Cooling device for inverter

Abstract

To efficiently cool an inverter.SOLUTION: In an electric vehicle 1 having a driving motor M, a generator 5, an inverter 10 including a plurality of power modules and a cooling device 20 for cooling the inverter 10, the cooling device 20 includes a refrigerant passage 22, a pump 21 for sending out a refrigerant and a valve gear 23 provided in a refrigerant passage 22, and the power module includes a voltage control unit 11 that controls voltage supplied to the drive motor M, a motor control unit 12 that controls rotation of the drive motor M and a power generator control unit 13 that controls electric power generation by using the generator 5. In the electric vehicle, the valve gear 23 enables switching between a first state where the refrigerant is supplied to all of the voltage control unit 11, the motor control unit 12 and the power generator control unit 13 and a second state where a supply amount of the refrigerant to the motor control unit 12 or the power generator control unit 13 is restricted compared to the first state.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a cooling device for an inverter used in an electric vehicle. [Background technology]

[0002] In electric vehicles equipped with a motor as a driving source, the motor is driven by electricity stored in a battery or electricity generated while the vehicle is traveling. The motor also functions as a generator to generate regenerative power, mainly during coasting. This motor is controlled through an inverter.

[0003] Inverters mounted on electric vehicles are cooled by a refrigerant such as water, as shown in Patent Document 1. In particular, it is important to keep the inverter within an appropriate temperature range because the power module (power semiconductor) mounted on the inverter plays a role in passing current, i.e., outputting torque, within a range that does not exceed a predetermined upper limit temperature. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2020-88180 Summary of the Invention [Problem to be solved by the invention]

[0005] Generally, inverters for electric vehicles (EVs) that do not have an engine as a driving source are composed of an MCU (Motor Control Unit) for driving the motor.In contrast, hybrid vehicles (HVs / PHEVs) that have an engine and a motor as a driving source for driving the vehicle have a power module located inside the inverter that includes an MCU for driving the motor as well as a GCU (Generator Control Unit) for driving the generator, and if there is a voltage step-up mechanism, a VCU (Voltage Control Unit) is also added.

[0006] In conventional hybrid vehicles (HV / PHEV), the VCU, MCU, and GCU are all constantly cooled, regardless of whether the generator is running or not. For this reason, for example, when driving in EV mode, the GCU, which does not actually need to be cooled, may be cooled. In order for the inverter to perform as expected, it is desirable for the inverter to be cooled efficiently at all times.

[0007] Therefore, an object of the present invention is to efficiently cool the inverter. [Means for solving the problem]

[0008] In order to solve the above problems, the present invention provides an electric vehicle having a drive motor and generator, an inverter including a plurality of power modules, and a cooling device that cools the inverter, wherein the cooling device has a refrigerant passage provided within the inverter, a pump that sends refrigerant to the refrigerant passage, and a valve device provided in the refrigerant passage, and the power module has a voltage control unit that controls the voltage supplied to the drive motor, a motor control unit that controls the rotation of the drive motor, and a generator control unit that controls power generation by the generator, and the valve device is switchable between a first state in which refrigerant is supplied to all of the voltage control unit, the motor control unit, and the generator control unit, and a second state in which the amount of refrigerant supplied to the motor control unit or the generator control unit is more limited than in the first state (Configuration 1).

[0009] In the configuration 1, the second state may be set to a third state in which refrigerant is supplied only to the voltage control unit and the motor control unit (configuration 2).

[0010] In addition, in the configuration 1, the second state can be set to a fourth state in which refrigerant is supplied only to the voltage control unit and the generator control unit (configuration 3).

[0011] In any one of the configurations 1 to 3, a configuration can be adopted in which the voltage control unit is disposed upstream of the motor control unit and / or the generator control unit (configuration 4).

[0012] In any one of configurations 1 to 4, when the driving mode is an EV driving mode in which the vehicle is driven only by the driving force of the drive motor, a configuration can be adopted in which, under the second state, the supply of refrigerant to the generator control unit is stopped and control is performed to reduce the rotation speed of the pump (configuration 5).

