback control using the detection results of the current sensor 15 and the rotary sensor 13. The rotary electric machine control device 1 is configured to have various functional parts for current feedback control, and each functional part is realized by the cooperation of hardware such as a microcomputer and software (program). To.

The block diagram of FIG. 2 simply shows a part of the functional parts of the rotary electric machine control device 1. In the vector control method, the actual current (U-phase current Iu, V-phase current Iv, W-phase current Iw) flowing through the rotary electric machine 80 is the direction of the magnetic field (magnetic flux) generated by the permanent magnet arranged in the rotor of the rotary electric machine 80. Coordinate conversion to vector components (d-axis current Id, q-axis current Iq) of the d-axis and the q-axis in the direction orthogonal to the d-axis (direction advanced by π / 2 in electrical angle with respect to the direction of the magnetic field). And feedback control is performed. The rotary electric machine control device 1 performs coordinate conversion by the three-phase two-phase coordinate conversion unit 55 based on the detection result (θ: magnetic pole position, electric angle) of the rotation sensor 13.

The current feedback control unit 5 (FB) has a current command (d-axis current command Id ^* , q-axis current command Iq ^* ) based on the torque command of the rotary electric machine 80 and an actual current (d-axis) in the dq-axis orthogonal vector coordinate system. The rotary electric machine 80 is feedback-controlled based on the deviation from the current Id and the q-axis current Iq) to calculate the ^{voltage command (d-axis voltage command Vd *} , q-axis voltage command Vq ^*). The rotary electric machine 80 is driven via two inverters 10 of a first inverter 11 and a second inverter 12. Therefore, the d-axis voltage command Vd ^* and the q-axis voltage command Vq ^{* are the first d-axis voltage command Vd1 *} and the first q-axis voltage command Vq1 ^* for the first inverter 11 in the distribution unit 53 (DIV), respectively. 2 It is distributed to the second d-axis voltage command Vd2 ^* and the second q-axis voltage command Vq2 ^{* for the inverter 12.}

As described above, the rotary electric machine control device 1 can control each of the first inverter 11 and the second inverter 12 by a control method independent of each other, and has a three-phase voltage command calculation unit 73 and a modulation unit 74 (MOD). ) Is provided with two voltage control units 7. That is, the rotary electric 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 the second inverter 12. It includes 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. Details will be described later with reference to FIGS. 6 to 7, but the voltage command of the first inverter 11 (Vu1 ^** , Vv1 ^** , Vw1 ^** ) and the voltage command of the second inverter 12 (Vu2 ^**). , Vv2 ^** , Vw2 ^** ) are out of phase by "π". Therefore, a value obtained by subtracting “π” from the detection result (θ) of the rotation sensor 13 is input to the second voltage control unit 72.

As will be described later, the modulation method includes synchronous modulation synchronized with the rotation of the rotary electric machine 80 and asynchronous modulation independent of the rotation of the rotary electric machine 80. Generally, the block for generating a switching control signal by synchronous modulation (in the case of software, the generation flow) is different from the block for generating a switching control signal by asynchronous modulation. The voltage control unit 7 described above generates a switching control signal based on a voltage command and a carrier that is not synchronized with the rotation of the rotary electric machine 80. However, in the present embodiment, in order to simplify the description, synchronization is performed. The switching control signal by modulation (for example, the switching control signal in the case of the rectangular wave control described later) will also be described as being generated by the voltage control unit 7.

As described above, each arm 3A of the inverter 10 is composed of a series circuit of the upper switching element 3H and the lower switching element 3L. Although not distinguished in FIG. 2, the switching control signal of each phase is output as two types, an upper stage switching control signal and a lower stage switching control signal. For example, the first U-phase switching control signal Su1 that switches and controls the U-phase of the first inverter 11 is a first U-phase upper stage switching control signal Su1 + having a “+” at the end and a “−” at the end. It is output as two signals with the 1U phase lower switching control signal Su1-. When the upper switching element 3H and the lower switching element 3L constituting each arm 3A are turned on at the same time, the arm 3A is short-circuited. In order to prevent this, a dead time is provided in which both the upper switching control signal and the lower switching control signal for each arm 3A are in an ineffective state. This dead time is also added in the voltage control unit 7.

As shown in FIG. 1, 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 rotary electric machine control device 1 via the drive circuit 2 (DRV). , Each is individually switched and controlled. A high-voltage circuit (system connected to the DC power supply 6) for driving the rotary electric machine 80 such as the inverter 10 and a low-voltage circuit (from 3.3 volts) such as the rotary electric machine control device 1 centered on a microcomputer or the like. The operating voltage (power supply voltage of the circuit) is significantly different from the operating voltage system of about 5 volts. The drive circuit 2 relays by increasing the drive capability of the drive signal (switching control signal) for each switching element 3 (the ability to operate a subsequent circuit such as voltage amplitude and output current). 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.

The inverter 10 is provided with a circuit for detecting an abnormality of the inverter 10, for example, the temperature of the switching element, the presence or absence of overcurrent generation, etc., and the information is transmitted to the rotary electric machine control device 1 via the drive circuit 2. Provided to. These pieces of information do not have to specify the specific switching element 3, and may be such that, for example, an abnormality in the first inverter 11 and an abnormality in the second inverter 12 can be detected.

In the rotary electric machine control device 1, as a form of a switching pattern (a form of voltage waveform control) of the switching element 3 constituting the first inverter 11 and the second inverter 12, for example, a plurality of pulses having different patterns in one cycle of the electric angle are generated. Performing two operations: pulse width modulation (PWM) control and square wave control (1 pulse control (1-Pulse)) in which one pulse is output in one cycle of the electric angle. Can be done. That is, the rotary electric machine control device 1 can execute pulse width modulation control and square wave control as control methods for the first inverter 11 and the second inverter 12. As described above, the rotary electric machine control device 1 can control each of the first inverter 11 and the second inverter 12 by a control method independent of each other.

In addition, pulse width modulation includes continuous pulse width modulation (CPWM: Continuous PWM) such as sinusoidal pulse width modulation (SPWM: Sinusoidal PWM) and space vector pulse width modulation (SVPWM: Space Vector PWM), and discontinuous pulse width. There are methods such as modulation (DPWM: Discontinuous PWM). Therefore, the pulse width modulation control that can be executed by the rotary electric machine control device 1 includes continuous pulse width modulation control and discontinuous pulse width modulation as control methods.

Continuous pulse width modulation is a modulation method that continuously performs pulse width modulation for all of the multi-phase arms 3A, and discontinuous pulse width modulation is a switching element turned on or off for some of the multi-phase arms 3A. This is a modulation method in which pulse width modulation is performed including a period of fixing to a state. Specifically, in discontinuous pulse width modulation, for example, the signal level of the switching control signal of the inverter corresponding to one phase of the three-phase AC power is sequentially fixed, and the switching control signal corresponding to the other two phases is fixed. The signal level of is fluctuated. In continuous pulse width modulation, all phases are modulated without fixing the switching control signal corresponding to any phase in this way. These modulation methods are the operating conditions such as the rotational speed and torque required for the rotary electric machine 80, and the modulation factor required to satisfy the operating conditions (the effective value of the three-phase AC line voltage with respect to the DC voltage). It is decided according to the ratio).

In pulse width modulation, a pulse is generated based on the magnitude relationship between the amplitude of the AC waveform as a voltage command and the amplitude of the waveform of a triangular carrier (CA) like a triangular wave (including a sawtooth wave) (see FIG. 7 and the like). .. In some cases, the PWM waveform is directly generated by digital calculation without comparison with the carrier, but even in that case, the amplitude of the AC waveform as a command value and the amplitude of the virtual carrier waveform have a correlation.

In pulse width modulation by digital calculation, the carrier is determined according to the control cycle of the rotary electric machine control device 1, such as the calculation cycle of a microcomputer or the operation cycle of an electronic circuit. That is, even when a plurality of phases of AC power are used to drive the AC rotary electric machine 80, the carrier is not constrained by the rotation speed or rotation angle (electrical angle) of the rotary electric machine 80 (period not synchronized). have. Therefore, neither the carrier nor each pulse generated based on the carrier is synchronized with the rotation of the rotary electric machine 80. Therefore, modulation methods such as sinusoidal pulse width modulation and space vector pulse width modulation may be referred to as asynchronous modulation. On the other hand, a modulation method in which a pulse is generated in synchronization with the rotation of the rotary electric machine 80 is called synchronous modulation. For example, in the square wave control (square wave modulation), one pulse is output for each electric angle cycle of the rotary electric machine 80, so that the square wave modulation is synchronous modulation.

As described above, as an index showing the conversion rate from the DC voltage to the AC voltage, there is a modulation factor showing the ratio of the effective value of the line voltage of the multi-phase AC voltage to the DC voltage. Generally, the maximum modulation factor of sinusoidal pulse width modulation is about 0.61 (≈0.612), and the maximum modulation factor of space vector pulse width modulation control is about 0.71 (≈0.707). A modulation method having a modulation factor of more than about 0.71 is called "overmodulation pulse width modulation" as a modulation method having a modulation factor higher than usual. The maximum modulation factor of "overmodulation pulse width modulation" is about 0.78. This 0.78 is a physical (mathematical) limit value in power conversion from direct current to alternating current. In the overmodulation pulse width modulation, when the modulation factor reaches 0.78, it becomes a square wave modulation (1 pulse modulation) in which one pulse is output in one cycle of the electric angle. In square wave modulation, the modulation factor is fixed at the physical limit of about 0.78. The value of the modulation factor illustrated here is a physical (mathematical) value that does not consider the dead time.

The overmodulation pulse width modulation having a modulation factor of less than 0.78 can be realized by using any principle of the synchronous modulation method and the asynchronous modulation method. A typical modulation method for overmodulated pulse width modulation is discontinuous pulse width modulation. Discontinuous pulse width modulation can be realized by using either a synchronous modulation method or an asynchronous modulation method. For example, when the synchronous modulation method is used, in the square wave modulation, one pulse is output in one cycle of the electric angle, but in the discontinuous pulse width modulation, a plurality of pulses are output in one cycle of the electric angle. When a plurality of pulses are present in one cycle of the electric angle, the effective period of the pulses is reduced by that amount, so that the modulation factor is lowered. Therefore, not only the modulation factor fixed to about 0.78 but also any modulation factor less than 0.78 can be realized by the synchronous modulation method. For example, multi-pulse modulation (Multi-Pulses) such as 9-pulse modulation (9-Pulses) that outputs 9 pulses and 5-pulse modulation (5-Pulses) that outputs 5 pulses in one cycle of the electrical angle may be used. It is possible.

Further, the rotary electric machine control device 1 can execute shutdown control (SDN) or active short circuit control (ASC) as fail-safe control when an abnormality is detected in the inverter 10 or the rotary electric machine 80. The shutdown control is a control in which the switching control signals to all the switching elements 3 constituting the inverter 10 are inactive and the inverter 10 is turned off. Active short circuit control is a control in which either one of the upper switching element 3H of all the arms 3A of multiple phases or the lower switching element 3L of all the arms 3A of multiple phases is turned on and the other side is turned off. be. The case where the upper switching element 3H of all the arms 3A of the plurality of phases is turned on and the lower switching element 3L of all the arms 3A of the plurality of phases is turned off is called the upper active short circuit control (ASC-H). Refer to. Further, the case where the lower switching element 3L of all the arms 3A of the plurality of phases is turned on and the upper switching element 3H of all the arms 3A of the plurality of phases is turned off is called the lower active short circuit control (ASC-L). Refer to.

When the inverters 10 are connected to both ends of the stator coil 8 as in the present embodiment, when one of the inverters 10 is short-circuited by active short circuit control, the plurality of phases of the stator coil 8 are connected to the one inverter 10. It is short-circuited. That is, one of the inverters 10 becomes a neutral point, and the stator coil 8 is connected in a Y shape. Therefore, the rotary electric machine control device 1 controls the open winding type rotary electric machine 80 via two inverters 10 and one inverter 10 (inverter 10 on the side not controlled by the active short circuit). It is possible to realize a form in which the rotary electric machine 80 of the Y-type connection is controlled.

FIG. 3 illustrates a vector diagram at one operating point in the dq-axis vector coordinate system of the rotary electric machine 80. In the figure, “V1” indicates a first voltage vector indicating the voltage generated by the first inverter 11, and “V2” indicates a second voltage vector indicating the voltage generated by the second inverter 12. The voltage appearing in the stator coil 8 which is an open winding through the two inverters 10 corresponds to the difference “V1-V2” between the first voltage vector V1 and the second voltage vector V2. “Va” in the figure indicates a combined voltage vector appearing in the stator coil 8. Further, "Ia" indicates a current flowing through the stator coil 8 of the rotary electric machine 80. As shown in FIG. 3, when the first inverter 11 and the second inverter 12 are controlled so that the directions of the vectors of the first voltage vector V1 and the second voltage vector V2 differ by 180 degrees, the combined voltage vector Va becomes. , The magnitude of the second voltage vector V2 is added to the direction of the first voltage vector V1.

In the present embodiment, a plurality of control areas R (see FIG. 4) are set according to the operating conditions of the rotary electric machine 80, and the rotary electric machine control device 1 controls the inverter 10 by a control method according to each control area R. is doing. FIG. 4 shows an example of the relationship between the rotational speed and the torque of the rotary electric machine 80. For example, as shown in FIG. 4, as the control region R of the rotary electric machine 80, a first speed range VR1 and a second speed range VR2 in which the rotation speed of the rotary electric machine 80 at the same torque is higher than that of the first speed range VR1. A third speed range VR3 is set in which the rotation speed of the rotary electric machine 80 at the same torque is higher than that of the second speed range VR2.

As described above, the rotary electric machine control device 1 can control each of the first inverter 11 and the second inverter 12 by a plurality of control methods having different switching patterns. The control method includes pulse width modulation control (PWM) in which multiple pulses with different patterns are output in one cycle of the electrical angle, and the first period, which is 1/2 cycle (half cycle) of the electrical angle (full cycle). Multiple pulses with different patterns are output in T1 (see FIG. 5 etc.), and the ineffective state is controlled to continue in the second period T2 (see FIG. 5 etc.) which is the remaining 1/2 cycle (half cycle). It includes mixed pulse width modulation control (MX-PWM) (described later with reference to FIGS. 5 to 8). The rotary electric machine control device 1 controls both the inverters of the first inverter 11 and the second inverter 12 by the mixed pulse width modulation control in the first speed range VR1 and the second speed range VR2.

Mixed pulse width modulation control (MX-PWM) includes mixed continuous pulse width modulation control (MX-CPWM) and mixed discontinuous pulse width modulation control (MX-DPWM). Although the details will be described later, in the mixed continuous pulse width modulation control, the ineffective state is controlled to continue in the second period T2, and the pulse width modulation is continuously performed for all of the multi-phase arms 3A in the first period T1. (It will be described later with reference to FIGS. 5 and 7). Similarly, although the details will be described later, in the mixed discontinuous pulse width modulation control, the ineffective state is controlled to continue in the second period T2, and the switching element 3 is used for a part of the arms 3A of the plurality of phases in the first period T1. The pulse width modulation is performed including a period for fixing the on state or the off state (described later with reference to FIGS. 6 and 8).

In the mixed pulse width modulation control, since the switching control signal is ineffective even in the second period T2, the loss of the inverter 10 is reduced, and the harmonic current due to switching is also reduced, so that the loss of the rotary electric machine 80 (iron). Loss) is also reduced. That is, the system loss can be reduced by executing the mixed pulse width modulation control.

