Electric vehicle

Abstract

To suppress imposing of drive limit to a main driving motor before a sub-driving motor.SOLUTION: An electric vehicle includes: a first drive apparatus having a sub-driving first motor; a first drive circuit for driving the first motor; a first cooling apparatus for cooling the first drive apparatus; a second drive apparatus having a main driving second motor; a second drive circuit for driving the second motor; a second cooling apparatus for cooling the second drive apparatus; a third cooling apparatus for circulating a heat exchange medium in the first drive circuit, the second drive circuit, the second cooling apparatus and the first cooling apparatus in this order; and a control apparatus. The control apparatus adjusts a circulation volume of the first heat exchange medium on the basis of a first margin temperature representing a difference between a temperature of the first cooling medium and a first predefined temperature, and a third margin temperature representing a difference between a temperature of a third cooling medium in the first cooling apparatus and a third predefined temperature.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to an electric vehicle, and more particularly to an electric vehicle equipped with two motors, two inverters that drive the two motors, and a cooling device that cools the two motors and the two inverters. [Background technology]

[0002] Conventionally, this type of electric vehicle has been proposed to include a motor, an oil cooler that cools the motor, an inverter that drives the motor, and a cooling device that cools the oil cooler and the inverter (see, for example, Patent Document 1). In this vehicle's cooling device, a heat exchange medium cooled by a radiator flows through the inverter and then the oil cooler, and controls the start, increase, decrease, and stop of oil circulation in the oil cooler based on the temperature of the inverter or the temperature of the heat exchange medium. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-129632 Summary of the Invention [Problem to be solved by the invention]

[0004] In an electric vehicle equipped with a rear-wheel drive motor (main drive) and a front-wheel drive motor (auxiliary drive), an oil cooler for cooling the rear-wheel drive motor and an inverter for driving the rear-wheel drive motor are disposed near the rear-wheel drive motor, and an oil cooler for cooling the front-wheel drive motor and an inverter for driving the rear-wheel drive motor are disposed near the front-wheel drive motor. To cool these components, a heat exchange medium cooled by a radiator is circulated through the inverter for driving the front-wheel drive motor, the inverter for driving the rear-wheel drive motor, the oil cooler for cooling the rear-wheel drive motor, and the oil cooler for cooling the front-wheel drive motor in that order. In this case, depending on the adjustment of the oil circulation rate through the oil cooler for cooling the front-wheel drive motor, overheating of the inverter for driving the rear-wheel drive motor and the oil cooler for cooling the rear-wheel drive motor may cause the output torque of the rear-wheel drive motor (main drive) to be limited before that of the front-wheel drive motor (auxiliary drive), resulting in a worsening driving feel.

[0005] The electric vehicle of the present disclosure has a primary object to prevent drive limitations from being imposed on the main drive motor before those on the auxiliary drive motor. [Means for solving the problem]

[0006] The electric vehicle of the present disclosure employs the following measures to achieve the above-mentioned main object.

[0007] The electric vehicle of the present disclosure includes: a first drive device having a first motor for auxiliary driving; a first drive circuit that drives the first motor; a first cooling device that cools the first driving device using a first heat exchange medium; a second drive unit having a second motor for main drive; a second drive circuit that drives the second motor; a second cooling device that cools the second driving device using a second heat exchange medium; a third cooling device that circulates a third heat exchange medium through the first drive circuit, the second drive circuit, the second cooling device, and the first cooling device in this order; a control device that controls the first cooling device, the second cooling device, the third cooling device, the first motor, and the second motor; An electric vehicle comprising: the control device adjusts the circulation amount of the first heat exchange medium based on a first margin temperature as a difference between the temperature of the first cooling medium and a first predetermined temperature and a third margin temperature as a difference between the temperature of the third cooling medium in the first cooling device and a third predetermined temperature. It is characterized by:

