JP7137341B2 - power control system - Google Patents

Description

The present invention relates to power control systems.

2. Description of the Related Art In recent years, electric vehicles have been developed that run using the output of a motor generator that is driven using electric power stored in a battery. Specifically, as an electric vehicle, there is a vehicle that includes two or more motor generators that drive drive wheels. In a power control system for controlling power supply in such an electric vehicle, each motor generator is connected to a battery via an inverter, as disclosed in Patent Document 1, for example. By controlling, the electric power supplied to each motor generator can be controlled.

JP 2003-309997 A

By the way, in the power control system in which the electric power supplied to the motor generator is controlled by controlling the inverter as described above, if the inverter fails, it becomes difficult to appropriately control the inverter. It becomes difficult to appropriately control the motor generator connected to the inverter. In such a case, it is necessary to secure a sufficient cruising range, for example, in order to drive the vehicle to a repair shop. Therefore, for example, it is conceivable to run the vehicle by using the electric power stored in the battery with the output of a motor generator connected to a normal inverter that is not out of order. However, depending on the distance to the destination, the cruising range may be insufficient. Therefore, it is considered desirable to appropriately extend the cruising range when the inverter fails.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made in view of the above problems, and an object of the present invention is to extend the cruising range while suppressing overcharging of the battery when the inverter fails. To provide a new and improved power control system capable of

In order to solve the above problems, according to one aspect of the present invention, a first motor generator and a second motor generator that output power for driving driving wheels of a vehicle; a battery connected to a motor generator via a first inverter and a second inverter, respectively, and storing electric power supplied to the first motor generator and the second motor generator; a main relay provided closer to the battery than a connection portion of an inverter; a first sub-relay provided closer to the first inverter than a connection portion connecting the battery, the first inverter, and the second inverter; By controlling a second sub-relay provided closer to the second inverter than the connecting portion of the inverter and the second inverter, and the first inverter and the second inverter, the first motor generator and the second motor generator are connected to each other. a control device having a control unit that controls supplied electric power, wherein the control unit opens the main relay when one of the first inverter and the second inverter fails, A power control system is provided that executes regenerative running control to drive a motor generator on a normal inverter side using electric power regeneratively generated by a motor generator on the malfunctioning inverter side.

When one of the first inverter and the second inverter fails and the electromotive force of the motor generator on the side of the failed inverter is greater than the allowable voltage of the battery, the control unit controls the regenerative running control. may be executed.

The control unit closes the main relay and the sub-relay of the malfunctioning inverter when the electromotive force of the malfunctioning inverter-side motor generator drops to the allowable voltage during execution of the regenerative running control. The battery running control may be executed by setting the state and the open state to drive the motor generator on the normal inverter side using the electric power stored in the battery.

The controller may use a value corresponding to at least one of temperature and remaining capacity of the battery as the allowable voltage.

The control unit may perform the regenerative running control when one of the first inverter and the second inverter fails and a vehicle speed of the vehicle is greater than a threshold.

When the vehicle speed of the vehicle drops to the threshold value during execution of the regenerative running control, the control unit closes and opens the main relay and the sub-relay on the failed inverter side, respectively, so that the battery Battery travel control may be executed to drive the motor generator on the normal inverter side using the stored electric power.

The controller may use a value corresponding to at least one of temperature and remaining capacity of the battery as the threshold.

When both the first inverter and the second inverter are normal, the control unit closes the main relay, the first sub-relay, and the second sub-relay to cause the vehicle to run, and the first inverter to operate. and when one of the second inverter fails, the regenerative running control is executed, and then the main relay and the sub-relay on the side of the failed inverter are closed and opened, respectively, and the battery is charged. Battery running control may be executed to drive the motor-generator on the normal inverter side using the supplied electric power.

As described above, according to the present invention, it is possible to extend the cruising distance while suppressing overcharging of the battery when the inverter fails.

1 is a schematic diagram showing a schematic configuration of an electric vehicle equipped with a power control system according to an embodiment of the present invention; FIG. It is a block diagram showing an example of functional composition of a control device concerning the embodiment. It is a flowchart which shows an example of the flow of the process which the control apparatus which concerns on the same embodiment performs. FIG. 4 is a schematic diagram showing the state of the power control system according to the embodiment when regenerative running control is executed; FIG. 4 is a schematic diagram showing the state of the power control system according to the embodiment when battery travel control is executed; FIG. 4 is a flowchart showing an example different from FIG. 3 of the flow of processing performed by the control device according to the embodiment; FIG.

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. In the present specification and drawings, constituent elements having substantially the same functional configuration are denoted by the same reference numerals, thereby omitting redundant description.

<1. Configuration of Power Control System>
First, the configuration of a power control system 10 according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG.