For example, as shown in Table 1 below, the rotary electric machine control device 1 controls the mixed continuous pulse width modulation (MX) in which the inverters 10 of both the first inverter 11 and the second inverter 12 are described later in the first speed range VR1. -Control by CPWM). Further, the rotary electric machine control device 1 controls both the inverters 10 of the first inverter 11 and the second inverter 12 by the mixed discontinuous pulse width modulation control (MX-DPWM) described later in the second speed range VR2. Further, the rotary electric machine control device 1 controls both the inverters 10 of the first inverter 11 and the second inverter 12 by rectangular wave control in the third speed range VR3. Mi_sys, Mi_inv1 and Mi_inv2 in the table will be described later.

The boundary of each control region R (the boundary between the first speed range VR1 and the second speed range VR2 and the third speed range VR3) is the rotation speed of the rotary electric machine 80 according to the torque of the rotary electric machine 80 and the DC voltage. It is preferable that the setting is made according to at least one of the ratio of the effective value (either the command value or the converted value from the output voltage) of the line voltage of the multi-phase AC voltage.

The operating conditions of the rotary electric machine 80 are often defined by the relationship between the rotational speed and the torque, as illustrated in FIG. It is preferable that the control region R is set based on the rotation speed, which is one parameter. Here, it is possible to set the rotation speed that defines the boundary of the control area R to be constant regardless of the torque, but the rotation speed that defines the boundary of the control area R becomes a different value depending on the torque. It is more preferable that it is set as such. By doing so, the rotary electric machine 80 can be driven and controlled with high efficiency according to the operating conditions of the rotary electric machine 80.

Further, for example, when the rotary electric machine 80 is required to have a high output (fast rotation speed and high torque), in the voltage type inverter, the DC voltage is increased and the ratio of the DC voltage converted to the AC voltage is increased. By doing so, the requirement is realized. When the DC voltage is constant, the requirement can be realized by increasing the ratio of the DC voltage converted to the AC voltage. This ratio can be shown 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, there are various control methods for controlling the inverter 10, from those having a low ratio to those having a high ratio.

As shown in Table 1, when the control region R is set based on the ratio (modulation rate) of the effective value of the three-phase AC power to the DC power determined in response to the request for the rotary electric machine 80, the rotary electric machine 80 is set. The rotary electric machine 80 can be driven and controlled with high efficiency according to the operating conditions. In the table, "Vi_inv1" indicates the modulation factor of the first inverter 11, "Mi_inv2" indicates the modulation factor of the second inverter 12, and "Mi_sys" indicates the modulation factor of the entire system.

Table 1 above illustrates the modulation factors corresponding to the respective control regions R. In the present embodiment, the terminal voltage "E1" of the first DC power supply 61 and the terminal voltage "E2" of the second DC power supply 62 are the same (both are voltage "E"). Assuming that 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 factor "Mi_inv1" of the first inverter 11 and the modulation of the second inverter 12 The rate "Mi_inv2" is as shown in the following equations (1) and (2). Further, the modulation factor "Mi_sys" of the entire system is as shown in the following equation (3).

Mi_inv1 = Va_inv1 / E1 = Va_inv1 / E ... (1)
Mi_inv2 = Va_inv2 / E2 = Va_inv2 / E ... (2)
Mi_sys = (Va_inv1 + Va_inv2) / (E1 + E2)
= (Va_inv1 + Va_inv2) / 2E ... (3)

Regarding the instantaneous value of the voltage, it is necessary to consider the vector at the moment, but considering only the modulation factor, the modulation factor "Mi_sys" of the entire system is "(Mi_inv1 + Mi_inv2) from the equations (1) to (3). ) / 2 ”. In Table 1, the modulation factors corresponding to the respective control regions R are shown as rated values. Therefore, in actual control, the modulation factor corresponding to each control area R may include an overlapping range in consideration of hunting or the like when the control method changes in the control area R.

The modulation factor "a" shown in Table 1 and the modulation factor "b" shown in Table 2 described later are set based on the theoretical upper limit of the modulation factor in each modulation method and in consideration of the dead time. Will be done. For example, "a" is about 0.5 to 0.6, and "b" is about 0.25 to 0.3.

Here, with reference to FIGS. 5 to 8, regarding the mixed pulse width modulation control (MX-PWM) characteristic in the present embodiment, the U-phase voltage command (Vu1 ^** , Vu2 ^** ) and the U-phase upper stage An example of a waveform of a side switching control signal (Su1 +, Su2 +) will be described. The second U phase lower switching control signal Su2-, and the V phase and W phase are not shown. 5 and 7 show a waveform example of mixed continuous pulse width modulation control (MX-CPWM), and FIGS. 6 and 8 show a waveform example of mixed discontinuous pulse width modulation control (MX-DPWM).

5 and 6 show the first carrier CA1 which is the carrier CA of the first inverter 11, the second carrier CA2 which is the carrier CA of the second inverter 12, and the first inverter 11 and the second inverter 12. An example of the common U-phase voltage command Vu ^** , which is a U-phase voltage command, the first U-phase upper stage switching control signal Su1 +, and the second U-phase upper stage switching control signal Su2 + is shown. The first U phase lower switching control signal Su1-, the second U phase lower switching control signal Su2-, and the V phase and the W phase are not shown (the same applies to other control methods).

For example, the first carrier CA1 changes between "0.5 <CA1 <1", the second carrier CA2 changes between "0 <CA2 <0.5", and the voltage command (V ^** ) is. , "0 ≤ V ^** ≤ 1". By comparing the carrier CA (1st carrier CA1 and 2nd carrier VA2) with the voltage command (V ^** ), when the voltage command is carrier CA or higher, the switching control signal becomes "1" and the voltage command is carrier CA. If it is less than, the switching control signal becomes "0". The comparison logic between the carrier CA and the voltage command (V ^** ) is the same in the following description.

As shown in FIGS. 5 and 6, the amplitude of the first carrier CA1 and the second carrier CA2 is half the amplitude allowed for the ^{voltage command (V **).} In general pulse width modulation, the amplitude of the carrier CA is equivalent to the amplitude allowed for the voltage command, and the carrier CA in mixed pulse width modulation can be referred to as a half carrier. ^{By using such a half carrier, such a half carrier and a voltage command (V **} ) intersect in the first period T1 (half cycle), which is 1/2 cycle of the electric angle (full cycle). Therefore, a plurality of pulses having different patterns are output as switching control signals. In the second period T2 (half cycle), which is the remaining 1/2 cycle, the half carrier and the voltage command (V ^** ) do not intersect, so the switching control signal is output so that the ineffective state continues. ..

In the mixed discontinuous pulse width modulation control, as shown in FIG. 6, a pulse that is partially in an effective state is output as a switching control signal even in the second period T2. This is because the modulation factor of the base discontinuous pulse width modulation is larger than that of the continuous pulse width modulation. The pulse to be valid state in the second period T2 is output, the amplitude near the center of the voltage command (V ^**), which is near the inflection point of the voltage command (V ^**). As shown in FIG. 6, it can be said that the ineffective state is continuously output in the second period T2 even in the mixed discontinuous pulse width modulation control. Further, the second period T2 is defined as only the period in which the switching control signal is ineffective (the period less than 1/2 cycle), and the period other than the second period T2 (the period of 1/2 cycle or more) in one cycle. Once set, mixed pulse width modulation can also be defined as follows: In the mixed pulse width modulation control, a plurality of pulses having different patterns are output in the first period T1 which is 1/2 cycle or more of the electric angle, and the ineffective state is in the second period T2 which is the rest of one cycle of the electric angle. It can also be controlled to continue.

7 and 8 illustrate different forms of mixed continuous pulse width modulation control and mixed discontinuous pulse width modulation control from FIGS. 5 and 6. The switching control signals generated are the same. 7 and 8 show a first carrier CA1 which is a carrier CA of the first inverter 11, a second carrier CA2 which is a carrier CA of the second inverter 12, and a U-phase voltage command of the first inverter 11. 1U phase voltage command Vu1 ^{** , 2nd U phase voltage command Vu2 **} which is the U phase voltage command of the 2nd inverter 12, 1st U phase upper stage side switching control signal Su1 +, 2nd U phase upper stage side switching control signal Su2 + An example of is shown. For example, the first carrier CA1 and the second carrier CA2 change between "0.5 <CA1 <1", and the voltage command (V ^** ) can change between "0 ≤ V ^** ≤ 1". Is. The first carrier CA1 and the second carrier CA2 are 180 degrees (π) different in phase. Further, the phases of the 1st U phase voltage command Vu1 ^** and the 2nd U phase voltage command Vu2 ^** are 180 degrees (π) different from each other.

As shown in FIGS. 7 and 8, the amplitude of the first carrier CA1 and the second carrier CA2 is half the amplitude allowed for the ^{voltage command (V **).} Therefore, the carrier CA in the form shown in FIGS. 7 and 8 is also a half carrier. ^{By using such a half carrier, such a half carrier and a voltage command (V **} ) intersect in the first period T1 which is 1/2 cycle (or 1/2 cycle or more) of the electric angle. Therefore, a plurality of pulses having different patterns are output as switching control signals. In the second period T2, which is the remaining period of the cycle, since the half carrier and the voltage command (V ^** ) do not intersect, the switching control signal is output so that the ineffective state continues.

The embodiment illustrated in FIGS. 5 and 6 is a system in which modulation is performed by two half carriers and a voltage command (V ^** ) as one common reference, and can be called a double half carrier / single reference system. On the other hand, the embodiment illustrated in FIGS. 7 and 8 is ^{a system in which modulation is performed by two half carriers and two voltage commands (V **} ), and can be called a double half carrier / double reference system.

As described above with reference to FIGS. 5 to 8, the mixed pulse width modulation control is a command value (voltage command, U-phase voltage command in the above example (Vu ^** (Vu ^** = Vu1 ^** = Vu2 ^{*). *} ), Vu1 ^** , Vu2 ^** )) Multiple pulses based on the half carrier (1st carrier CA1, 2nd carrier CA2), which is a carrier CA with a wave height of 1/2 of the range, and the command value. Generate. In the present embodiment, two methods, a double half carrier single reference method and a double half carrier double reference method, are exemplified as the mixed pulse width modulation control method.

In the double half carrier / single reference system, as described with reference to FIGS. 5 and 6, the ^{high voltage side or the low voltage side of the command value (common U-phase voltage command Vu **} ) as the half carrier is located on the higher voltage side or the lower voltage side than the amplitude center. ^{The command value (common U-phase voltage command Vu **} ) common to the first half carrier (first carrier CA1) set on one side (here, the high voltage side) and the first inverter 11 and the second inverter 12 Based on this, a pulse for the first inverter 11 is generated. Further, in the same method, the other side (here, low voltage side) of the amplitude center of the command value (common U-phase voltage command Vu ^{**) in the same phase as the first half carrier (first carrier CA1) is on the higher voltage side or the lower voltage side.} A pulse for the second inverter 12 is generated based on the second half carrier (second carrier CA2) set on the voltage side) and the command value (common U-phase voltage command Vu ^**).

In the double half carrier / double reference system, as described with reference to FIGS. 7 and 8, the amplitude center ^{of the command value (1st U phase voltage command Vu1 **} , 2nd U phase voltage command Vu2 ^{**) as the half carrier.} The first command value (first U phase voltage command Vu1) for the first half carrier (first carrier CA1) and the first inverter 11 set on either the higher voltage side or the lower voltage side (here, the high voltage side). ^** ) and generate a pulse for the first inverter 11. Further, in the same method, the second half carrier (first half carrier) set on the same side (high voltage side) as the first half carrier (first carrier CA1) with a phase 180 degrees different from that of the first half carrier (first carrier CA1). 2 carrier CA2) and the first command value (first U phase voltage command Vu1 ^** ) are based on ^{the second command value (second U phase voltage command Vu2 **} ) for the second inverter 12 whose phase is 180 degrees different. Generates a pulse for the second inverter 12.

As will be described later with reference to Table 2, in the first speed range VR1 and the second speed range VR2, the inverter 10 may be controlled by pulse width modulation instead of mixed pulse width modulation. ^{FIG. 9 shows the first U phase voltage command Vu1 **} and the second U phase voltage command Vu2 when both the first inverter 11 and the second inverter 12 are controlled by continuous pulse width modulation control in the first speed range VR1. ^{An example of **} , a carrier CA, a first U phase upper stage side switching control signal Su1 +, and a second U phase upper stage side switching control signal Su2 + is shown. ^{Further, FIG. 10 shows the first U phase voltage command Vu1 **} and the second U phase when both the first inverter 11 and the second inverter 12 are controlled by discontinuous pulse width modulation control in the second speed range VR2. An example of the voltage command Vu2 ^** , the carrier CA, the first U phase upper stage side switching control signal Su1 +, and the second U phase upper stage side switching control signal Su2 + is shown.

When both the first inverter 11 and the second inverter 12 are switched and controlled, the first U-phase voltage command Vu1 ^** and the second U-phase voltage command Vu2 ^** have phases that differ by approximately 180 degrees. 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 the vector diagram in FIG. 3). The first DC power supply 61 and the second DC power supply 62 are independent of each other, and the first DC voltage E1 of the first DC power supply 61 and the second DC voltage E2 of the second DC power supply 62 have different values. There may be. 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, "E1 =" in the present specification. E2 = E ”. Equivalent power is supplied to the rotary electric machine 80 from the two inverters 10. At this time, the same voltage command (V ^** ) having a phase difference of 180 degrees (π) is given to both inverters 10.

By the way, when the inverter 10 is switched and controlled, the pulsating component superimposed on the fundamental wave of the alternating current may generate noise in the audible frequency band. When the two inverters 10 are controlled by pulses having different forms, pulsation corresponding to each pulse may occur and noise in the audible frequency band may increase. In particular, when the rotation speed of the rotary electric machine 80 is low, there is a high possibility that the frequency of the pulsating component (or its sideband frequency) is included in the audible frequency band. It is desirable that the control method of the rotary electric machine 80, that is, the control method of the inverter 10, is appropriately set according to the operating conditions so that the operation with high system efficiency and the reduction of audible noise can be compatible with each other.

The rotary electric machine control device 1 of the present embodiment is provided with switchable between a loss reduction priority mode (efficiency priority mode) and a noise reduction priority mode as the control mode of the rotary electric machine 80. In the loss reduction priority mode, the rotary electric machine control device 1 switches and controls the inverter 10 by using the mixed pulse width modulation control as described above with reference to Table 1. In the noise reduction priority mode, the rotary electric machine control device 1 switches and controls the inverter 10 by using the pulse width modulation control as illustrated in Table 2 below.

When the inverter 10 is switched and controlled, the 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 rotary electric machine 80 is low, there is a high possibility that the frequency of the pulsating component (or its sideband frequency) is included in the audible frequency band. In the mixed pulse width modulation, as shown in FIGS. 5 to 8, since the two inverters 10 are controlled in different pulse forms in the half cycle of the electric angle, pulsations corresponding to the respective pulses occur and are audible. Frequency band noise may increase. In the first speed range VR1 and the second speed range VR2 where the rotation speed of the rotary electric machine 80 is relatively low, the noise caused by the running of the vehicle (running noise such as the grounding noise between the tire and the road surface) is also small, so that the rotary electric machine 80 is driven. When the noise output from one inverter 10 is noise in the audible frequency band, the noise may be easily heard by the user.

For example, the noise reduction priority mode is selected in consideration of the fact that noise in the audible frequency band is easily heard by the user when the vehicle starts or decelerates to stop, and the loss reduction priority is given when the vehicle is in steady driving. It is preferable that the mode is selected. It should be noted that these modes may be selected by an operation by the user (setting switch (including input from a touch panel or the like)).