[0008] In the electric vehicle disclosed herein, the third cooling device circulates the third heat exchange medium in the following order: a first drive circuit that drives a first auxiliary drive motor; a second drive circuit that drives a second main drive motor; a second cooling device that cools a second drive unit having the second motor using a second heat exchange medium; and a first cooling device that cools a first drive unit having the first motor using a first heat exchange medium. The control device adjusts the circulation amount of the first heat exchange medium based on a first margin temperature, which is the difference between the temperature of the first cooling medium and the first predetermined temperature, and a third margin temperature, which is the difference between the temperature of the third cooling medium in the first cooling unit and the third predetermined temperature. By more appropriately adjusting the first predetermined temperature and the first heat exchange medium, it is possible to limit the drive of the first auxiliary drive motor before the drive of the second main drive motor. This makes it possible to prevent the drive limit from being imposed on the second main drive motor before the first auxiliary drive motor. Here, the first and third predetermined temperatures may be lower limit temperatures that impose drive restrictions on the first motor.

[0009] In the electric vehicle disclosed herein, the control device may control the circulation amount of the first heat exchange medium to increase as the first margin temperature decreases and to increase as the third margin temperature decreases, based on the fact that the smaller the first margin temperature is, the greater the need to cool the first motor, and the smaller the third margin temperature is, the greater the need to cool the first motor.

[0010] In the electric vehicle disclosed herein, the control device may impose a drive limit on the first motor when the temperature of the first cooling medium is equal to or higher than a first predetermined temperature or when the temperature of the third cooling medium is equal to or higher than the third predetermined temperature. By imposing a drive limit on the first motor used for auxiliary driving in this manner, the drive limit on the second motor used for main driving can be delayed. In this case, the control device may cut the drive force of the first drive device when the temperature of the first cooling medium is equal to or higher than a first specific temperature higher than the first predetermined temperature or when the temperature of the third cooling medium in the first cooling device is equal to or higher than a third specific temperature higher than the third predetermined temperature. In this way, the drive limit on the second motor used for main driving can be delayed or relaxed.

[0011] In the electric vehicle disclosed herein, the control device may control the circulation amount of the second heat exchange medium based on a second margin temperature, which is the difference between the temperature of the second cooling medium and a second predetermined temperature, and a fourth margin temperature, which is the difference between the temperature of the third cooling medium in the second cooling device. This allows for more appropriate drive restriction of the second main drive motor. In this case, the control device may adjust the circulation amount of the second heat exchange medium so that the smaller the second margin temperature is, the greater the circulation amount of the second heat exchange medium, and so that the smaller the third margin temperature is, the greater the need for cooling the second motor. This is based on the fact that the smaller the second margin temperature is, the greater the need for cooling the second motor, and the smaller the fourth margin temperature is, the greater the need for cooling the second motor. The control device may also impose a drive restriction on the second motor when the temperature of the second cooling medium is equal to or higher than the second predetermined temperature. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a configuration diagram showing an outline of the configuration of an electric vehicle according to an embodiment of the present disclosure. [Figure 2] 6 is a flowchart showing an example of a first oil pump process executed by an electronic control unit 70. [Figure 3]6 is a flowchart showing an example of a second oil pump process executed by an electronic control unit 70. [Figure 4] 10 is a flowchart showing an example of a motor limiting process executed by an electronic control unit 70. [Figure 5] FIG. 4 is an explanatory diagram showing an example of a drive duty setting map. [Figure 6] 10 is an explanatory diagram showing an example of the relationship between the first oil temperature To1, the first coolant temperature Tw1, and the drive force limit of the first motor 31, and the relationship between the second oil temperature To2, the second coolant temperature Tw2, and the drive force limit of the second motor 41. DETAILED DESCRIPTION OF THE INVENTION

[0013] Next, a mode (embodiment) for carrying out the present disclosure will be described. Fig. 1 is a configuration diagram showing an outline of the configuration of an electric vehicle 20 according to one embodiment of the present disclosure. The electric vehicle 20 of the embodiment includes a first drive unit 30 for auxiliary drive that drives the front wheels, a first power control unit (hereinafter referred to as the first PCU) 33 that drives the first drive unit 30, a first cooling device 34 that cools the first drive unit 30, a second drive unit 40 for main drive that drives the rear wheels, a second power control unit (hereinafter referred to as the second PCU) 43 that drives the second drive unit 40, a second cooling device 43 that cools the second drive unit 40, a third cooling device 60, and an electronic control unit 70.

