Control method for electric vehicles and electric vehicles

Abstract

This invention provides a control method for electric vehicles that enables efficient battery warming. [Solution] A control method for an electric vehicle is provided, comprising an air conditioning system 7 having a cooling water passage 1 through which cooling water flows to cool a battery 31, and a refrigerant passage 70 through which a refrigerant flows. The cooling water passage 1 includes a first water passage 10 in which the electric powertrain 11 is located, a second water passage 20 in which a cooling device 21 capable of heat exchange between cooling water and refrigerant is located, a third water passage 30 in which the battery 31 is located, and a fourth water passage 40 in which a condenser 41 capable of heat exchange between refrigerant and cooling water is located. Switching valves 80 are provided on the cooling water passage 1 to connect or disconnect each of the first to fourth water passages. When warming up the battery 31, the waste heat from the electric powertrain 11 is absorbed by the refrigerant via the cooling device 21, the refrigerant and cooling water are heat exchanged via the condenser 41 to heat the cooling water, and the switching valves 80 are controlled to supply the heated cooling water to the battery 31.

Description

Technical Field

[0001] The present invention relates to a control method for an electric vehicle and an electric vehicle.

Background Art

[0002] Patent Document 1 discloses an electric vehicle including a battery cooling water passage through which cooling water for cooling a battery flows, an electrical component cooling water passage through which cooling water for cooling electrical components flows, and a motor cooling water passage through which cooling water for cooling a motor flows. In this electric vehicle, the battery cooling water passage, the electrical component cooling water passage, and the motor cooling water passage are independently arranged without allowing the cooling water to flow back and forth between them.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the electric vehicle described in Patent Document 1, since the cooling water passage for the battery and the cooling water passage for the electric power train (ePT) including the motor and the inverter are independent, when the battery is warming up, the waste heat of the ePT cannot be used for warming up the battery by using the cooling water flowing through the cooling water passage.

[0005] On the other hand, it is conceivable to arrange the battery and the ePT on one cooling water passage, recover the waste heat from the ePT due to the loss generated by d-axis discharge with cooling water, and warm up the battery by supplying it to the battery. However, there are limitations to the losses that can be generated by d-axis discharge, and there is a possibility that the battery cannot be warmed up efficiently enough.

[0006] The present invention has been made in view of the above problems, and an object thereof is to provide a control method for an electric vehicle and an electric vehicle capable of efficiently warming up a battery.

Means for Solving the Problem

[0007] According to one aspect of the present invention, there is provided a control method for an electric vehicle including an air conditioning system including a cooling water passage through which cooling water for cooling a battery flows and a refrigerant passage through which a refrigerant flows. The cooling water passage includes a first water passage where an electric power train including a motor and an inverter is disposed, a second water passage where a cooling device capable of exchanging heat between the cooling water and the refrigerant is disposed, a third water passage where a battery is disposed, and a fourth water passage where a condenser capable of exchanging heat between the refrigerant and the cooling water is disposed. On the cooling water passage, switching valves for connecting or disconnecting the first to fourth water passages from each other are provided. When warming up the battery, the waste heat of the electric power train is absorbed by the refrigerant through the cooling device, heat is exchanged between the refrigerant and the cooling water through the condenser, the cooling water is heated, and the switching valves are controlled so as to supply the heated cooling water to the battery.

Advantages of the Invention

[0008] According to the present invention, when warming up the battery, the waste heat of the electric power train is absorbed by the refrigerant of the air conditioning system through the cooling device, heat is exchanged between the refrigerant and the cooling water by a water-cooled condenser capable of exchanging heat between the refrigerant and the cooling water, the cooling water is heated, and the switching valves are controlled so as to supply the heated cooling water to the battery. Thus, by supplying the waste heat of the electric power train to the battery through the air conditioning system, the amount of heat supplied to the battery can be increased compared to recovering the waste heat of the electric power train with cooling water and directly supplying it to the battery. Therefore, the battery can be warmed up efficiently.

Brief Description of the Drawings

[0009] [Figure 1] FIG. 1 is a schematic configuration diagram of a cooling system mounted on an electric vehicle according to an embodiment of the present invention. [Figure 2] FIG. 2 is a diagram showing the cooling water passage and the refrigerant passage during battery warm-up. [Figure 3] FIG. 3 is a diagram showing the flow direction of the cooling water during battery warm-up. [Figure 4]Figure 4 shows the flow direction of the coolant during battery warm-up after the ePT has finished warming up. [Figure 5] Figure 5 shows the cooling water passage and refrigerant flow path during battery warm-up after the ePT has finished warming up. [Figure 6] Figure 6 shows the cooling water channels and refrigerant flow paths during battery cooling. [Figure 7] Figure 7 shows the cooling water channels and refrigerant flow paths during battery cooling. [Figure 8] Figure 8 shows the cooling water channels and refrigerant flow paths during battery cooling. [Figure 9] Figure 9 shows the cooling water channels and refrigerant flow paths during battery cooling. [Figure 10] Figure 10 shows the cooling water channel and refrigerant flow path when there is no temperature control requirement for the battery. [Figure 11] Figure 11 shows the cooling water channel and refrigerant flow path when there is no temperature control requirement for the battery. [Figure 12] Figure 12 shows the cooling water channel and refrigerant flow path when there is no temperature control requirement for the battery. [Figure 13] Figure 13 shows the cooling water channel and refrigerant flow path when there is no temperature control requirement for the battery. [Figure 14] Figure 14 is a flowchart illustrating waterway switching control based on temperature control and heating / cooling requirements. [Figure 15] Figure 15 is a flowchart illustrating the control for determining the direction of cooling water flow. [Modes for carrying out the invention]

[0010] The following describes a control method for an electric vehicle according to an embodiment of the present invention, with reference to the drawings. The electric vehicle according to the embodiment of the present invention is equipped with a battery cooling system 100. The electric vehicle referred to herein includes not only BEVs (Battery Electric Vehicles) but also HEVs (Hybrid Electric Vehicles), etc.

[0011] Figure 1 is a schematic diagram of a cooling system 100 mounted on an electric vehicle according to an embodiment of the present invention.

[0012] As shown in Figure 1, the cooling system 100 comprises a cooling water channel 1 through which cooling water flows, an air conditioning system (heat pump) 7, and a cooling water channel controller 9.

[0013] The cooling water channel 1 is composed of a first channel 10, a second channel 20, a third channel 30, a fourth channel 40, a fifth channel 50, and a sixth channel 60. An electric powertrain (ePT) 11 including a motor and inverter is located on the first channel 10, a chiller (cooling device) 21 is located on the second channel 20, and a battery 31 is located on the third channel 30. A water-cooled condenser 41 is located on the fourth channel 40, and a radiator 51 is located on the fifth channel 50. A heater core 61 is located on the sixth channel 60.

[0014] Furthermore, water pumps 12, 22, 32, and 42 are provided on the first to fourth water channels 10, 20, 30, and 40, respectively, to circulate the cooling water flowing through the cooling water channel 1.

[0015] Furthermore, multiple switching valves 80 are provided on the cooling water channel 1 to connect or disconnect the first to sixth water channels 10, 20, 30, 40, 50, and 60, respectively.

[0016] The air conditioning system 7 is equipped with a refrigerant flow path 70 through which the refrigerant flows, and when heating the vehicle interior, it functions as a heat pump capable of absorbing heat from the outside air, the ePT 11 and the waste heat from the battery 31, etc. The refrigerant flow path 70 consists of a first refrigerant flow path 70A, a second refrigerant flow path 70B and a third refrigerant flow path 70C. A compressor 71 and a condenser (water-cooled condenser) 41 are provided in that order on the first refrigerant flow path 70A. An evaporator 72 is located on the second refrigerant flow path 70B, and a chiller 21 is provided on the third refrigerant flow path 70C. The refrigerant flow path 70 is also equipped with switching valves 73 and 74 for switching the circulation path of the refrigerant.

