Drive system and vehicle equipped therewith

Abstract

In a vehicle's drive system equipped with a battery, the necessary driving performance is ensured while protecting the drive unit that drives the drive wheels. [Solution] The drive system 9 includes a right front unit 1 that drives the drive wheels 71 using discharge power from a battery pack 6, a right rear unit 2 that drives the drive wheels 72 using discharge power from a battery pack 6, sensors 511 and 512 that detect the temperature or current of the right front unit 1 and output a first detection value, sensors 521 and 522 that detect the temperature or current of the right rear unit 2 and output a second detection value, and an ECU 8 configured to perform a first suppression control that suppresses the discharge power from the battery pack 6 to the right front unit 1 according to the first detection value, and a second suppression control that suppresses the discharge power from the battery pack 6 to the right rear unit 2 according to the second detection value. The ECU 8 performs the first suppression control and the second suppression control independently of each other.

Description

Technical Field

[0001] The present disclosure relates to a drive system and a vehicle equipped with the same.

Background Art

[0002] The vehicle disclosed in Japanese Patent Application Laid-Open No. 2023-140189 (Patent Document 1) includes a front electric motor and a rear electric motor (see paragraphs

[0022] to

[0025] ). Further, the electronic control device of the vehicle uses the chargeable power Win and the dischargeable power Wout calculated based on the battery temperature and the SOC (State Of Charge) to limit the input power of the battery or limit the output power of the battery (see paragraph

[0046] ).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

[0004] In a drive system of a vehicle equipped with a battery, it is required to protect a drive device (inverter and motor generator) that drives drive wheels from overheating or overcurrent. On the other hand, if excessive protection is performed, the driving performance of the drive wheels by the drive system (that is, the power performance of the vehicle) may decrease, and it may not be possible to ensure the required driving performance.

Problems to be Solved by the Invention

[0005] The present disclosure has been made to solve the above problems, and one of the objects of the present disclosure is to ensure the required driving performance while protecting the drive device in a drive system of a vehicle equipped with a battery.

Means for Solving the Problems

[0006] (1) A drive system according to a certain aspect of the present disclosure is mounted on a vehicle including a battery and first drive wheels and second drive wheels. The drive system includes a first drive unit that drives the first drive wheels with discharge power from the battery, a second drive unit that drives the second drive wheels with discharge power from the battery, a first sensor that detects the temperature or current of the first drive unit and outputs a first detected value, a second sensor that detects the temperature or current of the second drive unit and outputs a second detected value, and a control unit configured to perform a first suppression control that suppresses the first discharge power from the battery to the first drive unit according to the first detected value, and a second suppression control that suppresses the second discharge power from the battery to the second drive unit according to the second detected value. The control unit performs the first suppression control and the second suppression control independently of each other.

[0007] (2) In the first suppression control and the second suppression control, the control device suppresses both the first discharge power and the second discharge power if the first detected value exceeds the first reference value and the second detected value exceeds the second reference value. The control device suppresses the first discharge power but does not suppress the second discharge power if the first detected value exceeds the first reference value and the second detected value falls below the second reference value. The control device suppresses the second discharge power but does not suppress the first discharge power if the first detected value falls below the first reference value and the second detected value exceeds the second reference value. The control device does not suppress either the first or second discharge power if the first detected value falls below the first reference value and the second detected value falls below the second reference value.

[0008] In the configurations described in (1) and (2) above, the control device performs the first suppression control and the second suppression control independently of each other. Therefore, it is prevented that the first discharge power from the battery to the first drive unit and the second discharge power from the battery to the second drive unit are suppressed in conjunction. Thus, according to the configurations described in (1) and (2) above, the drive unit can be protected while ensuring the necessary drive performance.

[0009] (3) The control device is configured to perform total suppression control, which suppresses the total discharge power from the battery to the first drive unit and the second drive unit according to the battery temperature or SOC. The control device performs total suppression control, first suppression control and second suppression control independently of each other.

[0010] In the configuration described in (3) above, total suppression control is also performed independently in addition to the first suppression control and the second suppression control. This ensures the necessary driving performance while appropriately protecting not only the drive unit but also the battery.