[0013] In any one of configurations 1 to 5, when the driving mode is an EV driving mode in which the vehicle is driven only by the driving force of the drive motor, a configuration can be adopted in which the supply of refrigerant to the generator control unit is stopped under the second state, and control is performed to increase the flow rate of the refrigerant in the refrigerant passage (configuration 6).

[0014] In any one of configurations 1 to 6, an engine is provided as a driving source for driving, and when the driving mode is a parallel driving mode using the driving force of the engine and the motor shaft of the driving motor is disconnected from the rotating shaft on the drive wheel side, a configuration can be adopted in which the supply of refrigerant to the motor control unit is stopped under the second state and control is performed to reduce the rotation speed of the pump (configuration 7).

[0015] In any one of configurations 1 to 7, when the vehicle speed is in a low speed state below a predetermined value and the generator is generating electricity, a configuration can be adopted in which the supply of refrigerant to the motor control unit is stopped under the second state and control is performed to reduce the rotation speed of the pump (configuration 8). [Effects of the Invention]

[0016] According to the present invention, the inverter can be cooled efficiently. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is an overall view schematically illustrating a vehicle equipped with an inverter and a cooling device therefor according to an embodiment of the present invention; [Figure 2] FIG. 1 is a schematic diagram illustrating a cooling device for an inverter according to a first embodiment. [Figure 3] FIG. 10 is a schematic diagram illustrating a cooling device for an inverter according to a second embodiment. [Figure 4] FIG. 10 is a schematic diagram illustrating a cooling device for an inverter according to a third embodiment. [Figure 5] FIG. 10 is a schematic diagram showing a cooling device for an inverter according to a fourth embodiment. [Figure 6] 4 is a flowchart showing a control according to the first embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0018] An embodiment of the present invention will be described with reference to the drawings. This embodiment is a hybrid vehicle 1 (hereinafter referred to as vehicle 1) equipped with an inverter 10 that controls a drive motor M as a drive source for traveling, and a cooling device 20 for the inverter 10.

[0019] As shown in Fig. 1, a vehicle 1 is equipped with a drive motor M (hereinafter referred to as motor M) and an engine 4 as drive sources for traveling, and the front wheels 2 are driven by the motor M and the engine 4. In the embodiment, the front motor 31 is controlled by a single inverter 10, but a rear motor may also be controlled by a single inverter 10 instead of the front motor 31. Also, a rear motor may be provided separately from the front motor 31 and controlled by the same inverter 10, or a rear inverter different from the inverter 10 may be provided and each motor may be controlled by its own inverter.

[0020] The vehicle 1 also includes a battery (secondary battery) 30 that supplies power to the front motor 31, an accelerator sensor 6 that detects the amount of depression of the accelerator pedal by the driver, a steering sensor 7 that detects the amount of steering, a vehicle speed sensor that detects the speed of the vehicle 1, and various other sensors that acquire information necessary for the running of the vehicle 1. A generator 5 that generates electricity using the driving force of the engine 4 is provided adjacent to the engine 4. The electricity generated by the generator 5 is charged into the battery 30.

[0021] The front motor 31 is connected to the drive shaft of the front wheels 2 via a transmission 33. The output of the front motor 31 is controlled by an inverter 10, which converts between direct current and alternating current. The inverter 10 also has a boost mechanism that converts power from the battery 30 to a predetermined voltage required to drive the motor M. The drive torque of the front motor 31 is controlled by the inverter 10 via an electronic control unit 40 in response to input from the driver. The electronic control unit 40 also controls the gear shifting operation by the transmission 33 based on the vehicle speed, the amount of accelerator depression, etc. These controls are performed by a driving control unit 41 within the electronic control unit 40.