[0017] In the first refrigerant flow path 70A, the refrigerant (air) flowing through the first refrigerant flow path 70A is compressed by the compressor 71. The compressed refrigerant is supplied to the water-cooled condenser 41 downstream of the compressor 71. The water-cooled condenser 41 condenses and liquefies the refrigerant (air) compressed by the compressor 71. As will be described later, the refrigerant flowing through the refrigerant flow path 70 in the water-cooled condenser 41 undergoes heat exchange with the cooling water flowing through the cooling water passage 1. The refrigerant that has undergone heat exchange with the cooling water in the water-cooled condenser 41 is rapidly expanded by an expansion valve (not shown), becoming low temperature and low pressure, and this low temperature and low pressure refrigerant is supplied to the evaporator 72 and / or chiller 21. The evaporator 72 on the second refrigerant flow path 70B evaporates the refrigerant (air) flowing through the second refrigerant flow path 70B and supplies the evaporated refrigerant to the compressor 71. The operation of the compressor 71 is controlled by the controller 9.

[0018] As will be described later, the chiller (cooling device) 21 on the third refrigerant flow path 70C exchanges heat between the cooling water flowing through the cooling water passage 1 and the refrigerant flowing through the refrigerant flow path 70 (third refrigerant flow path 70C), and supplies the refrigerant that has exchanged heat with the cooling water to the compressor 71.

[0019] The switching valve 73 is located in the refrigerant flow path 70 downstream of the water-cooled condenser 41 and connects the first refrigerant flow path 70A to the second refrigerant flow path 70B and / or the third refrigerant flow path 70C. By adjusting its opening degree, the switching valve 73 can control the amount of refrigerant supplied from the first refrigerant flow path 70A to the second refrigerant flow path 70B and / or the third refrigerant flow path 70C. The operation of the switching valve 73 is controlled by the controller 9.

[0020] The switching valve 74 is located in the refrigerant flow path 70 upstream of the compressor 71 and connects the second refrigerant flow path 70B and / or the third refrigerant flow path 70C to the first refrigerant flow path 70A. By adjusting its opening degree, the switching valve 74 can control the amount of refrigerant supplied from the second refrigerant flow path 70B and / or the third refrigerant flow path 70C to the first refrigerant flow path 70A. The operation of the switching valve 74 is controlled by the controller 9.

[0021] Furthermore, the refrigerant (air) whose temperature is controlled by the air conditioning system 7 is supplied to the passenger compartment by a blower (not shown), thereby cooling or heating the passenger compartment. The operation of the blower is controlled by the controller 9.

[0022] The ePT11, located on the first water channel 10, includes a DC-DC converter, an inverter, and a motor (for traction), etc. The cooling water channel 1 on the outlet side of the ePT11 is equipped with a temperature sensor (not shown) that detects the temperature of the cooling water at the outlet of the ePT11 (hereinafter referred to as the outlet temperature of the ePT11). The temperature detected by the temperature sensor is transmitted to the cooling water channel controller 9.

[0023] As described above, the chiller (cooling device) 21, which is located on the second water channel 20, is installed on the second water channel 20 and is also located on the refrigerant flow path 70 of the air conditioning system 7, and is configured to exchange heat between the cooling water flowing in the cooling water channel 1 and the refrigerant flowing in the refrigerant flow path 70. That is, the chiller 21 exchanges heat between the refrigerant in the refrigerant flow path 70, which has been made cold and low pressure by the expansion valve, and the heat of the cooling water flowing in the cooling water channel 1. The cooling water channel 1 on the outlet side of the chiller 21 is equipped with a temperature sensor (not shown) that detects the temperature of the cooling water at the outlet of the chiller 21 (hereinafter referred to as the chiller 21 outlet temperature). The detected chiller 21 outlet temperature is transmitted to the controller 9.

[0024] The battery 31, located on the third water channel 30, supplies power to the motor of the ePT 11. The cooling water channel 1 of the battery 31 is equipped with a temperature sensor (not shown) that detects the temperature of the cooling water at the outlet of the battery 31 (hereinafter referred to as the temperature of the battery 31). The detected temperature of the battery 31 is transmitted to the controller 9.

[0025] As described above, the water-cooled condenser (condenser) 41, which is located on the fourth water channel 40, is provided on the fourth water channel 40 and is located on the refrigerant flow path 70 of the air conditioning system 7, and is configured to exchange heat between the refrigerant flowing through the refrigerant flow path 70 and the cooling water flowing through the cooling water channel 1. That is, the water-cooled condenser 41 exchanges heat between the heat of the cooling water flowing through the cooling water channel 1 and the refrigerant flowing through the refrigerant flow path 70.

[0026] The radiator 51, positioned on the fifth water channel 50, is a cooling mechanism that performs heat exchange between the coolant flowing through the cooling water channel 1 and the atmosphere. A fan (not shown) is provided near the radiator 51, and by operating the fan, the coolant flowing through the cooling water channel 1 can be cooled. The radiator 51 is also located near a grill shutter (not shown) that introduces airflow into the vehicle, and by opening the grill shutter and directing airflow onto the radiator 51, the coolant in the cooling water channel 1 can also be cooled. The operation of the fan near the radiator 51 and the grill shutter (hereinafter referred to as the operation of the radiator 51) is controlled by the controller 9. A temperature sensor (not shown) is provided in the cooling water channel 1 on the outlet side of the radiator 51 to detect the temperature of the coolant at the outlet of the radiator 51 (hereinafter referred to as the outlet temperature of the radiator 51). The detected outlet temperature of the radiator 51 is transmitted to the controller 9.

[0027] The heater core 61, positioned on the sixth water channel 60, is a heat exchanger that exchanges heat between the heated cooling water flowing through the cooling water channel 1 and the air inside the vehicle cabin. Through this heat exchange, it generates warm air which is supplied to the vehicle cabin.

[0028] The switching valve 80 includes the first to fifth valves 81 to 85. The operation of the switching valve 80 (first to fifth valves 81 to 85) is controlled by the controller 9 described later.

[0029] The first valve 81 is configured to connect or disconnect the first water channel 10 downstream of the ePT 11, the second water channel 20 downstream of the chiller 21, and the third water channel 30 upstream of the battery 31.

[0030] The second valve 82 is configured to connect or disconnect the first water channel 10 upstream of the ePT 11, the second water channel 20 upstream of the chiller 21, the third water channel 30 downstream of the battery 31, and the sixth water channel 60 downstream of the heater core 61.

[0031] The third valve 83 is configured to connect or disconnect the first water channel 10 upstream of the ePT 11, the third water channel 30 upstream of the battery 31, the fourth water channel 40 upstream of the water-cooled condenser 41, and the sixth water channel 60 downstream of the heater core 61.

[0032] The fourth valve 84 is configured to connect or disconnect the first water channel 10 upstream of the ePT 11 and the fifth water channel in which the radiator 51 is located.

[0033] The fifth valve 85 is configured to connect or disconnect the second water channel 20 between the upstream of the chiller 21 and the water pump 22, and the third water channel 30 between the downstream of the battery 31 and the water pump 32.

[0034] Furthermore, the fourth water channel 40 downstream of the water-cooled condenser 41 branches into the sixth water channel 60 upstream of the heater core 61 and the third water channel 30 downstream of the battery 31.