[0011] (4) The vehicle further includes a third drive wheel and a fourth drive wheel. The drive system further includes a third drive unit that drives the third drive wheel with discharge power from the battery, a fourth drive unit that drives the fourth drive wheel with discharge power from the battery, a third sensor that detects the temperature or current of the third drive unit and outputs a third detection value, and a fourth sensor that detects the temperature or current of the fourth drive unit and outputs a fourth detection value. The control unit is configured to further perform a third suppression control that suppresses the third discharge power from the battery to the third drive unit according to the third detection value, and a fourth suppression control that suppresses the fourth discharge power from the battery to the fourth drive unit according to the fourth detection value. The control unit performs the total suppression control, the first suppression control, the second suppression control, the third suppression control, and the fourth suppression control independently of each other.

[0012] In the configuration described in (4) above, in addition to the first and second suppression control, the third and fourth suppression control are also executed independently. This ensures that the necessary driving performance is secured for all four drive wheels of the vehicle while protecting the drive system.

[0013] (5) Vehicles relating to other aspects of the present disclosure include the drive system described in (4) above, a battery, and a first drive wheel, a second drive wheel, a third drive wheel, and a fourth drive wheel.

[0014] According to the configuration described in (5) above, it is possible to provide a vehicle that can protect the drive system while ensuring the necessary driving performance. [Effects of the Invention]

[0015] According to this disclosure, in a vehicle drive system equipped with a battery, it is possible to ensure the necessary drive performance while protecting the drive unit. [Brief explanation of the drawing]

[0016] [Figure 1] This is a block diagram showing an example of the hardware configuration of a vehicle equipped with a drive system according to an embodiment of the present disclosure. [Figure 2] This is a time chart to explain the suppression control in the comparative example. [Figure 3] This is a time chart illustrating the post-distribution suppression control in this embodiment. [Figure 4] This flowchart shows an example of the processing procedure for suppression control in this embodiment. [Figure 5] This is a conceptual diagram to explain total suppression control. [Figure 6] This is a conceptual diagram to explain post-distribution suppression control. [Modes for carrying out the invention]

[0017] The embodiments of this disclosure will be described in detail below with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and their descriptions will not be repeated.

[0018] [Embodiment] <Vehicle configuration> FIG. 1 is a block diagram showing an example of the hardware configuration of a vehicle equipped with a drive system according to an embodiment of the present disclosure. Vehicle 100 is, for example, a battery electric vehicle (BEV). However, vehicle 100 may be a plug-in hybrid electric vehicle (PHEV) or a hybrid electric vehicle (HEV) as long as it is a vehicle equipped with a driving battery (battery pack 6 described later).

[0019] Vehicle 100 includes a right front unit 1, a right rear unit 2, a left front unit 3, a left rear unit 4, a sensor group 5, a battery pack 6, drive wheels 71 to 74, and an ECU (Electronic Control Unit) 8.

[0020] The right front unit 1 drives the right front drive wheel 71. The right front unit 1 includes a first inverter 11, a first motor generator 12, and a first transaxle 13. The first inverter 11 performs bidirectional power conversion (DC-AC conversion) between the battery pack 6 and the first motor generator 12 according to a control command from the ECU 8. The first motor generator 12 is, for example, a three-phase AC synchronous motor in which permanent magnets are embedded in the rotor. The first transaxle 13 includes a transmission for the right front drive wheel 71, a differential gear (not shown), and the like.

[0021] The right rear unit 2 drives the right rear drive wheel 72. The left front unit 3 drives the left front drive wheel 73. The left rear unit 4 drives the left rear drive wheel 74. Since the configurations of these units are equivalent to the configuration of the right front unit 1, the description will not be repeated.

[0022] The right front unit 1, right rear unit 2, left front unit 3, and left rear unit 4 correspond to any of the "first drive unit" to "fourth drive unit" described herein. The correspondence between each unit and each drive unit is not particularly limited.

[0023] The battery pack 6 is a battery assembly containing multiple cells (not shown). Each cell is a secondary battery such as a lithium-ion battery or a nickel-metal hydride battery. Each cell may also be a solid-state battery. The battery pack 6 discharges power to drive the first motor generator 12 to the fourth motor generator 42. The battery pack 6 is also charged during regenerative power generation by the first motor generator 12 to the fourth motor generator 42.