FIG. 1 is a schematic diagram showing a schematic configuration of an electric vehicle 1 equipped with a power control system 10 according to this embodiment. In FIG. 1, the traveling direction of the electric vehicle 1 is the front direction, the opposite direction to the traveling direction is the rear direction, and the left side and the right side in the state facing the traveling direction are the left direction and the right direction, respectively. It is shown.

The electric vehicle 1 is merely an example of a vehicle on which the power control system 10 according to the present embodiment is mounted, and the configuration of the vehicle on which the power control system 10 is mounted is not particularly limited to such an example.

As shown in FIG. 1, the power control system 10 includes a first motor generator 31, a second motor generator 32, a first inverter 41, a second inverter 42, a battery 51, a main relay 61, a second A first sub-relay 71, a second sub-relay 72, a first electromotive force sensor 81, a second electromotive force sensor 82, a first failure sensor 83, a second failure sensor 84, a battery sensor 85, and a vehicle speed sensor 86. , and the control device 100 .

The first motor generator 31 and the second motor generator 32 are drive sources that output power for driving the drive wheels of the electric vehicle 1, and are specifically multiphase AC motor generators.

Specifically, the first motor generator 31 outputs power for driving the left front wheel 11 and the right front wheel 12 as drive wheels. Furthermore, the first motor generator 31 has a function (regenerative function) as a generator that generates electricity using the rotational energy of the front left wheel 11 and the front right wheel 12 .

First motor generator 31 is connected to battery 51 via first inverter 41 . The DC power discharged from the battery 51 is converted into AC power by the first inverter 41 and supplied to the first motor generator 31 . The first motor generator 31 generates power using the electric power supplied from the battery 51 via the first inverter 41 in this manner.

Also, the output shaft of the first motor generator 31 is connected to the front differential device 21 via, for example, a reduction gear (not shown). The power output from the first motor generator 31 is transmitted to the front differential device 21 , and is distributed and transmitted to the front left wheel 11 and the front right wheel 12 by the front differential device 21 .

Specifically, the second motor generator 32 outputs power for driving the left rear wheel 13 and the right rear wheel 14 as drive wheels. Further, the second motor generator 32 has a function (regenerative function) as a generator that generates power using the rotational energy of the left rear wheel 13 and the right rear wheel 14 .

The second motor generator 32 is connected to the battery 51 via the second inverter 42 . The DC power discharged from the battery 51 is converted into AC power by the second inverter 42 and supplied to the second motor generator 32 . The second motor generator 32 generates power using the electric power supplied from the battery 51 through the second inverter 42 in this manner.

Also, the output shaft of the second motor generator 32 is connected to the rear differential device 22 via, for example, a reduction gear (not shown). The power output from the second motor generator 32 is transmitted to the rear differential device 22 , and distributed to the left rear wheel 13 and the right rear wheel 14 by the rear differential device 22 .

The first inverter 41 and the second inverter 42 are power conversion devices that perform bidirectional power conversion, and specifically include multiphase bridge circuits.

Specifically, the first inverter 41 can convert DC power supplied from the battery 51 into AC power and supply the AC power to the first motor generator 31 . Further, the first inverter 41 can convert the AC power regenerated by the first motor generator 31 into DC power and supply the DC power to the battery 51 side. A switching element is provided in the first inverter 41 , and the conversion of electric power by the first inverter 41 is controlled by controlling the operation of the switching element.

Specifically, the second inverter 42 can convert the DC power supplied from the battery 51 into AC power and supply the AC power to the second motor generator 32 . Further, the second inverter 42 can convert the AC power regenerated by the second motor generator 32 into DC power and supply the DC power to the battery 51 side. A switching element is provided in the second inverter 42 , and the conversion of electric power by the second inverter 42 is controlled by controlling the operation of the switching element.

The battery 51 is a secondary battery that can charge and discharge electric power. As the battery 51, for example, a lithium ion battery, a lithium ion polymer battery, a nickel-metal hydride battery, a nickel-cadmium battery, or a lead-acid battery is used, but batteries other than these may also be used.

Specifically, the battery 51 stores electric power supplied to the first motor generator 31 and the second motor generator 32 . The battery 51 is, for example, configured to be connectable to an external charging device outside the electric vehicle 1 via a charging circuit and a connector (not shown), and supplies electric power from the external charging device while being connected to the external charging device when parked. can be charged by Also, the battery 51 may be charged using electric power regenerated by the first motor generator 31 or the second motor generator 32 .

Each relay of the main relay 61, the first sub-relay 71, and the second sub-relay 72 is driven by a driving device (not shown) to open and close to switch the energized state of the installed portion. Hereinafter, a state in which the relay is closed and the portion where the relay is installed is energized is called a closed state, and a state in which the relay is opened and the portion where the relay is installed is not energized is called an open state. Here, FIG. 1 shows the positive electrode side connection portion 91p and the negative electrode side connection portion 91m of the battery 51, the first inverter 41, and the second inverter 42, respectively.