[0035] The controller 9 consists of a computer equipped with a central processing unit (CPU), read-only memory (ROM), random access memory (RAM), and input / output interfaces (I / O interfaces), and programmed to execute the processes described later. It is also possible to configure the controller 9 with multiple computer hardware components that distribute the execution of each process.

[0036] The controller 9 acquires information such as driving force and accelerator opening from a torque sensor and accelerator position sensor (not shown) installed in the electric vehicle. The controller 9 also acquires various temperature information detected by a temperature sensor. Although not shown, the electric vehicle in this embodiment is equipped with a temperature sensor that detects the temperature outside the vehicle (outside air), and the controller 9 also acquires the outside temperature detected by this temperature sensor. Furthermore, when warming up the vehicle system, the controller 9 performs a d-axis discharge by supplying current to the ePT 11 so that no torque is generated. This warms up the ePT 11, and the battery 31 is also warmed up by the waste heat from the ePT 11.

[0037] Furthermore, the controller 9 controls the operation of the switching valve 80 in the cooling water passage 1 and the switching valves 73 and 74 in the refrigerant passage 70, and executes each process by switching the pattern of the water passage through which the cooling water flows and the pattern of the water passage through which the refrigerant flows in the cooling system 100. For example, the controller 9 performs water passage switching control based on temperature control requests and heating / cooling requests, switching the water passage pattern of the cooling water passage 1 based on temperature control requests from the battery 31 and heating / cooling requests from the air conditioning system 7.

[0038] In the electric vehicle cooling system 100 configured as described above, various patterns of cooling water passages can be configured by switching the switching valve 80.

[0039] Incidentally, if the cooling water passage for the battery and the cooling water passage for the electric powertrain (ePT), including the motor and inverter, are provided separately, the waste heat from the ePT cannot be used to warm up the battery using the cooling water flowing through the cooling water passage. In other words, the waste heat from the ePT cannot be effectively utilized. As an alternative, one could consider placing the battery and ePT on a single cooling water passage and warming up the battery by recovering the waste heat from the ePT due to losses generated by d-axis discharge with the cooling water and supplying it to the battery. However, since the d-axis discharge is performed by flowing current in a way that does not generate torque, there is a limit to the losses that can be generated by d-axis discharge due to torque limitations. Therefore, there is a risk that the battery cannot be warmed up sufficiently efficiently.

[0040] Therefore, in this embodiment, when warming up the battery 31, the waste heat from the electric powertrain (ePT) 11 is absorbed into the refrigerant of the air conditioning system 7 via a cooling device (chiller) 21, and the cooling water is heated by heat exchange between the refrigerant and the cooling water in a water-cooled condenser (water-cooled condenser) 41. The heated cooling water is then supplied to the battery 31, and the switching valve 80 is controlled accordingly. Specifically, first, the waste heat from the ePT 11 is absorbed into the refrigerant of the air conditioning system 7, thereby driving the air conditioning system 7 (heat pump). Then, the cooling water heated by heat exchange in the water-cooled condenser 41 is supplied to the battery 31 to warm up the battery 31. In this way, by using the waste heat from the ePT 11 as a heat source for the air conditioning system 7 (heat pump), the air conditioning system 7 (heat pump) is driven efficiently, and by absorbing the heat absorbed by the refrigerant into the cooling water via the condenser (water-cooled condenser) 41 and supplying it to the battery 31, a larger amount of heat can be recovered into the cooling water. Therefore, the amount of heat supplied to the battery 31 can be increased compared to recovering the waste heat from the ePT11 with cooling water and supplying it directly to the battery 31, allowing the battery 31 to be warmed up more efficiently.

[0041] The following describes the patterns of the cooling water channel 1 and the refrigerant flow path 70 in each scene.

[0042] <If a battery warm-up request is made> When there is a request to warm up the battery 31, the waste heat from the ePT 11 is absorbed by the refrigerant of the air conditioning system 7 via the chiller 21, and the water-cooled condenser 41 heats the cooling water by exchanging heat with the refrigerant, and the heated cooling water is supplied to the battery 31 in a water channel pattern. Specifically, as shown in Figure 2, the first valve 81 and the second valve 82 connect the first water channel 10 where the ePT 11 is located and the second water channel 20 where the chiller 21 is located. The third valve 83 connects the third water channel 30 where the battery 31 is located and the fourth water channel 40 where the water-cooled condenser 41 is located. The fourth valve 84 disconnects the first water channel 10 and the fifth water channel 50. The switching valve 73 of the air conditioning system 7 connects the first refrigerant flow path 70A to the third refrigerant flow path 70C, and the switching valve 74 connects the third refrigerant flow path 70C to the first refrigerant flow path 70A. As a result, when warming up the battery 31, the waste heat from the ePT 11, generated by the d-axis discharge loss, is absorbed by the refrigerant of the air conditioning system 7 via the chiller 21, driving the air conditioning system 7 (heat pump). Then, the cooling water is heated by heat exchange in the water-cooled condenser 41, and the heated cooling water is supplied to the battery 31.

[0043] In electric vehicles, if the condenser of the air conditioning system is air-cooled, it can only exchange heat with the outside air. Even if waste heat from ePT, etc., is absorbed by the refrigerant, it cannot exchange heat between the refrigerant and the cooling water in the cooling water passage. Therefore, the waste heat from ePT, etc., cannot be used to warm up the battery. In contrast, in the electric vehicle of this embodiment, a water-cooled condenser (water-cooled condenser) 41 is used to exchange heat between the refrigerant and the cooling water. As a result, the waste heat from ePT 11, etc., absorbed by the refrigerant can be supplied to the battery 31 via the cooling water in the cooling water passage 1. Therefore, the waste heat from ePT 11, etc., can be used to drive the air conditioning system 7 and to warm up the battery 31. In other words, waste heat can be effectively utilized, and the energy efficiency is improved.

[0044] A request for warming up the battery 31 occurs when the temperature of the battery 31 is lower than a predetermined temperature, resulting in poor output or charging efficiency of the battery 31, and therefore it is necessary to raise the temperature of the battery 31.

[0045] Furthermore, when the battery 31 is warming up, if the air conditioning system 7 requests heating, the vehicle interior will be heated using a PTC heater (not shown) or the like. A heating request occurs when the air conditioning system 7 is turned on and the temperature inside the vehicle is lower than the air conditioning set temperature.

[0046] Incidentally, in electric vehicles, the cooling water passages for the ePT are usually configured so that the cooling water flows through the inverter and then the motor in order to efficiently cool the inverter, which has a high cooling requirement. However, when the battery is warmed up and the d-axis discharge occurs, if the cooling water flows through the inverter and then the motor, the inverter generates more heat than the motor, and the motor is heavier and larger. As a result, the heat generated by the inverter is absorbed by the motor, and there is a risk that the cooling water will not be able to adequately recover the heat from the d-axis discharge. Consequently, there is a risk that the battery cannot be warmed up efficiently and quickly.

[0047] Therefore, in this embodiment, when warming up the battery 31, the switching valve 80 is controlled so that the cooling water flows in the order of motor, then inverter. Specifically, for example, as shown in Figure 3, if the motor 111 and inverter 112 are arranged in the order of motor 111 and inverter 112 from right to left in the figure, the fifth valve 85 disconnects the second waterway 20 and the third waterway 30. As a result, the cooling water flowing through the first flow path 10 flows in the clockwise direction as shown in Figures 2 and 3. Consequently, the cooling water flows in the order of motor 111 and inverter 112. Thus, the waste heat from the inverter 112 is not absorbed by the motor 111, and a higher temperature cooling water can be supplied to the battery 31. Hereinafter, the pattern of the cooling water path 1 and refrigerant flow path 70 shown in Figure 2 will be referred to as the first waterway pattern.

