JP7380115B2 - Control device and control method - Google Patents

Description

The disclosure in this specification relates to a control device and a control method.

BACKGROUND ART Conventionally, electric vehicles driven by battery power are known. Patent Document 1 discloses a configuration in which a motor generator (MG) is connected to a front wheel and a rear wheel of an electric vehicle, respectively. In this configuration, the front and rear MGs are driven by independent inverters.

JP 2019-129617 Publication

It is assumed that an abnormality occurs in an inverter due to a failure of a power element or a failure of an inverter peripheral device. Prior Art Document 1 does not mention such inverter abnormalities.

In view of the above-mentioned aspects and other aspects not mentioned, further improvements are required in the control device for a vehicle drive system.

One object of the disclosure is to provide a control device and a control method that can respond to abnormalities in an inverter.

The control device disclosed herein controls a vehicle drive device. The vehicle drive device includes a first inverter (I1) and a second inverter (I2), a power source (50) that supplies power to the first inverter and the second inverter, and a first winding connected to the first inverter. , a second winding connected to the second inverter, and a relay (60) that conducts or disconnects the connection between the power source and the first inverter and the second inverter.
The control device includes an abnormality detection section (S111, S112) that detects an abnormality in each of the first inverter and the second inverter, and detects an abnormality when the abnormality detection section detects an abnormality in one of the first inverter and the second inverter. A physical quantity acquisition unit (30) that acquires a physical quantity correlated to a back electromotive voltage with respect to the first winding or the second winding connected to the first inverter or the second inverter in which the A control unit (S121, S122, S125, S202, S203, S206,
S210, S121A, S121B, S121C, S121D).
The physical quantity acquisition unit acquires, as a physical quantity, the rotation speed of an abnormal motor generator (11, 21) having a first winding or a second winding connected to the first inverter or the second inverter in which the abnormality has been detected. . The control unit (S121, S122, S125) opens the relay when it is determined that the rotation speed acquired by the physical quantity acquisition unit has increased to a rotation speed threshold that is a physical quantity threshold, and when the rotation speed has decreased below the rotation speed threshold. If it is determined, the relay is closed.
The control device includes a power supply voltage acquisition unit (30) that acquires the power supply voltage of the power supply, a rotation speed threshold setting unit (30) that determines the rotation speed threshold, and a temperature control unit that acquires the temperature of the rotor of the abnormal motor generator. It further includes an acquisition unit (30). The rotation speed threshold setting section sets the rotation speed threshold so that the back electromotive force generated by the abnormal side motor generator is less than the power supply voltage obtained by the power supply voltage acquisition section, and further sets the rotation speed threshold so that the The higher the temperature, the lower the rotation speed threshold is set.

According to the disclosed control device, the relay is opened when the back electromotive voltage acting on the inverter on the side where an abnormality has been detected is high, and the relay is closed when it is low. As a result, in the event of an abnormality in the inverter, the generation of brake torque due to regenerative current due to the back electromotive force is avoided, and the vehicle is enabled to retreat, thereby improving the retreating performance. As a result, it is possible to provide a control device that can respond to abnormalities in the inverter. Similarly, a control method capable of responding to inverter abnormalities can be provided.

The multiple aspects disclosed in this specification employ different technical means to achieve their respective objectives. The claims and the reference numerals in parentheses described in this section exemplarily indicate correspondence with parts of the embodiment described later, and are not intended to limit the technical scope. The objects, features, and advantages disclosed in this specification will become more apparent by reference to the subsequent detailed description and accompanying drawings.

FIG. 1 is a block diagram showing a control device for a vehicle drive device according to a first embodiment. FIG. 2 is a schematic diagram showing the power supply configuration of the first embodiment. It is a flowchart which shows the processing of an inverter ECU. It is a flowchart which shows the processing of main ECU. 7 is a flowchart showing inverter abnormality processing according to the first embodiment. 5 is a time chart showing inverter abnormality processing according to the first embodiment. FIG. 3 is a diagram showing a map defining the relationship between battery voltage and rotation speed threshold according to the first embodiment. It is a flow chart which shows inverter abnormality processing of a 2nd embodiment. 7 is a time chart showing inverter abnormality processing according to the second embodiment. It is a schematic diagram showing a power supply composition of a 3rd embodiment. It is a flow chart which shows inverter abnormality processing of a 4th embodiment. It is a flow chart which shows inverter abnormality processing of a 5th embodiment. It is a flow chart which shows inverter abnormality processing of a 6th embodiment. It is a flowchart which shows inverter abnormality processing of a 7th embodiment. FIG. 7 is a logic circuit diagram showing processing in a third embodiment.

Embodiments are described with reference to the drawings. In embodiments, functionally and/or structurally corresponding and/or related parts may be provided with the same reference numerals or with reference numerals that differ by hundreds or more. Descriptions of other embodiments can be referred to for corresponding and/or related parts.

<First embodiment>
The configuration according to this embodiment will be described in detail with reference to FIGS. 1 and 2.

The vehicle according to this embodiment is an electric vehicle in which the first MG 11 drives the front wheels FW, which are the drive wheels of the vehicle, and the second MG 21 drives the rear wheels RW, which are the drive wheels of the vehicle. The vehicle includes a first power system 1 and a second power system 2. The first power system 1 includes a first MG11, a first inverter I1, and a first inverter ECU10. The second power system 2 includes a second MG21, a second inverter I2, and a second inverter ECU20. The first MG 11 is connected to the front wheel FW of the vehicle. The second MG21 is connected to the rear wheel RW of the vehicle. The first and second inverters I1 and I2 are provided independently of each other. The first inverter I1 drives the first MG11. The second inverter I2 drives the second MG21. The first inverter ECU 10, the second inverter ECU 20, and the main ECU 30 are communicably connected to each other via a communication bus of an in-vehicle network based on a communication protocol such as CAN (Control Area Network). CAN is a registered trademark.

(motor generator and drive wheels)
The first MG 11 is a synchronous motor including a rotor. The rotor has, for example, an embedded structure in which permanent magnets are embedded in an iron core. The first MG 11 is a three-phase motor in which the first windings of the UVW phase are connected in a star shape. The first MG11 receives power from the first inverter I1 and drives the front wheel FW, which is a drive wheel. The first MG 11 further performs power regeneration in conjunction with braking of the front wheels FW, and supplies the regenerated current generated by the power regeneration to the first inverter I1.

The first MG11 includes a rotational position sensor R11 that detects the rotational position of the rotor, and a rotor temperature sensor T18 that detects the temperature of the rotor. In this embodiment, a resolver is used as the rotational position sensor R11. The rotor temperature sensor T18 is installed inside the housing of the first MG11 and detects the temperature inside the housing. Alternatively, the rotor temperature sensor T18 may be installed close to or inside the rotor of the first MG11 to detect the temperature of the rotor. The front wheel FW includes a rotational position sensor R12 that detects the rotational position of the front wheel FW.

The second MG21 and the rear wheel RW may have the same configuration as the first MG11 and the front wheel FW. The second MG21 and rear wheel RW according to the present embodiment are obtained by replacing the first of each element in the first MG11 and the front wheel FW with the second, and replacing the last second digit of the reference code with 1 from 2, so that they overlap. The explanation will be omitted.

(Inverter)
As shown in FIG. 2, the first inverter I1 is a three-phase inverter and has three legs corresponding to the first winding, which is the three-phase winding of the first MG11. The positive end of each leg of the first inverter I1 is connected to a positive electrode line P11 of the power lines. The negative terminal of each leg of the first inverter I1 is connected to a negative electrode line N11 of the power lines.

The first inverter I1 has six transistors Tr11 to Tr16 and six diodes D11 to D16. These six diodes D11 to D16 are connected in antiparallel to each of the six transistors Tr11 to Tr16.

The midpoint of each leg is connected to the first winding of each UVW phase of the first MG 11. Each leg includes transistors Tr11 to Tr16 on an upper arm and a lower arm with a midpoint between them. The gates of the six transistors Tr11 to Tr16 are each connected to a corresponding output port of the first inverter ECU10. The transistors Tr11 to Tr16 according to this embodiment are IGBTs (Insulated Gate Bipolar Transistors).

The first inverter I1 includes inverter temperature sensors T11 to T16 that detect the temperature of the first inverter I1, a line current sensor A14 that detects the current between the power lines, and a phase current sensor that detects the phase current of the first winding of each UVW phase. It has current sensors A11 to A13 and interphase voltage sensors V11 to V13 that detect UVW interphase voltages. The inverter temperature sensors T11 to T16 are, for example, temperature sensing diodes formed in the same elements as the transistors Tr11 to Tr16, respectively, and detect the temperatures of the transistors Tr11 to Tr16, respectively. The line current sensor A14 is arranged on the positive electrode line P11 of the first inverter I1. The phase current sensors A11 to A13 are arranged on a power line connected from the midpoint of each leg to the first winding of each UVW phase of the first MG11. Interphase voltage sensors V11 to V13 are arranged between the U phase and the V phase, between the V phase and W phase, and between the U phase and W phase, respectively. The positive terminal of the smoothing capacitor C11 is connected to the positive pole line P11 of the power line, and the negative terminal is connected to the negative pole line N11 of the power line. Thereby, the smoothing capacitor C11 is connected in parallel with the first inverter I1. A line voltage sensor V14 that detects the potential difference between the positive electrode line P11 and the negative electrode line N11 of the power line is arranged in parallel with the smoothing capacitor C11.