The main relay 61 is provided closer to the battery 51 than the connecting portions 91 p and 91 m of the battery 51 , the first inverter 41 and the second inverter 42 . Specifically, the main relay 61 is provided between the positive electrode side of the battery 51 and the connection portion 91p and between the negative electrode side of the battery 51 and the connection portion 91m.

The first sub-relay 71 is provided closer to the first inverter 41 than the connecting portions 91 p and 91 m of the battery 51 , the first inverter 41 and the second inverter 42 . Specifically, the first sub-relay 71 is provided between the positive electrode side of the first inverter 41 and the connection portion 91p and between the negative electrode side of the first inverter 41 and the connection portion 91m.

The second sub-relay 72 is provided closer to the second inverter 42 than the connecting portions 91 p and 91 m of the battery 51 , the first inverter 41 and the second inverter 42 . Specifically, the second sub-relay 72 is provided between the positive electrode side of the second inverter 42 and the connection portion 91p and between the negative electrode side of the second inverter 42 and the connection portion 91m.

First electromotive force sensor 81 detects the electromotive force of first motor generator 31 while first motor generator 31 is performing regenerative power generation, and outputs the detection result to control device 100 .

Second electromotive force sensor 82 detects the electromotive force of second motor generator 32 while second motor generator 32 is performing regenerative power generation, and outputs the detection result to control device 100 .

First failure sensor 83 detects whether or not first inverter 41 has failed, and outputs the detection result to control device 100 .

Second fault sensor 84 detects whether or not second inverter 42 is faulty, and outputs the detection result to control device 100 .

Battery sensor 85 detects information about battery 51 and outputs the detection result to control device 100 . Specifically, the battery sensor 85 detects the temperature and remaining capacity (SOC: State Of Charge) of the battery 51 as information on the battery 51 .

Vehicle speed sensor 86 detects the vehicle speed of electric vehicle 1 and outputs the detection result to control device 100 .

The control device 100 includes a CPU (Central Processing Unit) that is an arithmetic processing unit, a ROM (Read Only Memory) that is a storage element that stores programs used by the CPU and calculation parameters, and parameters that change as appropriate during execution of the CPU. It is composed of a RAM (Random Access Memory) or the like, which is a storage element for temporary storage.

Further, the control device 100 communicates with each device mounted on the electric vehicle 1 . Communication between the control device 100 and each device is realized using CAN (Controller Area Network) communication, for example. The control device 100 communicates with a driving device that drives each relay, each inverter, and each sensor.

Note that the functions of the control device 100 according to the present embodiment may be divided by a plurality of control devices, and in that case, the plurality of control devices may be connected to each other via a communication bus such as CAN. .

FIG. 2 is a block diagram showing an example of the functional configuration of the control device 100 according to this embodiment.

As shown in FIG. 2, the control device 100 includes an acquisition unit 110 and a control unit 130, for example.

Acquisition unit 110 acquires various types of information used in processing performed by control device 100 . Acquisition unit 110 also outputs the acquired information to control unit 130 . For example, the acquisition unit 110 acquires detection results output from each sensor by communicating with each sensor in the electric vehicle 1 .

Control unit 130 executes each process using the information acquired by acquisition unit 110 . Control unit 130 specifically controls the operation of each relay and each motor generator.

The control unit 130 includes, for example, a relay control unit 131, a motor control unit 132, and a determination unit 133.

The relay control unit 131 controls operations of the main relay 61 , the first sub-relay 71 and the second sub-relay 72 . Specifically, the relay control unit 131 controls the opening/closing operation of each relay by controlling the operation of a driving device (not shown) that drives each relay. Thereby, the relay control unit 131 can control the open/close state of each relay.

After the power control system 10 is activated, the relay control unit 131 basically keeps the main relay 61, the first sub-relay 71, and the second sub-relay 72 closed, thereby supplying power from the battery 51 to each inverter. maintain a state in which it can be

Here, in the present embodiment, the relay control unit 131 controls the open/close state of the relay based on the presence or absence of failure of the inverter. Specifically, the relay control unit 131 opens the main relay 61 when one of the first inverter 41 and the second inverter 42 fails. As a result, the motor generator on the normal inverter side (hereinafter also referred to as the normal side) is driven by the electric power regenerated by the motor generator on the malfunctioning inverter side (hereinafter also referred to as the failed side). Travel control can be executed. As a result, it becomes possible to appropriately extend the cruising range when the inverter fails. It should be noted that such control at the time of failure of the inverter will be described in detail later.