[0048] On the other hand, when the electric vehicle is running or the battery 31 is charging, if the ePT 11 is fully warmed up by d-axis discharge, the motor 111, which has a larger heat capacity, will generate more heat. Also, when the drive load increases while the electric vehicle is running and the losses of the motor 111 become greater than the losses of the inverter 112, the amount of heat generated by the motor 111 will be greater than that of the inverter 112. In this way, when the amount of heat generated by the motor 111 is greater, if the cooling water is flowed in the order of motor 111 and then inverter 112, the heat stored in the motor 111 cannot be sufficiently used to warm up the battery 31. Furthermore, because of the large amount of heat generated from the motor 111, the temperature at the inlet of the inverter 112 may rise, potentially leading to output limitation. Therefore, when the ePT 11 is fully warmed up, or when the losses of the motor 111 are greater than the losses of the inverter 112, the switching valve 80 is controlled so that the cooling water flows in the order of inverter 112 and then motor 111. Specifically, as shown in Figure 4, when the motor 111 and inverter 112 are arranged in that order from right to left in the ePT11, the fifth valve 85 connects the second waterway 20 and the third waterway 30, as shown in Figure 5. As a result, the cooling water flowing through the first flow path 10 flows in the counterclockwise direction shown in Figures 4 and 5. Therefore, the cooling water flows in the order of inverter 112 and motor 111. Thus, the heat stored in the motor 111 can be utilized to the maximum extent for warming up the battery 31, improving the warming efficiency of the battery 31. Hereinafter, the pattern of the cooling water path 1 and refrigerant flow path 70 shown in Figure 5 will be referred to as the second waterway pattern.

[0049] In this embodiment, if the outlet temperature of the ePT 11 is above a predetermined value while the battery 31 is being charged or the vehicle is running, it is determined that the ePT 11 has finished warming up. That is, if the outlet temperature of the ePT 11 is sufficiently high, it can be estimated that the ePT 11 has finished warming up. In addition, the relative magnitudes of the losses of the inverter 112 and the motor 111 can be estimated from the driving force (torque) of the electric vehicle, etc.

[0050] <If battery cooling is required> Figures 6 to 9 show the patterns of the cooling water passage 1 when there is a cooling requirement for the battery 31. When there is a cooling requirement for the battery 31, the battery 31 is cooled by the chiller 21 or the radiator 51. Figure 6 shows the case when the battery 31 is cooled by the radiator 51 when there is no cooling requirement, and Figure 7 shows the case when the battery 31 is cooled by the radiator 51 when there is a cooling requirement. Figure 8 shows the case when the battery 31 is cooled by the chiller 21 when there is no cooling requirement, and Figure 9 shows the case when the battery 31 is cooled by the chiller 21 when there is a cooling requirement. A cooling requirement for the battery 31 is when the temperature of the battery 31 is higher than a predetermined temperature, and the output or charging efficiency of the battery 31 is poor, so it is necessary to lower the temperature of the battery 31. A cooling requirement is when the temperature inside the vehicle is higher than the air conditioning set temperature when the air conditioning system 7 is on.

[0051] First, if the outlet temperature of the radiator 51 is lower than the temperature of the battery 31, the switching valve 80 is controlled to supply coolant cooled by outside air taken in through the radiator 51 to the battery 31.

[0052] Specifically, as shown in Figures 6 and 7, the fourth valve 84 connects the first waterway 10 to the fifth waterway 50 where the radiator is located, and the third valve 83 connects the first waterway 10 to the third waterway 30 where the battery 31 is located. As a result, the coolant cooled by the radiator 51 is supplied to the battery 31, and the battery 31 is cooled. The first valve 81 connects the first waterway 10 to the second waterway 20, and the second valve 82 connects the third waterway 30 to the second waterway 20 when there is no air conditioning request, and connects the third waterway 30 to the second waterway 20 when there is an air conditioning request, as well as connecting the sixth waterway 60 to the first waterway 10.

[0053] Here, if there is no cooling request in the air conditioning system 7, as shown in Figure 6, the third valve 83 connects the first waterway 10 only to the third waterway 30 where the battery 31 is located. On the other hand, if there is a cooling request, as shown in Figure 7, the third valve 83 connects the first waterway to both the third waterway 30 and the fourth waterway 40 where the water-cooled condenser 41 is located. In addition, the switching valve 73 of the air conditioning system 7 connects the first refrigerant flow path 70A to the second refrigerant flow path 70B, and the switching valve 74 connects the second refrigerant flow path 70B to the first refrigerant flow path 70A. As a result, heat exchange occurs between the cooling water cooled by the radiator 51 in the water-cooled condenser 41 and the refrigerant in the refrigerant flow path 70, the air conditioning system 7 is driven, and the heat-exchanged refrigerant is supplied to the vehicle interior to cool the interior. Hereinafter, the pattern of the cooling water channel 1 and refrigerant flow path 70 shown in Figure 6 will be referred to as the third channel pattern, and the pattern of the cooling water channel 1 and refrigerant flow path 70 shown in Figure 7 will be referred to as the fourth channel pattern.

[0054] Next, if the outlet temperature of the radiator 51 is higher than or equal to the temperature of the battery 31, the switching valve 80 is controlled to supply coolant cooled by the chiller 21 to the battery 31.

[0055] Specifically, as shown in Figures 8 and 9, the first valve 81 connects the second water channel 20, where the chiller 21 is located, to the third water channel 30, where the battery 31 is located, and disconnects the first water channel 10 from the second water channel 20 and the third water channel 30. The second valve 82 connects the first water channel 10 to the sixth water channel 60 and connects the third water channel 30, where the battery 31 is located, to the second water channel 20. As a result, the cooling water cooled in the chiller 21 is supplied to the battery 31, and the battery 31 is cooled. The third valve 83 connects the first water channel 10 to the fourth water channel 40, and the fourth valve 84 connects the fifth water channel 50 to the first water channel 10.

[0056] Here, when there is no cooling request in the air conditioning system 7, as shown in Figure 8, the switching valve 73 of the air conditioning system 7 connects the first refrigerant flow path 70A to the third refrigerant flow path 70C, and the switching valve 74 connects the third refrigerant flow path 70C to the first refrigerant flow path 70A. On the other hand, when there is a cooling request, as shown in Figure 9, the switching valve 73 of the air conditioning system 7 connects the first refrigerant flow path 70A to the second refrigerant flow path 70B and the third refrigerant flow path 70C, and the switching valve 74 connects the second refrigerant flow path 70B and the third refrigerant flow path 70C to the first refrigerant flow path 70A. As a result, the refrigerant in the refrigerant flow path 70 is also supplied to the evaporator 72, and the refrigerant circulating in the water-cooled condenser 41 and the evaporator 72 is supplied to the vehicle interior, thereby cooling the vehicle interior. Hereinafter, the pattern of the cooling water flow path 1 and refrigerant flow path 70 shown in Figure 8 will be called the fifth water flow path pattern, and the pattern of the cooling water flow path 1 and refrigerant flow path 70 shown in Figure 9 will be called the sixth water flow path pattern.

[0057] <If there is no battery temperature control requirement> Figures 10 to 13 show the patterns of the cooling water passage 1 when there is no temperature control request for the battery 31, that is, when there is neither a warm-up request nor a cooling request for the battery 31. Figures 10 to 12 show the patterns of the cooling water passage 1 when there is a heating request, and Figure 13 shows the patterns when there is a cooling request.

[0058] When heating is required, the system absorbs heat from the outside air, waste heat from the ePT11, waste heat from the battery31, etc., into the refrigerant in the refrigerant flow path 70 of the air conditioning system 7, and drives the air conditioning system 7 as a heat pump.