In the noise reduction priority mode, in the first speed range VR1 and the second speed range VR2 where the rotation speed of the rotary electric machine 80 is relatively low, the first inverter 11 and the second inverter 12 are not mixed pulse width modulation control but a pulse. It is controlled by width modulation control. Since the two inverters 10 that pass the current through the stator coil 8 differ in the phase of the current by about 180 degrees, the phase of the current including the pulsating component is different by about 180 degrees. Therefore, at least a part of the pulsating components can cancel each other out, and noise in the audible frequency band can be reduced.

By the way, the switching element 3 constituting the inverter 10 may cause a short-circuit failure in which the switching element 3 is always in the on state or an open failure in which the switching element 3 is always in the off state. For example, when a rotary electric machine equipped with a general Y-shaped stator coil is driven by one inverter, if a short-circuit failure or an open failure occurs, all switching elements of the inverter are turned off. The vehicle is stopped by the control and the active short circuit control in which the upper switching element of all the multi-phase arms is turned on or the lower switching element of all the multi-phase arms is turned on.

However, as in the present embodiment, when the rotary electric machine 80 having a plurality of phases of open windings independent of each other as the stator coil 8 is driven and controlled via the first inverter 11 and the second inverter 12, the first It is possible to drive and control the rotary electric machine 80 via one of the inverters 10 of the inverter 11 and the second inverter 12. As described above, when one inverter 10 is short-circuited by active short circuit control, the multi-phase stator coil 8 is short-circuited in the one inverter 10, the one inverter 10 becomes a neutral point, and the stator coil becomes a neutral point. 8 will be connected in a Y shape. Therefore, the rotary electric machine control device 1 can realize a form in which the rotary electric machine 80 of the Y-type connection is controlled via one inverter 10 (inverter 10 on the side not controlled by the active short circuit).

When the rotary electric machine is driven by one inverter, if a short circuit failure or an open failure occurs, it is necessary to stop the vehicle using the rotary electric machine as a driving force source. However, when the rotary electric machine 80 is driven by two inverters 10 as in the present embodiment, even if a short circuit failure or an open failure occurs, the vehicle using the rotary electric machine 80 as a driving force source is not stopped. , The vehicle can continue to run within a certain limit. For example, it is possible to travel to an immediate destination such as a home or a maintenance shop.

For example, when a short-circuit failure occurs in one of the inverters 10, all the switching elements 3 of the upper arm and the lower arm on the side including the short-circuited switching element 3 are turned on, and the other side of the inverter 10 is turned on. It is preferable to execute the active short circuit control with all the switching elements 3 of the arm turned off. By turning on all the switching elements 3 of the arm on the side including the short-circuited switching element 3, the short-circuited switching element 3 can be used as the non-failed switching element 3.

Further, when an open failure occurs in one of the inverters 10, all the switching elements 3 of the upper arm and the lower arm on the side not including the switching element 3 having the open failure are turned on and the open failure occurs. It is preferable to execute the active short circuit control with all the switching elements 3 of the arm on the side including the switching element 3 turned off. By turning off all the switching elements 3 of the arm on the side including the open-failed switching element 3, the open-failed switching element 3 can be used as the non-failed switching element 3.

Therefore, at least, it is necessary to specify which of the first inverter 11 and the second inverter 12 and which of the upper arm and the lower arm the failed switching element 3 belongs to. More preferably, it is preferable to be able to identify which of the plurality of phases the failed switching element 3 is.

Hereinafter, when an open failure occurs in any one of the switching elements 3 constituting the first inverter 11 and the second inverter 12 (when a one-phase open failure occurs), the switching element 3 having an open failure is referred to. A mode in which the rotary electric machine 80 is driven by fail-safe control will be described so that the vehicle can be specified and the vehicle can continue to run after the identification.

11 to 14 (and FIGS. 36 to 39 described later) are waveform diagrams showing an example of a three-phase AC waveform (U-phase current Iu, V-phase current Iv, W-phase current Iw) when an open failure occurs. Is. 11 and 12 (and FIGS. 36 and 37) show a three-phase AC waveform when an open failure occurs during power running, and FIGS. 13 and 14 (and FIGS. 38 and 39) show an open failure during regeneration. The three-phase AC waveform when the above occurs is shown. FIGS. 11 to 14 (and FIGS. 36 to 39, which will be described later) show waveforms when the U-phase switching element 3 has an open failure. Further, in common with FIGS. 11 to 14 (and FIGS. 36 to 39 described later), a waveform when the switching element 3 on the upper side (HIGHSIDE) of the first inverter 11 fails to open, the lower stage of the first inverter 11. Waveform when the switching element 3 on the side (LOWSIDE) has an open failure, waveform when the switching element 3 on the upper side (HIGHSIDE) of the second inverter 12 has an open failure, switching on the lower side (LOWSIDE) of the second inverter 12. The waveform when the element 3 has an open failure is shown in a matrix. Further, FIG. 12 (and FIG. 37 with respect to FIG. 36) shows a case where the rotation speed of the rotary electric machine 80 is high with respect to FIG. 11 and FIG. 14 (and FIG. 37 with respect to FIG. 38) with respect to FIG. FIG. 39) shows a case where the rotation speed of the rotary electric machine 80 is high at the same torque.

As shown in FIGS. 11 and 12, when an open failure occurs during power running, the three-phase AC waveform is asymmetric and distorted regardless of whether it is on the upper side or the lower side of the first inverter 11 and the second inverter 12. It becomes a waveform. Further, the three-phase AC waveform has the same waveforms when the upper side of the first inverter 11 has an open failure and when the lower side of the second inverter 12 has an open failure, and when the lower side of the first inverter 11 has an open failure. And, the same waveform is obtained when the upper side of the second inverter 12 fails to open.

On the other hand, as shown in FIGS. 13 and 14, when an open failure occurs on the lower side of the first inverter 11 and the second inverter 12 during regeneration, the three-phase AC waveform becomes an asymmetric and distorted waveform. When an open failure occurs on the upper end side of the first inverter 11 and the second inverter 12, the three-phase AC waveform becomes a waveform that is substantially symmetric and has almost no distortion.

That is, as shown in FIG. 15, during power running (excluding power running at ultra-low speed, which will be described later with reference to FIGS. 16 to 18), the three-phase AC waveform shows an abnormality no matter where an open failure occurs. The form of the abnormality can be roughly classified into two failure patterns FP, that is, the first failure pattern FP1 and the second failure pattern FP2 shown in FIG. At the time of regeneration, the three-phase AC waveform shows an abnormality only when an open failure occurs on the lower side of the first inverter 11 and the second inverter 12. The form of the abnormality can be roughly classified into two lower side failure patterns LF, that is, the first lower side failure pattern LF1 and the second lower side failure pattern LF2 shown in FIG.

The first failure pattern FP1 is a failure pattern FP when either the upper arm of the first inverter 11 or the lower arm of the second inverter 12 is a failure side arm in which an open failure has occurred. The second failure pattern FP2 is a failure pattern FP when either the lower arm of the first inverter 11 or the upper arm of the second inverter 12 is the failure side arm. The first lower stage failure pattern LF1 is a lower stage side failure pattern LF when the lower stage side arm of the second inverter is the failure side arm. The second lower stage failure pattern LF2 is a lower stage side failure pattern LF when the lower stage side arm of the first inverter is the failure side arm.

As shown in FIG. 15, the shapes of the failure pattern FP and the lower failure pattern LF are partially overlapping and different. Therefore, if the state of the three-phase AC waveform at the time of power running is compared with the state of the three-phase AC waveform at the time of regeneration, when an open failure is detected, an open failure occurs on either the upper side or the lower side of the inverter 10. It is possible to determine if it has occurred (where the faulty arm is).

Specifically, if the first failure pattern FP1 is detected during power running and no abnormality is detected in the three-phase AC waveform during regeneration, an open failure occurs on the upper side (inv1-HIGHSIDE) of the first inverter 11. Can be determined to have occurred. When the first failure pattern FP1 is detected during power running and the first lower side failure pattern LF1 is detected during regeneration, it is considered that an open failure has occurred on the lower side (inv2-LOWSIDE) of the second inverter 12. It can be determined. Further, if the second failure pattern FP2 is detected during power running and no abnormality is detected in the three-phase AC waveform during regeneration, an open failure occurs on the upper side (inv2-HIGHSIDE) of the second inverter 12. It can be determined that there is. When the second failure pattern FP2 is detected during power running and the second lower side failure pattern LF2 is detected during regeneration, it is considered that an open failure has occurred on the lower side (inv1-LOWSIDE) of the first inverter 11. It can be determined.

16 and 17 show three-phase AC waveforms when an open failure occurs at an ultra-low rotation speed where the rotation speed of the rotary electric machine 80 is lower than that of FIGS. 11 and 13. Both FIGS. 16 and 17 show three-phase AC waveforms when an open failure occurs during power running. FIG. 16 shows a waveform when the U-phase switching element 3 on the upper or lower side of the first inverter 11 has an open failure, and FIG. 17 shows the U-phase on the upper or lower side of the second inverter 12. The waveform when the switching element 3 of the above is open failure is shown. Common to FIGS. 16 and 17, waveforms at three different rotation speeds (RS1, RS2, RS3), waveforms when the switching element 3 on the upper stage side (HIGHSIDE) fails open, and switching on the lower stage side (LOWSIDE). The waveform when the element 3 has an open failure is shown in a matrix. The rotation speed is "RS1 <RS2 <RS3", and "RS3", which has the highest rotation speed among the three, is also an ultra-low rotation speed in which the rotation speed of the rotary electric machine 80 is lower than that in FIGS. 11 and 13. ..

As shown in FIGS. 16 and 17, when an open failure occurs on the lower side of the first inverter 11 and the second inverter 12, the three-phase AC waveform becomes an asymmetric and distorted waveform as in the case of regeneration. When an open failure occurs on the upper end side of the first inverter 11 and the second inverter 12, the three-phase AC waveform becomes a waveform that is substantially symmetric and has almost no distortion. That is, as shown in FIG. 18, when the rotation speed is reduced to an ultra-low rotation speed, the state of the three-phase AC waveform when an open failure occurs changes. Since the behavior of the three-phase AC waveform at the ultra-low rotation speed is the same as that in the case of regeneration, as described above with reference to FIG. 15, at the time of power running at the ultra-low rotation speed and at the time of power running at a higher speed than that. By collating the state of the three-phase AC waveform, when an open failure is detected, it is possible to determine which inverter 10 has an open failure on the upper side or the lower side.

FIG. 19 shows an operating point in the control area of the rotary electric machine 80. The control area "Rs" in FIG. 19 indicates a single inverter control area Rs when the rotary electric machine 80 is controlled by one inverter 10, and "Rd" indicating the entire control area is rotated by two inverters 10. The dual inverter control area Rd when controlling the electric machine 80 is shown.

For example, when an open failure is detected during power running at the first operating point Q1 outside the single inverter control region Rs, the operating point is moved to the second operating point Q2 on the regenerative side, with reference to FIG. As described above, it is possible to determine the location of the open failure. FIG. 20 shows the relationship between the torque command of the rotary electric machine 80 and the rotation speed. At the time t1 when an open failure is detected during power running at the first operating point Q1, the torque command changes from the power running torque to the regenerative torque. has been changed. Due to the regeneration control, the rotation speed of the rotary electric machine 80 decreases between the time t1 and the time t2, and at the time t2, the rotation speed decreases to the rotation speed of the single inverter control region Rs.

When the location of the open failure is specified, the rotary electric machine 80 is driven via the other inverter 10 that has not failed by controlling the active short circuit of one of the inverters 10 on the failed side in the single inverter control region Rs. Can be controlled. Although the rotation speed of the third operating point Q3 is lower than that of the original first operating point Q1, the same torque can be output, and the vehicle can continue to run within a certain limited range.

Although detailed description is omitted here, when an open failure is detected during power running, the rotation speed is changed to an ultra-low rotation speed by, for example, shutdown control, without moving the operating point to the regenerative side as described above. It may be lowered to identify the location of the open failure. Details will be described later with reference to FIG. 34.

By the way, as described above, when an open failure is detected during power running at the first operating point Q1 outside the single inverter control region Rs, the operating point is moved to the second operating point Q2 on the regenerative side, and the regenerative operation is performed. When the rotation speed of the regenerative electric machine 80 is reduced, the three-phase AC waveform is in a distorted state when the failure point is on the lower stage side. When the waveform is distorted, harmonic components appear, which consumes the DC power supply 6, DC link capacitor 4, etc., affects other equipment due to electromagnetic noise, and causes audible noise. In some cases. Therefore, it is preferable that distortion in the current waveform during regeneration is suppressed.

As described above, when an open failure occurs on the upper stage side, almost no distortion occurs in the three-phase alternating current during regeneration. Therefore, in the present embodiment, the distortion of the three-phase alternating current is eliminated by changing the switching pattern. 21 and 22 show switching control signals for eliminating distortion of the three-phase current waveform during regeneration in a state where an open failure has occurred. FIG. 21 shows the switching control signal of the first case (case 1), and FIG. 22 shows the switching control signal of the second case (case 2).

In the first case, first, the switching control signal on the upper stage side of the first inverter 11 and the switching control signal on the lower stage side are exchanged, and the switching control signal on the upper stage side and the switching control signal on the lower stage side of the second inverter 12 are exchanged. And replace. Further, the switching control signal of the first inverter 11 and the switching control signal of the second inverter 12 are exchanged. That is, in the first case, the switching pattern of the upper arm of the first inverter 11 and the switching pattern of the lower arm of the second inverter 12 are exchanged, and the switching pattern of the lower arm of the first inverter 11 and the second inverter. Replace with the switching pattern of the upper arm.

In the second case, as in the first case, first, the switching control signal on the upper stage side of the first inverter 11 and the switching control signal on the lower stage side are exchanged. Then, the direction of the current flowing through the stator coil 8 is changed. For example, the positive / negative of the three-phase current may be inverted in the three-phase two-phase coordinate conversion unit 55 shown in FIG. That is, in the second case, the switching pattern of the upper arm of the first inverter 11 and the switching pattern of the lower arm are exchanged, and the switching pattern of the upper arm and the switching pattern of the lower arm of the second inverter 12 are exchanged. The exchange is performed, and the positive and negative of each of the multi-phase alternating currents (Iu, Iv, Iw) are inverted.

FIG. 23 shows a three-phase current waveform (left) during regeneration in a state where an open failure has occurred on the upper stage side, and a first case (case 1) during regeneration in a state where an open failure has occurred on the lower stage side. The three-phase current waveform (upper and lower on the right) in which the distortion is eliminated by the switching control signal and the switching control signal of the second case (case 2) is shown. As shown in FIG. 23, even if an open failure occurs on the lower stage side, the three-phase AC waveform is a waveform with almost no distortion, as in the case where an open failure occurs on the lower stage side. The control for adjusting the waveform at the time of regeneration in this way is called a regenerative fail action.

FIG. 24 shows an example of a schematic procedure for determining a location where an open failure occurs. When the rotary electric machine control device 1 detects the occurrence of an open failure (OPEN-FAIL) (# 5), it determines whether or not the rotational speed of the rotary electric machine 80 is a rotation speed that can be regenerated (# 6). ). As described above, in the present embodiment, after the open failure location is specified, the drive control of the rotary electric machine 80 is continued via the one inverter 10 that has not failed. When regeneration is performed, the rotation speed of the rotary electric machine 80 is lowered. Therefore, if the rotation speed of the rotary electric machine 80 is low, the speed may be reduced until the rotary electric machine 80 stops.