[0014] The first drive device 30 is disposed at the front of the vehicle and includes a first motor 31 and a first gear unit 32. The first motor 31 is configured as, for example, a synchronous generator motor or the like, and is connected to the first gear unit 32. The first gear unit 32 is configured as a gear mechanism such as a reduction gear or a differential gear, and is connected to front wheels 39a, 39b. Note that the first gear unit 32 is provided with a clutch (not shown) on the side of the front wheels 39a, 39b, so that the first motor 31 and the first gear unit 32 can be disconnected from the front wheels 39a, 39b.

[0015] The first PCU 33 is configured as a drive circuit that boosts power from a battery (not shown), converts it into three-phase AC, and applies it to the first motor 31, and is configured, for example, by a well-known boost circuit or a well-known inverter. The first PCU 33 is arranged around the first drive device 30.

[0016] The first cooling device 34 is disposed adjacent to the first drive device 30 and includes a first oil cooler 35 that supplies cooled oil to the first motor 31 and the first gear unit 32 through a circulation flow path 36. A first temperature sensor 38 that detects the oil temperature (first oil temperature) To1 and a first oil pump 37 that adjusts the amount of oil circulated are attached to the circulation flow path 36 near the outlet of the first oil cooler 35. The cooling oil also functions as lubricating oil.

[0017] The second drive device 40 is disposed at the rear of the vehicle and includes a second motor 41 and a second gear unit 42. The second motor 41 is configured as, for example, a synchronous generator motor, and is connected to the second gear unit 42. The second gear unit 42 is configured as a gear mechanism such as a reduction gear or a differential gear, and is connected to rear wheels 49a, 49b.

[0018] The second PCU 43 is configured as a drive circuit that boosts power from a battery (not shown), converts it into three-phase AC, and applies it to the second motor 41, and is configured, for example, by a well-known boost circuit or a well-known inverter. The second PCU 43 is arranged around the second drive device 40.

[0019] The second cooling device 44 is disposed adjacent to the second drive device 40 and includes a second oil cooler 45 that supplies cooled oil to the second motor 41 and the second gear unit 42 through a circulation flow path 46. A second temperature sensor 48 that detects the oil temperature (second oil temperature) To2 and a second oil pump 47 that adjusts the amount of oil circulated are attached to the circulation flow path 46 near the outlet of the second oil cooler 45. The cooling oil also functions as lubricating oil.

[0020] The third cooling device 60 includes a radiator 61 disposed at the front of the vehicle, a circulation flow path 62, and a water pump 63 that circulates cooling water. The cooling water flows from the radiator 61 through the water pump 63, a cooling flow path formed in the first PCU 33, a cooling flow path formed in the second PCU 43, a cooling flow path formed in the second oil cooler 45, a cooling flow path formed in the first oil cooler 35, and the radiator 61 in this order, cooling the boost circuit and inverter of the first PCU 33, the boost circuit and inverter of the second PCU 43, the oil in the second oil cooler 45, and the oil in the first oil cooler 35, in that order. Temperature sensors 64, 65, and 66 are attached to the circulation flow path 62 near the outlet of the radiator 61, near the outlet of the first oil cooler 35, and near the inlet of the second oil cooler 45.