The second inverter I2 may have the same configuration as the first inverter I1. The second inverter I2 according to the present embodiment replaces the first of each element in the first inverter I1 with a second, replaces the last second digit of the reference code with 1 from 2, and replaces the UVW phase with an XYZ phase. As such, duplicate explanations will be omitted.

(power line)
First and second inverters I1 and I2 are connected in parallel to the positive electrode line P11 and negative electrode line N11 of the power line. A load such as a vehicle air conditioner 40 is further connected in parallel to the positive electrode line P11 and the negative electrode line N11 of the power line. In FIG. 1, the air conditioner 40 is shown as air conditioner 40.

(power supply)
The power source 50 is, for example, a battery pack in which a plurality of lithium ion secondary batteries or nickel hydride secondary batteries are connected in series, and constitutes a DC power source. The voltage of the battery according to this embodiment is in the range of 200V-400V, for example 350V. Power source 50 is connected to first and second inverters I1 and I2 via a power line. A power supply voltage sensor V15 that detects the voltage between the terminals of the power supply 50 is connected in parallel to the power supply 50.

The main relay 60 is, for example, a contact electromagnetic switch having a solenoid mechanism. Main relay 60 is arranged on positive electrode line P11 of a power line that connects smoothing capacitor C11 of first inverter I1 and smoothing capacitor C11 of second inverter I2 to power supply 50. Main relay 60 is closed to electrically connect power source 50 and first and second inverters I1 and I2. Furthermore, by opening the main relay 60, the electrical connection between the power source 50 and the first and second inverters I1 and I2 is cut off.

The above-described first inverter I1 and first winding, second inverter I2 and second winding, power supply 50, and main relay 60 constitute a vehicle drive device.

(Inverter ECU)
The first inverter ECU 10 is composed of a microcomputer including a hardware processor, an input/output port, a communication port, an IO bus, and the like. In addition to the hardware processor, the first inverter ECU 10 may include a non-transitional storage medium such as a ROM that records data that does not need to be changed, and a RAM that stores programs and data in an overwritable manner. The hardware processor according to this embodiment executes the processing described below by executing a program stored in a non-transitional storage medium.

The first inverter ECU 10 is connected to the main ECU 30 and the second inverter ECU 20 via a communication port and a CAN bus.

The first inverter ECU 10 has six output ports. These six output ports are respectively connected to the gates of six transistors Tr11 to Tr16 of the first inverter I1. The first inverter ECU10 outputs gate commands S to these six transistors Tr11 to Tr16 through output ports.

The first inverter ECU 10 obtains a signal indicating the required torque from the main ECU 30 via the communication port and the CAN bus. The first inverter ECU10 drives the first inverter I1 based on the required torque.

Specifically, the first inverter ECU 10 generates a modulated wave that is a sine wave and an inverted modulated wave that is an inversion of this modulated wave. The first inverter ECU 10 increases or decreases the wave heights of the modulated wave and the inverted modulated wave according to the required torque. The first inverter ECU 10 determines the pulse width by comparing the modulated wave and the inverted modulated wave with a triangular wave that is a carrier wave. The first inverter ECU10 performs pulse width control (PWM control) by applying the gate command S to the gates of the transistors Tr11 to Tr16 for a period corresponding to this pulse width.

In addition to the modulated wave, the first inverter ECU 10 generates three-phase modulated waves whose phases are shifted by +π/3 and -π/3 from the modulated wave for each phase of the UVW, and similarly changes the pulse width of the UVW. is determined for each phase, and PWM control is performed. In this way, the first inverter ECU10 forms a rotating magnetic field in the first winding, which is a three-phase winding, of the first MG11 by adjusting the ratio of the gate command S time of each transistor Tr11 to Tr16. drive

The first inverter ECU 10 acquires signals from the various sensors described above via the input port. Various signals include, for example, detection signals from rotation position sensors R11 and R12, detection signals from phase current sensors A11 to A13, detection signals from interphase voltage sensors V11 to V13, detection signals from line voltage sensor V14, and rotation. These include a detection signal from child temperature sensor T18, a detection signal from inverter temperature sensors T11 to T16, a detection signal from power supply voltage sensor V15, and so on.

The first inverter ECU 10 includes a first monitoring circuit M10, which is an IC that monitors whether its own hardware processor is operating normally.

The second inverter ECU 20 may have the same configuration as the first inverter ECU 10. The second inverter ECU 20 according to the present embodiment is obtained by replacing the first of each element with the second in the second inverter ECU 20, and replacing the last second digit of the reference code with 1 from 2, and redundant explanation will be omitted. do.

(Main ECU30)
The main ECU 30 is composed of a microcomputer including a hardware processor, an input/output port, a communication port, and an IO bus. In addition to the hardware processor, a non-transitional storage medium such as a ROM that records data that does not need to be changed, and a RAM that stores programs and data in an overwritable manner may be provided. The hardware processor according to this embodiment executes the processing described below by executing a program stored in a non-transitional storage medium.

Main ECU 30 is connected to first and second inverter ECUs 10 and 20 through a communication port and a CAN bus. The main ECU 30 acquires the various detection signals inputted by the first and second inverter ECUs 10 and 20, and various signals such as inverter abnormality, which will be described later, through the communication port and the CAN bus.

The main ECU 30 further acquires signals from various other devices via the communication port and the CAN bus. Specifically, the main ECU 30 detects a signal from a starting switch 80, a signal from an accelerator pedal sensor 82 that detects the amount of depression of the accelerator pedal, a signal from a brake pedal sensor 84 that detects the amount of depression of the brake pedal, and the vehicle speed. A signal etc. from the vehicle speed sensor 86 are acquired.

Main ECU 30 is further connected to main relay 60 via an output port. Main ECU 30 outputs a control signal to main relay 60 via an output port to open and close main relay 60.

The main ECU 30 functions as an abnormality acquisition section, a physical quantity acquisition section, a control section, a power supply voltage acquisition section, a rotation speed threshold setting section, and a temperature acquisition section of the present disclosure.

The above-described vehicle drive device, first inverter ECU 10, second inverter ECU 20, and main ECU 30 constitute a vehicle drive system.

(Detection of inverter abnormality)
When detecting an abnormality in the first inverter I1 and the peripheral devices of the first inverter I1, the first inverter ECU 10 notifies the main ECU 30 of the occurrence of the abnormality. Alternatively, main ECU 30 determines that there is an abnormality in first inverter ECU 10 in response to communication with first inverter ECU 10 being interrupted due to a failure of first inverter ECU 10 itself. Abnormalities in the first inverter I1, the peripheral devices of the first inverter I1, and the first inverter ECU 10 are collectively referred to as inverter abnormalities.

The following is assumed to be an inverter abnormality. Although the first inverter I1 and the first inverter ECU10 are illustrated here, the same configuration is applied to the second inverter I2 and the second inverter ECU20.

- Transistor open failure When the transistors Tr11 to Tr16 have an open failure due to overcurrent, aging deterioration, etc., the transistors Tr11 to Tr16 become stuck in the off state. As a result, irrespective of the presence or absence of the gate command S, the collectors and emitters of the transistors Tr11 to Tr16 are insulated. The first inverter ECU 10 detects an abnormality due to this open failure based on the current of each phase.

First, when the transistors Tr11 to Tr16 are normal, the current of each phase of the UVW becomes a sine wave shifted by π/3 rad with 0 as the center value. On the other hand, when an open failure occurs in the transistors Tr11 to Tr16, the center value of at least one of the three-phase sine waves shifts from 0 to positive or negative. The first inverter ECU10 detects an open failure in the transistors Tr11 to Tr16 based on the shift of this sine wave.

Specifically, the first inverter ECU 10 obtains a sine wave of the current value of each phase by detecting the time transition of the current value obtained from the phase current sensors A11 to A13 of each phase. The first inverter ECU10 determines that an open failure has occurred in the transistors Tr11 to Tr16 when the difference between the center values of the sine waves of each phase exceeds a threshold value. For example, the first inverter ECU 10 calculates the difference between the center value of the sine wave of the phase on the most positive side and the center value of the sine wave of the phase on the most negative side, and when this difference exceeds a threshold value, opens the It is judged as a failure. The first inverter ECU 10 transmits a signal indicating an open failure of the transistors Tr11 to Tr16 to the main ECU 30 through the communication port and the CAN bus.