[0022] The vehicle 1 is set to three driving modes: an electric driving mode (hereinafter referred to as EV mode) in which the vehicle runs solely on the driving force of the motor M; a series driving mode in which the vehicle runs solely on the driving force of the motor M while generating electricity with the generator 5; and a parallel driving mode in which the engine 4 and the motor M are used as the driving source for running. The driving control unit 41 selects the optimal driving mode depending on the state and driving condition of the vehicle 1 at that time, the driver's requests, etc. The motor M, the engine 4, etc. are controlled depending on the selected driving mode.

[0023] As shown in FIG. 1, the inverter 10 includes, within a casing 14, power modules including a VCU 11 (Voltage Control Unit 11) for controlling the boosting by the boost mechanism, an MCU 12 (Motor Control Unit 12) for controlling the driving of the motor M, and a GCU 13 (Generator Control Unit 13) for controlling the driving of the generator 5.

[0024] Also, a cooling device 20 using a refrigerant is provided to cool the inverter 10. The cooling device 20 includes a refrigerant passage 22 connected to the casing 14, and a pump 21 that sends the refrigerant into the refrigerant passage 22. The refrigerant is supplied into the casing 14 by the action of the pump 21, causing the refrigerant to absorb heat from the internal power module and dissipate the heat absorbed by the refrigerant to the outside. The heat is dissipated to the outside by a heat dissipation unit (not shown), such as a radiator, provided midway through the refrigerant passage 22. In the embodiment, water is used as the refrigerant, but various fluid refrigerants made of other liquids such as oil or gases may also be used.

[0025] The casing 14 has an input section which is an inlet for the refrigerant and an output section which is an outlet for the refrigerant. The input section and the output section are equipped with nipples, and are connected to pipes for supplying the refrigerant to form a refrigerant passage 22. A valve device 23 capable of adjusting the flow rate is disposed at an appropriate position in the refrigerant passage 22. This valve device 23 is hereinafter referred to as a flow rate adjustment valve 23. By opening and closing the flow rate adjustment valve 23 or adjusting the opening degree, the flow path for supplying the refrigerant can be switched depending on the operating state (driving mode, etc.) of the vehicle 1. These controls are performed by an inverter cooling control section 42 in the electronic control unit 40.

[0026] The refrigerant passage 22 and the flow rate adjustment valve 23 are arranged so as to be switchable between a first state in which the refrigerant is supplied to all of the VCU 11, the MCU 12, and the GCU 13, and a second state in which the refrigerant is supplied to the VCU 11 while the amount of refrigerant supplied to the MCU 12 or the GCU 13 is limited more than in the first state. In the first state, the refrigerant is supplied to all the power modules as usual, and in the second state, cooling of the VCU 11, which generates a large amount of heat, is essential, while the amount of refrigerant supplied to the power modules with a lower priority than the other power modules is limited, thereby reducing cooling loss.

[0027] Cooling states that can be set as the second state include a third state in which refrigerant is supplied only to the VCU 11 and the MCU 12, a fourth state in which refrigerant is supplied only to the VCU 11 and the GCU 13, and a fifth state in which refrigerant is supplied to the VCU 11 while different amounts of refrigerant are supplied to the MCU 12 and the GCU 13. That is, the second state is intended to adjust the degree of cooling for the MCU 12 that controls the motor M and the degree of cooling for the GCU 13 that controls the generator 5 according to the operating state of the vehicle 1. This allows, for example, prioritizing cooling of the MCU 12 when driving in EV mode, thereby improving power performance. Furthermore, for example, cooling the GCU 13 when driving the generator 5 allows improving power generation performance.

[0028] (First embodiment) 2 shows the main components of the first embodiment. Since the vehicle 1 has a boost mechanism, the VCU 11 is used frequently. For this reason, the VCU 11 is arranged upstream of the MCU 12. By arranging the VCU 11, which is used frequently, upstream, the VCU 11 can be cooled efficiently.