[0021] The electronic control unit 70 is configured with a microcomputer centered around a CPU (not shown). The electronic control unit 70 receives as input the first oil temperature To1 from the first temperature sensor 38, the second oil temperature To2 from the second temperature sensor 48, and the coolant temperature Tw0, first coolant temperature Tw1, and second coolant temperature Tw2 from the temperature sensors 64, 65, and 66. The electronic control unit 70 outputs a drive control signal to the first oil pump 37, a drive control signal to the second oil pump, and a drive control signal to the water pump 61. The electronic control unit 70 also controls the drive of the electric vehicle 20. For this reason, the electronic control unit 70 also receives inputs such as the shift position SP, accelerator opening Acc, brake pedal position BP, three-phase currents I1u, I1v, I1w applied to the first motor 31, and three-phase currents I2u, I2v, I2w applied to the second motor 41, and outputs switching control signals for switching the switching elements of the boost circuit and inverter of the first PCU 33, and switching control signals for switching the switching elements of the boost circuit and inverter of the second PCU 43.

[0022] Next, the operation of the electric vehicle 20 configured as described above will be described, in particular the operation of the first oil pump 37 and the second oil pump 47, and the operation when imposing drive force limits on the first drive device 30 and the second drive device 40. Fig. 2 is a flowchart showing an example of a first oil pump process executed by the electronic control unit 70 to set the drive duty D1 of the first oil pump 37, Fig. 3 is a flowchart showing an example of a second oil pump process executed by the electronic control unit 70 to set the drive duty D2 of the second oil pump 47, and Fig. 4 is a flowchart showing an example of a motor limiting process executed by the electronic control unit 70. These will be described in order below.

[0023] When the first oil pump process of FIG. 2 is executed, the electronic control unit 70 first executes a process of inputting data necessary for setting the drive duty D1 of the first oil pump 37, such as the first oil temperature To1 from the first temperature sensor 38 and the first coolant temperature Tw1 from the temperature sensor 65 (step S100). Next, the electronic control unit 70 calculates a first margin temperature ΔT1 by subtracting the first oil temperature To1 from a first predetermined value Tref1 (step S110), and calculates a third margin temperature ΔT3 by subtracting the first coolant temperature Tw1 from a third predetermined value Tref3 (step S120). The first predetermined value Tref1 is set as the lower limit oil temperature near the outlet of the first oil cooler 35, which imposes a drive force limit on the first drive device 30. The third predetermined value Tref3 is set as the lower limit coolant temperature near the inlet of the first oil cooler 35, which imposes a drive force limit on the first drive device 30.

[0024] Next, the drive duty D1 of the first oil pump 37 is set based on the first margin temperature ΔT1 and the third margin temperature ΔT3 (step S130), and the process ends. In this embodiment, the relationship between the first margin temperature ΔT1, the third margin temperature ΔT3, and the drive duty D1 is determined in advance through experiments, machine learning, or the like and stored as a drive duty setting map. When the first margin temperature ΔT1 and the third margin temperature ΔT3 are given, the corresponding drive duty D1 is derived from the map and set. FIG. 5 shows an example of the drive duty setting map. As shown in the figure, the drive duty D1 is set to increase as the first margin temperature ΔT1 decreases and as the third margin temperature ΔT3 decreases. This is based on the fact that the degree of cooling of the first drive unit 30 increases as the first margin temperature ΔT1 decreases and as the third margin temperature ΔT3 decreases.

[0025] When the second oil pump process of FIG. 3 is executed, the electronic control unit 70 first executes a process of inputting data necessary for setting the drive duty D2 of the second oil pump 47, such as the second oil temperature To2 from the second temperature sensor 48 and the second coolant temperature Tw2 from the temperature sensor 66 (step S200). Next, the electronic control unit 70 calculates a second margin temperature ΔT2 by subtracting the second oil temperature To2 from a second predetermined value Tref2 (step S210), and calculates a fourth margin temperature ΔT4 by subtracting the second coolant temperature Tw2 from a fourth predetermined value Tref4 (step S220). The second predetermined value Tref2 is set as the lower limit oil temperature near the outlet of the second oil cooler 45, which imposes a drive force limit on the second drive unit 40. The fourth predetermined value Tref4 is set as the lower limit coolant temperature near the inlet of the second oil cooler 45, which imposes a drive force limit on the second drive unit 40.