-Processor abnormality The first monitoring circuit M10 included in the first inverter ECU10 is, for example, a watchdog timer IC. The first monitoring circuit M10 periodically acquires, via the IO bus, a predetermined signal that is periodically generated by, for example, a hardware processor of the first inverter ECU 10 executing a program. The first monitoring circuit M10 determines that an abnormality is due to a failure of the hardware processor when the predetermined signal is interrupted or the predetermined signal is different from a normal one. The first monitoring circuit M10 stops the operation of the first inverter ECU10 when it is determined that the abnormality is due to a processor failure. The main ECU 30 detects an abnormality in the first inverter ECU 10 in response to communication disruption due to the stoppage of the first inverter ECU 10. Alternatively, the first monitoring circuit M10 may operate a communication module connected to the communication port to transmit a signal indicating a failure of the hardware processor to the main ECU 30 via the CAN bus.

・Phase current sensor A11 to A13 abnormality Due to a failure of phase current sensor A11 to A13, the output value from phase current sensor A11 to A13 does not change for a certain period of time, the output value is larger than the predetermined upper limit, or the output value is lower than the predetermined limit. A situation where the value is smaller than the lower limit is assumed. In response to this situation, the first inverter ECU 10 determines that the phase current sensors A11 to A13 are abnormal. The first inverter ECU 10 transmits a signal indicating that the phase current sensors A11 to A13 are abnormal to the main ECU 30 through the communication port and the CAN bus.

- Abnormality of the rotational position sensor R11 The resolver used for the rotational position sensor R11 includes an excitation coil that rotates together with the rotor, and a cosine component detection coil and a sine component detection coil arranged at 90° intervals. As the excitation coil rotates, the cos component detection coil excites an output signal corresponding to the cos θ component, and the sine component detection coil excites an output signal corresponding to the sin θ component. The resolver converts these output signals into rotational positions of the rotor and outputs them to the first inverter ECU10.

Due to a failure of the resolver, it is assumed that the output value from the resolver does not change for a certain period of time, the output value is greater than a predetermined upper limit, or the output value is smaller than a predetermined lower limit. In such a case, the first inverter ECU 10 determines that the resolver is abnormal. The first inverter ECU 10 transmits a signal indicating that the resolver is abnormal to the main ECU 30 through the communication port and the CAN bus.

- Inverter ECU power supply abnormality The first inverter ECU 10 according to the present embodiment is powered with a supply voltage of 12V. The first inverter ECU 10 steps down the supply voltage of 12V to 5V using a voltage step-down device such as a switching regulator, and supplies power to a control circuit such as a hardware processor.

When the power line to the first inverter ECU10 is disconnected, the first inverter ECU10 stops. The main ECU 30 detects an abnormality in the first inverter ECU 10 in response to communication disruption due to the stoppage of the first inverter ECU 10.

(evacuation run)
Next, evacuation driving of the vehicle due to inverter abnormality will be explained.

Assume that an inverter abnormality occurs in the power system of either the front wheel FW side or the rear wheel RW side while the vehicle is running. The control device of the present disclosure, when an abnormality occurs in either the first inverter I1 or the second inverter I2, stops the abnormal inverter and continues the operation of the other inverter that is not abnormal. This enables the driver to evacuate the vehicle to a safe location, or the vehicle to automatically evacuate to a safe location.

Specifically, in response to either the first inverter ECU 10 or the second inverter ECU 20 detecting an inverter abnormality, or the communication being interrupted due to one of the abnormalities, the main ECU 30 detects the abnormality in one of the inverters. Cut off the gate command to the abnormal inverter. The main ECU 30 continues to issue a gate command to the other normal inverter (normal side inverter) to enable the vehicle to run in an evacuation mode.

Here, during such evacuation driving, the drive wheel connected to one of the first MG or the second MG (abnormal side MG) connected to the abnormal side inverter rotates, so that the abnormal side MG is assumed to regenerate power and generate back electromotive force.

As described above, power supply 50 and first and second inverters I1 and I2 are connected via main relay 60 and smoothing capacitors C11 and C21. That is, there is no element between the power supply 50 and the first and second inverters I1 and I2 that inhibits regenerative current, such as a boost converter including a rectifier. Therefore, when the back electromotive force generated by the abnormal side MG becomes equal to or higher than the voltage of the power supply 50, even if the gate command of the abnormal side inverter is stopped, the regenerative current from the abnormal side MG passes through the abnormal side inverter and the main relay 60 to the power supply. A circuit is formed that flows to the positive electrode of 50.

Specifically, a circuit is formed from the abnormal side MG to the positive electrode of the power supply 50 via one of the diodes arranged in antiparallel to the transistor in the abnormal side inverter and the main relay 60. The regenerative current generated by the back electromotive force of the abnormal side MG flows to the positive electrode of the power supply 50 as a rectified current that flows in the forward direction from the anode to the cathode of the diode. As the abnormal side MG generates a regenerative current in this way, the winding of the abnormal side MG generates magnetic flux in a direction that inhibits the rotation of the permanent magnets in the rotor. As a result, brake torque is generated on the abnormal side MG. The generated brake torque is transmitted from the abnormal side MG to the drive wheels through the axle, and there is a concern that the drive wheels may suddenly brake, causing the vehicle to suddenly decelerate. As a result of this sudden deceleration, there are concerns that the vehicle's tires may slip and the vehicle may be rear-ended by a following vehicle.

When the back electromotive force generated by the abnormal MG exceeds the voltage of the power supply 50, regenerative current from the abnormal MG flows to the power supply 50 through the main relay 60, thereby generating brake torque. The main ECU 30 according to the present disclosure opens the main relay 60 to cut off the regenerative current when the back electromotive force generated by the abnormal side MG increases to the voltage of the power source 50 or higher and the regenerative current flows to the power source 50. . However, when the main relay 60 is open, the normal inverter also stops. For this reason, it becomes impossible for the vehicle to retreat. Therefore, the main ECU 30 closes the main relay 60 again when the back electromotive force caused by the abnormal side MG falls below the voltage of the power source 50 and the regenerative current no longer flows to the power source 50 and there is no need to cut off the regenerative current. As a result, the normal inverter resumes driving, making evacuation driving possible.

(Determination of back electromotive voltage)
In the present disclosure, opening and closing of the main relay 60 is operated based on a physical quantity correlated to a back electromotive force caused by the winding of the MG.

In this embodiment, attention is paid to the fact that the back electromotive force caused by the abnormal side MG is proportional to the rotation speed of the abnormal side MG. Specifically, in this configuration, the main relay 60 is opened in response to the rotation speed of the abnormal side MG increasing to or above a predetermined rotation speed threshold. This configuration further closes the main relay 60 in response to the rotation speed of the abnormal side MG decreasing below the rotation speed threshold. In this embodiment, the physical quantity correlated to the back electromotive force caused by the MG is the rotational speed of the MG.

The operation of this configuration will be explained below.

First, starting the vehicle will be explained.

Main ECU 30, first inverter ECU 10, and second inverter ECU 20 are activated, for example, when vehicle power source 50 is turned on by operating activation switch 80. Thereafter, main ECU 30 closes main relay 60 to connect power source 50 and first and second inverters I1 and I2 via the power line. Thereby, the power supply 50 supplies power to the first and second inverters I1 and I2 through the power line.

When the vehicle travels, the main ECU 30 calculates the required torque for the front wheels FW and the required torque for the rear wheels RW. Specifically, the main ECU 30 calculates the required torque that the vehicle requires for the front wheels FW and rear wheels RW based on, for example, the detected value of the accelerator pedal depression amount, the detected value of the brake pedal depression amount, and the detected value of the vehicle speed. Calculate each. Alternatively, the main ECU 30 calculates the required torques required by the vehicle for the front wheels FW and rear wheels RW, respectively, based on the deviation between the detected value of the vehicle speed and the speed setting value.

Main ECU 30 outputs the calculated required torque of front wheels FW and required torque of rear wheels RW to first and second inverter ECUs 10 and 20, respectively, as first and second required torques.

The first and second inverter ECUs 10 and 20 generate gate commands S, respectively, based on the first and second required torques input from the main ECU 30. The first and second inverter ECUs 10 and 20 output the generated gate commands S to the corresponding first and second inverters I1 and I2, respectively.

(Processing that the inverter ECU regularly executes)
The processes regularly executed by the first and second inverter ECUs 10 and 20 and the main ECU 30 will be described with reference to FIGS. 3 to 5.

The first inverter ECU 10 executes the process shown in FIG. 3 at predetermined intervals, for example every 0.1 seconds, after the power source 50 of the vehicle is turned on by operating the start switch 80.