[0024] The battery pack 6 includes a battery voltage sensor 61, a battery current sensor 62, and a battery temperature sensor 63. The battery voltage sensor 61 detects the voltage Vb of the battery pack 6. The battery current sensor 62 detects the current Ib being charged and discharged from the battery pack 6. The battery temperature sensor 63 detects the temperature Tb of the battery pack 6 (hereinafter referred to as "battery temperature"). Each sensor outputs its detection result to the ECU 8.

[0025] Sensor group 5 includes a temperature sensor 511 and a current sensor 512. The temperature sensor 511 detects the temperature T1 of the first inverter 11 (hereinafter referred to as "inverter temperature") and outputs the detection result to the ECU 8. The current sensor 512 detects the current Ib flowing through the first motor generator 12 (hereinafter referred to as "motor current") and outputs the detection result to the ECU 8. Sensor group 5 also includes the same temperature sensor and current sensor for each of the right rear unit 2, left front unit 3, and left rear unit 4. These temperature sensors and current sensors perform the same functions as the temperature sensor 511 and current sensor 512, so no further explanation is given.

[0026] The ECU8 includes a processor 81 and memory 82. The processor 81 is a processing unit such as a CPU (Central Processing Unit) or MPU (Micro-Processing Unit). The memory 82 includes volatile memory (working memory) such as RAM (Random Access Memory) and rewritable non-volatile memory such as flash memory. The memory 82 stores a system program including the OS (Operating System) and a control program including computer-readable code necessary for control. The processor 81 performs various processes by reading the system program and control program, loading them into the memory 82, and executing them.

[0027] The right front unit 1, right rear unit 2, left front unit 3, left rear unit 4, sensor group 5, and ECU 8 constitute the drive system 9. For convenience of explanation, in the following, the right front unit 1 may be referred to as unit n=1, the right rear unit 2 as unit n=2, the left front unit 3 as unit n=3, and the left rear unit 4 as unit n=4.

[0028] <Post-distribution suppression control> In this embodiment, the main controls performed by the ECU8 include "total suppression control" and "post-distribution suppression control".

[0029] Total suppression control is a control method that suppresses the total discharge power and charge power of the battery pack 6. In total suppression control, the ECU 8 suppresses the total discharge power from the battery pack 6 to the four units n=1 to 4, and suppresses the total charge power from those four units to the battery pack 6, depending on the temperature (battery temperature Tb) and state of charge (SOC) of the battery pack 6. The parameters used for this suppression are the dischargeable power Wout (control upper limit of the total discharge power from the battery pack 6 to the four units) and the chargeable power Win (control upper limit of the total charge power from the four units to the battery pack 6).

[0030] Post-distribution suppression control is a control method that individually suppresses the discharge power and charge power after distribution from the battery pack 6 to each unit. In post-distribution suppression control, if overheating or overcurrent is detected in any of the four units n=1 to 4, the ECU 8 suppresses the individual discharge power from the battery pack 6 to that unit, and also suppresses the individual charge power from that unit to the battery pack 6, compared to when overheating or overcurrent is not detected in that unit. The parameters used for this suppression are the post-dischargeable power MWout(n) (control upper limit of discharge power from battery pack 6 to unit n) and the post-chargeable power MWin(n) (control upper limit of charge power from unit n to battery pack 6).

[0031] In this example, post-distribution suppression control includes "first suppression control" to "fourth suppression control". First suppression control is post-distribution suppression control for unit n=1 (right front unit 1). Second to fourth suppression control are post-distribution suppression controls for units n=2 to 4, respectively.

[0032] To facilitate understanding of the post-distribution suppression control in this embodiment, we will first describe the suppression control in a comparative example. Due to space limitations, we will only use two units (right front unit 1 and right rear unit 2) with n=1 and n=2 for the following explanation, but post-distribution suppression control can be implemented on any unit.

[0033] ≪Comparative Example≫ Figure 2 is a time chart illustrating the suppression control in the comparative example. The horizontal axis represents elapsed time. The vertical axis, from top to bottom, represents inverter temperature T1, discharge power (output) W1 from battery pack 6 to the first inverter 11, inverter temperature T2, and discharge power W2 from battery pack 6 to the second inverter 21. The same applies to the following Figure 3.