The motor control unit 132 controls electric power supplied to the first motor generator 31 and the second motor generator 32 by controlling the first inverter 41 and the second inverter 42 . Specifically, the motor control unit 132 outputs an operation command to the first inverter 41 to control the operation of the switching elements of the first inverter 41, thereby causing the first motor generator 31 to generate and generate power. can be controlled. In addition, the motor control unit 132 outputs an operation command to the second inverter 42 to control the operation of the switching elements of the second inverter 42, thereby controlling power generation and power generation by the second motor generator 32. obtain.

Thus, the operation of each motor generator is controlled by controlling the operation of the switching element of the inverter connected to each motor generator. Therefore, when the inverter fails, it becomes difficult to appropriately control the inverter, and thus it becomes difficult to appropriately control the motor generator connected to the inverter. Any failure of the inverter may cause difficulty in properly controlling the inverter. This includes software failures such as abnormalities related to the output of signals for These failures are detected by the first failure sensor 83 and the second failure sensor 84 .

Here, when the inverter fails, the failed inverter can be made to function as a rectifier, and regenerative power generation can be performed by the motor generator on the failed side. Specifically, the inverter includes a polyphase bridge circuit as described above, and each arm circuit connected to each phase coil of the motor generator in the polyphase bridge circuit includes diodes connected in parallel to each other. and switching elements are provided. In the event of an inverter failure, for example, the switching elements are opened to form a diode bridge with the diodes provided in the polyphase bridge circuit. Therefore, when the inverter fails, the failed inverter can be made to function as a rectifier and, for example, AC power regenerated by the failed motor generator can be full-wave rectified.

The motor control unit 132 controls the output of each motor generator according to the acceleration request calculated based on the accelerator opening, for example. Specifically, the motor control unit 132 calculates a torque target value in response to the acceleration request, and performs Controls the operation of each motor generator.

The determination unit 133 uses the information acquired by the acquisition unit 110 to perform each determination process. A determination result of each determination process is used for control performed by the relay control unit 131 and the motor control unit 132 .

<2. Operation of Power Control System>
Next, operations of the power control system 10 according to the embodiment of the present invention will be described with reference to FIGS. 3 to 6. FIG.

FIG. 3 is a flowchart showing an example of the flow of processing performed by the control device 100 according to this embodiment. The control flow shown in FIG. 3 is started after the power control system 10 is activated, for example.

When the control flow shown in FIG. 3 is started, first, in step S501, the determination unit 133 determines whether or not one of the first inverter 41 and the second inverter 42 has failed. If it is determined that one of the first inverter 41 and the second inverter 42 is out of order (step S501/YES), the process proceeds to step S503. On the other hand, if it is not determined that one of the first inverter 41 and the second inverter 42 is out of order (step S501/NO), the determination process of step S501 is repeated.

Note that if both the first inverter 41 and the second inverter 42 fail at the same time, the relay control unit 131, for example, causes the battery 51 to be recharged by electric power regenerated by the first motor generator 31 and the second motor generator 32. In order to prevent overcharging, the main relay 61 is opened to cut off electrical connection between the battery 51 and the first inverter 41 and the second inverter 42 .

In step S<b>503 , determination unit 133 determines whether or not the electromotive force of the failed motor generator is greater than the allowable voltage of battery 51 . If it is determined that the electromotive force of the malfunctioning motor generator is greater than the allowable voltage of the battery 51 (step S503/YES), the process proceeds to step S505. On the other hand, if it is not determined that the electromotive force of the failed motor generator is greater than the allowable voltage of the battery 51 (step S503/NO), the process proceeds to step S509.

Specifically, the allowable voltage of the battery 51 is a voltage higher than the terminal voltage of the battery 51 and corresponds to a voltage that can properly charge the battery 51 without overcharging the battery 51 . Since the state of the battery 51 (for example, internal resistance, terminal voltage, etc.) can change depending on the temperature, remaining capacity, etc. of the battery 51, the determination unit 133 determines a value corresponding to at least one of the temperature and remaining capacity of the battery 51. It is preferable to use it as the allowable voltage. For example, a map that defines the relationship between the temperature and remaining capacity of the battery 51 and the value used as the allowable voltage is stored in advance in the storage element of the control device 100, and the determination unit 133 determines the allowable voltage based on the map. The values to use can be determined. Specifically, the determination unit 133 determines the value to be used as the allowable voltage based on the characteristic that the internal resistance changes according to the temperature of the battery 51 and the characteristic that the terminal voltage changes according to the remaining capacity of the battery 51. preferably. More specifically, the allowable voltage value used by determination unit 133 is preferably set based on the specifications of battery 51 .

In step S505, the control unit 130 opens the main relay 61, and executes regenerative running control to drive the motor generator on the normal side using electric power regenerated by the motor generator on the malfunction side.