Therefore, the rotary electric machine control device 1 determines in step # 6 whether or not the rotational speed of the rotary electric machine 80 is a regenerative rotation speed, and if regenerative is possible, the first failure location determination process accompanied by regeneration. Execute (# 10). On the other hand, when regeneration is not possible, the rotary electric machine control device 1 executes a deceleration process (# 8) for decelerating the rotational speed of the rotary electric machine 80 to the above-mentioned ultra-low rotation speed, and then does not involve regeneration. 2 Execute the failure location determination process (# 20). If the rotation speed of the rotary electric machine 80 is already an ultra-low rotation speed at the time of step # 6, it is not necessary to further decelerate. The deceleration process of step # 8 includes a rotation speed determination process (# 81), as will be described later with reference to FIG. 34. Therefore, the deceleration process in step # 8 does not necessarily involve deceleration.

When the open failure location is determined in the first failure location determination process (# 10) or the second failure location determination process (# 20), the rotary electric machine control device 1 fails in the single inverter control region Rs as described above. The rotary electric machine 80 is driven and controlled via the inverter 10 which is not used (# 60: 1-inv drive). As will be described later with reference to FIGS. 32 and 35, the open failure location may be determined by the third failure location determination process (# 30).

Hereinafter, the principle of determining the location where the open failure has occurred based on the three-phase current waveform will be described with reference to FIGS. 25 to 31, and the open failure has occurred with reference to the flowcharts of FIGS. 32 to 35. The procedure for determining the location will be described.

As shown in FIGS. 11 to 14, 16 and 17, when an open failure occurs, the three-phase AC waveform is distorted and becomes an asymmetric waveform. For example, when an open failure occurs on the upper side of the first inverter 11 (or the lower side of the second inverter 12), the U-phase current Iu is deflected to the negative side, and the V-phase current Iv and The W-phase current Iw has a waveform deflected to the positive side. Here, when the three-phase currents (U-phase current Iu, V-phase current Iv, W-phase current Iw) are integrated over a predetermined time (for example, 200 [ms]), as will be described later with reference to FIG. 25 and the like. The U-phase integrated current ΣIu, the V-phase integrated current ΣIv, and the W-phase integrated current ΣIw can be obtained. The U-phase integrated current ΣIu, the V-phase integrated current ΣIv, and the W-phase integrated current ΣIw remarkably show distortion of the three-phase AC waveform, and by using these, the location of the open failure can be determined. When integrating the current, if the integration is started from the peak value of each AC current, it is possible to suppress the offset of the integrated value and the occurrence of an error.

25 and 26 show an example of a three-phase AC waveform and an integrated current that can discriminate an open fault location, and FIG. 27 shows an example of a three-phase AC waveform and an integrated current that make it difficult to discriminate a fault location. Shows. Further, FIGS. 28 and 29 show the integrated current before the distortion of the alternating current is eliminated and the integrated current after the distortion is eliminated at the time of regeneration as described above. Further, FIGS. 30 and 31 show an example of the integrated current when an open failure occurs during power running at an ultra-low rotation speed. FIG. 30 shows an example of an integrated current in which it is difficult to determine a faulty part, and FIG. 31 shows an example of an integrated current in which a faulty part can be discriminated.

25, 27, and 30 show an example in which the upper switching element 3H of the U phase of the first inverter 11 fails in an open manner, and FIGS. 26, 28, and 31 show the U of the first inverter 11. An example is shown in the case where the lower switching element 3L of the phase has an open failure. Further, FIG. 28 shows an example in which the lower U-phase switching element 3L of the first inverter 11 has an open failure, and FIG. 29 shows an open failure of the U-phase lower switching element 3L of the second inverter 12. An example of the case is shown. 25, 26, 30, and 31 are waveforms during power running, and FIGS. 27 to 29 are waveforms during regeneration. The alternate long and short dash line in FIGS. 25, 26, 30 and 31 indicates the time when the open failure occurs, and the alternate long and short dash line in FIGS. 28 and 29 switches the switching control signal in order to eliminate the distortion. Indicates the time of day.

As shown in FIG. 25, when the U-phase upper switching element 3H of the first inverter 11 is powered by the mixed pulse width modulation control in a state of open failure, the three-phase current waveform becomes an asymmetric and distorted waveform. The U-phase current Iu is deflected to the negative side, and the V-phase current Iv and the W-phase current Iw are waveforms deflected to the positive side. Here, the rotary electric machine control device 1 integrates a three-phase current (U-phase current Iu, V-phase current Iv, W-phase current Iw) over a predetermined time (for example, 200 [ms]). As shown in FIG. 25, the U-phase integrated current ΣIu in which the U-phase current Iu deflected to the negative side is integrated increases toward the negative side (the value decreases and the waveform decreases). Further, the V-phase integrated current ΣIv and the W-phase integrated current ΣIw obtained by integrating the V-phase current Iv and the W-phase current Iw deflected to the positive side increase to the positive side (the waveform increases).

The rotary electric machine control device 1 sets a predetermined integrated threshold value on the positive side and the negative side, and when the integrated threshold value is exceeded on the positive side or the negative side, it is determined that a short circuit failure has occurred and a short circuit failure has occurred. It is possible to identify the occurrence pattern of short-circuit failure. Here, the integration threshold value on the positive side is set to "It +", and the threshold value on the negative side is set to "Itth-". In the embodiment illustrated in FIG. 25, the occurrence of an open failure is determined when the following conditions are satisfied. This condition is the first pattern.

(ΣIu <It-) && (ΣIv> Is +) && (ΣIw> Is +)

It should be noted that this condition is satisfied not only when the upper switching element 3H of the U phase of the first inverter 11 fails open, but also when the lower switching element 3L of the U phase of the second inverter 12 fails open. ..

As shown in FIG. 26, the three-phase current waveform becomes an asymmetric and distorted waveform even when the power is applied by the mixed pulse width modulation control in a state where the lower switching element 3L of the U phase of the first inverter 11 is open-failed. .. The U-phase current Iu is deflected to the positive side, and the V-phase current Iv and the W-phase current Iw are waveforms deflected to the negative side. As shown in FIG. 26, the U-phase integrated current ΣIu in which the U-phase current Iu deflected to the positive side is integrated increases to the positive side (the waveform increases). Further, the V-phase integrated current ΣIv and the W-phase integrated current ΣIw obtained by integrating the V-phase current Iv and the W-phase current Iw deflected to the negative side increase to the negative side (the value decreases and the waveform decreases). go). In the embodiment illustrated in FIG. 26, the occurrence of an open failure is determined when the following conditions are satisfied. This condition is used as the second pattern.

(ΣIu> Is +) && (ΣIv <Itth-) && (ΣIw <Ith-)

It should be noted that this condition is satisfied not only when the lower U-phase switching element 3L of the first inverter 11 has an open failure, but also when the U-phase upper switching element 3H of the second inverter 12 has an open failure. ..

As shown in Table 3 below, there are six types of conditions that are satisfied when the 12 switching elements 3 constituting the first inverter 11 and the second inverter 12 fail in an open manner, from the first pattern to the sixth pattern. In the following description, each switching element 3 has a three-phase identification symbol (U, V, W), an identification number (1, 2) for the first inverter 11 and the second inverter 12, an upper switching element 3H, and a lower stage. Using the identification symbols (H, L) of the side switching element 3L, for example, "U1H" for the upper switching element 3H of the U phase of the first inverter 11, and the lower switching element of the W phase of the second inverter 12. If it is 3L, it is written as "W2L".

FIG. 27 shows the integrated current when the U-phase upper switching element 3H of the first inverter 11 is regenerated by the mixed pulse width modulation control in a state of open failure. As shown in FIG. 14 and the like, the distortion of the three-phase AC waveform is slight. The U-phase current Iu is slightly biased to the negative side, and the V-phase current Iv is slightly deflected to the positive side, but the W-phase current Iw is hardly deflected. Therefore, as shown in FIG. 27, the U-phase integrated current ΣIu tends to increase to the negative side (the value decreases and the waveform decreases), and the V-phase integrated current ΣIv increases to the positive side. Although it shows a tendency to increase (the waveform increases), the W-phase integrated current ΣIw hardly increases or decreases on either the positive side or the negative side. Therefore, even after a lapse of time, the W-phase integrated current ΣIw does not satisfy any of the conditions of patterns 1 to 6 shown in Table 3, and does not satisfy the open failure detection condition. Therefore, when the upper switching element 3H has an open failure, it is not detected as an abnormality during regeneration (see FIG. 15 and the like).

FIG. 28 shows the integrated current when the lower stage side switching element 3L of the U phase of the first inverter 11 is regenerated by the mixed pulse width modulation control in a state of open failure. As shown in FIGS. 13 and 14, the U-phase current Iu has a waveform deflected to the positive side, and the V-phase current Iv and the W-phase current Iw have waveforms deflected to the negative side. As shown in FIG. 28, the U-phase integrated current ΣIu in which the U-phase current Iu deflected to the positive side is integrated increases to the positive side (the waveform increases). Further, the V-phase integrated current ΣIv and the W-phase integrated current ΣIw obtained by integrating the V-phase current Iv and the W-phase current Iw deflected to the negative side increase to the negative side (the value decreases and the waveform decreases). go). Similar to the second pattern at the time of power running, the following is satisfied, and the occurrence of an open failure is determined.

(ΣIu> Is +) && (ΣIv <Itth-) && (ΣIw <Ith-)

After that, as described above with reference to FIGS. 21 and 22, when the regenerative fail action is executed by exchanging the switching control signals in order to eliminate the distortion, the upper switching of the U phase of the first inverter 11 is performed during regeneration. It is equivalent to the state in which the element 3H has an open failure (it shows the same tendency as in FIG. 27). Therefore, the increase of the integrated current to the positive side and the negative side is also eliminated.

FIG. 29 shows the integrated current when the lower stage side switching element 3L of the U phase of the second inverter 12 is regenerated by the mixed pulse width modulation control in a state of open failure. As shown in FIGS. 13 and 14, the U-phase current Iu has a waveform deflected to the negative side, and the V-phase current Iv and the W-phase current Iw have waveforms deflected to the positive side. As shown in FIG. 29, the U-phase integrated current ΣIu in which the U-phase current Iu deflected to the negative side is integrated increases toward the negative side (the value decreases and the waveform decreases). Further, the V-phase integrated current ΣIv and the W-phase integrated current ΣIw obtained by integrating the V-phase current Iv and the W-phase current Iw deflected to the positive side increase to the positive side (the waveform increases). Therefore, as in the first pattern during power running, the following is satisfied and the occurrence of an open failure is determined.

(ΣIu <It-) && (ΣIv> Is +) && (ΣIw> Is +)

After that, as described above with reference to FIGS. 21 and 22, when the regenerative fail action is executed by exchanging the switching control signals in order to eliminate the distortion, the upper switching of the U phase of the second inverter 12 is performed during regeneration. It is equivalent to the state in which the element 3H has an open failure. Therefore, the increase of the integrated current to the positive side and the negative side is also eliminated.

As shown in Table 4 below, the conditions that are satisfied when the six switching elements 3 on the lower side of the first inverter 11 and the second inverter 12 fail to open during regeneration are from the first pattern to the sixth pattern. There are 6 types. The numbers and logical expressions of each pattern are the same as those in Table 3.

By combining Table 3 and Table 4, as shown in Table 5 below, it is possible to specify which of the 12 switching elements the open failure has occurred.

FIG. 30 shows the integrated current when the U-phase upper switching element 3H of the first inverter 11 is driven at an ultra-low rotation speed by mixed pulse width modulation control in a state of open failure. As shown in FIGS. 16 and 17, the three-phase AC waveform has almost no distortion. Therefore, as shown in FIG. 30, the U-phase integrated current ΣIu, the V-phase integrated current ΣIv, and the W-phase integrated current ΣIw hardly increase or decrease on either the positive side or the negative side. Therefore, even after a lapse of time, the W-phase integrated current ΣIw does not satisfy any of the conditions of patterns 1 to 6 shown in Tables 3 and 4, and does not satisfy the open failure detection condition.

FIG. 31 shows the stacking current when the lower switching element 3L of the U phase of the first inverter 11 is powered at an ultra-low rotation speed by the mixed pulse width modulation control in a state where the lower switching element 3L is open-failed. As shown in FIGS. 16 and 17, the three-phase current waveform is an asymmetric and distorted waveform. The U-phase current Iu is deflected to the positive side, and the V-phase current Iv and the W-phase current Iw are waveforms deflected to the negative side. As shown in FIG. 31, the U-phase integrated current ΣIu in which the U-phase current Iu deflected to the positive side is integrated increases to the positive side (the waveform increases). Further, the V-phase integrated current ΣIv and the W-phase integrated current ΣIw obtained by integrating the V-phase current Iv and the W-phase current Iw deflected to the negative side increase to the negative side (the value decreases and the waveform decreases). go). In the embodiment illustrated in FIG. 31, the occurrence of an open failure is determined when the following conditions are satisfied. This condition is the same as the second pattern in Tables 3 and 4.

(ΣIu> Is +) && (ΣIv <Itth-) && (ΣIw <Ith-)

As shown in Table 6 below, the conditions that are satisfied when the six switching elements 3 on the lower side of the first inverter 11 and the second inverter 12 fail in open failure in power running at an ultra-low rotation speed are from the first pattern. There are 6 types up to the 6th pattern. The numbers and logical expressions of each pattern are the same as those in Tables 3 and 4, and Table 6 is the same as Table 4.

By combining Table 3 and Table 6, as shown in Table 7 below, it is possible to specify which of the 12 switching elements the open failure has occurred. This is the same as Table 5.

Hereinafter, a procedure for determining the faulty side arm will be described with reference to the flowcharts of FIGS. 32 to 35. FIG. 32 shows an example of an overall procedure for determining the faulty side arm. FIG. 33 shows an example of the procedure of the first failure location determination process (# 10), FIG. 34 shows an example of the procedure of the second failure location determination process (# 20), and FIG. 35 shows a third failure location. An example of the procedure of the discrimination process (# 30) is shown.

As described above, in order to detect an open failure and determine the failure side arm, it is necessary to obtain an integrated current which is an integrated value of the alternating current. Therefore, the integration of the alternating current (phase current) is started (# 1). As described above, for example, 200 [ms] of alternating current (Iu, Iv, Iw) is integrated, and the integrated current (ΣIu, ΣIv, ΣIw) is calculated.

In the following step # 2, it is determined whether or not the overcurrent state (OC) is present. According to the experiments and simulations of the inventors, when an open failure occurs in an operating region where the output torque of the rotary electric machine 80 is large and the rotation speed is high, for example, as in the high output region Roc shown in FIG. It was confirmed that the instantaneous value of the three-phase alternating current became a very large value. In such a case, an overcurrent detection sensor or an overcurrent detection sensor (not shown) provided in the inverter 10 or the rotary electric machine 80 detects that the overcurrent state is present, and the detection result is transmitted to the rotary electric machine control device 1. Be transmitted. Since the response to the overcurrent has a high priority, the rotary electric machine control device 1 preferentially executes the control for resolving the overcurrent state by limiting other controls. Here, the rotary electric machine control device 1 executes shutdown control (SDN) and active short circuit control (ASC) (# 3a) to reduce the rotational speed of the rotary electric machine 80 (# 3: deceleration processing). When the rotation speed reaches the target speed (for example, the rotation speed at which the operating point is outside the high output region Roc), the rotary electric machine control device 1 returns to normal control (torque control) (# 3b, # 3c). ..