In S101, the first inverter ECU 10 determines whether there is an abnormality in the first inverter I1. If it is determined that the first inverter I1 is abnormal, the first inverter ECU 10 stops generating and outputting the gate command S for the first inverter I1 in S102. In S103, the first inverter ECU 10 outputs an abnormality signal indicating that the first inverter I1 is abnormal to the main ECU 30.

Note that if the first inverter ECU 10 determines that the first inverter I1 is normal in S101, it generates and outputs a gate command S for the first inverter I1 in S104. Thereby, the first inverter ECU10 continues driving the first inverter I1.

Since the second inverter ECU 20 also executes the same processing as the first inverter ECU 10, a description thereof will be omitted.

(Process that main ECU 30 regularly executes)
The main ECU 30 executes the process shown in FIG. 4 at predetermined intervals, for example every 0.1 seconds, after the power source 50 of the vehicle is turned on by operating the start switch 80.

In S111, main ECU 30 determines an inverter abnormality based on whether an abnormality signal has been acquired from first inverter ECU 10 or whether communication from first inverter ECU 10 has been interrupted. Main ECU 30 determines that the inverter is abnormal when it has acquired an abnormal signal from first inverter ECU 10 or when it has determined that communication from first inverter ECU 10 has been interrupted. In this case, in S112, the main ECU 30 stops calculating and outputting the required torque to the first inverter I1. In S113, the main ECU 30 performs abnormality processing for the first inverter I1. The abnormality processing will be described later.

Note that in S111, if main ECU 30 determines that the abnormal signal has not been acquired from first inverter ECU 10 or that communication from first inverter ECU 10 has continued, main ECU 30 determines that first inverter I1 is normal. In this case, in S114, main ECU 30 determines whether an abnormal signal has been acquired from second inverter ECU 20 or whether communication from second inverter ECU 20 has been interrupted. When main ECU 30 determines that an abnormal signal has been acquired from second inverter ECU 20 or that communication from second inverter ECU 20 has been interrupted, main ECU 30 determines that the inverter is abnormal. In this case, in S115, the main ECU 30 stops calculating and outputting the required torque to the second inverter I2. At S116, the main ECU 30 performs abnormality processing for the second inverter I2.

(Inverter abnormality processing)
Next, abnormality processing of the first inverter I1 will be explained with reference to FIG.

In S121, the main ECU 30 acquires the rotation speed of the first MG 11, and determines whether the acquired rotation speed is less than a predetermined rotation speed threshold. If it is determined that the rotation speed of the first MG 11 is less than the rotation speed threshold, the main ECU 30 continues to close the main relay 60 in S122, and continues to calculate and output the second required torque in S123. Furthermore, in S124, the main ECU 30 operates the vehicle's display device to prompt the driver to retreat. Specifically, for example, information to urge evacuation driving is displayed on a display device provided in the console of the vehicle to notify the user, and information to urge evacuation driving is notified by voice using an audio device to urge evacuation driving. Alternatively, in S124, the main ECU 30 may be configured to cause the vehicle to automatically perform an evacuation drive instead of prompting the driving vehicle to perform an evacuation drive. In this case, the display device may notify the driver that the vehicle is automatically performing shelter-in-place travel.

Note that if it is determined in S121 that the rotation speed of the first MG 11 is equal to or higher than the rotation speed threshold, the main ECU 30 opens the main relay 60 in S125, and stops calculating and outputting the second required torque in S126. As a result, power supply from the power supply 50 is also stopped to the normal inverter. Furthermore, in S127, the main ECU 30 operates the vehicle's display device to notify the driver that the power supply to the motor has been temporarily stopped.

After a predetermined cycle for performing the abnormality processing for the first inverter I1 has elapsed, the main ECU 30 performs the abnormality processing for the first inverter I1 again. In S121, the main ECU 30 again determines whether the rotation speed of the first MG 11 is less than the rotation speed threshold. If it is determined that the rotation speed of the first MG 11 is lower than the rotation speed threshold as a result of the decrease, the main ECU 30 closes the main relay 60 again in S122, and restarts calculation and output of the second required torque in S123. This makes it possible for the vehicle to run in an evacuation mode again.

In this way, when the rotation speed of the first MG 11 is less than a predetermined rotation speed threshold, main relay 60 is closed to enable evacuation travel, thereby improving evacuation travel performance.

The abnormality processing for the second inverter I2 is the same as the above-described abnormality processing for the first inverter I1 by replacing the first and second inverters I1 and I2, and the explanation thereof will be omitted.

This process will be explained using the time chart of FIG.

The vehicle starts evacuation driving at time T10. During the evacuation run, the abnormal side MG rotation speed exceeds the rotation speed threshold at time T11. In response to this, main ECU 30 opens main relay 60 and stops power supply to first and second inverters I1 and I2. As a result, the vehicle runs by inertia. After a while, when the abnormal side MG rotation speed becomes lower than the rotation speed threshold at time T12, the main ECU 30 closes the main relay 60 and resumes the evacuation driving. The main ECU 30 performs similar operations at times T13 and T14. In this way, the main ECU 30 repeatedly opens and closes the main relay 60 according to the increase/decrease in the abnormal side MG rotation speed, thereby enabling the vehicle to move in an evacuation manner while avoiding the generation of brake torque due to electric power regeneration by the MG. Make it.

In response to detecting an abnormality in either one of the first and second inverters I1 and I2, the main ECU 30 according to the embodiment described above further determines that the abnormal MG rotation speed has increased to a predetermined rotation speed threshold or more. In this case, the main relay 60 is opened. Further, main ECU 30 closes main relay 60 when determining that the abnormal side MG rotation speed has decreased below a predetermined rotation speed threshold.

Main ECU 30 opens main relay 60 to avoid power regeneration by the abnormal MG, thereby preventing generation of brake torque due to power regeneration. Thereby, the main ECU 30 can reduce concerns such as tire slip or rear-end collision with a following vehicle due to sudden deceleration of the vehicle due to brake torque.

<Modification 1 of the first embodiment>
As described above, when the back electromotive voltage caused by the abnormal side MG becomes higher than the voltage of the power supply 50, power regeneration occurs from the MG to the power supply 50. In other words, the lower the voltage of the power supply 50, the lower the back electromotive voltage at which power regeneration occurs.

The power supply 50 also supplies power to loads such as the air conditioner 40 and the like. Therefore, the voltage of the power supply 50 varies depending on the operating state of the load. Further, the voltage of the power source 50 also varies depending on the state of charge of the power source 50.

In consideration of such fluctuations in the voltage of the power source 50, the main ECU 30 may increase or decrease the rotation speed threshold in accordance with the increase or decrease in the voltage of the power source 50 detected by the power source voltage sensor V15.

The main ECU 30 may calculate the rotation speed threshold using the following equation (1), for example.
Rth=k×Vs/Ke (Formula 1)
Rth: rotation speed threshold (rad/s)
k: Predetermined coefficient less than 1.0 Vs: Voltage (V) of power supply 50
Ke: Back electromotive force constant of abnormal motor generator (Vs/rad)
The rotation speed threshold Rth of the present modification 1 is the same as the rotation speed threshold described above.

In the configuration of Modification 1, by setting the rotation speed threshold according to the voltage of the power source 50, the rotation speed threshold can be set with higher accuracy. This configuration can reduce unnecessary closing operations of the main relay 60, and can effectively carry out evacuation travel, compared to a case where the rotation speed threshold is set to a fixed value.

<Modification 2 of the first embodiment>
The magnetic flux generated by the rotor inside the first MG11 and the second MG21 correlates with the temperature of the rotor. Specifically, the higher the temperature of the rotor, the smaller the magnetic flux generated by the rotor. Furthermore, the lower the temperature of the rotor, the greater the magnetic flux generated by the rotor. Considering such fluctuations in magnetic flux, the main ECU 30 may set the rotation speed threshold according to the temperature of the rotor. Specifically, the main ECU 30 may set the rotation speed threshold lower as the rotor temperature is higher, and may set the rotation speed threshold higher as the rotor temperature is lower.

The main ECU 30 may have a map shown in FIG. 7, for example. This map defines the relationship between the voltage of the power supply 50 and the rotation speed threshold for each rotor temperature. Main ECU 30 refers to this map to obtain a rotation speed threshold corresponding to the voltage of power supply 50 detected by power supply voltage sensor V15 and the rotor temperature detected by rotor temperature sensor T18.

In the configuration of Modification 2, by setting the rotation speed threshold according to the voltage of the power source 50 and the temperature of the rotor, the rotation speed threshold can be set with even higher accuracy.

<Variation 3 of the first embodiment>
The temperature of the rotor, particularly the permanent magnets inside the rotor, affects the back electromotive force generated by the rotor. In consideration of this, the rotor temperature sensor T18 may be configured to directly detect the temperature of the permanent magnet. However, directly detecting the temperature of the permanent magnets inside the rotor requires a relatively complicated mechanism. Therefore, a configuration may be adopted in which the magnetic flux of the permanent magnet in the rotor is acquired and the temperature of the rotor is acquired from the acquired magnetic flux.