FIG. 4 is a schematic diagram showing the state of the power control system 10 when regenerative running control is executed. Specifically, FIG. 4 shows the state of the power control system 10 during execution of regenerative running control when the first inverter 41 is out of order. In addition, in FIG. 4, the flow of electric power is schematically shown by a two-dot chain line arrow.

As shown in FIG. 4, in the regenerative running control, the relay control unit 131 opens the main relay 61 to disconnect the electrical connection between the battery 51 and the connection portions 91p and 91m. On the other hand, the relay control unit 131 maintains the first sub-relay 71 and the second sub-relay 72 in the closed state, and maintains the state in which the first inverter 41 and the second inverter 42 are electrically connected. Thereby, the first inverter 41 and the second inverter 42 are electrically connected, and the electrical connection between the battery 51 and the first inverter 41 and the second inverter 42 is cut off. When the first inverter 41 fails, the motor control unit 132 causes the failed first inverter to function as a rectifier as shown in FIG. The electric power regenerated by the generator 31 is used to drive the second motor generator 32 which is the motor generator on the normal side.

As described above, in the regenerative running control, the electric vehicle 1 can be run using the electric power regenerated by the faulty motor generator without consuming the electric power stored in the battery 51 . In regenerative running control, electrical connection between the faulty inverter and the battery 51 is cut off, so overcharging of the battery 51 by electric power regenerated by the faulty motor generator is suppressed. can do. Therefore, the cruising distance can be extended while suppressing overcharging of the battery 51 .

As the electromotive force of the faulty motor-generator is greater, the power regenerated by the faulty motor-generator can drive the normal motor-generator with greater driving force. On the other hand, if the faulty inverter and the battery 51 are electrically connected when the electromotive force of the faulty motor generator is relatively large (more specifically, greater than the allowable voltage of the battery 51), the The electric power regenerated by the motor generator tends to overcharge the battery 51 . Therefore, by executing regenerative running control when the electromotive force of the failed motor generator is greater than the allowable voltage of the battery 51, the overcharging of the battery 51 is more appropriately suppressed, and the cruising distance is further effectively increased. can be extended.

In step S<b>507 , determination unit 133 determines whether or not the electromotive force of the failed motor generator has decreased to the allowable voltage of battery 51 . If it is determined that the electromotive force of the malfunctioning motor generator has decreased to the allowable voltage of the battery 51 (step S507/YES), the process proceeds to step S509. On the other hand, if it is not determined that the electromotive force of the malfunctioning motor generator has decreased to the allowable voltage of the battery 51 (step S507/NO), the process returns to step S505, and the state in which the regenerative running control is being executed is maintained. .

Here, when the inverter fails, basically, the vehicle speed of the electric vehicle 1 decreases over time. Further, as the vehicle speed of the electric vehicle 1 decreases, the electromotive force of the failed motor generator decreases. Therefore, when the inverter fails, the electromotive force of the motor generator on the failed side decreases over time.

In step S509, the control unit 130 closes and opens the main relay 61 and the sub-relay on the failure side, respectively, and executes battery running control in which the electric power stored in the battery 51 is used to drive the motor generator on the normal side. do.

FIG. 5 is a schematic diagram showing the state of the power control system 10 when battery travel control is executed. Specifically, FIG. 5 shows the state of the power control system 10 when the battery traveling control is executed when the first inverter 41 is out of order. Note that in FIG. 5, the flow of electric power is schematically shown by two-dot chain line arrows in the same manner as in FIG.

As shown in FIG. 5 , in battery drive control, relay control unit 131 closes main relay 61 to electrically connect battery 51 and connection portions 91p and 91m. Further, when the first inverter 41 is in failure, the relay control unit 131 opens the first sub-relay 71, which is the sub-relay on the failure side, to electrically connect the first inverter 41 and the connection portions 91p and 91m. block the Thereby, the battery 51 and the second inverter 42 are electrically connected, and the electrical connection between the first inverter 41 and the battery 51 and the second inverter 42 is cut off. Then, as shown in FIG. 5, the motor control unit 132 drives the second motor generator 32, which is the motor generator on the normal side, using the electric power stored in the battery 51. As shown in FIG.

The driving force for driving the motor-generator on the normal side by the electric power regenerated by the motor-generator on the failure side decreases as the electromotive force of the motor-generator on the failure side decreases. Here, when the electromotive force of the failed motor generator drops to the allowable voltage, the voltages of the battery 51 side and each inverter side of the main relay 61 in the power control system 10 are substantially the same. Therefore, if the electromotive force of the motor generator on the faulty side drops to the allowable voltage during execution of regenerative running control, by executing the battery running control, the power supply source used to drive the motor generator on the normal side will not fail. The side motor generator can be appropriately switched to the battery 51 .

In the battery running control, from the viewpoint of smoothly switching the power supply path, it is preferable to first close the main relay 61 and then open the first sub-relay 71, which is the sub-relay on the failure side.