[0029] In the embodiment shown in FIG. 2, the refrigerant passage 22 is formed such that an upstream passage 22a extending from the pump 21 branches into a first passage 22b and a second passage 22c within the casing 14 (the casing 14 is not shown in FIG. 2; the same applies to other embodiments described below). The first passage 22b passes through the VCU 11 and the MCU 12 in this order to reach the downstream passage 22d. The second passage 22c passes through the first valve device 23a and the GCU 13 in this order to reach the downstream passage 22d. The downstream passage 22d returns to the pump 21 via a heat dissipation section.

[0030] For example, when the driving mode is the series driving mode, by fully opening the first valve device 23a, the entire flow rate is passed through the VCU 11, and the flow rate of the refrigerant to the MCU 12 and the GCU 13 is made equal (5:5), thereby achieving both improved power performance and improved power generation performance (first state).

[0031] When the driving mode is the EV mode, the generator 5 does not generate electricity and the GCU 13 is not switched. Therefore, cooling of the MCU 12 takes priority over cooling of the GCU 13. For example, the first valve device 23a may be fully closed, not cooling the GCU 13, and only cooling the MCU 12 (second state (third state)). In this case, the first valve device 23a may be set to an intermediate opening between the fully closed state and the fully open state. Even when the first valve device 23a is at an intermediate opening, cooling of the MCU 12 takes priority (second state (fifth state)).

[0032] When the driving mode is the parallel driving mode, as in the series driving mode, the first valve device 23a is fully opened, allowing the entire flow rate to pass through the VCU 11 and cooling both the MCU 12 and the GCU 13 (first state).

[0033] (Second embodiment) 3 shows the main part of the second embodiment. As in the first embodiment, the VCU 11 is used frequently, so the VCU 11 is arranged upstream of the MCU 12 and GCU 13.

[0034] 3, the refrigerant passage 22 is configured such that an upstream passage 22a extending from the pump 21 passes through the VCU 11 within the casing 14 and then branches into a third passage 22e and a fourth passage 22f. The third passage 22e passes through a third valve device 23b and the MCU 12 in this order to reach a downstream passage 22d. The fourth passage 22f passes through a fourth valve device 23c and the GCU 13 in this order to reach the downstream passage 22d. The downstream passage 22d returns to the pump 21 via a heat dissipation section.

[0035] For example, when the driving mode is the series driving mode, by fully opening the third valve device 23b and the fourth valve device 23c, the cooling of the upstream VCU 11 is given top priority, while the flow rate of refrigerant to the downstream MCU 12 and GCU 13 is made equal (5:5), thereby achieving both improved power performance and improved power generation performance (first state).

[0036] When the driving mode is the EV mode, the generator 5 does not generate electricity and the GCU 13 is not switched. Therefore, cooling of the MCU 12 takes priority over cooling of the GCU 13. For example, the fourth valve device 23c may be fully closed to not cool the GCU 13, and the third valve device 23b may be fully opened to cool only the MCU 12 (second state (third state)). In this case, both the third valve device 23b and the fourth valve device 23c may be set to intermediate openings, with the opening of the third valve device 23b set to a larger opening than the opening of the fourth valve device 23c. In such a setting, cooling of the MCU 12 also takes priority (second state (fifth state)).

[0037] When the driving mode is the parallel driving mode, as in the series driving mode, the third valve device 23b and the fourth valve device 23c are fully opened, thereby cooling all of the VCU 11, the MCU 12, and the GCU 13 (first state). Note that, in a case where a motor disconnection mechanism is provided, when the power transmission path between the motor M and the drive wheels is disconnected, cooling of the GCU 13 may be prioritized over cooling of the MCU 12. For example, the third valve device 23b may be fully closed and the fourth valve device 23c may be fully opened, thereby cooling only the GCU 13 and not the MCU 12 (second state (fourth state)). Similarly, when generating electricity while the vehicle is stopped, the setting may be such that only the GCU 13 is cooled and not the MCU 12 (second state (fourth state)). In this case, the amount of refrigerant supplied to the GCU 13 may be maintained at the same level as in the first state, and the amount of refrigerant supplied to the MCU 12 may be reduced from that in the first state (second state (fifth state)).