[0026] Next, the drive duty D2 of the second oil pump 47 is set based on the second margin temperature ΔT2 and the fourth margin temperature ΔT4 (step S330), and the process ends. In this embodiment, the relationship between the second margin temperature ΔT2, the fourth margin temperature ΔT4, and the drive duty D2 is determined in advance through experiments, machine learning, or the like and stored as a drive duty setting map. When the second margin temperature ΔT2 and the fourth margin temperature ΔT4 are given, the corresponding drive duty D2 is derived from the map and set. The drive duty D2 of the second oil pump 47 can also be determined using the drive duty setting map shown in FIG. 5. As shown in the figure, the drive duty D2 is set to increase as the second margin temperature ΔT2 decreases and as the fourth margin temperature ΔT4 decreases. This is based on the fact that the degree of cooling of the second drive unit 40 increases as the second margin temperature ΔT2 decreases and as the fourth margin temperature ΔT4 decreases.

[0027] 4, the electronic control unit 70 first executes a process of inputting data necessary to impose a driving force limit on the first motor 31 and the second motor 41, such as the first coolant temperature Tw1 from the temperature sensor 65, the second coolant temperature Tw2 from the temperature sensor 66, the first oil temperature To1 from the first temperature sensor 38, and the second oil temperature To2 from the second temperature sensor 48 (step S300).

[0028] Next, it is determined whether the first oil temperature To1 is equal to or greater than a first predetermined value Tref1 or whether the first cooling water temperature Tw1 is equal to or greater than a third predetermined value Tref3 (step S310), and it is also determined whether the first oil temperature To1 is less than a first specific value Tset1 or whether the first cooling water temperature Tw1 is less than a third specific value Tset3 (step S320). Here, the first specific value Tset1 is set as the lower limit oil temperature near the outlet of the first oil cooler 35 at which a driving force cut (driving force value 0) is imposed on the first drive device 30, and is a value greater than the first predetermined value Tref1. The third specific value Tset3 is set as the lower limit cooling water temperature near the inlet of the first oil cooler 35 at which a driving force cut is imposed on the first drive device 30, and is a value greater than the third predetermined value Tref3.

[0029] When it is determined in steps S310 and S320 that the first cooling water temperature Tw1 is less than the third specific value Tset3 and the first oil temperature To1 is equal to or greater than the first predetermined value Tref but less than the first specific value Tset1, or when it is determined that the first oil temperature To1 is less than the first specific value Tset1 and the first cooling water temperature Tw1 is equal to or greater than the third predetermined value Tref3 but less than the third specific value Tset3, a driving force limit is imposed on the first motor 31 (first drive device 30) (step S330). The driving force limit is preferably imposed so as to increase as the first oil temperature To1 increases and as the first cooling water temperature Tw1 increases.

[0030] When it is determined in step S320 that the first oil temperature To1 is equal to or greater than the first specific value Tset1 or the first cooling water temperature Tw1 is equal to or greater than the third specific value Tset3, a drive force cut is imposed on the first motor 31 (first drive device 30) (step S340). The drive force cut can be performed by disengaging a clutch (not shown) of the first gear unit 32 to disconnect the first drive device 30 from the front wheels 39a, 39b.

[0031] When the first oil temperature To1 is lower than the first predetermined value Tref1 and the first coolant temperature Tw1 is lower than the first predetermined value Tref1, no drive force limitation is imposed on the first motor 31.

[0032] Next, it is determined whether the second oil temperature To2 is equal to or greater than the second predetermined value Tref2 or whether the second coolant temperature Tw2 is equal to or greater than the fourth predetermined value Tref4 (step S350). When it is determined that the second oil temperature To2 is equal to or greater than the second predetermined value Tref2 or when it is determined that the second coolant temperature Tw2 is equal to or greater than the fourth predetermined value Tref4, a driving force limit is imposed on the second motor 41 (second drive device 40) (step S360), and this process ends. Note that when it is determined that the second oil temperature To2 is less than the second predetermined value Tref2 and the second coolant temperature Tw2 is less than the fourth predetermined value Tref4, no driving force limit is imposed on the second motor 41 (second drive device 40).