Then, for example, when the power control system 10 stops, the control flow shown in FIG. 3 ends.

Here, as described above, the relay control unit 131 basically maintains the main relay 61, the first sub-relay 71, and the second sub-relay 72 in the closed state after the power control system 10 is started, so that the battery is A state is maintained in which power can be supplied from 51 to each inverter. In this way, when both the first inverter 41 and the second inverter 42 are normal, the control unit 130 closes the main relay 61, the first sub-relay 71, and the second sub-relay 72 to allow the electric vehicle 1 to run. . Then, as described with reference to FIG. 3, when one of the first inverter 41 and the second inverter 42 fails, the control unit 130 first executes the regenerative running control, and then performs battery running. control can be exercised. It should be noted that if the determination process in step S503 results in NO, control unit 130 executes battery drive control without executing regenerative drive control.

FIG. 6 is a flowchart showing an example of the flow of processing performed by the control device 100 according to this embodiment, which is different from that shown in FIG. The control flow shown in FIG. 6 is started after the power control system 10 is activated, for example.

The control flow shown in FIG. 6 differs from the control flow shown in FIG. 3 in the determination processing that is performed when YES is determined in the determination processing in step S501 and the next determination processing in step S505.

In the control flow shown in FIG. 6, if YES is determined in the determination process of step S501, the process proceeds to step S603.

In step S603, the determination unit 133 determines whether or not the vehicle speed of the electric vehicle 1 is greater than a threshold. If it is determined that the vehicle speed of the electric vehicle 1 is greater than the threshold (step S603/YES), the process proceeds to step S505. On the other hand, if it is not determined that the vehicle speed of the electric vehicle 1 is greater than the threshold (step S603/NO), the process proceeds to step S509.

Specifically, the threshold value corresponds to a value with which it can be determined whether or not the vehicle speed of the electric vehicle 1 is so high that the electromotive force of the faulty motor generator is greater than the allowable voltage of the battery 51 . Since the state of the battery 51 (for example, internal resistance, terminal voltage, etc.) can change depending on the temperature, remaining capacity, etc. of the battery 51 as described above, the determination unit 133 determines whether at least one of the temperature and remaining capacity of the battery 51 is A corresponding value is preferably used as the threshold. For example, a map that defines the relationship between the temperature and remaining capacity of the battery 51 and the values used as thresholds is stored in advance in the storage element of the control device 100, and the determination unit 133 determines the values used as thresholds based on the map can be determined. Specifically, the determination unit 133 determines a value to be used as a threshold value based on the characteristic that the internal resistance changes according to the temperature of the battery 51 and the characteristic that the terminal voltage changes according to the remaining capacity of the battery 51. is preferred. More specifically, the threshold value used by determination unit 133 is preferably set based on the specification of battery 51, the specification of each motor generator, and the specification of the reduction gear connected to each motor generator.

In step S505, control unit 130 executes regenerative running control in the same manner as in the control flow shown in FIG.

As described above, when one of the first inverter 41 and the second inverter 42 fails, the control unit 130 may perform regenerative running control when the vehicle speed of the electric vehicle 1 is greater than the threshold. Here, when the vehicle speed of the electric vehicle 1 is greater than the threshold, it corresponds to the case where the electromotive force of the motor generator on the failure side is greater than the allowable voltage of the battery 51 . Therefore, by executing the regenerative running control when the vehicle speed of the electric vehicle 1 is higher than the threshold, it is possible to more effectively extend the cruising range while more appropriately suppressing overcharging of the battery 51 . . In this way, control unit 130 may determine whether or not to execute regenerative running control using parameters different from those in the control flow shown in FIG.

Next, in step S607, the determination unit 133 determines whether or not the vehicle speed of the electric vehicle 1 has decreased to a threshold value. If it is determined that the vehicle speed of the electric vehicle 1 has decreased to the threshold value (step S607/YES), the process proceeds to step S509. On the other hand, if it is not determined that the vehicle speed of the electric vehicle 1 has decreased to the threshold value (step S607/NO), the process returns to step S505, and the state in which the regenerative running control is being executed is maintained.

In step S509, control unit 130 executes battery running control, as in the control flow shown in FIG.

As described above, control unit 130 may execute battery driving control when the vehicle speed of electric vehicle 1 decreases to the threshold value during execution of regenerative driving control. Here, when the vehicle speed of the electric vehicle 1 drops to the threshold value, it corresponds to the case where the electromotive force of the faulty motor generator drops to the allowable voltage. Therefore, by executing the battery drive control when the vehicle speed of the electric vehicle 1 has decreased to the threshold value, the power supply source used for driving the motor generator on the normal side can be appropriately switched from the motor generator on the malfunctioning side to the battery 51. can be done. In this manner, control unit 130 may determine whether or not to execute battery traveling control using parameters different from those in the control flow shown in FIG. 3 during execution of regenerative traveling control.