[0059] First, if the ambient temperature is higher than the outlet temperature of the chiller 21, the cooling water channel 1 is configured to absorb heat from the ambient air and the waste heat from the ePT 11 into the coolant. Specifically, as shown in Figure 10, the fourth valve 84 connects the fifth channel 50, where the radiator 51 is located, to the first channel 10, and the first valve 81 connects the first channel 10, where the ePT 11 is located, to the second channel 20, where the chiller 21 is located. In addition, the fifth valve 85 connects the second channel 20, between the upstream of the chiller 21 and the water pump 22, to the third channel 30, between the downstream of the battery 31 and the water pump 32, and the second valve 20 connects the third channel 20 downstream of the water pump 32 to the first channel 10. As a result, the heat from the outside air taken in by the radiator 51 and the waste heat from the ePT 11 are absorbed from the cooling water to the refrigerant through heat exchange in the chiller 21, the air conditioning system 7 (heat pump) is activated, and heat exchange occurs in the heater core 61 between the cooling water heated in the water-cooled condenser 41 and the air in the vehicle interior, heating the vehicle interior. The third valve 83 connects the sixth waterway 60 and the fourth waterway 40. In addition, the switching valve 73 of the air conditioning system 7 connects the first refrigerant flow path 70A to the third refrigerant flow path 70C, and the switching valve 74 connects the third refrigerant flow path 70C to the first refrigerant flow path 70A. Hereinafter, the pattern of the cooling water flow path 1 and refrigerant flow path 70 shown in Figure 10 will be referred to as the seventh waterway pattern.

[0060] Next, when the outlet temperature of the chiller 21 is above the ambient temperature, and when the outlet temperature of the ePT 11 is above the temperature of the battery 31, the cooling water channel 1 is configured to absorb the waste heat from the ePT 11 into the coolant. Specifically, as shown in Figure 11, the first valve 81 connects the first water channel 10 where the ePT 11 is located and the second water channel 20 where the chiller 21 is located. The fifth valve 85 connects the second water channel 20 between the upstream of the chiller 21 and the water pump 22 and the third water channel 30 between the downstream of the battery 31 and the water pump 32, and the second valve 20 connects the third water channel 20 downstream of the water pump 32 to the first water channel 10. As a result, the waste heat from the ePT11 is absorbed from the cooling water to the refrigerant through heat exchange in the chiller 21, the air conditioning system 7 (heat pump) operates, and heat exchange occurs in the heater core 61 between the cooling water heated in the water-cooled condenser 41 and the air in the vehicle interior, heating the vehicle interior. The third valve 83 connects the sixth waterway 60 and the fourth waterway 40, and the fourth valve 84 disconnects the fifth waterway 50 and the first waterway 10. In addition, the switching valve 73 of the air conditioning system 7 connects the first refrigerant flow path 70A to the third refrigerant flow path 70C, and the switching valve 74 connects the third refrigerant flow path 70C to the first refrigerant flow path 70A. Hereinafter, the pattern of the cooling water flow path 1 and refrigerant flow path 70 shown in Figure 11 will be referred to as the eighth waterway pattern.

[0061] Next, when the outlet temperature of the chiller 21 is higher than the ambient temperature, and the temperature of the battery 31 is higher than the outlet temperature of the ePT 11, the cooling water channel 1 is configured to absorb the waste heat from the ePT 11 and the battery 31 into the coolant. Specifically, as shown in Figure 12, the first valve 81 connects the second channel where the chiller 21 is located to the third channel where the battery 31 is located, and the second valve 82 connects the first channel 10 where the ePT 11 is located to the second channel where the chiller 21 is located, and also connects the third channel 30 to the first channel 10. As a result, the waste heat from the battery 31 and the waste heat from the ePT 11 are absorbed into the coolant from the cooling water through heat exchange in the chiller 21, the air conditioning system 7 (heat pump) is activated, and heat exchange occurs between the cooling water heated by the water-cooled condenser 41 and the air inside the vehicle at the heater core 61, heating the vehicle interior. Furthermore, the third valve 83 connects the sixth waterway 60 and the fourth waterway 40. Also, the switching valve 73 of the air conditioning system 7 connects the first refrigerant flow path 70A to the third refrigerant flow path 70C, and the switching valve 74 connects the third refrigerant flow path 70C to the first refrigerant flow path 70A. Hereinafter, the pattern of the cooling water flow path 1 and refrigerant flow path 70 shown in Figure 12 will be referred to as the ninth waterway pattern.

[0062] On the other hand, when there is a request for air conditioning, the refrigerant circulating through the water-cooled condenser 41 and evaporator 72 is supplied to the vehicle interior to cool it. Specifically, as shown in Figure 13, the switching valve 73 of the air conditioning system 7 connects the first refrigerant passage 70A to the second refrigerant passage 70B, and the switching valve 74 connects the second refrigerant passage 70B to the first refrigerant passage 70A. Regarding the cooling water passage 1, the first valve 81 connects the second water passage 20 and the third water passage 30, the second valve 82 connects the third water passage 30 to the second water passage 20 and also connects the sixth water passage to the first water passage, and the fourth valve 84 connects the fifth water passage 50 and the first water passage 10. In addition, the third valve 83 connects the first water passage 10 and the fourth water passage 40. Hereinafter, the pattern of the cooling water passage 1 and refrigerant passage 70 shown in Figure 13 will be referred to as the 10th water passage pattern.

[0063] Figure 14 is a flowchart illustrating the waterway switching control based on temperature control requests and heating / cooling requests in this embodiment. The following controls are all repeatedly executed by the controller 9 at predetermined intervals. The controller 9 acquires the temperature detected by each temperature sensor as appropriate.

[0064] When the vehicle system starts up, the controller 9 begins controlling the water channels based on temperature control and heating / cooling requests. For example, the vehicle system starts up when the ignition switch is turned on or when the battery 31 is connected to an external charger.

[0065] In step S101, the controller 9 checks the temperature T of the battery 31. Batt Based on this, it is determined whether or not the battery 31 requires warming up. Specifically, the temperature T of the battery 31 Batt at a predetermined temperature T th1 If the temperature is lower, it is determined that a warm-up is required. The predetermined temperature T here is th1 This temperature is such that the efficiency of the battery 31's output and charging becomes poor due to the low temperature, and can be set in advance through experiments, etc. If a warm-up request is made, the controller 9 starts d-axis discharge, or if it has already started, continues d-axis discharge and executes the process in step S102. On the other hand, if there is no warm-up request, the controller 9 executes the process in step S107. If d-axis discharge is being performed, the controller 9 terminates d-axis discharge and executes the process in step S107.

[0066] In step S102, the controller 9 determines the direction of the coolant flow (coolant flow direction determination control). That is, it determines whether to flow the coolant in the order of motor 111 then inverter 112, or inverter 112 then motor 111. Specifically, it determines whether the ePT 11 has finished warming up, or whether the loss of motor 111 is greater than the loss of inverter 112. If the ePT 11 has not finished warming up, and the loss of inverter 112 is greater than or equal to the loss of motor 111, it determines to flow the coolant in the order of motor 111 then inverter 112. On the other hand, if the ePT 11 has finished warming up, or if the loss of motor 111 is greater than the loss of inverter 112, it determines to flow the coolant in the order of inverter 112 then motor 111. Details of the coolant flow direction determination control flow will be described later.

[0067] In step S102, if it is determined that the ePT11 has not warmed up and that the losses of the inverter112 are greater than or equal to the losses of the motor111, the controller 9 executes the process in step S103.