Specifically, the following configuration can be adopted. The main ECU 30 acquires the magnetic flux of the permanent magnet using, for example, the magnetic flux acquisition method disclosed in Japanese Patent No. 2,943,657 (US Pat. No. 5,650,706). The contents of the prior art documents are incorporated by reference as explanations of technical elements in this specification.

The main ECU 30 uses this method to calculate the magnetic flux φ using the following equation (2).
φ=(Vq-RIq-Lq△Iq/△T-LdId)/ω (Formula 2)
φ: Magnetic flux (wb)
Vq: q-axis voltage (V)
R: Impedance of the first MG11 (Ω)
Iq: q-axis current (A)
Lq: q-axis inductance (H)
△Iq/△T: Amount of change in Iq between △T (A/s)
Ld: d-axis inductance (H) of the first MG11
Id: d-axis current (A)
ω: Number of rotations of the first MG11 (rad/s)

Iq and Id are obtained by performing dq conversion on the current values of each phase detected by phase current sensors A11 to A13. R, Lq, and Ld are numerical values specific to the first MG 11 and are obtained by measurement in advance.

The main ECU 30 further has a map showing the relationship between the reference magnetic flux φref of the permanent magnet at room temperature and the magnetic flux φ of the permanent magnet at each temperature higher than room temperature. The main ECU 30 refers to this map and obtains the temperature corresponding to the magnetic flux φ of the permanent magnet obtained by the above-described method as the temperature of the rotor.

As described above, since the magnetic flux of the rotor is acquired and the temperature of the rotor is acquired from the acquired magnetic flux, the cost of the apparatus can be reduced without requiring a complicated configuration.

<Second embodiment>
This embodiment is a modified example based on the previous embodiment.

In this embodiment, an upper limit threshold and a lower limit threshold are set as rotation speed thresholds, and hysteresis is provided between these thresholds. Specifically, the main ECU 30 according to this embodiment has a first rotation speed threshold and a second rotation speed threshold. The first rotation speed threshold is the same as the rotation speed threshold of the first embodiment. The second rotation speed threshold is smaller than the first rotation speed threshold.

In this embodiment, the processing by the first and second inverter ECUs 10 and 20 and the processing by the main ECU 30, which were previously explained with reference to FIGS. 3 and 4, are the same as in the first embodiment. In this embodiment, the inverter abnormality processing shown in FIG. 8 is different from the inverter abnormality processing of the first embodiment.

Next, inverter abnormality processing according to this embodiment will be explained with reference to FIG.

First, in S201, the main ECU 30 determines whether the flag is 0. Since the flag is 0 in the first processing, the processing advances to S202. In S202, the main ECU 30 acquires the rotation speed of the first MG 11, and determines whether the acquired rotation speed is less than the first rotation speed threshold. If it is determined that the rotation speed of the first MG 11 is less than the first rotation speed threshold, the main ECU 30 continues to close the main relay 60 in S203, and continues to calculate and output the second required torque in S204. Furthermore, in S205, the main ECU 30 operates the vehicle's display device to urge the driver to retreat, or causes the vehicle to automatically perform retreat.

If it is determined in S202 that the rotation speed of the first MG 11 is equal to or higher than the rotation speed threshold, the main ECU 30 opens the main relay 60 in S206, and stops calculating and outputting the second required torque in S207. Furthermore, in S209, the main ECU 30 operates the vehicle's display device to notify the driver that the power supply to the motor has been temporarily stopped. In S209, the main ECU 30 sets a flag to 1. Next, in S210, the rotation speed of the first MG 11 is obtained and compared with a rotation speed threshold. Since the rotation speed of the first MG 11 is naturally equal to or higher than the second rotation speed threshold, the main ECU 30 ends this process with the flag set to 1.

After a predetermined cycle for performing the abnormality processing for the first inverter I1 has elapsed, the main ECU 30 performs the abnormality processing for the first inverter I1 again. In S201, the main ECU 30 determines that the flag is 1, and in S210 determines whether the first MG rotation speed has decreased to be less than the second rotation speed threshold. In S210, if the main ECU 30 determines that the first MG rotation speed has not yet decreased below the second rotation speed threshold, this process ends. In this way, the main ECU 30 maintains the flag at 1 and continues the temporary suspension of power supply by repeating the processes of S201 and S210, unless the first MG rotation speed falls below the second rotation speed threshold.

If the main ECU 30 determines in S210 that the first MG rotation speed has decreased below the second rotation speed threshold, the main ECU 30 resets the flag to 0 in S211, and the process ends.

After a predetermined cycle has elapsed, when the main ECU 30 executes the abnormality processing for the first inverter I1 again, it determines that the flag is 0 in S201. In S202, since the rotation speed of the first MG 11 is naturally less than the first rotation speed threshold, the main ECU 30 executes the processes from S202 onwards. In S202 to S204, main ECU 30 closes main relay 60, restarts power supply to second inverter I2, and restarts calculation and output of the required torque. As a result, the main ECU 30 resumes driving the second inverter I2, and the vehicle is again able to retreat.

Note that the main ECU 30 resets the above-mentioned flag when the power source 50 of the vehicle is turned off.

The abnormality processing for the second inverter I2 is the same as the above-described abnormality processing for the first inverter I1 by replacing the first and second inverters I1 and I2, and the explanation thereof will be omitted.

This process will be explained using the time chart of FIG.

The vehicle starts evacuation driving at time T20. During the evacuation run, when the abnormal side MG rotation speed exceeds the first rotation speed threshold at time T21, main ECU 30 opens main relay 60 and stops power supply to first and second inverters I1 and I2. This causes the vehicle to coast. After a while, when the abnormal side MG rotational speed becomes lower than the second rotational speed threshold at time T22, the main ECU 30 closes the main relay 60 and resumes the evacuation driving. The main ECU 30 performs similar operations at times T23 and T24. According to the present embodiment, after the rotation speed of the MG increases beyond the first rotation speed threshold and opens the main relay 60, the main ECU 30 prevents the rotation speed from falling below the second rotation speed threshold, which is smaller than the first rotation speed threshold. The main relay 60 will not be returned to the closed position for as long as possible. With this configuration, it is possible to prevent the main relay 60 from frequently opening and closing, which is caused by the rotational speed of the MG increasing or decreasing around the first rotational speed threshold.
The first rotation speed threshold according to this embodiment corresponds to the first physical quantity threshold, and the second rotation speed threshold corresponds to the second physical quantity threshold.

<Third embodiment>
This embodiment is a modified example based on the previous embodiment.

As shown in FIG. 10, the MG311 of this embodiment is a single 6-phase motor in which three windings corresponding to the UVW phase and three windings corresponding to the XYZ phase are arranged circumferentially with respect to each other. It is a generator.

This MG311 is connected to either the front wheel FW or the rear wheel RW. The UVW phase winding of MG311 is connected to first inverter I1. The XYZ phase windings of MG311 are connected to second inverter I2. Also in this embodiment, the main ECU 30 and the first and second inverter ECUs 10 and 20 perform the same processing as in the first embodiment or the second embodiment.

The configuration of this embodiment includes a first power system 1 including a UVW phase winding and a first inverter I1, and a second power system 2 including an XYZ phase winding and a second inverter I2. With this configuration, when an inverter abnormality occurs in one of the first and second inverters I1 and I2, the evacuation drive can be continued in the other one. Furthermore, in this configuration, by combining the MGs into a single device, the MG 311, it is possible to reduce the proportion that the MG 311 occupies in the vehicle interior space. In addition, as a modification, the MG311, which is a six-phase motor generator according to this embodiment, may be arranged on each of the front wheel FW and the rear wheel RW.
The three windings corresponding to the UVW phase according to this embodiment correspond to the first winding element, and the three windings corresponding to the XYZ phase correspond to the second winding element.

<Fourth embodiment>
This embodiment is a modified example based on the previous embodiment.

In this embodiment, the generation of regenerative current due to the back electromotive force of the abnormal side MG is determined based on the phase current of the abnormal side inverter. In this embodiment, the phase current of the abnormal inverter is a physical quantity that correlates with the back electromotive force caused by the first winding or the second winding connected to the abnormal MG.

Assume that a regenerative current is generated due to the back electromotive force of the abnormal side MG when the main relay 60 is in a closed state. When this regenerative current flows to the positive electrode of the power source 50, a phase current of either UVW phase flows toward the power source 50 from the winding of the abnormal side MG. Therefore, the main ECU 30 detects when the current flowing from the winding of the abnormal side MG to the power supply 50, detected by either the phase current sensors A11 to A13 or A21 to A23 of the abnormal inverter, exceeds a predetermined phase current threshold. It is determined that a phase current has occurred.