Next, it is determined whether the operating state of the rotary electric machine 80 is power running (PWR) or regeneration (ReGEN) (# 4). In the case of regeneration, the third failure location determination process (# 30) is executed after $ 1 as described later with reference to FIG. 35. When the rotary electric machine 80 is powering, it is determined whether or not an open failure (OPEN-FAIL) has been detected (# 5). Here, it is determined whether or not any one of the six patterns of determination conditions shown in Table 3 is satisfied, and if any one of the determination conditions is satisfied, it is detected that an open failure has occurred. The control state of the rotary electric machine 80 when step # 5 is executed corresponds to the first control state. Further, here, it is assumed that an open failure is detected in the first control state at the first operating point Q1 shown in FIG. $ 3 and $ 5 will be described later with reference to FIGS. 40 and 41.

When it is determined that an open failure has occurred, it is next determined whether or not the rotary electric machine 80 can be regenerated (# 6). As described above, in the present embodiment provided with the two inverters 10, the rotary electric machine 80 is continuously controlled and the vehicle is controlled to continue running even when an open failure occurs. When the rotary electric machine 80 is regenerated, the rotary electric machine 80 decelerates. Therefore, if the traveling speed of the vehicle is low and the rotation speed of the rotary electric machine 80 is also low, the rotary electric machine 80 is stopped by the regeneration and the vehicle is also stopped. There is a risk. That is, it becomes difficult to continue the running of the vehicle. In step # 6, for example, it is determined whether or not the rotation speed of the rotary electric machine 80 is equal to or higher than the predetermined first specified rotation speed.

When the rotation speed of the rotary electric machine 80 is equal to or higher than the first specified rotation speed, the rotary electric machine control device 1 sets a regenerative torque (ReGEN-TR) (# 7) and performs a first failure location determination process (# 10). ) Is executed. Depending on the setting of the regenerative torque, the operating point of the rotary electric machine 80 moves from the first operating point Q1 shown in FIG. 19 to the second operating point Q2. The rotary electric machine control device 1 executes single inverter drive control (1-inv drive) for driving the rotary electric machine 80 with one inverter 10 after identifying the failure arm by executing the first failure location determination process (# 10). (# 61 (# 60)).

In step # 6, if the rotation speed of the rotary electric machine 80 is less than the first specified rotation speed, the second failure location determination process (# 20) is executed. The second failure location determination process (# 20) is a process involving power running at an ultra-low rotation speed, as described above with reference to FIGS. 16 to 18, 30, 31, and 6 and 7. .. That is, the second failure location determination process (# 20) is executed at a rotation speed lower than the first specified rotation speed and lower than the second specified rotation speed. Therefore, prior to the second failure location determination process (# 20), a process of setting the rotation speed of the rotary electric machine 80 to the second specified rotation speed (super-high speed side specified speed) is executed (# 8). The rotary electric machine control device 1 executes single inverter drive control (1-inv drive) for driving the rotary electric machine 80 with one inverter 10 after identifying the failure arm by executing the second failure location determination process (# 20). (# 62 (# 60)).

Hereinafter, the first failure location determination process (# 10) will be described with reference to FIG. 33. In the first failure location determination process (# 10), it is first determined whether or not an open failure is detected in the regenerative state (second control state) (# 11). Here, it is determined whether or not any one of the six patterns of determination conditions shown in Table 4 is satisfied, and if any one of the determination conditions is satisfied, it is detected that an open failure has occurred.

When it is determined in step # 11 that an open failure has occurred, the distortion and deflection of the AC current (Iu, Iv, Iw) waveform in regeneration are eliminated as described above with reference to FIGS. 21 to 23. A regenerative fail action (# 12) is executed in order to cause the failure. Due to normal regeneration or regeneration accompanied by a regenerative fail action, the rotational speed of the rotary electric machine 80 decreases, and the operating point moves into the single inverter control region Rs. In step # 13a (# 13) following step # 12, it is determined whether or not the operating point of the rotary electric machine 80 is within the single inverter control region Rs. If the operating point is not within the single inverter control region Rs, deceleration by regeneration is continued until the operating point is determined to be within the single inverter control region Rs (# 14a (# 14)).

When the operating point is in the single inverter control region Rs, it is determined whether or not the failure pattern FP when the open failure is detected in step # 5 is the first failure pattern FP1 (# 15a). (# 15)). When the failure pattern is the first failure pattern FP1, the failure side arm is the upper arm (inv1: H) of the first inverter 11 or the lower arm (inv2-L) of the second inverter 12. In step # 11, since the open failure is detected even in the regeneration, the failure side arm is the lower arm (inv2-L) of the second inverter 12. Therefore, in step # 16a (# 16), the failure point (FAIL) is set to be the lower arm (inv2-LOW) of the second inverter 12.

The rotary electric machine control device 1 moves the operating point to the third operating point Q3 via zero Newton control (0Nm) that controls the output torque of the rotary electric machine 80 to be zero, and an open failure occurs in the lower arm. The second inverter 12 is controlled by the upper active short circuit control (ASC-H), and the first inverter 11 is controlled by pulse width modulation (# 17a (# 17)). Then, the regeneration is restored to power running (# 18a (# 18)), and single inverter drive control (1-inv drive) for driving the rotary electric machine 80 with one inverter 10 is executed (# 61 (# 60)). ..

The same applies to the transition path from step # 15a (# 15) to steps # 16b (# 16), # 17b (# 17), # 18b (# 18), and # 61 (# 60). Omit. Further, from step # 11, steps # 13b (# 13), # 14b (# 14), # 15b (# 15), # 16c (# 16), # 17c (# 17), # 18c (# 18), # The path that transitions to 61 (# 60), and the transition from step # 15b (# 15) to steps # 16d (# 16), # 17d (# 17), # 18d (# 18), # 61 (# 60). Since the same applies to the route to be used, detailed description thereof will be omitted.

As described above with reference to FIGS. 21, 22, 28, 29 and the like, when the regenerative fail action is executed, distortion and deflection of the AC current (Iu, Iv, Iw) are also suppressed and integrated. The deflection of the current (ΣIu, ΣIv, ΣIw) is also small. Therefore, the determination condition at the time of regeneration as described above with reference to Table 4 is no longer satisfied. Therefore, the integrated current (ΣIu, ΣIv, ΣIw) used for the determination in steps # 15 and # 16 is a value acquired before the regenerative fail action is executed in step # 12 (for example, at the time of determination in step # 11). The acquired value) is preferable. Alternatively, the determination in steps # 15 and # 16 is preferably performed before the regenerative fail action.

Hereinafter, the second failure location determination process (# 20) will be described with reference to FIG. 34. As described above with reference to FIG. 32, the super-speed side specified speed setting for setting the rotation speed of the rotary electric machine 80 to the second specified rotation speed (super-speed side specified speed) prior to the second failure location determination process (# 20). The process (# 8) is executed. In the ultra-high speed side specified speed setting process, first, it is determined whether or not the rotation speed of the rotary electric machine 80 is equal to or less than the second specified rotation speed (ultra-speed side specified speed) (# 81). When the rotation speed is higher than the specified speed on the ultra-high speed side, the rotation electric machine control device 1 controls the rotation speed of the rotary electric machine 80 by shutdown control (SDN), active short circuit control (ASC), and zero Newton control (0Nm). Decelerates (# 82). When the rotation speed of the rotary electric machine 80 is equal to or less than the second specified rotation speed (super-high speed side specified speed), the control mode of the rotary electric machine 80 is set to the torque mode (# 83). That is, if the control for deceleration in step # 82 is not performed, the torque mode is continued, and if the control for deceleration is performed, the torque mode is restored.

The rotary electric machine control device 1 has an open failure in a state where the rotary electric machine 80 is running at a rotation speed equal to or lower than the second specified rotation speed (super speed side specified speed) (power running at an ultra-low rotation speed (second control state)). Is determined (# 21). Here, it is determined whether or not any one of the determination conditions of the six patterns shown in Table 6 is satisfied, and if any one of the determination conditions is satisfied, it is detected that an open failure has occurred.

If it is determined in step # 21 that an open failure has occurred, it is determined whether or not the failure pattern FP when the open failure is detected in step # 5 is the first failure pattern FP1 (#). 25a (# 25)). When the failure pattern is the first failure pattern FP1, the failure side arm is the upper arm (inv1: H) of the first inverter 11 or the lower arm (inv2: L) of the second inverter 12. In step # 21, since the open failure is detected even in the power running at the ultra-low rotation speed, the failure side arm is the lower arm (inv2: L) of the second inverter 12. Therefore, in step # 26a (# 26), the failure location (FAIL) is set to be the lower arm (inv2-LOW) of the second inverter 12.

The rotary electric machine control device 1 controls the second inverter 12 in which the lower arm has an open failure by the upper active short circuit control (ASC-H), and controls the first inverter 11 by pulse width modulation (). # 27a (# 27)). Then, the power running at the ultra-low rotation speed is restored to the normal power running (# 28a (# 28)), and the single inverter drive control (1-inv drive) for driving the rotary electric machine 80 with one inverter 10 is executed. (# 62 (# 60)).

The same applies to the transition path from step # 25a (# 15) to steps # 26b (# 16), # 27b (# 17), # 28b (# 18), and # 62 (# 60). Omit. Further, the path transitioning from step # 21 to step # 25b (# 25), # 26c (# 26), # 27c (# 27), # 28c (# 28), # 62 (# 60), and step #. The same applies to the path transitioning from 25b (# 25) to steps # 26d (# 26), # 27d (# 27), # 28d (# 28), and # 62 (# 60), so detailed description thereof will be omitted. ..

Hereinafter, the third failure location determination process (# 30) will be described with reference to FIG. 35. As shown in FIG. 32, the third failure location determination process (# 30) is branched and executed before the open failure determination process in the first control state of step # 5. The third failure location determination process (# 30) corresponds to the failure determination process in the second control state because the rotary electric machine 80 is executed during regeneration. However, the third failure location determination process (# 30) is executed independently of the failure determination process in the first control state. As described above, when the inverter 10 is switched by the mixed pulse width modulation control, even if an open failure occurs in the upper arm, the distortion generated in the AC waveform during regeneration is small, and the occurrence of the open failure is detected. Is difficult. Therefore, in the third failure location determination process (# 30), the occurrence of the open failure is detected and the failed inverter 10 is determined only when an open failure occurs in the lower arm. When the operating state of the rotary electric machine 80 shifts to power running, open failure detection in the first control state is possible. Therefore, the third failure location determination process is executed to promptly detect that a short-circuit failure has occurred at least in the lower arm during regeneration of the rotary electric machine 80 and to identify the failure location.

In the third failure location determination process (# 30), it is first determined whether or not an open failure is detected in the regenerative state (second control state) (# 31). Also in the third failure location determination process, it is determined whether or not any one of the six patterns of determination conditions shown in Table 4 is satisfied, and if any one of the determination conditions is satisfied, an open failure occurs. Is detected. Here, it is detected that the failure pattern LF is on the lower side. As described above, when an open failure has occurred in the upper arm, the third failure location determination process (# 30) cannot detect the failure or determine the failure location.

When it is determined in step # 31 that an open failure has occurred, the distortion and deflection of the AC current (Iu, Iv, Iw) waveform in regeneration are eliminated as described above with reference to FIGS. 21 to 23. A regenerative fail action (# 32) is executed in order to cause the failure. By executing the regenerative fail action, the rotation speed of the rotary electric machine 80 decreases, and the operating point moves into the single inverter control region Rs. In step # 33 following step # 32, it is determined whether or not the operating point of the rotary electric machine 80 is within the single inverter control region Rs. If the operating point is not within the single inverter control region Rs, deceleration by regeneration is continued until the operating point is determined to be within the single inverter control region Rs (# 34).

When the operating point is within the single inverter control region Rs, it is determined in which of the lower arm of the first inverter 11 and the lower arm of the second inverter 12 the open failure has occurred. Here, it is determined whether or not the detection phase of the open failure is the second inverter 12 (# 35). As described above with reference to Table 4, the rotary electric machine control device 1 can identify the switching element 3 that has an open failure depending on which of the six patterns of determination conditions is satisfied. That is, it is known whether the open failure occurs in the first inverter 11 or the second inverter 12.

When the open failure occurs in the second inverter 12, in step # 36a (# 36), the failure location (FAIL) is set to be the lower arm (inv2-LOW) of the second inverter 12. .. If an open failure has occurred in the first inverter 11, it is set in step # 36b (# 36) that the failure location (FAIL) is the lower arm (inv2-LOW) of the first inverter 11. Will be done.

When the open failure occurs in the second inverter 12, the rotary electric machine control device 1 controls the second inverter 12 in which the lower arm has an open failure by the upper active short circuit control (ASC-H). At the same time, the first inverter 11 is controlled by pulse width modulation (# 37a (# 37)). Then, a single inverter drive control (1-inv drive) for driving the rotary electric machine 80 with one inverter 10 is executed (# 63 (# 60)). Further, when the open failure occurs in the first inverter 11, the rotary electric machine control device 1 controls the first inverter 11 in which the open failure has occurred in the lower arm by the upper active short circuit control (ASC-H). In addition to controlling, the second inverter 12 is controlled by pulse width modulation (# 37b (# 37)). Then, a single inverter drive control (1-inv drive) for driving the rotary electric machine 80 with one inverter 10 is executed (# 63 (# 60)).

The control mode in the single inverter drive control (# 60) is not limited to continuous pulse width modulation control (CPWM) and discontinuous pulse width modulation control (DPWM), but may be rectangular wave control (1-Pulse). good. These are examples, and any modulation format may be used. Here, in the mixed pulse width modulation control, the switching control signal becomes ineffective in the second period T2, and the system loss can be reduced. By setting the period different from each other between the first inverter 11 and the second inverter 12 as the second period T2, it is possible to realize a state in which switching is continuously performed by a plurality of pulses as a whole. However, in the single inverter drive control, only one of the inverters 10 is switched, so that in the mixed pulse width modulation control, the AC waveform may be distorted. Therefore, it is preferable that the single inverter drive control is executed by pulse width modulation control or rectangular wave control in which a plurality of pulses having different patterns are output through one cycle of the electric angle. However, it does not prevent the mixed pulse width modulation control (MX-PWM) from being selected as the control mode.

Further, as described above with reference to FIGS. 21, 22, 28, 29 and the like, when the regenerative fail action is executed, the distortion and deflection of the alternating current (Iu, Iv, Iw) are suppressed and integrated. The deflection of the current (ΣIu, ΣIv, ΣIw) is also small. Therefore, the determination condition at the time of regeneration as described above with reference to Table 4 is no longer satisfied. Therefore, as in the first failure location determination process (# 10), the integrated current (ΣIu, ΣIv, ΣIw) used for the determination in step # 35 is acquired before the regenerative fail action is executed in step # 32. It is preferable that the value is (for example, the value acquired at the time of determination in step # 31). Alternatively, the determination in step # 35 is preferably performed prior to the regenerative fail action.

As described above, the rotary electric machine control device 1 has a plurality of phases of alternating current (Iu, Iv, Iw) when an open failure (one-phase open failure) occurs in which one switching element 3 is always in an open state. ) Are integrated to calculate the current integrated value (ΣIu, ΣIv, ΣIw) of each phase, and the occurrence of an open failure is detected based on the positive and negative of each current integrated value (ΣIu, ΣIv, ΣIw). , Determine where the open failure occurred. When the first inverter 11 and the second inverter 12 are switched and controlled by the mixed pulse width modulation control, the rotary electric machine control device 1 has the respective current integrated values (ΣIu, ΣIv, ΣIw) in the first control state (power line). ), Which of the first failure pattern FP1 and the second failure pattern FP2 is the failure pattern FP is determined. Further, the rotary electric machine control device 1 is based on the respective current integrated values (ΣIu, ΣIv, ΣIw) in the second control state (regeneration / power running at an ultra-low rotation speed) different from the first control state (power running). It is determined which of the first lower stage side failure pattern LF1 and the second lower stage side failure pattern LF2 is the lower stage side failure pattern LF. Then, the rotary electric machine control device 1 has an upper arm of the first inverter 11, a lower arm of the first inverter 11, and a second arm based on the discrimination result in the first control state and the discrimination result in the second control state. It is determined which of the upper arm of the inverter 12 and the lower arm of the second inverter 12 is the failure side arm.