[0034] A reference temperature Tref for protecting the first inverter 11 and the second inverter 21 is predetermined. For simplicity, it is assumed here that the reference temperature Tref is common to both the first inverter 11 and the second inverter 21, but the reference temperature Tref may be different between the first inverter 11 and the second inverter 21.

[0035] At the initial time t90, both inverter temperatures T1 and T2 are lower than the reference temperature Tref. As the vehicle 100 is running, the inverter temperatures T1 and T2 gradually rise as the first inverter 11 and second inverter 21 operate to drive the first motor generator 12 and the second motor generator 22, respectively.

[0036] At time t91, the inverter temperature T1 reaches the reference temperature Tref. At this point, the suppression control is initiated. More specifically, in the comparative example's suppression control, the discharge power W1 from the battery pack 6 to the first inverter 11 and the discharge power W2 from the battery pack 6 to the second inverter 21 are suppressed compared to the case where the inverter temperature T1 is below the reference temperature Tref.

[0037] This suppresses further temperature increases in inverter temperatures T1 and T2, protecting the first inverter 11 and the second inverter 21 from overheating. On the other hand, because the discharge power W1 and W2 from the battery pack 6 to both the first inverter 11 and the second inverter 21 is suppressed, the driving performance of the drive wheels 71 and 72 by the first motor generator 12 and the second motor generator 22 (i.e., the power performance of the vehicle 100) may decrease, and the required driving performance may not be secured.

[0038] Therefore, in this embodiment, the ECU 8 independently executes suppression control (first suppression control) for the right front unit 1 and suppression control (second suppression control) for the right rear unit 2.

[0039] <<This Embodiment>> Figure 3 is a time chart illustrating the post-distribution suppression control in this embodiment. At the initial time t0, both inverter temperature T1 and inverter temperature T2 are lower than the reference temperature Tref, similar to the comparative example.

[0040] At time t1, the inverter temperature T1 reaches the reference temperature Tref. At this point, the first suppression control for the right front unit 1 is initiated. Meanwhile, the inverter temperature T2 has not reached the reference temperature Tref. Therefore, the second suppression control for the right rear unit 2 is not executed. At the following time t3, the inverter temperature T2 reaches the reference temperature Tref. At this point, the second suppression control is initiated.

[0041] During the period between time t1 and time t3, although the discharge power W1 from the battery pack 6 to the first inverter 11 is suppressed (first suppression control), the discharge power W2 from the battery pack 6 to the second inverter 21 is not suppressed. Therefore, the driving performance of the drive wheels 72 by the second motor generator 22 is maintained, and there is a high possibility that the required driving performance can be secured compared to the comparative example.

[0042] From time t3 onward, both the first and second suppression control are executed. This suppresses further temperature increases in inverter temperatures T1 and T2, as in the comparative example, and protects the first inverter 11 and the second inverter 21 from overheating.

[0043] Thus, if the inverter temperature T1 exceeds the reference temperature Tref and the inverter temperature T2 also exceeds the reference temperature Tref, the ECU8 suppresses both the discharge power W1 to the first inverter 11 and the discharge power W2 to the second inverter 21. If the inverter temperature T1 exceeds the reference temperature Tref and the inverter temperature T2 falls below the reference temperature Tref, the ECU8 suppresses the discharge power W1 to the first inverter 11 while not suppressing the discharge power W2 to the second inverter 21. If the inverter temperature T1 falls below the reference temperature Tref and the inverter temperature T2 exceeds the reference temperature Tref, the ECU8 does not suppress the discharge power W1 to the first inverter 11 while suppressing the discharge power W2 to the second inverter 21. If the inverter temperature T1 falls below the reference temperature Tref and the inverter temperature T2 also falls below the reference temperature Tref, the ECU8 does not suppress either the discharge power W1 to the first inverter 11 or the discharge power W2 to the second inverter 21.

[0044] Figures 2 and 3 illustrate an example in which post-distribution suppression control is performed based on inverter temperatures T1, T2 (i.e., overheating of the first inverter 11 and the second inverter 21). However, post-distribution suppression control may also be performed based on motor currents I1, I2 (i.e., overcurrents of the first motor generator 12 and the second motor generator 22).