<3. Effect of Power Control System>
Next, effects of the power control system 10 according to the embodiment of the present invention will be described.

In the power control system 10 according to the present embodiment, the main relay 61 is provided on the battery 51 side of the connecting portions 91 p and 91 m of the battery 51 , the first inverter 41 and the second inverter 42 . A first sub-relay 71 is provided on the side of the first inverter 41 from the connection portions 91p and 91m. A second sub-relay 72 is provided closer to the second inverter 42 than the connection portions 91p and 91m. In addition, when one of the first inverter 41 and the second inverter 42 fails, the control unit 130 opens the main relay 61 so that the electric power regenerated by the motor generator of the failed inverter is regenerative running control for driving the motor-generator on the normal inverter side. As a result, the electric vehicle 1 can be run without consuming the electric power stored in the battery 51 . Furthermore, it is possible to prevent the battery 51 from being overcharged by the electric power regenerated by the malfunctioning motor generator. Therefore, the cruising distance can be extended while suppressing overcharging of the battery 51 . Therefore, it is possible to appropriately extend the cruising distance when the inverter fails.

Further, in the power control system 10 according to the present embodiment, when one of the first inverter 41 and the second inverter 42 fails, the control unit 130 reduces the electromotive force of the motor generator of the failed inverter. If it is higher than the allowable voltage of the battery 51, it is preferable to execute regenerative running control. As a result, it is possible to more effectively extend the cruising range while more appropriately suppressing overcharging of the battery 51 . Therefore, the cruising distance can be extended more appropriately when the inverter fails.

Further, in the power control system 10 according to the present embodiment, when the electromotive force of the motor-generator on the malfunctioning inverter side drops to the allowable voltage during execution of regenerative running control, the control unit 130 controls the main relay 61 and It is preferable to execute battery travel control in which the sub-relays on the failed inverter side are closed and opened, respectively, and the electric power stored in the battery 51 is used to drive the motor generator on the normal inverter side. As a result, it is possible to appropriately switch the power supply source used for driving the motor-generator on the normal side to the battery 51 from the motor-generator on the failure side. Therefore, the electric power stored in the battery 51 is removed after the driving force for driving the motor generator on the normal side by the electric power regenerated by the motor generator on the faulty side decreases with the lapse of time and becomes relatively small. The electric vehicle 1 can be made to run using it.

Further, in the power control system 10 according to the present embodiment, the controller 130 preferably uses a value corresponding to at least one of the temperature and the remaining capacity of the battery 51 as the allowable voltage of the battery 51 . As a result, the value used as the allowable voltage can be optimized according to changes in at least one of the temperature and remaining capacity of the battery 51 . Therefore, it is possible to appropriately perform each determination process using the allowable voltage.

Further, in the control device 100 according to the present embodiment, when one of the first inverter 41 and the second inverter 42 fails and the vehicle speed of the electric vehicle 1 is greater than the threshold, the control unit 130 performs regenerative running control. is preferably performed. As a result, the cruising range can be extended more effectively while overcharging the battery 51 is more appropriately suppressed. Therefore, the cruising distance can be extended more appropriately when the inverter fails.

Further, in the power control system 10 according to the present embodiment, when the vehicle speed of the electric vehicle 1 decreases to a threshold value during execution of regenerative running control, the control unit 130 are closed and opened, respectively, and the electric power stored in the battery 51 is used to drive the motor-generator on the normal inverter side. As a result, the power supply source used for driving the motor generator on the normal side can be appropriately switched from the motor generator on the failure side to the battery 51 . Therefore, the electric power stored in the battery 51 is removed after the driving force for driving the motor generator on the normal side by the electric power regenerated by the motor generator on the faulty side decreases with the lapse of time and becomes relatively small. The electric vehicle 1 can be made to run using it.

Moreover, in the power control system 10 according to the present embodiment, the controller 130 preferably uses a value corresponding to at least one of the temperature and the remaining capacity of the battery 51 as the threshold value. As a result, the value used as the threshold can be optimized according to changes in at least one of the temperature and remaining capacity of the battery 51 . Therefore, each determination process using a threshold can be performed appropriately.

<4. Conclusion>
As described above, in the power control system 10 according to the present embodiment, from the connection portions 91p and 91m of the battery 51, the first inverter 41, and the second inverter 42, the battery 51 side, the first inverter 41 side, and the second inverter 42 are connected. A main relay 61, a first sub-relay 71 and a second sub-relay 72 are provided on each side. In addition, when one of the first inverter 41 and the second inverter 42 fails, the control unit 130 opens the main relay 61 so that the electric power regenerated by the motor generator of the failed inverter is regenerative running control for driving the motor-generator on the normal inverter side. As a result, the cruising distance can be extended by running the electric vehicle 1 without consuming the electric power stored in the battery 51 while suppressing the overcharging of the battery 51 . Therefore, it is possible to appropriately extend the cruising distance when the inverter fails.