[0068] In step S103, the controller 9 controls the switching valve 80 of the cooling water channel 1 and the switching valves 73 and 74 of the refrigerant flow path 70 to achieve the first water channel pattern (Figure 2). As a result, the waste heat from the ePT 11 is absorbed by the refrigerant of the air conditioning system 7 via the chiller 21, the cooling water is heated by heat exchange between the refrigerant and the cooling water in the water-cooled condenser 41, the heated cooling water is supplied to the battery 31, and the battery (BT) 31 is warmed up. The cooling water also flows in the order of motor (MT) 111 and inverter (INV) 112. This allows the battery 31 to be supplied with cooling water at a higher temperature without the waste heat from the inverter 112 being absorbed by the motor 111. After controlling the switching valve 80 of the cooling water channel 1 and the switching valves 73 and 74 of the refrigerant flow path 70 to achieve the first water channel pattern in step S103, the controller 9 executes the process in step S105.

[0069] On the other hand, if in step S102 the controller determines that the ePT11 has finished warming up, or that the motor 111's losses are greater than the inverter 112's losses, the controller 9 executes the process in step S104.

[0070] In step S104, the controller 9 controls the switching valve 80 of the cooling water channel 1 and the switching valves 73 and 74 of the refrigerant flow path 70 to achieve the second water channel pattern (Figure 3). As a result, the waste heat from the ePT 11 is absorbed by the refrigerant of the air conditioning system 7 via the chiller 21, the cooling water is heated by heat exchange between the refrigerant and the cooling water in the water-cooled condenser 41, the heated cooling water is supplied to the battery 31, and the battery 31 is warmed up. The cooling water also flows in the order of inverter 112 and motor 111. This allows the heat stored in the motor 111 to be used to the maximum extent to warm up the battery 31. After controlling the switching valve 80 of the cooling water channel 1 and the switching valves 73 and 74 of the refrigerant flow path 70 to achieve the second water channel pattern in step S104, the controller 9 executes the process in step S105.

[0071] In step S105, the controller 9 determines whether or not there is a heating request in the air conditioning system 7. In this embodiment, if the air conditioning system 7 is turned on and the temperature inside the vehicle is lower than the air conditioning set temperature, the controller 9 determines that there is a heating request.

[0072] If heating is requested, in step S106, the controller 9 heats the vehicle interior using a PTC heater or the like.

[0073] In step S106, when the vehicle interior is heated, the controller 9 terminates the water channel switching control based on the temperature control request and the heating / cooling request.

[0074] In step S105, if there is no heating request, the controller 9 terminates the waterway switching control based on the temperature control request and the heating / cooling request.

[0075] In step S101, when there is no warm-up requirement for the battery 31, the controller 9, in step S107, determines whether there is a cooling requirement for the battery 31 based on the temperature T of the battery 31. Specifically, when the temperature T of the battery 31 is higher than a predetermined temperature T, the controller 9 determines that there is a cooling requirement. The predetermined temperature T here is a temperature at which the efficiency of the output, charging, etc. of the battery 31 deteriorates due to high temperature, and can be set in advance by experiments or the like. When there is a cooling requirement, the controller 9 executes the process of step S108. On the other hand, when there is no cooling requirement, the controller 9 executes the process of step S115. Batt Based on this, the controller 9 determines whether there is a cooling requirement for the battery 31. Specifically, when the temperature T of the battery 31 Batt is higher than a predetermined temperature T th2 , the controller 9 determines that there is a cooling requirement. The predetermined temperature T here th2 is a temperature at which the efficiency of the output, charging, etc. of the battery 31 deteriorates due to high temperature, and can be set in advance by experiments or the like. When there is a cooling requirement, the controller 9 executes the process of step S108. On the other hand, when there is no cooling requirement, the controller 9 executes the process of step S115.

[0076] In step S108, the controller 9 determines whether the outlet temperature T of the radiator 51 is lower than the temperature T of the battery 31. When the outlet temperature T of the radiator 51 is lower than the temperature T of the battery 31, the controller 9 executes the process of step S109. On the other hand, when the outlet temperature T of the radiator 51 is equal to or higher than the temperature T of the battery 31, the controller 9 executes the process of step S112. RAD is lower than the temperature T of the battery 31 Batt ? When the outlet temperature T of the radiator 51 RAD is lower than the temperature T of the battery 31 Batt , the controller 9 executes the process of step S109. On the other hand, when the outlet temperature T of the radiator 51 RAD is equal to or higher than the temperature T of the battery 31 Batt , the controller 9 executes the process of step S112.

[0077] When the outlet temperature T of the radiator 51 RAD is lower than the temperature T of the battery 31 Batt , in step S109, the controller 9 determines whether there is a cooling requirement in the air-conditioning system 7. In this embodiment, when the air-conditioning system 7 is on and the temperature inside the vehicle cabin is higher than the air-conditioning set temperature, the controller 9 determines that there is a cooling requirement. When there is no cooling requirement, the controller 9 executes the process of step S110. On the other hand, when there is a cooling requirement, the controller 9 executes the process of step S111.

[0078] If there is no cooling request, in step S110, the controller 9 controls the switching valve 80 of the cooling water channel 1 and the switching valves 73 and 74 of the refrigerant flow path 70 so that the third water channel pattern (Figure 6) is achieved. As a result, cooling water cooled by outside air taken in via the radiator (RAD) 51 is supplied to the battery 31, and the battery 31 is cooled. After executing the process in step S110, the controller 9 terminates the water channel switching control based on temperature control requests and heating / cooling requests.

[0079] If there is a request for cooling, in step S111, the controller 9 controls the switching valve 80 of the cooling water passage 1 and the switching valves 73 and 74 of the refrigerant passage 70 so that the fourth water passage pattern (Figure 7) is achieved. As a result, the cooling water cooled by the outside air taken in via the radiator 51 is supplied to the battery 31, and the battery 31 is cooled. In addition, heat exchange occurs between the cooling water cooled by the radiator 51 and the refrigerant in the refrigerant passage 70 in the water-cooled condenser 41, the air conditioning system 7 is driven, and the heat-exchanged refrigerant is supplied to the vehicle interior by the blower, thereby cooling the vehicle interior. After executing the process in step S111, the controller 9 terminates the water passage switching control based on the temperature control request and the heating / cooling request.

[0080] In step S108, the outlet temperature T of the radiator 51 RAD The temperature of battery 31 T Batt In the above case, the controller 9 determines in step S112 whether or not there is a cooling request in the air conditioning system 7. As mentioned above, if the temperature inside the vehicle is higher than the air conditioning set temperature when the air conditioning system 7 is ON, the controller 9 determines that there is a cooling request. If there is no cooling request, the controller 9 executes the process in step S113. On the other hand, if there is a cooling request, the controller 9 executes the process in step S114.

[0081] If there is no cooling request, in step S113, the controller 9 controls the switching valve 80 of the cooling water channel 1 and the switching valves 73 and 74 of the refrigerant flow path 70 so that the fifth water channel pattern (Figure 8) is achieved. As a result, the cooling water cooled in the chiller 21 is supplied to the battery 31, and the battery 31 is cooled. After executing the process in step S113, the controller 9 terminates the water channel switching control based on temperature control requests and heating / cooling requests.

[0082] If there is a request for cooling, in step S114, the controller 9 controls the switching valve 80 of the cooling water channel 1 and the switching valves 73 and 74 of the refrigerant flow path 70 so that the sixth water channel pattern (Figure 9) is achieved. As a result, the cooling water cooled in the chiller 21 is supplied to the battery 31, and the battery 31 is cooled. In addition, the refrigerant circulating in the water-cooled condenser 41 and evaporator 72 is supplied to the vehicle interior by the blower, thereby cooling the vehicle interior. After executing the process in step S114, the controller 9 terminates the water channel switching control based on the temperature control request and the heating / cooling request.