[0045] Thus, in this embodiment, the ECU 8 independently performs the nth suppression control on the four units: the right front unit 1, the right rear unit 2, the left front unit 3, and the left rear unit 4. This ensures the necessary driving performance while protecting the four units from overheating or overcurrent.

[0046] <Processing Flow> Figure 4 is a flowchart showing an example of the suppression control processing procedure in this embodiment. The processing shown in this flowchart is executed when predetermined conditions are met (for example, at predetermined intervals). Each step is implemented by software processing by the ECU8 (processor 81), but may also be implemented by hardware (electrical circuits) located within the ECU8. Hereinafter, each step will be abbreviated as S.

[0047] ECU8 performs total suppression control in S1 to S5 as described below, and performs post-distribution suppression control in S6 to S13.

[0048] Total suppression control In S1, the ECU 8 obtains the voltage Vb, current Ib, and battery temperature Tb of the battery pack 6 from the battery voltage sensor 61, battery current sensor 62, and battery temperature sensor 63, respectively.

[0049] In S2, the ECU8 calculates the State of Charge (SOC) of the battery pack 6. Known methods are used to calculate the SOC, including methods using the SOC-OCV (Open Circuit Voltage) curve, methods using current integration, or combinations thereof.

[0050] In S3, ECU8 determines whether the battery temperature Tb is below the lower limit temperature TLL or above the upper limit temperature TUL. If the battery temperature Tb is below the lower limit temperature TLL or above the upper limit temperature TUL (YES in S3), ECU8 proceeds to S5 and executes total suppression control. On the other hand, if the battery temperature Tb is above the lower limit temperature TLL and below the upper limit temperature TUL (NO in S3), ECU8 proceeds to S4.

[0051] In S4, ECU8 determines whether the SOC calculated in S2 is less than the lower limit SOC (SLL) or greater than the upper limit SOC (SUL). If the SOC is less than the lower limit SOC (SLL) or greater than the upper limit SOC (SUL) (YES in S4), ECU8 proceeds to S5 and executes total suppression control. On the other hand, if the SOC is greater than or equal to the lower limit SOC (SLL) and less than or equal to the upper limit SOC (SUL) (NO in S4), ECU8 skips S5 and proceeds to S6 without executing total suppression control.

[0052] Figure 5 is a conceptual diagram illustrating total suppression control. The upper horizontal axis represents the battery temperature Tb. The lower horizontal axis represents the state of charge (SOC) of the battery pack 6. The vertical axis represents power. The upper part of the vertical axis (upward) represents the dischargeable power Wout from the battery pack 6, and the lower part of the vertical axis (downward) represents the chargeable power Win to the battery pack 6.

[0053] In this example, ECU8 begins suppressing the dischargeable power Wout when the battery temperature Tb exceeds the upper limit temperature TUL, and sets the dischargeable power Wout to 0 (i.e., prohibits discharge from battery pack 6) when the battery temperature Tb exceeds the maximum temperature TMAX. ECU8 also begins suppressing the dischargeable power Wout when the battery temperature Tb falls below the lower limit temperature TLL, and sets the dischargeable power Wout to 0 when the battery temperature Tb falls below the minimum temperature TMIN. The same applies to the rechargeable power Wint.

[0054] In addition, ECU8 starts suppressing the rechargeable power Win when the SOC of battery pack 6 exceeds the upper SOC (SUL), and sets the rechargeable power Win to 0 when the SOC exceeds the maximum SOC (SMAX) (i.e., prohibits charging of battery pack 6). Furthermore, ECU8 starts suppressing the rechargeable power Win when the SOC falls below the lower SOC (SLL), and sets the rechargeable power Win to 0 when the SOC falls below the minimum SOC (SMIN).

[0055] <<Post-distribution suppression control>> Returning to Figure 4, in S6, the ECU8 acquires the inverter temperatures T1 to T4 from temperature sensors 511, 521, 531, and 541, respectively.

[0056] In S7, the ECU8 obtains motor currents I1 to I4 from current sensors 512, 522, 532, and 542, respectively.

[0057] In S8, ECU8 initializes the control parameter n (n=1,2,3,4) and sets n=1.