[0033] FIG. 6 shows an example of the relationship between the first oil temperature To1, the first coolant temperature Tw1, and the drive force limit of the first motor 31, as well as the relationship between the second oil temperature To2, the second coolant temperature Tw2, and the drive force limit of the second motor 41. In the example of FIG. 6, the first specific value Tset1 and the third specific value Tset3 used when cutting the drive force of the first motor 31 are the same as the second specific value Tref2 and the fourth specific value Tref4 used when limiting the drive force of the second motor 41. The drive force limit of the first motor 31 is imposed in the range from the first specific value Tref1 to the first specific value Tset1 and in the range from the third specific value Tref3 to the third specific value Tset3, and the drive force is cut in the range equal to or greater than the first specific value Tset1 and the range equal to or greater than the third specific value Tset3. The drive force limit of the second motor 41 is imposed in the range in which the drive force of the first motor 31 is cut.

[0034] In the electric vehicle 20 of the embodiment described above, cooling water flows in the following order: the first PCU 33 that drives the first drive unit 30 (auxiliary drive unit) that drives the front wheels; the second PCU 43 that drives the second drive unit 40 (main drive unit) that drives the rear wheels; the second oil cooler 45 of the second cooling unit 44 that cools the second drive unit 40; and the first oil cooler 35 of the first cooling unit 34 that cools the first drive unit 30. The drive duty D1 of the first oil pump 37 is set to increase as the first margin temperature ΔT1 decreases and as the third margin temperature ΔT3 decreases. The drive duty D2 of the second oil pump 47 is set to increase as the second margin temperature ΔT2 decreases and as the fourth margin temperature ΔT4 decreases. By appropriately setting the predetermined values ​​Tref1 to Tref4 and the specific values ​​Tset1 and Tset3, it is possible to limit the driving force of the first auxiliary driving motor 31 before that of the second main driving motor 41. This makes it possible to prevent the driving force limit from being imposed on the second main driving motor 41 before that of the first auxiliary driving motor 31.

[0035] 6, in the electric vehicle 20 of this embodiment, the first specific value Tset1 and the third specific value Tset3 used when cutting the driving force of the first motor 31 are the same as the second predetermined value Tref2 and the fourth predetermined value Tref4 used when limiting the driving force of the second motor 41. However, the second predetermined value Tref2 and the fourth predetermined value Tref4 used when limiting the driving force of the second motor 41 may be different from the first specific value Tset1 and the third specific value Tset3 used when cutting the driving force of the first motor 31. In this case, in order to impose a driving force limit on the second motor 41 for main driving before the first motor 31 for auxiliary driving, the second predetermined value Tref2 may be set to a value larger than the first predetermined value Tref1, and the fourth predetermined value Tref4 may be set to a value larger than the third predetermined value Treef3.

[0036] In the electric vehicle 20 of the embodiment, the temperature near the outlet of the first oil cooler 35 (first oil temperature To1) is used as the oil temperature of the first cooling device 34, but the temperature near the inlet of the first oil cooler 35 may also be used. Similarly, the temperature near the inlet of the second oil cooler 45 may also be used as the oil temperature of the second cooling device 44.

[0037] The correspondence between the main elements of the embodiment and the main elements of the invention described in the "Means for Solving the Problem" section will be described below. In the embodiment, the first motor 31 corresponds to the "first motor," the first drive device 30 corresponds to the "first drive device," the first PCU 33 corresponds to the "first drive circuit," the first cooling device 34 corresponds to the "first cooling device," the second motor 41 corresponds to the "second motor," the second drive device 40 corresponds to the "second drive device," the second PCU 43 corresponds to the "second drive circuit," the second cooling device 44 corresponds to the "second cooling device," the third cooling device 60 corresponds to the "third cooling device," and the electronic control unit 70 corresponds to the "control device."