Although the preferred embodiments of the present invention have been described in detail with reference to the accompanying drawings, the present invention is not limited to such examples. It is obvious that a person having ordinary knowledge in the technical field to which the present invention belongs can conceive of various modifications or applications within the scope of the technical idea described in the claims. It is understood that these also naturally belong to the technical scope of the present invention.

For example, processes described herein using flowcharts do not necessarily have to be performed in the order shown in the flowcharts. Some processing steps may be performed in parallel. Also, additional processing steps may be employed, and some processing steps may be omitted.

Further, for example, the number of motor generators provided in the power control system 10 may be at least two or more, and may be three or more. For example, different motor generators (four motor generators in total) may be provided as drive sources for the respective wheels of the vehicle on which the power control system 10 is mounted. In that case, for example, each motor generator is connected to a battery via an inverter, and a sub-relay is provided for each inverter. As a result, when one of the motor generators fails, the same control as the regenerative running control described above is performed, so that the vehicle is driven using the electric power regenerated by the motor generator on the failed inverter side. can be run.

Also, for example, the power control system 10 may be additionally provided with components other than the components described with reference to FIG. For example, a boost converter may be provided on the battery 51 side of the connecting portions 91 p and 91 m of the battery 51 , the first inverter 41 and the second inverter 42 .

1 Electric Vehicle 10 Power Control System 11 Left Front Wheel 12 Right Front Wheel 13 Left Rear Wheel 14 Right Rear Wheel 21 Front Differential Device 22 Rear Differential Device 31 First Motor Generator 32 Second Motor Generator 41 First Inverter 42 Second Inverter 51 Battery 61 Main relay 71 First sub-relay 72 Second sub-relay 81 First electromotive force sensor 82 Second electromotive force sensor 83 First failure sensor 84 Second failure sensor 85 Battery sensor 86 Vehicle speed sensor 100 Control device 110 Acquisition unit 130 Control unit 131 Relay control Unit 132 Motor control unit 133 Determination unit

Claims (8)

a first motor generator and a second motor generator that output power for driving driving wheels of a vehicle;
a battery connected to the first motor generator and the second motor generator via a first inverter and a second inverter, respectively, and storing electric power supplied to the first motor generator and the second motor generator;
a main relay provided closer to the battery than a connecting portion of the battery, the first inverter, and the second inverter;
a first sub-relay provided closer to the first inverter than a connecting portion of the battery, the first inverter, and the second inverter;
a second sub-relay provided closer to the second inverter than a connecting portion of the battery, the first inverter, and the second inverter;
a control device having a control unit that controls electric power supplied to the first motor generator and the second motor generator by controlling the first inverter and the second inverter;
with
When one of the first inverter and the second inverter fails, the control unit opens the main relay and uses the electric power regenerated by the motor generator of the failed inverter. Execute regenerative running control to drive the motor generator on the normal inverter side,
power control system. When one of the first inverter and the second inverter fails and the electromotive force of the motor generator on the side of the failed inverter is greater than the allowable voltage of the battery, the control unit controls the regenerative running control. run the
The power control system of claim 1. The control unit closes the main relay and the sub-relay of the malfunctioning inverter when the electromotive force of the malfunctioning inverter-side motor generator drops to the allowable voltage during execution of the regenerative running control. state and open state, and execute battery running control to drive the motor generator on the normal inverter side using the electric power stored in the battery;
3. A power control system according to claim 2. The control unit uses a value corresponding to at least one of temperature and remaining capacity of the battery as the allowable voltage.
A power control system according to claim 2 or 3. The control unit executes the regenerative running control when one of the first inverter and the second inverter fails and the vehicle speed of the vehicle is greater than a threshold.
The power control system according to any one of claims 1-4. When the vehicle speed of the vehicle drops to the threshold value during execution of the regenerative running control, the control unit closes and opens the main relay and the sub-relay on the failed inverter side, respectively, so that the battery Execute battery travel control to drive the motor generator on the normal inverter side using the stored electric power;
A power control system according to claim 5 . The control unit uses a value corresponding to at least one of temperature and remaining capacity of the battery as the threshold,
A power control system according to claim 5 or 6. The control unit
running the vehicle with the main relay, the first sub-relay and the second sub-relay closed when both the first inverter and the second inverter are normal;
executing the regenerative running control when one of the first inverter and the second inverter fails;
After that, the main relay and the sub-relay on the side of the malfunctioning inverter are closed and opened, respectively, and battery running control is executed to drive the motor generator on the side of the normal inverter using the electric power stored in the battery. ,
The power control system according to any one of claims 1-7.

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