In this embodiment, S121 shown in FIG. 5 of the inverter abnormality processing in the first embodiment is replaced with S121A shown in FIG. 11.

As shown in FIG. 11, in S121A, the main ECU 30 obtains the phase current, and if it is determined that the obtained phase current is equal to or higher than the phase current threshold, in S125-S127, the main ECU 30 opens the main relay 60 and requests Stops torque calculation and output, and displays a message indicating that power supply has been temporarily stopped.

If the main ECU 30 determines in S121A that the phase current is less than the phase current threshold, the main ECU 30 closes the main relay 60 in S122-S124, calculates and outputs the required torque, and displays a display prompting evacuation driving. Alternatively, the vehicle may be caused to perform an evacuation drive.

Note that in this embodiment, the processing by the main ECU 30 and the processing by the first and second inverter ECUs 10 and 20 described in the first embodiment with reference to FIGS. 3-4 are the same as in the first embodiment.

As described above, in this embodiment, the generation of regenerative current is directly detected based on the phase current to open the relay. In other words, this configuration directly detects the generation of back electromotive current. Therefore, compared to a configuration in which the occurrence of a back electromotive current is determined based on indirect acquisition, this configuration can determine the occurrence of a back electromotive current with high accuracy. Therefore, with this configuration, unnecessary closing operations of the main relay 60 can be reduced, and evacuation driving can be effectively carried out.

In this embodiment, similarly to the second embodiment, a first phase current threshold that is the same as the phase current threshold and a second phase current threshold that is smaller than the first phase current threshold may be set. In this case, the main relay 60 may be closed when the phase current decreases below the second phase current threshold, and the main relay 60 may be opened when the phase current increases above the first phase current threshold.
The first phase current threshold according to this embodiment corresponds to the first physical quantity threshold, and the second phase current threshold corresponds to the second physical quantity threshold.

<Fifth embodiment>
This embodiment is a modified example based on the previous embodiment.

In this embodiment, the generation of regenerative current due to the back electromotive force of the abnormal side MG is directly detected by the current sensor A14 or A24. In this modification, the physical quantity correlated to the back electromotive force due to the first winding or the second winding connected to the abnormal side MG is defined as the line current flowing from the negative pole line N11 or N21 of the power line to the positive pole line P11 or P21. do.

Assume that a regenerative current is generated due to the back electromotive force of the abnormal side MG when the main relay 60 is in a closed state. This regenerative current flows from the negative pole line to the positive pole line, and then to the positive pole of the power supply 50. Therefore, the main ECU 30 determines that a line current has occurred when the line current flowing from the negative line to the positive line detected by the current sensor A14 or A24 exceeds a predetermined line current threshold.

In this embodiment, S121A shown in FIG. 11 of the inverter abnormality processing in the fourth embodiment is replaced with S121B shown in FIG. 12.

As shown in FIG. 12, in S121B, the main ECU 30 obtains the line current, and if it is determined that the obtained line current is equal to or greater than the line current threshold, the main ECU 30 opens the main relay 60 in S125-S127. Then, the required torque calculation and output are stopped, and a message indicating that the power supply has been temporarily stopped is displayed.

Further, in S121B, if the main ECU 30 determines that the line current is less than the line current threshold, the main ECU 30 closes the main relay 60 in S122-S124, calculates and outputs the required torque, and displays a display prompting evacuation driving. conduct. Alternatively, the vehicle may be caused to perform an evacuation drive.

Note that in this embodiment, the processing by the main ECU 30 and the processing by the first and second inverter ECUs 10 and 20 described in the first embodiment with reference to FIGS. 3-4 are the same as in the first embodiment.

In this manner, in this embodiment, the generation of regenerative current is directly detected based on the line current to open the relay. In other words, this configuration also directly detects the generation of back electromotive current. Therefore, compared to a configuration in which the occurrence of a back electromotive current is determined based on indirect acquisition, this configuration can determine the occurrence of a back electromotive current with high accuracy.

In this embodiment, similarly to the second embodiment, a first line current threshold that is the same as the line current threshold and a second line current threshold that is smaller than the first line current threshold may be set. In this case, the main relay 60 may be closed when the line current decreases below the second line current threshold, and the main relay 60 may be opened when the line current increases to or above the first line current threshold. .
The first line current threshold according to this embodiment corresponds to the first physical quantity threshold, and the second line current threshold corresponds to the second physical quantity threshold.

<Sixth embodiment>
This embodiment is a modified example based on the previous embodiment.

In this embodiment, the generation of regenerative current due to the back electromotive force of the abnormal side MG is determined based on the phase-to-phase voltage of the UVW phase in the abnormal side inverter. In the present embodiment, the physical quantity correlated to the back electromotive force caused by the first winding or the second winding connected to the abnormal side MG is the phase-to-phase voltage of the UVW phase in the abnormal side inverter.

When the main relay 60 is closed, a regenerative current is generated by the back electromotive force of the abnormal side MG, and when this regenerative current flows to the power supply 50 via the abnormal side inverter, a phase-to-phase voltage is generated. This phase-to-phase voltage generates a positive potential difference between the anode and cathode of the diodes D11 to D16 or D21 to D26 in the abnormal inverter, so that regenerative current flows to the power supply 50 through the diodes D11 to D16 or D21 to D26. Therefore, the main ECU 30 acquires the inter-phase voltage using each of the inter-phase voltage sensors V11 to V13 or V21 to V23, and determines that an inter-phase voltage has occurred when any of the inter-phase voltages exceeds a predetermined inter-phase voltage threshold.

In this embodiment, S121 shown in FIG. 5 of the inverter abnormality processing in the first embodiment is replaced with S121C shown in FIG. 13.

As shown in FIG. 13, in S121C, the main ECU 30 acquires the phase-to-phase voltage, and if it is determined that the acquired phase-to-phase voltage is equal to or higher than the phase-to-phase voltage threshold, the main ECU 30 opens the main relay 60 in S125-S127, and requests Stops torque calculation and output, and displays a message indicating that power supply has been temporarily stopped.

If the main ECU 30 determines in S121C that the interphase voltage is less than the interphase voltage threshold, the main ECU 30 closes the main relay 60 in S122-S124, calculates and outputs the required torque, and displays a display prompting evacuation driving. Alternatively, the vehicle may be caused to perform an evacuation drive.

Note that in this embodiment, the processing by the main ECU 30 and the processing by the first and second inverter ECUs 10 and 20 described in the first embodiment with reference to FIGS. 3-4 are the same as in the first embodiment.

In this way, in this embodiment, the generation of regenerative current is directly detected based on the correlated voltage to open the relay. In other words, this configuration also directly detects the generation of back electromotive current. Therefore, compared to a configuration in which the occurrence of a back electromotive current is determined based on indirect acquisition, this configuration can determine the occurrence of a back electromotive current with high accuracy.

Also in this embodiment, similarly to the second embodiment, a first inter-phase voltage threshold that is the same as the inter-phase voltage threshold and a second inter-phase voltage threshold that is smaller than the first inter-phase voltage threshold may be set. In this case, the main relay 60 may be closed when the phase-to-phase voltage decreases below the second phase-to-phase voltage threshold, and the main relay 60 may be opened when the phase-to-phase voltage increases to or above the first phase-to-phase voltage threshold.
The first phase-to-phase voltage threshold according to the present embodiment corresponds to the first physical quantity threshold, and the second phase-to-phase voltage threshold corresponds to the second physical quantity threshold.

<Seventh embodiment>
This embodiment is a modified example based on the previous embodiment.

In this embodiment, the generation of regenerative current due to the back electromotive force of the abnormal side MG is determined based on the line potential difference between the negative electrode line N11 or N21 and the positive electrode line P11 or P21 of the power line. In this embodiment, the physical quantity correlated to the back electromotive force due to the first winding or the second winding connected to the abnormal side MG is defined as the line potential difference between the negative electrode line and the positive electrode line of the power line in the abnormal side inverter. do.

When the main relay 60 is closed, a regenerative current is generated by the back electromotive force of the abnormal side MG, and when this regenerative current flows to the power supply 50, the potential of the negative electrode line becomes higher than the potential of the positive electrode line. The resulting line potential difference causes a regenerative current to flow from the anode to the cathode of the diodes D11 to D16 or D21 to D26 in the inverter, and this regenerative current flows to the positive electrode of the power source 50.

The main ECU 30 detects when the line potential difference detected by the line voltage sensor V14 or V24 exceeds a predetermined line potential difference threshold, that is, when the potential of the negative line becomes higher than the line potential difference threshold than the potential of the positive line. It is determined that a line-to-line potential difference has occurred.

In this embodiment, S121C shown in FIG. 13 of the inverter abnormality processing in the sixth embodiment is replaced with S121D shown in FIG. 14.