[0083] In step S107, if there is no cooling request for the battery 31, that is, if there is neither a warm-up request nor a cooling request for the battery 31, the controller 9 determines in step S115 whether there is a heating request for the air conditioning system 7. As mentioned above, when the air conditioning system 7 is on and the temperature inside the vehicle is lower than the air conditioning set temperature, the controller 9 determines that there is a heating request. If there is a heating request, the controller 9 executes the process in step S116. On the other hand, if there is no heating request, the controller 9 executes the process in step S121.

[0084] In step S115, if there is a heating request, the controller 9, in step S116, sets the outside air temperature T OUT The outlet temperature T of chiller 21 Chill Determine whether it is higher or lower. (Outside air temperature T) OUT The outlet temperature T of chiller 21 Chill If it is higher than T, the controller 9 performs the process in step S117. Meanwhile, the outlet temperature T of the chiller 21Chill The outside temperature T OUT In the above case, the controller 9 executes the process in step S118.

[0085] Outside temperature T OUT The outlet temperature T of chiller 21 Chill If the temperature is higher, in step S117, the controller 9 controls the switching valve 80 of the cooling water channel 1 and the switching valves 73 and 74 of the refrigerant flow path 70 so that the seventh water channel pattern (Figure 10) is achieved. As a result, the heat from the outside air taken in by the radiator 51 and the waste heat from the ePT 11 are absorbed from the cooling water to the refrigerant through heat exchange in the chiller 21, the air conditioning system 7 (heat pump) is activated, and heat exchange occurs between the cooling water heated in the water-cooled condenser 41 and the air in the vehicle interior in the heater core 61, heating the vehicle interior. After executing the process in step S117, the controller 9 terminates the water channel switching control based on the temperature control request and the heating / cooling request.

[0086] In step S116, the outlet temperature T of the chiller 21 Chill The outside temperature T OUT In the above case, in step S118, the controller 9 controls the outlet temperature T of the ePT11. ePT The temperature of battery 31 T Batt Determine whether it is above or below the above. ePT11 outlet temperature T ePT The temperature of battery 31 T Batt In the above case, the controller 9 executes the process in step S119. Meanwhile, the temperature T of the battery 31 Batt The outlet temperature T of ePT11 ePT If the value is higher, the controller 9 executes the process of step S120.

[0087] ePT11 outlet temperature T ePT The temperature of battery 31 T BattIn the above case, in step S119, the controller 9 controls the switching valve 80 of the cooling water channel 1 and the switching valves 73 and 74 of the refrigerant flow path 70 so that the eighth water channel pattern (Figure 11) is achieved. As a result, the waste heat from the ePT 11 is absorbed from the cooling water to the refrigerant through heat exchange in the chiller 21, the air conditioning system 7 (heat pump) is activated, and heat exchange occurs between the cooling water heated in the water-cooled condenser 41 and the air in the vehicle interior at the heater core 61, heating the vehicle interior. After executing the process in step S119, the controller 9 terminates the water channel switching control based on the temperature control request and the heating / cooling request.

[0088] In step S118, the temperature T of the battery 31 Batt The outlet temperature T of ePT11 ePT If the temperature is higher than the specified value, in step S120, the controller 9 controls the switching valve 80 of the cooling water channel 1 and the switching valves 73 and 74 of the refrigerant flow path 70 so that the ninth water channel pattern (Figure 12) is achieved. As a result, the waste heat from the battery 31 and the waste heat from the ePT 11 are absorbed from the cooling water into the refrigerant through heat exchange in the chiller 21, the air conditioning system 7 (heat pump) is activated, and heat exchange occurs between the cooling water heated in the water-cooled condenser 41 and the air in the vehicle interior in the heater core 61, heating the vehicle interior. After executing the process in step S120, the controller 9 terminates the water channel switching control based on the temperature control request and the heating / cooling request.

[0089] In step S115, if there is no heating request for the air conditioning system 7, the controller 9 determines in step S121 whether there is a cooling request for the air conditioning system 7. As mentioned above, when the air conditioning system 7 is ON and the temperature inside the vehicle is higher than the air conditioning set temperature, the controller 9 determines that there is a cooling request. If there is a cooling request, the controller 9 executes the process in step S122. On the other hand, if there is no cooling request, the controller 9 executes the process in step S123.

[0090] In step S121, if there is a request for cooling, in step S122, the controller 9 controls the switching valve 80 of the cooling water channel 1 and the switching valves 73 and 74 of the refrigerant flow path 70 so that the 10th water channel pattern (Figure 13) is achieved. As a result, the refrigerant circulating through the water-cooled condenser 41 and evaporator 72 is supplied to the vehicle interior, and the vehicle interior is cooled. After executing the process in step S122, the controller 9 terminates the water channel switching control based on the temperature control request and the heating / cooling request.

[0091] In step S121, if there is no cooling request, the controller 9 controls the switching valve 80 in step S123 so that cooling water circulates through the cooling water channel 1. The controller 9 controls the switching valve 80 in the same manner as, for example, the ninth water channel pattern (Figure 12), but is not limited to this. Also, at this time, the air conditioning system 7 is not driven. After executing the process in step S123, the controller 9 terminates the water channel switching control based on temperature control requests and heating / cooling requests.

[0092] Figure 15 is a flowchart illustrating the cooling water flow direction determination control in this embodiment, i.e., the process of step S102 in Figure 14.

[0093] In step S101 (Figure 14), if there is a request to warm up the battery 31, the controller 9 starts the coolant flow direction determination control.

[0094] When the cooling water flow direction determination control is started, the controller 9 determines in step S1021 whether or not the electric vehicle is running. Whether or not the electric vehicle is running can be determined based on, for example, torque or accelerator opening, but is not limited to this. If the electric vehicle is running, the controller 9 executes the process in step S1022. On the other hand, if the electric vehicle is stopped, the controller 9 executes the process in step S1024.

[0095] In step S1022, the controller 9 sets the outlet temperature T of the ePT11. ePT However, a predetermined value (threshold) T th3Determine whether or not the threshold is greater than or equal to the above. th3 This is a temperature high enough that there is no need to warm up the ePT11, and can be set in advance through experiments, etc. The outlet temperature T of the ePT11 ePT is a predetermined value (threshold) T th3 If the above conditions are met, it can be determined that the ePT11 has finished warming up. As mentioned above, when the ePT11 has finished warming up, it is estimated that the heat generated by the motor with a larger heat capacity will be greater. Therefore, the outlet temperature T of the ePT11 ePT is a predetermined value (threshold) T th3 If the above conditions are met, the controller 9 controls the switching valve 80 so that the cooling water flows in the order of inverter 112 and motor 111, and terminates the cooling water flow direction determination control. That is, the controller 9 executes the process of step S104 in Figure 14.

[0096] On the other hand, the outlet temperature T of ePT11 ePT However, a predetermined value (threshold) T th3 If the value is lower, the controller 9 executes the process in step S1023.

[0097] In step S1023, the controller 9 determines whether the loss of the motor 111 is greater than the loss of the inverter 112. Specifically, it determines whether the driving force d of the electric vehicle is greater than a predetermined value (threshold) d. th Determine whether it is above or below the threshold. th This value is such that the loss of motor 111 is greater than the loss of inverter 112, and can be set in advance through experiments or other means. In this embodiment, the relationship between the loss of motor 111 and the loss of inverter 112 is estimated from the driving force of the vehicle, but this is not necessarily the only way; for example, the relationship may be estimated from the temperature of motor 111 and inverter 112. The driving force d of the electric vehicle is the threshold d th If the value is greater than (i.e., the loss of motor 111 is greater than the loss of inverter 112), then it can be determined that the amount of heat generated by motor 111 is greater than the amount of heat generated by inverter 112. Therefore, if the driving force d is greater than the threshold d thIf the value is greater than the specified value, the controller 9 controls the switching valve 80 so that the cooling water flows in the order of inverter 112 and motor 111, and terminates the cooling water flow direction determination control. That is, the controller 9 performs the process of step S104 in Figure 14.