[0038] (Third embodiment) 4 shows the main part of the third embodiment. Similarly, the VCU 11 is arranged upstream of the MCU 12 and GCU 13, thereby prioritizing cooling of the VCU 11.

[0039] 4, the refrigerant passage 22 includes an upstream passage 22a extending from the pump 21, which passes through the VCU 11 and the MCU 12 in this order within the casing 14, and then branches into a fifth passage 22g and a sixth passage 22h. The fifth passage 22g passes through a fifth valve device 23d to reach the downstream passage 22d. The sixth passage 22h passes through a sixth valve device 23e and the GCU 13 in this order to reach the downstream passage 22d. The downstream passage 22d returns to the pump 21 via a heat dissipation section.

[0040] For example, when the driving mode is the series driving mode, the fifth valve device 23d is fully closed and the sixth valve device 23e is fully open, thereby cooling the GCU 13 (first state).

[0041] When the driving mode is the EV mode, the GCU 13 is not switched, and therefore, for example, the fifth valve device 23d is fully opened and the sixth valve device 23e is fully closed, thereby preventing cooling of the GCU 13 (second state (third state)). At this time, depending on the operating state, the opening of the sixth valve device 23e may be set to an intermediate opening smaller than the opening of the fifth valve device 23d, thereby continuing to cool the GCU 13 slightly. In other words, the amount of refrigerant supplied to the MCU 12 may be maintained the same as in the first state, and the amount of refrigerant supplied to the GCU 13 may be reduced from that in the first state (second state (fifth state)).

[0042] When the driving mode is the parallel driving mode, as in the case of the series driving mode, the fifth valve device 23d is fully closed and the sixth valve device 23e is fully open, thereby cooling all of the VCU 11, MCU 12, and GCU 13 (first state).

[0043] (Fourth embodiment) 5 shows the main part of the fourth embodiment. The VCU 11 is disposed upstream of the MCU 12 and the GCU 13, so that cooling of the VCU 11 is prioritized.

[0044] In the embodiment of FIG. 5, the refrigerant passage 22 includes an upstream passage 22a extending from the pump 21. The upstream passage 22a passes through the VCU 11 and a seventh valve device 23f within the casing 14, and then branches into a seventh passage 22i and an eighth passage 22j. The seventh valve device 23f may be a three-way valve, or a valve device may be provided in each of the branched seventh passage 22i and eighth passage 22j. The eighth passage 22j passes through the MCU 12 and then merges with the seventh passage 22i, which bypasses (bypasses) the MCU 12, and reaches the eighth valve device 23g. After passing through the eighth valve device 23g, the passage branches into a ninth passage 22k and a tenth passage 22l. The eighth valve device 23g may be a three-way valve, or a valve device may be provided in each of the branched ninth passage 22k and tenth passage 22l. The tenth passage 22l passes through the GCU 13, and then merges with the ninth passage 22k that bypasses (bypasses) the GCU 13, and reaches the downstream passage 22d. The downstream passage 22d returns to the pump 21 via a heat dissipation section.

[0045] For example, when the driving mode is the series driving mode, the seventh valve device 23f is switched to the eighth passage 22j side and the eighth valve device 23g is switched to the tenth passage 22l side, thereby cooling all of the VCU 11, MCU 12 and GCU 13 (first state).

[0046] When the driving mode is the EV mode, the GCU 13 is not switched, and therefore, for example, the eighth valve device 23g can be switched to the ninth passage 22k side to prevent cooling of the GCU 13 (second state (third state)). At this time, depending on the operating state, the opening of the eighth valve device 23g may be set to an intermediate opening to continue cooling the GCU 13 slightly. That is, the amount of refrigerant supplied to the MCU 12 may be maintained the same as in the first state, and the amount of refrigerant supplied to the GCU 13 may be controlled to be reduced from that in the first state (second state (fifth state)).