As shown in FIG. 14, in S121D, the main ECU 30 acquires the above-mentioned line potential difference, and if it is determined that the acquired line potential difference is equal to or greater than a predetermined line potential difference threshold, the main ECU 30 acquires the line potential difference in S125-S127. The relay 60 is opened, required torque calculation and output are stopped, and a display indicating that the power supply is temporarily stopped is displayed.

Further, in S121D, if the main ECU 30 determines that the line potential difference is less than the line potential difference threshold, the main ECU 30 closes the main relay 60 in S122-S124, calculates and outputs the required torque, and displays a display prompting evacuation driving. conduct. Alternatively, the vehicle may be caused to perform an evacuation drive.

In this modification, similarly to the third embodiment, a first line potential difference threshold that is the same as the line potential difference threshold and a second line potential difference threshold that is smaller than the first line potential difference threshold may be set. In this case, the main relay 60 may be closed when the line potential difference decreases below the second line potential difference threshold, and the main relay 60 may be opened when the line potential difference increases to or above the first line potential difference threshold. .
The first line potential difference threshold according to this embodiment corresponds to the first physical quantity threshold, and the second line potential difference threshold corresponds to the second physical quantity threshold.

(Functional department response)
The main ECU 30 corresponds to an abnormality detection section, a physical quantity acquisition section, a control section, a power supply voltage acquisition section, a rotation speed threshold setting section, and a temperature acquisition section.

More specifically, S111 and S114 executed by the main ECU 30 correspond to the abnormality detection section. Further, S121, S122, S125, S202, S203, S206, S210, S121A, S121B, S121C, and S121D executed by the main ECU 30 correspond to the control section.

<Other embodiments>
- Detection of inverter abnormality In addition to the examples given above, at least one of the following may be added to the inverter abnormality.

If the main ECU 30 determines that the inverter temperature detected by the temperature sensor exceeds a predetermined threshold, it may be determined that the inverter is overheating and that the inverter is abnormal.

The main The ECU 30 detects that the detected values of the phase current sensors A11, A12, A13, A21, A22, A23, current sensors A14, A24, interphase voltage sensors V11, V12, V13, V21, V22, V23, and voltage sensors V14, V24 are predetermined. If it is determined that the inverter has decreased below the threshold value, it may be determined that the inverter is abnormal.

If the main ECU 30 determines that one of the phase currents of each phase detected by the phase current sensor exceeds a predetermined threshold due to an overcurrent due to an OPEN failure of transistors Tr11 to Tr16 or a ground fault in the power line, the inverter It may be considered abnormal.

-Sensor configuration A Rogowski coil, Hall element, or shunt resistor may be used as the current sensor. Specifically, for example, a power line may be passed through a Rogowski coil or a Hall element, and a potential difference generated due to a change in a magnetic field due to a change in current may be detected. Alternatively, the current may be determined from the potential difference between shunt resistors connected in parallel to the detection target.

Instead of providing phase current sensors for all UVW phases, phase current sensors may be provided for two of the UVW phases, and the remaining one phase current may be obtained from the detected phase currents of the two phases.

The voltage sensor may have a configuration in which, for example, the potential on the positive electrode side and the potential on the negative electrode side are input to a comparator to obtain a potential difference.

As a temperature sensor, a thermistor, thermocouple, resistor, etc. can be used.
A Hall element or an induction coil may be used as the rotational position sensor.

As the rotational position sensor of the MG, a Hall element or a photointerrupter may be used instead of a resolver.

・Configuration for detecting the rotation speed of the MG The main ECU 30 may obtain the rotation speed of the MG from a detection value of a rotor rotation speed sensor provided on the MG, or from a drive wheel rotation speed sensor provided on the drive wheel. It's good to get more. When obtaining the rotation speed of the MG from the drive wheel rotation sensor, the main ECU 30 may calculate the rotation speed of the MG in consideration of a gear ratio of a transmission provided between the MG and the drive wheels.

- System configuration The configurations of the main ECU 30 and the first and second inverter ECUs 10 and 20 described above are merely examples, and the device configuration of the present disclosure is not limited to the above, and may take various forms.

The first and second inverter ECUs 10 and 20 may perform at least part of the processing performed by the main ECU 30. Specifically, the first and second inverter ECUs 10 and 20 may function as at least one of an abnormality detection section, a physical quantity acquisition section, a control section, a power supply voltage acquisition section, a rotation speed threshold setting section, and a temperature acquisition section. good. Alternatively, the main ECU 30 may perform at least a part of the processing performed by the first and second inverter ECUs 10 and 20, such as detecting inverter abnormality and generating the gate command S by the inverter ECU.

The main ECU 30 and the first and second inverter ECUs 10 and 20 may be integrated. The system may further include an additional ECU, and the additional ECU may execute part of the processing of the main ECU 30 and the first and second inverter ECUs 10 and 20.

At least a portion of the above-described processing may be performed by an external device outside the vehicle, and the vehicle may obtain the processing results from the external device through communication between the vehicle and the external device.

Instead of the CAN bus, the main ECU 30, the first and second inverter ECUs 10 and 20, etc. may be connected using independent signal lines (straight lines). In the above-described configuration, the main ECU 30 may directly input various input signals obtained from the first and second inverter ECUs 10 and 20 through an input port.

In the above, each processing unit is illustrated as an independent functional element, but these processing units do not need to be clearly divided functional elements. The processing unit is configured by storing, for example, a collection of computer programs executed by at least one hardware processor in at least one non-transitory storage medium. A portion corresponding to each processing section in a collection of these programs constitutes a processing section.

At least a part of the processing section may be configured by a logic circuit including an operational amplifier, a gate circuit, and the like. For example, the configuration of the third embodiment may be configured using a logic circuit shown in FIG. 15. In this logic circuit, the first operational amplifier EL1 obtains the rotation speed of the MG and the first rotation speed threshold. AND gate EL3 obtains the output of first operational amplifier EL1 and the inverter abnormality signal. The SET terminal of the self-holding circuit EL4 acquires the output of the AND gate EL3. The second operational amplifier EL2 acquires the rotation speed of the MG and the second rotation speed threshold. The RESET terminal of the self-holding circuit EL4 receives the inverted output of the second operational amplifier EL2. The inverted output of self-holding circuit EL4 is used as the output of main relay 60.

In response to the increase in the rotational speed of the MG to the first rotational speed threshold or higher, the output of the first operational amplifier EL1 is turned ON. In response to the inverter abnormality, the inverter abnormality signal turns ON. AND gate EL3 receives these ON signals and outputs the ON signal to the SET terminal of self-holding circuit EL4. The self-holding circuit EL4 receives the ON signal input to the SET terminal and outputs an inverted output that is an OFF signal. This turns main relay 60 OFF, that is, opens. In response to the fact that the rotational speed of the MG is reduced below the second rotational speed threshold, the second operational amplifier EL2 outputs an inverted output, which is an ON signal, to the self-holding circuit EL4. The self-holding circuit EL4 resets the output upon receiving the ON signal input to the RESET terminal, and outputs an inverted output that is the ON signal. As a result, the main relay 60 is turned on, that is, closed.

Such a logic circuit may be an integrated circuit that is an application specific IC (ASIC), or may be constructed as a ladder circuit using a programmable logic controller (PLC).

That is, the present disclosure is not limited to a configuration in which a computer program is executed by a hardware processor, but may also be a configuration in which an output signal is logically generated according to an input signal.

There may be three or more power systems including the inverter and the windings of the motor generator.

The configurations according to the present disclosure described above may be implemented as a computer program comprising computer instructions stored on a computer-readable non-transitory storage medium. In this case, the computer instructions may be executed by a hardware processor to perform the following processes 1) to 5).

Process 1) Detect abnormality in each of the first inverter and the second inverter.

Processing 2) When an abnormality is detected in one of the first inverter and the second inverter, the back electromotive voltage is reduced for the first or second winding connected to the first inverter or the second inverter in which the abnormality was detected. Obtain physical quantities correlated to.

Process 3) Compare the physical quantity and the physical quantity threshold.

Process 4) When it is determined that the physical quantity is equal to or greater than the physical quantity threshold, a relay that conducts or interrupts the connection between the power supply and the first inverter and the second inverter is opened.

Process 5) If it is determined that the physical quantity is less than the physical quantity threshold, close the relay.

<Others>
Power MOSFETs may be used instead of IGBTs as the transistors Tr11 to Tr16.

It is also possible to adopt a double-cut structure in which the main relay 60 is arranged on both the positive electrode line P11 and the negative electrode line N11.

The configuration of the present disclosure may be used not only for electric vehicles but also for hybrid vehicles having an internal combustion engine.

The control device in this specification may also be referred to as an electronic control unit (ECU). The control device or control system is provided by (a) an algorithm as a plurality of logics called if-then-else, or (b) an algorithm as a trained model tuned by machine learning, e.g. a neural network. .