[0058] In S9, the ECU8 determines whether the inverter temperature Tn is greater than the reference temperature Tref. If the inverter temperature Tn (Tn=T1,T2,T3,T4) is greater than the reference temperature Tref (YES in S9), the ECU8 proceeds to S11 and executes the nth suppression control. On the other hand, if the inverter temperature Tn is less than or equal to the reference temperature Tref (NO in S9), the ECU8 proceeds to S10.

[0059] In S10, the ECU8 determines whether the motor current In (In=I1,I2,I3,I4) is greater than the reference current Iref. If the motor current In is greater than the reference current Iref (YES in S10), the ECU8 proceeds to S11 and executes the nth suppression control. On the other hand, if the motor current In is less than or equal to the reference current Iref (NO in S10), the ECU8 skips S11 and proceeds to S12 without executing the nth suppression control.

[0060] In S12, ECU8 increments the control parameter by 1.

[0061] In S13, the ECU8 determines whether the control parameter n is greater than 4. If the control parameter n is 4 or less (NO in S13), the ECU8 returns to S9. This process is repeated until n=4. If the control parameter n is greater than 4 (YES in S13), the ECU8 terminates the series of processes.

[0062] Figure 6 is a conceptual diagram illustrating post-distribution suppression control. The upper horizontal axis represents the inverter temperature Tn. The lower horizontal axis represents the motor current In. The vertical axis represents power. The upper part represents the dischargeable power MWout(n) after distribution from battery pack 6 to each unit n=1, 2, 3, and 4, and the lower part represents the chargeable power MWin(n) after distribution from each unit to battery pack 6.

[0063] A representative explanation is given for the control parameter n=1. When the inverter temperature T1 exceeds the reference temperature Tref, the ECU8 starts suppressing the distributed dischargeable power MWout(n=1) for the right front unit 1, and when the inverter temperature T1 exceeds the maximum temperature Tmax, it sets the distributed dischargeable power MWout(n=1) to 0 (i.e., prohibits discharge from the battery pack 6 to the first inverter 11). Also, when the inverter temperature T1 exceeds the reference temperature Tref, the ECU8 starts suppressing the distributed chargeable power MWin(n=1) for the right front unit 1, and when the inverter temperature T1 exceeds the maximum temperature Tmax, it sets the distributed chargeable power MWin(n=1) to 0 (i.e., prohibits charging from the first inverter 11 to the battery pack 6).

[0064] Similarly, when the motor current I1 exceeds the reference current Iref, the ECU8 starts suppressing the distributed dischargeable power MWout(n=1), and when the motor current I1 exceeds the maximum current Imax, it sets the distributed dischargeable power MWout(n=1) to 0. In addition, when the motor current I1 exceeds the reference current Iref, the ECU8 starts suppressing the distributed chargeable power MWin(n=1), and when the motor current I1 exceeds the maximum current Imax, it sets the distributed chargeable power MWin(n=1) to 0.

[0065] Here, we have described the control parameter n=1, but the same applies to n=2, 3, and 4. This allows the power that can be discharged after distribution MWout(n) and the power that can be charged after distribution MWin(n) to be controlled independently between the right front unit 1, the right rear unit 2, the left front unit 3, and the left rear unit 4.

[0066] The execution order of the total suppression control (S1-S5) and the post-distribution suppression control (S6-S13) may be swapped. Alternatively, the total suppression control and post-distribution suppression control may be executed completely independently of each other in separate flows.

[0067] As described above, in this embodiment, the ECU8 performs post-distribution suppression control, including the first to fourth suppression control. In the first to fourth suppression control, for each unit n=1 to 4, it is determined whether the temperature (inverter temperature Tn) or current (motor current In) of the unit exceeds a standard. If the temperature or current of the unit exceeds the standard, the discharge power from the battery pack 6 to the unit (post-distribution dischargeable power MWout(n)) and the charge power from the unit to the battery pack 6 (post-distribution chargeable power MWin(n)) are suppressed independently of the other units. The discharge power or charge power of all units will not be uniformly suppressed just because the temperature or current of some units exceeds the standard. Therefore, according to this embodiment, the necessary drive performance can be ensured while protecting units n=1 to 4 from overheating or overcurrent.

[0068] In addition, an example was described in which the ECU8 controls both the dischargeable power MWout(n) and the rechargeable power MWin(n) after distribution in the post-distribution suppression control. However, the ECU8 may also control only the dischargeable power MWout(n) after distribution in the post-distribution suppression control. This is because overheating or overcurrent in units n=1 to 4 mainly occurs when the battery pack 6 discharges to the unit.