[0038] The correspondence between the main elements of the embodiments and the main elements of the invention described in the "Means for Solving the Problem" section does not limit the elements of the invention described in the "Means for Solving the Problem" section, since the embodiments are examples for specifically explaining the mode for implementing the invention described in the "Means for Solving the Problem" section. In other words, the interpretation of the invention described in the "Means for Solving the Problem" section should be based on the description in that section, and the embodiments are merely specific examples of the invention described in the "Means for Solving the Problem" section.

[0039] The present disclosure has been described above using embodiments, but the present disclosure is not limited to these embodiments in any way, and it goes without saying that the present disclosure can be embodied in various forms within the scope that does not deviate from the gist of the present disclosure. [Industrial Applicability]

[0040] The present disclosure is applicable to the electric vehicle 20 manufacturing industry and the like. [Explanation of symbols]

[0041] 20 electric vehicle, 30 first drive unit, 31 first motor, 32 first gear unit, 33 first PCU, 34 first cooling unit, 35 first oil cooler, 36 circulation flow path, 37 first oil pump, 38 first temperature sensor, 39a, 39b front wheels, 40 second drive unit, 41 second motor, 42 second gear unit, 43 second PCU, 44 second cooling unit, 45 second oil cooler, 46 circulation flow path, 47 second oil pump, 48 second temperature sensor, 49a, 49b rear wheels, 60 third cooling unit, 61 radiator, 62 circulation flow path, 63 water pump, 64, 65, 66 temperature sensors, 70 electronic control unit.

Claims

1. a first drive device having a first motor for auxiliary driving; a first drive circuit that drives the first motor; a first cooling device that cools the first driving device using a first heat exchange medium; a second drive unit having a second motor for main drive; a second drive circuit that drives the second motor; a second cooling device that cools the second driving device using a second heat exchange medium; a third cooling device that circulates a third heat exchange medium through the first drive circuit, the second drive circuit, the second cooling device, and the first cooling device in this order; a control device that controls the first cooling device, the second cooling device, the third cooling device, the first motor, and the second motor; An electric vehicle comprising: the control device adjusts the circulation amount of the first heat exchange medium based on a first margin temperature as a difference between a temperature of the first cooling medium and a first predetermined temperature and a third margin temperature as a difference between a temperature of the third cooling medium in the first cooling device and a third predetermined temperature. An electric vehicle characterized by:

2. The electric vehicle according to claim 1, the control device controls the circulation amount of the first heat exchange medium to be increased as the first margin temperature is smaller and the circulation amount of the first heat exchange medium to be increased as the third margin temperature is smaller. Electric car.

3. The electric vehicle according to claim 1, the control device imposes a drive restriction on the first motor when the temperature of the first cooling medium is equal to or higher than a first predetermined temperature or when the temperature of the third cooling medium is equal to or higher than the third predetermined temperature; Electric car.

4. The electric vehicle according to claim 3, the control device cuts off the driving force of the first drive device when the temperature of the first cooling medium is equal to or higher than a first specific temperature that is higher than the first predetermined temperature or when the temperature of the third cooling medium in the first cooling device is equal to or higher than a third specific temperature that is higher than the third predetermined temperature. Electric car.

5. An electric vehicle according to any one of claims 1 to 4, the control device controls the circulation amount of the second heat exchange medium based on a second margin temperature as a difference between the temperature of the second cooling medium and a second predetermined temperature and a fourth margin temperature as a difference between the temperature of the third cooling medium in the second cooling device. Electric car.

6. The electric vehicle according to claim 5, the control device adjusts the circulation amount of the second heat exchange medium so that the smaller the second margin temperature is, the larger the circulation amount of the second heat exchange medium becomes, and the smaller the third margin temperature is, the larger the circulation amount of the second heat exchange medium becomes. Electric car.

7. The electric vehicle according to claim 5, the control device imposes a drive restriction on the second motor when the temperature of the second cooling medium is equal to or higher than the second predetermined temperature. Electric car.

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