The control device is provided by a control system including at least one computer. A control system may include multiple computers linked by data communication devices. A computer includes at least one processor that is hardware (hardware processor). The hardware processor can be provided by (i), (ii), or (iii) below.

(i) A hardware processor may be at least one processor core that executes a program stored in at least one memory. In this case, the computer is provided by at least one memory and at least one processor core. The processor core is called a CPU: Central Processing Unit, a GPU: Graphics Processing Unit, a RISC-CPU, or the like. Memory is also called a storage medium. Memory is a non-transitory and tangible storage medium that non-temporarily stores "programs and/or data" readable by a processor. The storage medium is provided by a semiconductor memory, a magnetic disk, an optical disk, or the like. A program may be distributed alone or as a storage medium in which the program is stored.

(ii) The hardware processor may be a hardware logic circuit. In this case, the computer is provided by a digital circuit containing a large number of programmed logic units (gate circuits). The digital circuit is a logic circuit array, for example, ASIC: Application-Specific Integrated Circuit, FPGA: Field Programmable Gate Array, SoC: System on a Chip, PGA: Program. It is also called a mable gate array, CPLD: Complex Programmable Logic Device, etc. Digital circuits may include memory that stores programs and/or data. Computers may be provided by analog circuits. Computers may be provided with a combination of digital and analog circuits.

(iii) The hardware processor may be a combination of (i) and (ii) above. (i) and (ii) are placed on different chips or on a common chip. In these cases, part (ii) is also called an accelerator.

The control device, signal source, and controlled object provide various elements. At least some of those elements can be called blocks, modules, or sections. Moreover, the elements included in the control system are called functional means only if they are intentional.

The control unit and its method described in this disclosure are implemented by a dedicated computer provided by configuring a processor and memory programmed to perform one or more functions embodied by a computer program. may be done. Alternatively, the controller and techniques described in this disclosure may be implemented by a special purpose computer provided by configuring the processor with one or more dedicated hardware logic circuits. Alternatively, the controller and techniques described in this disclosure may include a processor configured with a processor and memory programmed to perform one or more functions and one or more hardware logic circuits. It may also be realized by one or more dedicated computers configured in combination. The computer program may also be stored as instructions executed by a computer on a computer-readable non-transitory tangible storage medium.

The disclosure in this specification, drawings, etc. is not limited to the illustrated embodiments. The disclosure includes the illustrated embodiments and variations thereon by those skilled in the art. For example, the disclosure is not limited to the combinations of parts and/or elements illustrated in the embodiments. The disclosure can be implemented in various combinations. The disclosure may have additional parts that can be added to the embodiments. The disclosure includes those in which parts and/or elements of the embodiments are omitted. The disclosure encompasses any substitutions or combinations of parts and/or elements between one embodiment and other embodiments. The disclosed technical scope is not limited to the description of the embodiments. The technical scope of some of the disclosed technical scopes is indicated by the description of the claims, and should be understood to include equivalent meanings and all changes within the scope of the claims.

The disclosure in the specification, drawings, etc. is not limited by the scope of the claims. The disclosure in the specification, drawings, etc. includes the technical ideas described in the claims, and further extends to a more diverse and broader range of technical ideas than the technical ideas described in the claims. Therefore, various technical ideas can be extracted from the disclosure of the specification, drawings, etc. without being restricted by the claims.

10...first inverter ECU,
20...Second inverter ECU,
30...Main ECU,
I1...first inverter,
I2...Second inverter

Claims (6)

A first inverter (I1) and a second inverter (I2),
a power source (50) that supplies power to the first inverter and the second inverter;
a first winding connected to the first inverter; and a second winding connected to the second inverter;
a relay (60) that conducts or interrupts the connection between the power source and the first inverter and the second inverter;
A control device for controlling a vehicle drive device comprising:
an abnormality detection unit (S111, S112) that detects abnormality in each of the first inverter and the second inverter;
When the abnormality detection unit detects an abnormality in one of the first inverter and the second inverter, the first winding or the second inverter connected to the first inverter or the second inverter in which the abnormality is detected a physical quantity acquisition unit (30) that acquires a physical quantity correlated to the back electromotive force for the second winding;
Comparing the physical quantity and a physical quantity threshold, opening the relay when it is determined that the physical quantity is greater than or equal to the physical quantity threshold, and closing the relay when determining that the physical quantity is less than the physical quantity threshold. A control unit (S121, S122, S125, S202, S203, S206, S210, S121A, S121B, S121C, S121D) ,
The physical quantity acquisition unit includes, as the physical quantity, an abnormal motor generator (11, 21) having the first winding or the second winding connected to the first inverter or the second inverter in which the abnormality is detected. ) get the rotation speed of
The control section (S121, S122, S125) opens the relay when it is determined that the rotation speed acquired by the physical quantity acquisition section has increased to a rotation speed threshold that is the physical quantity threshold. Close the relay when it is determined that the decrease has decreased below a threshold;
a power supply voltage acquisition unit (30) that acquires the power supply voltage of the power supply;
a rotation speed threshold setting unit (30) that determines the rotation speed threshold;
further comprising a temperature acquisition unit (30) that acquires the temperature of a rotor included in the abnormal motor generator,
The rotation speed threshold setting section sets the rotation speed threshold so that a back electromotive force generated by the abnormal motor generator is less than the power supply voltage acquired by the power supply voltage acquisition section, and The control device sets the rotation speed threshold to be lower as the temperature of the rotor acquired by the controller is higher . The control device according to claim 1 , wherein the rotation speed threshold setting unit calculates the rotation speed threshold using the following (Formula 1) so that the back electromotive force is less than the power supply voltage .
Rth=k×Vs/Ke (Formula 1)
Rth: rotation speed threshold (rad/s)
k: Predetermined coefficient less than 1.0 Vs: Power supply voltage (V)
Ke: Back electromotive force constant of abnormal motor generator (Vs/rad) The first inverter and the second inverter are each three-phase inverters,
The first winding has a three-phase first winding element,
The second winding has a three-phase second winding element,
The control device according to claim 1 or 2 , wherein the first winding element and the second winding element are arranged circumferentially with respect to each other to constitute a six-phase motor generator (311). The control device according to claim 1, wherein the physical quantity threshold includes a first physical quantity threshold and a second physical quantity threshold smaller than the first physical quantity threshold. Detecting abnormalities in each of the first inverter (I1) and the second inverter (I2),
When an abnormality is detected in one of the first inverter and the second inverter, a back electromotive force is applied to the first winding or the second winding connected to the first inverter or the second inverter in which the abnormality is detected. Obtain physical quantities correlated to voltage,
Comparing the physical quantity and a physical quantity threshold,
When it is determined that the physical quantity is equal to or greater than the physical quantity threshold, a relay (60) that conducts or interrupts the connection between the power supply (50) and the first inverter and the second inverter is opened;
A control method that closes the relay when it is determined that the physical quantity is less than the physical quantity threshold ,
The physical quantity is the rotation speed of an abnormal motor generator (11, 21) having the first winding or the second winding connected to the first inverter or the second inverter in which the abnormality was detected. ,
The relay is opened when it is determined that the rotation speed has increased above a rotation speed threshold that is the physical quantity threshold, and the relay is closed when it is determined that the rotation speed has decreased below the rotation speed threshold;
moreover,
obtaining the power supply voltage of the power supply;
obtaining the temperature of a rotor of the abnormal motor generator; and
determining the rotation speed threshold;
The rotation speed threshold is set so that a back electromotive force generated by the abnormal motor generator is less than the acquired power supply voltage, and is further set lower as the temperature of the rotor increases. A control device comprising a hardware processor,
The hardware processor includes:
Detecting abnormalities in each of the first inverter (I1) and the second inverter (I2),
When an abnormality is detected in one of the first inverter and the second inverter, a back electromotive force is applied to the first winding or the second winding connected to the first inverter or the second inverter in which the abnormality is detected. Obtain physical quantities correlated to voltage,
Comparing the physical quantity and a physical quantity threshold,
When it is determined that the physical quantity is equal to or greater than the physical quantity threshold, a relay (60) that conducts or interrupts the connection between the power supply (50) and the first inverter and the second inverter is opened;
closing the relay when determining that the physical quantity is less than the physical quantity threshold;
The physical quantity is the rotation speed of an abnormal motor generator (11, 21) having the first winding or the second winding connected to the first inverter or the second inverter in which the abnormality was detected. ,
The relay is opened when it is determined that the rotation speed has increased above a rotation speed threshold that is the physical quantity threshold, and the relay is closed when it is determined that the rotation speed has decreased below the rotation speed threshold;
moreover,
Obtain the power supply voltage of the power supply,
obtaining the temperature of a rotor of the abnormal motor generator;
determining the rotation speed threshold;
The rotation speed threshold is set such that a back electromotive force generated by the abnormal motor generator is less than the acquired power supply voltage, and is further set lower as the temperature of the rotor is higher.

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