[0069] Furthermore, an example was described in which the ECU8 performs post-distribution suppression control for all units n=1 to 4. However, the ECU8 may perform post-distribution suppression control for only two or three of the four units. For example, the ECU8 may perform post-distribution suppression control only for the front units n=1 and n=3 that drive the front wheels, or only for the rear units n=2 and n=4 that drive the rear wheels.

[0070] The ECU8 does not necessarily have to perform total suppression control. However, by performing total suppression control, it is possible to ensure the necessary drive performance while appropriately protecting the four units n=1 to 4, as well as the battery pack 6.

[0071] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of this disclosure is indicated by the claims rather than by the description of the embodiments above, and all modifications within the meaning and scope equivalent to the claims are intended to be included. [Explanation of Symbols]

[0072] 100 Vehicle, 1 Right front unit, 11 First inverter, 12 First motor generator, 13 First transaxle, 2 Right rear unit, 21 Second inverter, 22 Second motor generator, 23 Second transaxle, 3 Left front unit, 31 Third inverter, 32 Third motor generator, 33 Third transaxle, 4 Left rear unit, 41 Fourth inverter, 42 Fourth motor generator, 43 Fourth transaxle, 5 Sensor group, 511, 521, 531, 541 Temperature sensor, 512, 522, 532, 542 Current sensor, 6 Battery pack, 61 Battery voltage sensor, 62 Battery current sensor, 63 Battery temperature sensor, 71, 72, 73, 74 Drive wheels, 8 ECU, 81 Processor, 82 Memory, 9 Drive system.

Claims

1. A drive system mounted on a vehicle, including a battery and first drive wheels and second drive wheels, A first drive unit that drives the first drive wheel using the discharge power from the battery, A second drive unit that drives the second drive wheel using the discharge power from the aforementioned battery, A first sensor that detects the temperature or current of the first drive device and outputs a first detected value, A second sensor that detects the temperature or current of the second drive device and outputs a second detected value, The system includes a control device configured to perform a first suppression control that suppresses the first discharge power from the battery to the first drive unit according to the first detected value, and a second suppression control that suppresses the second discharge power from the battery to the second drive unit according to the second detected value. The control device is a drive system that independently executes the first suppression control and the second suppression control.

2. In the first suppression control and the second suppression control, the control device is If the first detected value exceeds the first reference value and the second detected value exceeds the second reference value, both the first discharge power and the second discharge power are suppressed. If the first detected value exceeds the first reference value and the second detected value falls below the second reference value, the first discharge power is suppressed while the second discharge power is not suppressed. If the first detected value falls below the first reference value and the second detected value exceeds the second reference value, the first discharge power is not suppressed, while the second discharge power is suppressed. The drive system according to claim 1, wherein if the first detected value falls below the first reference value and the second detected value falls below the second reference value, neither the first discharge power nor the second discharge power is suppressed.

3. The control device is configured to perform total suppression control, which suppresses the total discharge power from the battery to the first drive unit and the second drive unit according to the battery temperature or SOC. The drive system according to claim 1 or 2, wherein the control device independently performs the total suppression control, the first suppression control, and the second suppression control.

4. The vehicle further includes a third drive wheel and a fourth drive wheel, The aforementioned drive system is A third drive unit that drives the third drive wheel using the discharge power from the battery, A fourth drive unit that drives the fourth drive wheel using the discharge power from the battery, A third sensor that detects the temperature or current of the third drive device and outputs a third detection value, The system further includes a fourth sensor that detects the temperature or current of the fourth drive unit and outputs a fourth detection value, The control device is configured to further perform a third suppression control that suppresses the third discharge power from the battery to the third drive unit according to the third detected value, and a fourth suppression control that suppresses the fourth discharge power from the battery to the fourth drive unit according to the fourth detected value. The drive system according to claim 3, wherein the control device independently performs the total suppression control, the first suppression control, the second suppression control, the third suppression control, and the fourth suppression control.

5. The drive system according to claim 4, The aforementioned battery, A vehicle comprising the first drive wheel, the second drive wheel, the third drive wheel, and the fourth drive wheel.

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