[0047] Furthermore, when the traveling mode is the parallel traveling mode, as in the case of the series traveling mode, the seventh valve device 23f can be switched to the eighth passage 22j and the eighth valve device 23g can be switched to the tenth passage 22l to cool all of the VCU 11, MCU 12, and GCU 13 (first state). Note that when the driving of the motor M is stopped in the parallel traveling mode, cooling of the MCU 12 is not necessary, so for example, the seventh valve device 23f can be switched to the seventh passage 22i to prevent cooling of the MCU 12 (second state (fourth state)). At this time, the amount of refrigerant supplied to the GCU 13 may be maintained the same as in the first state, and the amount of refrigerant supplied to the MCU 12 may be controlled to be reduced from that in the first state (second state (fifth state)).

[0048] As described above, according to the present invention, the cooling of the VCU 11 is stabilized, and since the GCU 13 is not switched in EV mode, only the MCU 12 is cooled, and the GCU 13 is not cooled or the degree of cooling is limited. Furthermore, in series driving mode and parallel driving mode, control can be switched to cooling all of the VCU 11, MCU 12, and GCU 13 as in the past. When generating electricity while the vehicle is stopped, control can be performed to cool only the VCU 11 and GCU 13, and the MCU 12 is not cooled or the degree of cooling is limited. These controls improve cooling performance during driving in EV mode, thereby increasing the current value that can be passed (i.e., vehicle torque). Furthermore, cooling loss during driving in EV mode is reduced, increasing the continuous electric driving distance (potential distance).

[0049] When the driving mode is the EV mode, more efficient cooling is possible by controlling the rotation speed of the pump 21 to be reduced in the second state (third state). In the second state (third state), the refrigerant is not supplied to the GCU 13, and therefore, the amount of refrigerant flowing can be reduced more than in the first state, thereby suppressing the power consumption of the pump 21.

[0050] Conversely, in the second state (third state), control can be performed to increase the flow rate of the refrigerant in the refrigerant passage 22. In the second state (third state), the refrigerant is not supplied to the GCU 13, so the amount of refrigerant flowing may be less than in the first state. Therefore, for example, by continuing to supply the same amount of refrigerant as in the first state by the pump 21, the refrigerant flow rate increases, thereby improving the cooling performance of the VCU 11 and the MCU 12. This can be expected to improve torque performance.

[0051] In the case where a motor disconnection mechanism is provided and the power transmission path between the motor M and the drive wheels is disconnected during parallel driving mode, more efficient cooling can be achieved by controlling the rotation speed of the pump 21 to be reduced in the second state (fourth state). In the second state (fourth state), no refrigerant is supplied to the MCU 12, and therefore the amount of refrigerant flowing can be reduced more than in the first state, thereby suppressing the power consumption of the pump 21.

[0052] Furthermore, when the vehicle speed is low and below a predetermined value, and the generator 5 is generating electricity, a similar effect can be expected by controlling the pump 21 to reduce its rotation speed in the second state (fourth state).

[0053] The control content of the present invention will be described with reference to the flowchart of Fig. 6. Fig. 6 corresponds to the second embodiment shown in Fig. 3.

[0054] First, control is started in step S1. In step S2, it is determined whether the operation mode of the vehicle 1 is a driving mode. If the operation mode is not a driving mode (for example, if the shift lever is in the parking range), the process proceeds to step S6 and the control ends. If the operation mode is a driving mode, the process proceeds to step S3.

[0055] In step S3, it is determined whether the driving mode is the EV mode. If the driving mode is the EV mode, the process proceeds to step S10, and if the driving mode is not the EV mode, the process proceeds to step S4.

[0056] In step S10, the third valve device 23b is opened and the fourth valve device 23c is closed, thereby setting the cooling state to the second state (third state). Once the setting is complete, the process proceeds to step S6, where the control ends.

[0057] In step S4, it is determined whether the vehicle 1 is stopped and the generator 5 is generating electricity. If the vehicle 1 is stopped and generating electricity, the process proceeds to step S5, and if the vehicle 1 is not stopped and generating electricity, the process proceeds to step S7.