In addition, in the above, with reference to FIG. 32 and the like, the embodiment in which the discrimination in the second control state is performed after the discrimination in the first control state is illustrated. However, the order of the first control state and the second control state may be reversed. Further, the discrimination based on the discrimination result in the first control state and the discrimination result in the second control state includes, for example, the case where there is no discrimination result in the first control state. When there is no discrimination result in the first control state and the lower stage side failure pattern LF is determined in the second control state, the lower stage side arm of the second inverter 12 is the failure side arm by the first lower stage side failure pattern LF1. It is specified that the lower arm of the first inverter 11 is the failure side arm by the second lower side failure pattern LF2. The case where there are both the discrimination result in the first control state and the discrimination result in the second control state is as described above with reference to FIG.

If an open failure has occurred in the upper arm and there is no first control state, the failed side arm in which the open failure has occurred cannot be specified. However, in this case, the rotary electric machine 80 is regenerated, and even if an open failure occurs in the upper arm during regeneration, the alternating current (Iu, Iv, Iw) is not distorted. Therefore, since there is almost no effect, there is no problem even if an open failure is not detected. After that, when the rotary electric machine 80 is driven, an open failure is detected. At this time, as a result of the determination in the first control state, it is determined that the first failure pattern FP1 or the second failure pattern FP2. Since the discrimination result in the second control state (without the lower failure pattern LF) has already been acquired at the time of regeneration before power running, the rotary electric machine control device 1 has the discrimination result in the first control state and the discrimination result in the second control state. The faulty side arm can be identified based on the determination result. As a matter of course, after the open failure is detected in the power running, the power running is further regenerated or the power running at an ultra-low rotation speed, and the discrimination result in the second control state is acquired again, and then the discrimination result in the first control state and the second The faulty side arm may be specified based on the determination result in the control state.

By the way, as described above, the rotary electric machine control device 1 has a loss reduction priority mode and a noise reduction priority mode as control modes of the rotary electric machine 80. As described above with reference to Table 2, in the noise reduction priority mode, both the first inverter 11 and the second inverter 12 are driven by general pulse width modulation control instead of mixed pulse width modulation control. The behavior of the three-phase alternating current when an open failure occurs when both the first inverter 11 and the second inverter 12 are driven in the noise reduction priority mode is described above with reference to FIGS. 11 to 14 and the like. It is different from the behavior.

36 to 39 show three phases when an open failure occurs in the noise reduction priority mode (that is, when both inverters 10 are controlled by pulse width modulation control), as in FIGS. 11 to 14. It is a waveform diagram which shows an example of the AC waveform (U phase current Iu, V phase current Iv, W phase current Iw). 36 and 37 show a three-phase AC waveform when an open failure occurs during power running, as in FIGS. 11 and 12, and FIGS. 38 and 39 show a three-phase AC waveform during regeneration, as in FIGS. 13 and 14. The three-phase AC waveform when an open failure occurs is shown. Similar to FIGS. 11 to 14, FIGS. 36 to 39 show a waveform when the U-phase switching element 3 has an open failure. Further, similarly to FIGS. 11 to 14, in common with FIGS. 36 to 39, the waveform when the switching element 3 on the upper side (HIGHSIDE) of the first inverter 11 fails to open, the lower side of the first inverter 11. (LOWSIDE) waveform when the switching element 3 has an open failure, waveform when the switching element 3 on the upper side (HIGHSIDE) of the second inverter 12 has an open failure, switching element on the lower side (LOWSIDE) of the second inverter 12. The waveform when 3 has an open failure is shown in a matrix. Further, as in FIG. 12 with respect to FIG. 11, FIG. 37 with respect to FIG. 36 shows a case where the rotation speed of the rotary electric machine 80 is high with the same torque, and with respect to FIG. 38 as with FIG. 14 with respect to FIG. 39 shows a case where the rotation speed of the rotary electric machine 80 is high at the same torque.

Similar to FIGS. 11 and 12, as shown in FIGS. 36 and 37, when an open failure occurs during power running, the first inverter 11 and the second inverter 12 may be on the upper side or the lower side. The three-phase AC waveform is an asymmetric and distorted waveform. Further, the three-phase AC waveform has the same waveforms when the upper side of the first inverter 11 has an open failure and when the lower side of the second inverter 12 has an open failure, and when the lower side of the first inverter 11 has an open failure. And, the same waveform is obtained when the upper side of the second inverter 12 fails to open.

Further, as shown in FIGS. 38 and 39, even when an open failure occurs during regeneration, the three-phase AC waveform is on the upper side or the lower side of the first inverter 11 and the second inverter 12. Is an asymmetric and distorted waveform. Further, the three-phase AC waveform has the same waveforms when the upper side of the first inverter 11 has an open failure and when the lower side of the second inverter 12 has an open failure, and when the lower side of the first inverter 11 has an open failure. And, the same waveform is obtained when the upper side of the second inverter 12 fails to open.

In the loss reduction priority mode (that is, when both inverters 10 are controlled by the mixed pulse width modulation control), as shown in FIGS. 13 and 14, during regeneration, the first inverter 11 and the second inverter 12 If an open failure occurs on the lower side, the three-phase AC waveform becomes an asymmetric and distorted waveform, but if an open failure occurs on the upper end side of the first inverter 11 and the second inverter 12, the three-phase AC waveform Is a waveform that is almost symmetrical and has almost no distortion.

That is, in the loss reduction priority mode, as shown in FIG. 15, during power running (excluding ultra-low rotation speed), the three-phase AC waveform shows an abnormality no matter where an open failure occurs, and the form of the abnormality is. , The first failure pattern FP1 shown in FIG. 15 and the second failure pattern FP2 are roughly classified. On the other hand, at the time of regeneration, the three-phase AC waveform shows an abnormality only when an open failure occurs on the lower side of the first inverter 11 and the second inverter 12. Therefore, by collating the states of the three-phase AC waveforms during power running and regeneration, when an open failure is detected, it is determined which inverter 10 has an open failure on the upper side or the lower side. It is possible (see also Tables 3-5 and the above description with reference to them).

However, in the noise reduction priority mode, as shown in FIG. 42, the states of the three-phase AC waveform show the same tendency during power running and regeneration. That is, in both the power running time and the regeneration time, when an open failure occurs, the first failure pattern FP1 or the second failure pattern FP2 can be discriminated as the failure pattern FP. Therefore, it is not possible to determine which of the inverters 10 has an open failure on the upper side or the lower side. Therefore, the rotary electric machine control device 1 assumes that either the first inverter 11 or the second inverter 12 is a failed inverter, and based on that assumption, it is assumed that the single inverter control region Rs has not failed. The rotary electric machine 80 is driven and controlled (1-inv drive) via the inverter 10 on the other side.

After that, if no abnormality (open failure) is detected, the assumption is correct, and the inverter 10 assuming the failure is determined as the failed inverter. On the other hand, if an abnormality (open failure) is further detected, the assumption is incorrect. Therefore, the inverter 10 that is not the one that is assumed to be a failure is determined as the failed inverter. Then, with the correct failed inverter specified, the rotary electric machine 80 is driven and controlled (1-inv drive) via the inverter 10 (normal inverter) that has not failed in the single inverter control region Rs.

Hereinafter, the flowchart of FIG. 40 will also be referred to and described. As described above with reference to FIGS. 36, 37, and 42, even when the inverter 10 is switched by general pulse width modulation control instead of mixed pulse width modulation control, an open failure in the first control state The failure pattern FP can be determined by the detection of (step # 5). Therefore, here, the process following step # 5 will be described.

First, in step # 41, it is determined whether or not the operating point of the rotary electric machine 80 is within the single inverter control region Rs. If the operating point is not within the single inverter control area Rs, for example, shutdown control (SDN), active short circuit control (ASC), or zero Newton control (0Nm) is used until the operating point is determined to be within the single inverter control area Rs. Deceleration is performed (# 42). When the operating point is the single inverter control region Rs, the control mode of the rotary electric machine 80 is set to the torque mode (# 43). That is, if the control for deceleration in step # 42 is not performed, the torque mode is continued, and if the control for deceleration is performed, the torque mode is restored.

The failure pattern FP when an open failure is detected in step # 5 is the first failure pattern FP1 or the second failure pattern FP2. Therefore, it is unclear which of the inverters 10 of the first inverter 11 and the second inverter 12 has an open failure. Therefore, it is assumed that the rotary electric machine control device 1 has an open failure in either of the inverters 10. That is, the rotary electric machine control device 1 sets one of the inverters 10 of the first inverter 11 and the second inverter 12 as a failure assumption inverter assuming that an open failure has occurred, and sets the other inverter 10 as a failure assumption inverter. Assuming a normal inverter that has not failed, set it to a normal assumed inverter (# 51). Here, the first inverter 11 is set as a normal assumption inverter (NORMAL), and the second inverter 12 is set as a failure assumption inverter (OPEN-FAIL). Of course, this assumption may be reversed.

For example, if the failure pattern FP when the open failure is detected in step # 5 is the first failure pattern FP1, the failure side arm is the upper arm on the first inverter 11 or the lower arm on the second inverter 12. It is an arm. Since the second inverter 12 is set as the failure assumption inverter in step # 51, the failure side arm is assumed to be the lower arm of the second inverter 12. That is, the lower arm of the second inverter 12 is set as a failure side hypothetical arm.

In step # 52, the failure side arm (failure side assumption) in which an open failure (OPEN-FAIL) occurs based on the failure assumption inverter set in step # 51 and the failure pattern FP determined in step # 5. It is determined whether the arm) is the upper arm or the lower arm. Here, since the faulty side arm is the lower stage arm, the rotary electric machine control device 1 controls the second inverter 12 by the upper stage side active short circuit control (ASC-H), and the first inverter 11 is pulse width modulated. It is controlled by control (# 53a (# 53)).

When the switching of the inverter 10 according to the new control mode is started, the phase current starts to be reintegrated (# 54a (# 54)). That is, the integrated value of the three-phase current (Iu, Iv, Iw) is reset once, and the integrated current (ΣIu, ΣIv, ΣIw) is calculated again. Next, in step # 55a (# 55), it is determined whether or not an open failure is detected based on these integrated currents (ΣIu, ΣIv, ΣIw). Here, when an open failure is detected, it means that the assumptions in steps # 51 and # 52 are incorrect. That is, it can be seen that the failure-side arm is not the lower-stage side arm of the second inverter 12, but the upper-stage side arm of the first inverter 11 which is the other side in the first failure pattern FP1.

The rotary electric machine control device 1 sets that the failure point (FAIL) is the upper arm (inv1-HIGH) of the first inverter 11 (# 56a (# 56)). Then, the rotary electric machine control device 1 controls the first inverter 11 in which the upper arm has an open failure by the lower active short circuit control (ASC-L), and controls the second inverter 12 by pulse width modulation. (# 57a (# 57)). Then, a single inverter drive control (1-inv drive) for driving the rotary electric machine 80 with one inverter 10 is executed (# 65 (# 60)).

If no open failure is detected in step # 55a (# 55), it means that the assumptions in steps # 51 and # 52 were correct. That is, it can be seen that the faulty side arm is the lower arm on the second inverter 12 as assumed. The failure point (FAIL) is set to be the lower arm (inv2-LOW) of the second inverter 12 (# 56b (# 56)). Then, the rotary electric machine control device 1 controls the second inverter 12 in which the lower arm has an open failure by the upper active short circuit control (ASC-H), and controls the first inverter 11 by pulse width modulation. (# 57b (# 57)). Then, a single inverter drive control (1-inv drive) for driving the rotary electric machine 80 with one inverter 10 is executed (# 65 (# 60)).

Routes that transition from step # 52 to steps # 53b (# 53), # 54b (# 54), # 55b (# 55), # 56c (# 56), # 57c (# 57), # 65 (# 60). The same applies to the above, and detailed description thereof will be omitted. Further, since the same applies to the path transitioning from step # 55b (# 55) to steps # 56d (# 56), # 57d (# 27), and # 65 (# 60), detailed description thereof will be omitted. In the noise reduction priority mode, the inverter 10 is switched by general pulse width modulation control. Therefore, when executing the single inverter drive control (1-inv drive), it is not necessary to change the control method from the mixed pulse width modulation control to the general pulse width modulation control.

As described above, even when the control method of the inverter 10 is not the mixed pulse width modulation control, the rotary electric machine control device 1 has a failure pattern FP of an open failure based on the positive and negative of each current integrated value (ΣIu, ΣIv, ΣIw). Determines whether the inverter has the first failure pattern FP1 or the second failure pattern FP2, and then fails by assuming that the inverter 10 of either the first inverter 11 or the second inverter 12 is a failure inverter. Assumed inverter. Then, the rotary electric machine control device 1 is a switching element 3 of the failure side assumption arm assumed to be the failure side arm among the upper stage side arm and the lower stage side arm of the failure assumption inverter based on the determined failure pattern FP. The active short circuit control is performed with all of the switching elements 3 of the non-failure side assumption arm on the other side turned on, and the inverter 10 (normal assumption inverter) different from the failure assumption inverter is switched and controlled. .. After that, the rotary electric machine control device 1 determines that the failure assumption inverter is a failure inverter when an open failure is not detected based on the positive and negative of each current integrated value (ΣIu, ΣIv, ΣIw). It is determined that the faulty side assumed arm is the faulty side arm. When an open failure is detected, the rotary electric machine control device 1 determines that the inverter 10 different from the failure assumption inverter is the failure inverter, and determines the failure side arm in the failure inverter based on the failure pattern FP. do.

The method of assuming a failed inverter as described above with reference to the flowchart of FIG. 40 is, of course, applicable even when the control method is mixed pulse width modulation control.

Further, in the above, it is assumed that one of the first inverter 11 and the second inverter 12 is a failed inverter, and a mode of determining the failed inverter and specifying the failed portion is illustrated. However, as shown in the flowchart of FIG. 41, after changing the control method from pulse width modulation control to mixed pulse width modulation control, the first described above with reference to FIGS. 32 to 34 via $ 5. The faulty inverter may be discriminated and the faulty part may be specified by the faulty part discriminating process (# 10) or the second faulty part discriminating process (# 20).

That is, the rotary electric machine control device 1 outputs a plurality of pulses having different patterns to the inverters 10 of both the first inverter 11 and the second inverter 12 not in the mixed pulse width modulation control but also in the second period T2. In the first control state, when controlled by pulse width modulation control in which a plurality of pulses having different patterns are output through one cycle of the corner, or by square wave control in which one pulse is output in one cycle of the electric angle. When the occurrence of an open failure is detected, the failure pattern FP is determined in the first control state, and then the control method of the inverters 10 of both the first inverter 11 and the second inverter 12 is changed to the mixed pulse width modulation control. By changing, in the second control state, it is determined whether or not the lower side failure pattern LF is present, and then the failure side arm is set based on the determination result of the first control state and the determination result of the second control state. It may be determined.

As described above, in the noise reduction priority mode, when an open failure occurs in both the power running and the regeneration, the first failure pattern FP1 or the second failure pattern FP2 is used as the failure pattern FP. It can be discriminated. Therefore, in the noise reduction priority mode, the first control state includes power running and regeneration. That is, the first control state before changing the control method to the mixed pulse width modulation control includes power running and regeneration. The second control state after changing the control method to the mixed pulse width modulation control is regeneration or power running at an ultra-low rotation speed, as in the loss reduction priority mode.