[0058] In step S5, the third valve device 23b is closed and the fourth valve device 23c is opened, thereby setting the cooling state to the second state (fourth state). Once the setting is complete, the process proceeds to step S6, where the control is terminated.

[0059] In step S7, it is determined whether the vehicle 1 is in parallel running mode and whether the motor disconnection mechanism has disconnected the power transmission path between the motor M and the drive wheels. If the motor M and the drive wheels are not disconnected, the process proceeds to step S8, and if they are disconnected, the process proceeds to step S9.

[0060] In step S8, the third valve device 23b is opened and the fourth valve device 23c is opened, thereby setting the cooling state to the first state. Once the setting is complete, the process proceeds to step S6 and ends the control.

[0061] In step S9, the third valve device 23b is closed and the fourth valve device 23c is opened, thereby setting the cooling state to the second state (fourth state). Once the setting is complete, the process proceeds to step S6, where the control ends.

[0062] In each of the above embodiments, a hybrid vehicle is assumed as the vehicle 1, but the hybrid vehicle may be a plug-in hybrid car in which the battery 50 can be charged directly (external charging) using a plug from a household outlet or the like, or the battery 50 can supply power directly to household electrical appliances or the like (external power supply) using a plug. [Explanation of symbols]

[0063] 1 Hybrid vehicle (vehicle) 4 Engine 5. Generator 10 Inverter 11 Voltage Control Unit (VCU) 12 Motor Control Unit (MCU) 13 Generator Control Unit (GCU) 14 Casing 20 Cooling device 21 Pump 22 Refrigerant passage 23 Valve gear M Drive motor (motor)

Claims

1. An electric vehicle including a drive motor and a generator, an inverter including a plurality of power modules, and a cooling device that cools the inverter, the cooling device includes a refrigerant passage provided in the inverter, a pump that sends out refrigerant to the refrigerant passage, and a valve device provided in the refrigerant passage; the power module includes a voltage control unit that controls a voltage supplied to the drive motor, a motor control unit that controls rotation of the drive motor, and a generator control unit that controls power generation by the generator, The valve device is switchable between a first state in which refrigerant is supplied to all of the voltage control unit, the motor control unit, and the generator control unit, and a second state in which the amount of refrigerant supplied to the motor control unit or the generator control unit is more limited than in the first state.

2. The electric vehicle according to claim 1 , wherein the second state is set to a third state in which the refrigerant is supplied only to the voltage control unit and the motor control unit.

3. The electric vehicle according to claim 1 , wherein the second state is set to a fourth state in which the refrigerant is supplied only to the voltage control unit and the generator control unit.

4. The electric vehicle according to claim 1 , wherein the voltage control unit is disposed upstream of the motor control unit and / or the generator control unit.

5. 2. The electric vehicle according to claim 1, wherein, when the driving mode is an EV driving mode in which the vehicle is driven by driving force only from the drive motor, control is performed to stop the supply of refrigerant to the generator control unit and reduce the rotation speed of the pump under the second state.

6. 2. The electric vehicle according to claim 1, wherein, when the driving mode is an EV driving mode in which the vehicle is driven by driving force only from the drive motor, the supply of refrigerant to the generator control unit is stopped under the second state, and control is performed to increase the flow rate of the refrigerant in the refrigerant passage.

7. Equipped with an engine as a driving source, 2. The electric vehicle according to claim 1, wherein, when a driving mode is a parallel driving mode using the driving force of the engine and the motor shaft of the driving motor is separated from the rotary shaft on the drive wheel side, control is performed to stop the supply of refrigerant to the motor control unit and reduce the rotation speed of the pump under the second state.

8. 2. The electric vehicle according to claim 1, wherein, when the vehicle speed is in a low speed state where it is less than a predetermined value and the generator is generating electricity, the supply of refrigerant to the motor control unit is stopped under the second state, and the rotation speed of the pump is reduced.

Images