As described above, according to the present embodiment, when one of the switching elements 3 constituting the two inverters 10 provided at both ends of the stator coil 8 of the open winding causes an open failure. , The faulty part can be identified.

[Outline of Embodiment]
Hereinafter, the outline of the rotary electric machine control device (1) described above will be briefly described.

As one embodiment, a rotary electric machine control device (rotary electric machine control device) for driving and controlling a rotary electric machine (80) having a plurality of phases of open windings (8) independent of each other via a first inverter (11) and a second inverter (12). 1), the first inverter (11) is connected to one end side of the open winding (8) of a plurality of phases to convert power between a DC and a multi-phase AC, and the second inverter (11). The inverter (12) is connected to the other end side of the open winding (8) of the plurality of phases to convert power between the DC and the AC of the plurality of phases, and the first inverter (11) and the second inverter (11). In the inverter (12), the arm (3A) for one AC phase is composed of a series circuit of an upper switching element (3H) and a lower switching element (3L), respectively, and the first inverter (11) and the first inverter (11). Each of the two inverters (12) can be controlled independently of each other, and one switching element (10) in either the first inverter (11) or the second inverter (12) has one switching element ( When an open failure occurs in which 3) is always in the open state, each of the multi-phase AC currents (Iu, Iv, Iw) is integrated to calculate the current integrated value (ΣIu, ΣIv, ΣIw) of each phase. , The occurrence of the open failure is detected based on the positive and negative of each of the current integrated values (ΣIu, ΣIv, ΣIw), and the location where the open failure has occurred is determined, and the first inverter (11). ) And the inverter (10) of both of the second inverters (12), a plurality of pulses having different patterns are output in the first period, which is 1/2 cycle of the electric angle, and the remaining 1/2 cycle. If the occurrence of the open failure is detected during control by the mixed pulse width modulation control controlled so that the ineffective state continues in the second period, the current integration in each of the first control states is performed. Based on the positive or negative of the values (ΣIu, ΣIv, ΣIw), either the upper arm of the first inverter (11) or the lower arm of the second inverter (12) is the failed side arm in which the open failure occurred. A second failure pattern in which either the first failure pattern (FP1) and the lower arm of the first inverter (11) or the upper arm of the second inverter (12) is the failure side arm. (FP2), which failure pattern (FP) is determined, and the respective currents in the second control state different from the first control state. Based on the integrated values (ΣIu, ΣIv, ΣIw), the first lower stage side failure pattern (LF1) in which the lower stage side arm of the second inverter (12) is the failure side arm, and the first inverter (11). It is determined which lower stage side failure pattern (LF) of the second lower stage side failure pattern (LF2), which is the failure side arm, is the lower stage side arm, and the determination result in the first control state and the first 2. Based on the discrimination result in the control state, the upper arm of the first inverter (11), the lower arm of the first inverter (11), and the upper arm of the second inverter (12). It is determined which of the lower arm of the second inverter (12) is the faulty arm.

According to experiments and simulations by the inventors, when an open failure of the switching element (3) occurs in one of the two inverters (10), the three-phase current waveform becomes an asymmetric and distorted waveform. Was confirmed. For example, the AC current waveform of a phase is largely deflected to the positive side, and the AC current waveform of a phase is largely deflected to the negative side. Then, when the alternating current (Iu, Iv, Iw) is integrated over a predetermined time, this tendency of deflection becomes more remarkable. The direction of deflection depends on the position of the switching element (3) that has failed open. Therefore, based on the positive and negative of the current integrated value (ΣIu, ΣIv, ΣIw), it can be determined whether the open failure has occurred and which inverter (10) has the open failure in the upper arm or the lower arm. It can be determined. Further, according to the experiments and simulations of the inventors, in the second control state, when an open failure occurs in the upper arm, it is difficult to detect the open failure itself, but the open failure in the lower arm is difficult. When is occurring, it is possible to detect an open failure and determine which inverter (10) is the failure. In the first control state, it is possible to detect an open failure regardless of whether the upper arm or the lower arm has an open failure. However, in the first control state, it is possible to determine whether the failure pattern (FP) is the first failure pattern (FP1) or the second failure pattern (FP2), but which inverter (10) is used. It is not possible to determine whether it is. According to this configuration, when an open failure occurs in the lower arm, the failed arm can be determined at least based on the determination result in the second control state. Further, regardless of whether the open failure occurs in the upper arm or the lower arm, both the discrimination result in the first control state and the discrimination result in the second control state Based on this, the faulty side arm can be determined. As described above, according to this configuration, when one of the switching elements (3) constituting the two inverters (10) provided at both ends of the open winding (8) causes an open failure. , The faulty part can be identified.

When the rotary electric machine control device (1) is determined to be the first failure pattern (FP1) in the first control state and is determined to be the lower side failure pattern (LF) in the second control state. The lower arm of the second inverter (12) is determined to be the failure side arm, and is determined to be the first failure pattern (FP1) in the first control state, and the second control is performed. When it is determined that the lower stage side failure pattern (LF) is not obtained in the state, it is determined that the upper stage side arm of the first inverter (11) is the failure side arm, and the first control state is described. When it is determined to be the second failure pattern (FP2) and it is determined to be the lower stage side failure pattern (LF) in the second control state, the lower stage side arm of the first inverter (11) is determined. It was determined that it was the failure side arm, it was determined that it was the second failure pattern (FP2) in the first control state, and it was determined that it was not the lower side failure pattern (lF) in the second control state. In this case, it is preferable to determine that the upper arm of the second inverter (12) is the faulty arm.

According to this configuration, it is appropriate based on the failure pattern (FP) determined in the first control state and the determination result of whether or not the failure pattern (LF) is determined in the second control state. The faulty side arm can be identified.

Further, in the rotary electric machine control device (1), the current integrated value of one phase among the plurality of current integrated values (ΣIu, ΣIv, ΣIw) is negative, and the current integrated value of the other phase is positive. In this case, it is determined from the first failure pattern (FP1), the current integrated value of one phase among the plurality of current integrated values (ΣIu, ΣIv, ΣIw) is positive, and the current integrated value of the other phase is positive. When the value is negative, it is preferable to discriminate from the second failure pattern (FP2).

Through experiments and simulations by the inventors, it was confirmed that the AC current of the phase including the switching element (3) with the open failure is deflected in a tendency different from that of the AC currents of the other phases in the first control state. rice field. Therefore, the failure location can be specified based on the tendency of deflection as described above.

Further, in the rotary electric machine control device (1), the current integrated value of one phase among the plurality of current integrated values (ΣIu, ΣIv, ΣIw) is negative, and the current integrated value of the other phase is positive. In this case, it is determined that the pattern is the first lower side failure pattern (LF1), and the current integrated value of one phase among the plurality of current integrated values (ΣIu, ΣIv, ΣIw) is positive, and the other phase. When the current integrated value is negative, it is preferable to determine that the current integrated value is the second lower side failure pattern (LF2).

Through experiments and simulations by the inventors, it was confirmed that the AC current of the phase including the switching element (3) with the open failure is deflected in a tendency different from that of the AC currents of the other phases in the second control state. rice field. Therefore, the failure location can be specified based on the tendency of deflection as described above.

Further, it is preferable that the first control state is power running when the rotation speed of the rotary electric machine (80) is equal to or higher than the predetermined first specified rotation speed, and the second control state is regeneration.

According to the experiments and simulations of the inventors, when the inverter (10) is switched and controlled by the mixed pulse width modulation control when an open failure occurs, the alternating current (Iu, Iv, Iw) is controlled by power running and regeneration. It was confirmed that the behavior of was different. Therefore, by setting the first control state as power running and the second control state as regeneration, the faulty arm can be appropriately determined.

Further, in the rotary electric machine control device (1), when the second control state is regeneration and the occurrence of the open failure is detected in the second control state, the plurality of phases caused by the open failure It is preferable to perform a regenerative fail action that suppresses the distortion of the alternating current (Iu, Iv, Iw).

According to the experiments and simulations of the inventors, when an open failure occurs in the upper arm, the waveform of the alternating current (Iu, Iv, Iw) does not have a large distortion in the second control state. Therefore, even if an open failure occurs in the upper arm, there is room for controlling the inverter (10) in the second control state under certain conditions as in the case where the open failure does not occur. According to this configuration, by executing the regenerative fail action that suppresses the distortion of the multi-phase alternating current (Iu, Iv, Iw) caused by the open failure, the open failure occurs even if the open failure occurs. The inverter (10) can be controlled as if it were not present.

Here, the regenerative fail action replaces the switching pattern of the upper arm of the first inverter (11) with the switching pattern of the lower arm of the second inverter (12), and the first inverter (12). The switching pattern of the lower arm of the second inverter (12) is replaced with the switching pattern of the upper arm of the second inverter (12), or the switching pattern of the upper arm of the first inverter (11). And the switching pattern of the lower arm (12) are exchanged, and the switching pattern of the upper arm and the switching pattern of the lower arm of the second inverter (12) are exchanged, and further, the alternating current of a plurality of phases is exchanged. It is preferable that the positive and negative of each of the currents (Iu, Iv, Iw) are reversed.

According to the experiments and simulations of the inventors, when an open failure occurs in the upper arm, the waveform of the alternating current (Iu, Iv, Iw) does not have a large distortion in the second control state. According to this configuration, the upper arm and the lower arm are apparently interchanged, so that the faulty side arm causing the open failure is used as the upper side arm, and the alternating current (Iu, Iv, Iw) in which distortion is suppressed is used. ) Can be obtained.

Here, it is preferable to reduce the rotation speed of the rotary electric machine (80) by regeneration.

According to this configuration, the rotation speed of the rotary electric machine (80) is reduced by a regenerative operation for determining the failure location, and after the failure location is determined, the rotary electric machine (80) is used with one inverter (10). ) Can be driven, and the lead time until the next control can be shortened.

Further, the first control state is a force running when the rotation speed of the rotary electric machine (80) is equal to or higher than a predetermined first specified rotation speed, and the second control state is higher than the first specified rotation speed. It is preferable that the force is run at a low second specified rotation speed or less.

According to the experiments and simulations of the inventors, when the inverter (10) is switched and controlled by the mixed pulse width modulation control when an open failure occurs, the alternating current (Iu) depends on the rotation speed even if the power is the same. , Iv, Iw) were confirmed to be different. In particular, it was confirmed that when the rotation speed is low, the behavior is similar to that of regeneration. Therefore, by setting the first control state to power running and the second control state to power running at a rotation speed lower than that of the first control state, the faulty arm can be appropriately determined.

Further, the rotary electric machine control device (1) detects the occurrence of the open failure in the first control state and determines the failure pattern (FP), and then, in the second control state, the lower side failure. It is preferable to discriminate the pattern (LF) and then discriminate the faulty side arm based on the discriminant result of the first control state and the discrimination result of the second control state.

According to this configuration, the failure side arm can be appropriately determined by sequentially executing the control for realizing the first control state and the control for realizing the second control state.

Further, in the first control state, the rotary electric machine control device (1) detects the occurrence of the open failure and determines the failure pattern (FP), and then determines the rotation speed of the rotary electric machine (80) in advance. When the rotation speed is equal to or higher than the first specified rotation speed, the lower side failure pattern (LF) is determined with regeneration as the second control state, and the rotation speed of the rotary electric machine (80) is less than the first specified rotation speed. In the case of, it is preferable to discriminate the lower side failure pattern (LF) by setting the force running at the second specified rotation speed or less, which is lower than the first specified rotation speed, as the second control state.

When the control mode is changed from power running to regeneration, the rotation speed of the rotary electric machine (80) decreases. If the rotation speed of the rotary electric machine (80) is low, the rotary electric machine (80) may stop due to regeneration. According to this configuration, when the rotation speed of the rotary electric machine (80) is less than the first specified rotation speed, the force is performed at the first specified rotation speed or less instead of regeneration, so that the rotary electric machine (80) is stopped. The faulty part can be appropriately determined without causing the trouble.

Here, when the rotation speed of the rotary electric machine (80) is less than the predetermined first specified rotation speed, the shutdown control for turning off the switching elements (3) of all the plurality of phases, or the rotary electric machine (80). ) Is controlled so that the output torque becomes zero, and it is preferable to reduce the rotation speed of the rotary electric machine (80) to the second specified rotation speed or less.

According to this configuration, in the case of a rotation speed at which regeneration is not possible, the rotation speed of the rotary electric machine (80) can be appropriately reduced to the second specified rotation speed or less to enter the second control state.

Further, the rotary electric machine control device (1) does not control the mixed pulse width modulation of the inverters (10) of both the first inverter (11) and the second inverter (12), but the second period ( Also in T2), pulse width modulation control in which multiple pulses with different patterns are output and multiple pulses with different patterns are output throughout one cycle of the electric angle, or a square in which one pulse is output in one cycle of the electric angle. When the occurrence of the open failure is detected in the first control state when the control is performed by wave control, the failure pattern (FP) is determined in the first control state, and then the first control state is performed. The control method of the inverter (10) of both the inverter (11) and the second inverter (12) is changed to the mixed pulse width modulation control, and in the second control state, the lower side failure pattern (LF). After that, it is preferable to discriminate the faulty side arm based on the discriminant result of the first control state and the discrimination result of the second control state.

According to the experiments and simulations by the inventors, when the two inverters (10) are switched and controlled by the mixed pulse width modulation control, as described above, when an open failure occurs, it is the first control state. Differences in the behavior of alternating current (Iu, Iv, Iw) are observed in the second control state, but such differences are observed when switching is controlled by, for example, generally known pulse width modulation control. Was not observed. However, when an open failure occurs, it is determined that the open failure has occurred and whether the failure pattern (FP) is the first failure pattern (FP1) or the second failure pattern (FP2). .. According to this configuration, after these are determined in the first control state, the control method of the inverter (10) is changed to the mixed pulse width modulation control, and the second control state is realized. Therefore, a difference in the behavior of the alternating current (Iu, Iv, Iw) is observed between the first control state and the second control state, and the faulty side arm can be discriminated.

Further, as one embodiment, a rotary electric machine control in which a rotary electric machine (80) having a plurality of phases of open windings (8) independent of each other is driven and controlled via a first inverter (11) and a second inverter (12). In the apparatus (1), the first inverter (11) is connected to one end side of the open winding (8) having a plurality of phases to convert power between DC and AC of the plurality of phases, and the second inverter (11) is described. The inverter (12) is connected to the other end side of the open winding (8) of the plurality of phases and converts power between the DC and the AC of the plurality of phases, and the first inverter (11) and the second. In the inverter (12), an arm (3A) for one AC phase is composed of a series circuit of an upper switching element (3H) and a lower switching element (3L), respectively, and the first inverter (11) and the first. Each of the two inverters (12) can be controlled independently of each other, and in one of the first inverter (11) and the second inverter (12), one switching element (10) When an open failure occurs in which 3) is always in the open state, each of the multi-phase AC currents (Iu, Iv, Iw) is integrated to calculate the current integrated value (ΣIu, ΣIv, ΣIw) of each phase. , The occurrence of the open failure is detected based on the positive and negative of each of the current integrated values (ΣIu, ΣIv, ΣIw), and the location where the open failure has occurred is determined. When detected, either the upper arm of the first inverter (11) or the lower arm of the second inverter (12) is based on the positive or negative of each of the integrated current values (ΣIu, ΣIv, ΣIw). The open failure occurred in either the first failure pattern (FP1) in which the open failure occurred, the lower arm of the first inverter (11), or the upper arm of the second inverter (12). It is determined which of the second failure patterns (FP2) is the failure pattern (FP), and then the inverter (10) of either the first inverter (11) or the second inverter (12) is used. ) Is assumed to be a failure inverter that has caused the open failure, and is defined as a failure assumption inverter. All of the switching elements (3) of the failure side assumption arm assumed to be the failure side arm in which the open failure has occurred The active short circuit control is performed with all of the switching elements (3) of the non-failure side assumption arm on the other side turned on, and the inverter (10) different from the failure assumption inverter is switched and controlled. After that, if the open failure is not detected based on the positive / negative of the respective integrated current values (ΣIu, ΣIv, ΣIw), it is determined that the failure assumption inverter is the failure inverter, and the failure is performed. When it is determined that the side assumption arm is the failure side arm and the open failure is detected, it is determined that the inverter (10) different from the failure assumption inverter is the failure inverter, and the failure is detected. The failure side arm in the failure inverter is determined based on the pattern (FP).

According to this configuration, when it is detected that an open failure has occurred, the failure side arm is assumed to be the failure side assumption arm, and the inverter can be used even if the failure side assumption arm has an open failure. (10) is switched controlled. In this state, if it is not detected again as an open failure, it is known that the assumption was correct, and if it is detected again as an open failure, it is known that the assumption was incorrect. Therefore, according to this configuration, the faulty side arm can be specified.

Here, when the rotary electric machine control device (1) detects the occurrence of the open failure, it is any failure pattern (FP) of the first failure pattern (FP1) and the second failure pattern (FP2). After that, the active short circuit control, the shutdown control in which all the switching elements (3) of the plurality of phases are turned off, or the output torque of the rotary electric machine (80) is controlled to be zero. It is preferable to reduce the rotational speed of the rotary electric machine (80) by zero-newton control, and then switch control of the inverter (10) different from the failure assumption inverter.

Failure assumption When the rotary electric machine (80) is driven only by an inverter (10) different from the inverter, the operating range of the rotary electric machine (80) is narrower than that when it is driven by two inverters (10). Therefore, for example, the operable rotation speed is also lowered. According to this configuration, by reducing the rotation speed of the rotary electric machine (80) before switching control of the inverter (10) different from the failure assumption inverter, the rotary electric machine (80) can be appropriately used only with the inverter (10). Can be driven.

Further, the rotary electric machine control device (1) has a shutdown control or a plurality of phases in which all the switching elements (3) of the plurality of phases are turned off when an overcurrent state occurs due to the occurrence of the open failure. By active short circuit control that turns on the upper switching element (3H) of all the arms (3A) or turns on the lower switching element (3L) of all the multiple phases of the arm (3A). It is preferable to reduce the rotation speed of the rotary electric machine (80) to eliminate the overcurrent state, and then determine the faulty side arm.

According to the experiments and simulations of the inventors, for example, when an open failure occurs at an operating point where the output torque of the rotary electric machine (80) is large and the rotation speed is high, the instantaneous value of the three-phase AC current is extremely high. It was confirmed that the value may be large. In such a case, an overcurrent state is detected, and in general, the control of the inverter (10) is limited. Therefore, in such a case, it is preferable to determine the faulty side arm after eliminating the overcurrent state.

Further, in the rotary electric machine control device (1), among the first inverter (11) and the second inverter (12), the inverter (10) in which the open failure has occurred is used as a failure inverter, and the failure inverter is defined as a failure inverter. The different inverter (10) is a normal inverter, and of the upper arm and the lower arm of the faulty inverter, the side opposite to the faulty side arm is the non-failure side arm, and the faulty side arm of the faulty inverter is used. While performing active short circuit control in which all of the switching elements (3) of the above are turned off and all of the switching elements (3) of the non-failure side arm are turned on, the rotary electric machine is performed via the normal inverter. It is preferable to perform single inverter drive control for driving (80).

When an inverter (10) is connected to both ends of the open winding (8), when the failed inverter is short-circuited by active short circuit control, the multi-phase open winding (8) is short-circuited in the failed inverter. That is, the faulty inverter becomes the neutral point, and the open winding (8) is connected in a Y shape. Of the upper arm and lower arm of the failed inverter, the failed side arm including the open failed switching element (3) is turned off and active short circuit control is performed, so that the open failed switching element (3) ) Is equivalent to the open failure state. Therefore, the rotary electric machine control device 1 can appropriately drive and control the rotary electric machine (80) provided with the open winding (8) connected in a Y shape via a normal inverter.

Here, it is preferable that the rotary electric machine control device (1) performs the single inverter drive control by pulse width modulation control in which a plurality of pulses having different patterns are output through one cycle of the electric angle.

In the mixed pulse width modulation control, the switching control signal becomes ineffective in the second period (T2), and the system loss can be reduced. By setting the period different from each other between the first inverter (11) and the second inverter (12) as the second period (T2), it is possible to realize a state in which the first inverter (11) and the second inverter (12) are continuously switched by a plurality of pulses as a whole. However, in the single inverter drive control, only one of the inverters (10) is switched, so that in the mixed pulse width modulation control, the AC waveform is distorted. Therefore, it is preferable that the single inverter drive control is executed by pulse width modulation control in which a plurality of pulses having different patterns are output through one cycle of the electric angle.

1: Rotating electric machine control device 3: Switching element 3A: Arm 3H: Upper stage side switching element 3L: Lower stage side switching element 8: Stator coil (open winding)
10: Inverter 11: First inverter 12: Second inverter 80: Rotating electric machine FP: Failure pattern FP1: First failure pattern FP2: Second failure pattern LF: Lower side failure pattern LF1: First lower stage failure pattern LF2: Second Lower failure pattern T1: 1st period T2: 2nd period

Claims (18)

A rotary electric machine control device that drives and controls a rotary electric machine having a plurality of phases of open windings that are independent of each other via a first inverter and a second inverter.
The first inverter is connected to one end side of the open winding of the plurality of phases to convert electric power between direct current and alternating current of the plurality of phases.
The second inverter is connected to the other end of the multi-phase open winding to convert power between direct current and multi-phase alternating current.
In the first inverter and the second inverter, the arm for one AC phase is composed of a series circuit of an upper switching element and a lower switching element, respectively.
Each of the first inverter and the second inverter can be controlled independently of each other.
In the case of an open failure in which one switching element is always in an open state in either the first inverter or the second inverter, the alternating currents of a plurality of phases are integrated and the current of each phase is integrated. The integrated value is calculated, and the occurrence of the open failure is detected based on the positive and negative of each current integrated value, and the location where the open failure has occurred is determined.
A plurality of pulses having different patterns are output from the inverters of both the first inverter and the second inverter in the first period, which is 1/2 cycle of the electric angle, and the second period, which is the remaining 1/2 cycle. When the occurrence of the open failure is detected while controlling by the mixed pulse width modulation control controlled so that the ineffective state continues in
Based on the positive and negative of each of the current integrated values in the first control state, either the upper arm of the first inverter or the lower arm of the second inverter is the faulty side arm in which the open fault has occurred. It is determined which of the failure pattern and the second failure pattern in which either the lower arm of the first inverter or the upper arm of the second inverter is the failure side arm. ,
Based on the current integrated value in each of the second control states different from the first control state, the first lower stage failure pattern in which the lower arm of the second inverter is the failure side arm, and the first inverter. It is determined which lower stage side failure pattern of the second lower stage side failure pattern, which is the failure side arm, is the lower stage side arm.
Based on the discrimination result in the first control state and the discrimination result in the second control state, the upper arm of the first inverter, the lower arm of the first inverter, and the upper arm of the second inverter. A rotary electric machine control device for determining which of the side arm and the lower arm of the second inverter is the failure side arm. When the first failure pattern is determined in the first control state and the first lower failure pattern is determined in the second control state, the lower arm of the second inverter has the failure. Determined to be the side arm,
When it is determined that the first failure pattern is in the first control state and none of the lower side failure patterns is determined in the second control state, the upper arm of the first inverter is on the failure side. Determined to be an arm
When the second failure pattern is determined in the first control state and the second lower failure pattern is determined in the second control state, the lower arm of the first inverter has the failure. Determined to be the side arm,
When it is determined that the second failure pattern is in the first control state and none of the lower side failure patterns is determined in the second control state, the upper arm of the second inverter is on the failure side. The rotary electric machine control device according to claim 1, wherein the arm is determined to be an arm. When the current integrated value of one of the plurality of current integrated values is negative and the current integrated value of the other phase is positive, it is determined to be the first failure pattern.
According to claim 1 or 2, when the current integrated value of one phase among the plurality of current integrated values is positive and the current integrated value of the other phase is negative, it is determined to be the second failure pattern. The rotary electric control device described. When the current integrated value of one of the plurality of current integrated values is negative and the current integrated value of the other phase is positive, it is determined that the first lower stage failure pattern is obtained.
A claim that the second lower side failure pattern is determined when the current integrated value of one of the plurality of current integrated values is positive and the current integrated value of the other phase is negative. The rotary electric current control device according to any one of 1 to 3. The first control state is power running when the rotation speed of the rotary electric machine is equal to or higher than the predetermined first specified rotation speed, and the second control state is regeneration, any one of claims 1 to 4. The rotary electric machine control device described in the section. The rotation according to claim 5, wherein when the occurrence of the open failure is detected in the second control state, a regenerative fail action for suppressing the distortion of the alternating current of the plurality of phases caused by the open failure is executed. Electric control device. The regenerative fail action is
The switching pattern of the upper arm of the first inverter and the switching pattern of the lower arm of the second inverter are exchanged, and the switching pattern of the lower arm of the first inverter and the upper arm of the second inverter are exchanged. It replaces the switching pattern of the side arm, or
The switching pattern of the upper arm of the first inverter and the switching pattern of the lower arm are exchanged, and the switching pattern of the upper arm and the switching pattern of the lower arm of the second inverter are exchanged, and further. , The positive and negative of each of the multiple phases of the AC current are reversed.
The rotary electric machine control device according to claim 6. The rotary electric machine control device according to any one of claims 5 to 7, wherein the rotational speed of the rotary electric machine is reduced by regeneration. The first control state is a force running when the rotation speed of the rotary electric machine is equal to or higher than a predetermined first specified rotation speed, and the second control state is a second specified rotation lower than the first specified rotation speed. The rotary electric machine control device according to any one of claims 1 to 4, which is a power running at a speed or less. In the first control state, the occurrence of the open failure is detected and the failure pattern is discriminated, then in the second control state, the lower side failure pattern is discriminated, and then the first control state is discriminated. The rotary electric machine control device according to any one of claims 1 to 9, wherein the faulty side arm is discriminated based on the result and the determination result of the second control state. After detecting the occurrence of the open failure and determining the failure pattern in the first control state,
When the rotation speed of the rotary electric machine is equal to or higher than the predetermined first specified rotation speed, the lower side failure pattern is determined with regeneration as the second control state.
When the rotation speed of the rotary electric machine is less than the first specified rotation speed, the lower side failure pattern is set as the second control state with the force running at the second specified rotation speed lower than the first specified rotation speed. The rotary electric machine control device according to claim 10, wherein the determination is made. When the rotation speed of the rotary electric machine is less than the predetermined first specified rotation speed, shutdown control is performed to turn off the switching elements of all the plurality of phases, or control is performed so that the output torque of the rotary electric machine becomes zero. The rotary electric machine control device according to claim 11, wherein the rotation speed of the rotary electric machine is reduced to the second specified rotation speed or less by zero Newton control. A plurality of pulses having different patterns are output to the inverters of both the first inverter and the second inverter in the second period instead of the mixed pulse width modulation control, and the patterns are different throughout one cycle of the electric angle. The occurrence of the open failure is detected in the first control state when the pulse width modulation control in which a plurality of pulses are output or the rectangular wave control in which one pulse is output in one cycle of the electric angle is controlled. If you do,
In the first control state, the failure pattern is determined and
After that, the control method of the inverters of both the first inverter and the second inverter is changed to the mixed pulse width modulation control, and in the second control state, the lower side failure pattern is determined.
The rotary electric machine control device according to any one of claims 10 to 12, wherein the faulty side arm is discriminated based on the determination result of the first control state and the determination result of the second control state. A rotary electric machine control device that drives and controls a rotary electric machine having a plurality of phases of open windings that are independent of each other via a first inverter and a second inverter.
The first inverter is connected to one end side of the open winding of the plurality of phases to convert electric power between direct current and alternating current of the plurality of phases.
The second inverter is connected to the other end of the multi-phase open winding to convert power between direct current and multi-phase alternating current.
In the first inverter and the second inverter, the arm for one AC phase is composed of a series circuit of an upper switching element and a lower switching element, respectively.
Each of the first inverter and the second inverter can be controlled independently of each other.
In the case of an open failure in which one switching element is always in an open state in either one of the first inverter and the second inverter, the alternating currents of the plurality of phases are integrated. The current integrated value of each phase is calculated, and the occurrence of the open failure is detected based on the positive / negative of the current integrated value, and the location where the open failure has occurred is determined.
When the occurrence of the open failure is detected,
Based on the positive and negative of each of the current integrated values, the first failure pattern in which the open failure occurs in either the upper arm of the first inverter or the lower arm of the second inverter, the lower stage of the first inverter. It is determined which of the second failure patterns in which the open failure occurs in either the side arm or the upper arm of the second inverter.
After that, the inverter of either the first inverter or the second inverter is assumed to be a faulty inverter that has caused the open fault, and is used as a fault assumption inverter.
Based on the determined failure pattern, among the upper arm and the lower arm of the failure assumption inverter, the switching element of the failure side assumption arm assumed to be the failure side arm in which the open failure has occurred. Active short circuit control is performed with all of the switching elements of the non-failure side assumption arm on the other side turned on, and the inverter different from the failure assumption inverter is switched and controlled.
After that, when the open failure is not detected based on the positive / negative of each of the current integrated values, it is determined that the failure assumption inverter is the failure inverter, and the failure side assumption arm is the failure side arm. Determined to be
When the open failure is detected, it is determined that the inverter different from the failure assumption inverter is the failure inverter, and the failure side arm in the failure inverter is determined based on the failure pattern. Electric control device. When the occurrence of the open failure is detected, it is determined which of the first failure pattern and the second failure pattern is the failure pattern.
After that, the rotation speed of the rotary electric machine is controlled by the active short circuit control, the shutdown control in which all the switching elements of the plurality of phases are turned off, or the zero Newton control in which the output torque of the rotary electric machine is controlled to be zero. Decrease,
The rotary electric machine control device according to claim 14, wherein the inverter that is different from the failure assumption inverter is subsequently switched and controlled. When an overcurrent state occurs due to the occurrence of the open failure, shutdown control is performed by turning off the switching elements of all the plurality of phases, or the upper switching elements of the arms of all the multiple phases are turned on. By active short circuit control that turns on the lower switching element of the arm of all of the plurality of phases, the rotation speed of the rotary electric machine is reduced to eliminate the overcurrent state, and then the failed arm is turned on. The rotary electric machine control device according to any one of claims 1 to 15 for discriminating. Among the first inverter and the second inverter, the inverter that has caused the open failure is regarded as a failed inverter, the inverter different from the failed inverter is regarded as a normal inverter, and the upper arm and the lower side of the failed inverter are used. Of the arms, the side opposite to the failed side arm is used as the non-failed side arm.
Active short circuit control is performed in which all the switching elements of the failed side arm of the failed inverter are turned off and all of the switching elements of the non-failed side arm are turned on, and the above is performed via the normal inverter. The rotary electric machine control device according to any one of claims 1 to 16, which performs single inverter drive control for driving a rotary electric machine. The rotary electric machine control device according to claim 17, wherein the single inverter drive control is performed by pulse width modulation control in which a plurality of pulses having different patterns are output through one cycle of the electric angle.

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