[0098] On the other hand, the driving force d of the electric vehicle is at a threshold d th If the following conditions are met (i.e., the loss of inverter 112 is greater than or equal to the loss of motor 111), then it can be determined that the amount of heat generated by inverter 112 is greater than or equal to the amount of heat generated by motor 111. Therefore, the driving force d is equal to the threshold d. th In the following case, the controller 9 controls the switching valve 80 so that the cooling water flows in the order of motor 111 and inverter 112, and terminates the cooling water flow direction determination control. That is, it executes the process of step S103 in Figure 14.

[0099] If the electric vehicle is stopped in step S1021, the controller 9 determines in step S1024 whether or not the electric vehicle's battery 31 is being charged. For example, if the battery 31 is connected to an external charger and power is being supplied to the battery 31, the controller 9 determines that it is being charged. If the battery 31 is being charged, the controller 9 executes the process in step S1025. On the other hand, if the battery 31 is not being charged, it is presumed that the electric vehicle is either in a state before starting to run or before starting to charge. In this case, the controller 9 returns to the process in step S1021.

[0100] In step S1025, the controller 9 sets the outlet temperature T of the ePT11. ePT However, a predetermined value (threshold) T th3 Determine whether or not the above is true. As mentioned above, threshold T th3 This is a temperature high enough that there is no need to warm up the ePT11, and can be set in advance through experiments, etc. The outlet temperature T of the ePT11 ePT is a predetermined value (threshold) T th3If the above conditions are met, it can be determined that the warm-up of the ePT11 is complete. Therefore, the controller 9 controls the switching valve 80 so that the cooling water flows in the order of inverter 112 and motor 111, and terminates the cooling water flow direction determination control. That is, the controller 9 executes the process of step S104 in Figure 14. Meanwhile, the outlet temperature T of the ePT11 ePT However, a predetermined value (threshold) T th3 If the value is lower, the controller 9 controls the switching valve 80 so that the cooling water flows in the order of motor 111 and inverter 112, and terminates the cooling water flow direction determination control. That is, the controller 9 performs the process of step S103 in Figure 14.

[0101] As described above, in the cooling system 100 of this electric vehicle, the temperature of the battery 31 and the temperature inside the vehicle can be efficiently controlled by appropriately switching the switching valve 80 according to the state of the electric vehicle.

[0102] According to the electric vehicle control method and electric vehicle of the above-described embodiment, the following effects can be obtained.

[0103] In the control method for the electric vehicle of this embodiment, when warming up the battery 31, the waste heat from the electric powertrain (ePT) 11 is absorbed by the refrigerant of the air conditioning system 7 via the chiller (cooling device) 21, and the water-cooled condenser 41 heats the cooling water by exchanging heat with the refrigerant. The switching valve 80 is then controlled to supply the heated cooling water to the battery 31. That is, first, the waste heat from the ePT 11 is absorbed by the refrigerant of the air conditioning system 7, thereby driving the air conditioning system 7 (heat pump). Then, the cooling water heated by the heat exchange in the water-cooled condenser 41 is supplied to the battery 31 to warm up the battery 31. In this way, by using the waste heat from the ePT 11 as a heat source for the air conditioning system 7 (heat pump), the air conditioning system 7 (heat pump) is driven efficiently, and the heat absorbed by the refrigerant is absorbed by the cooling water via the water-cooled condenser 41 and supplied to the battery 31. This allows a larger amount of heat to be recovered into the cooling water. Therefore, the amount of heat supplied to the battery 31 can be increased compared to recovering the waste heat from the ePT11 with cooling water and supplying it directly to the battery 31, allowing the battery 31 to be warmed up more efficiently.

[0104] Furthermore, by using a water-cooled condenser (water-cooled capacitor) 41, the waste heat from the ePT 11 absorbed by the refrigerant can be absorbed into the cooling water and supplied to the battery 31. As a result, the waste heat from the ePT 11 can be used to drive the air conditioning system 7 and warm up the battery 31. Therefore, waste heat can be effectively utilized, and the energy consumption is improved.

[0105] In the electric vehicle control method of this embodiment, when warming up the battery 31, the switching valve 80 is controlled so that the cooling water flows in the order of motor 111 and inverter 112. As a result, the waste heat from the inverter 112 is not absorbed by the motor 111, and higher temperature cooling water can be supplied to the battery 31. Therefore, the battery 31 can be warmed up more efficiently.

[0106] In the electric vehicle control method of this embodiment, when the battery 31 is being charged or the electric vehicle is running, and the temperature of the coolant at the outlet of the ePT (electric powertrain) 11 is a predetermined value Tth3 In the above cases, or when the electric vehicle is running and the losses of the inverter 112 are less than or equal to the losses of the motor 111, the switching valve 80 is controlled so that the cooling water flows in the order of inverter 112 and then motor 111. This allows the heat stored in the motor 111 to be used to the maximum extent for warming up the battery 31 when the heat generated by the motor 111 is greater than that generated by the inverter 112, thereby improving the warming efficiency of the battery 31.

[0107] In the electric vehicle control method of this embodiment, when there is no request for the battery 31 to warm up and there is a request for heating inside the vehicle, if the temperature of the coolant at the outlet of the chiller (cooling device) 21 is lower than the ambient temperature, the switching valve 80 is controlled to supply the chiller (cooling device) 21 with coolant heated by ambient air taken in via the radiator 51 and waste heat from the ePT (electric powertrain) 11, and to exchange heat with the refrigerant. Furthermore, when the temperature of the coolant at the outlet of the chiller (cooling device) 21 is higher than the ambient temperature, and when the temperature of the coolant at the outlet of the ePT (electric powertrain) 11 is higher than the temperature of the battery 31, the switching valve 80 is controlled to supply the chiller (cooling device) 21 with coolant heated by the waste heat of the ePT (electric powertrain) 11 to exchange heat with the refrigerant. When the temperature of the coolant at the outlet of the ePT (electric powertrain) 11 is lower than the temperature of the battery 31, the switching valve 80 is controlled to supply the chiller (cooling device) 21 with coolant heated by the waste heat of the battery 31 and the waste heat of the ePT (electric powertrain) 11 to exchange heat with the refrigerant. This allows for efficient heating of the vehicle interior and improves energy efficiency.

[0108] In the electric vehicle control method of this embodiment, when cooling the battery 31, if the temperature of the coolant at the outlet of the radiator 51 is equal to or higher than the temperature of the battery 31, the switching valve 80 is controlled to supply the coolant cooled by the chiller (cooling device) 21 to the battery 31. If the temperature of the coolant at the outlet of the radiator 51 is lower than the temperature of the battery 31, the switching valve 80 is controlled to supply the coolant cooled by the outside air taken in through the radiator 51 to the battery 31. This allows for efficient cooling of the vehicle interior and improves energy efficiency.

[0109] In this embodiment, control in cases where there is a cooling request for the battery 31 and cases where there is no temperature control request for the battery 31 has also been described. However, the control in these cases is not necessarily limited to what has been described in this embodiment. That is, as long as the switching valve 80 is controlled so that, at least when there is a warm-up request for the battery 31, the waste heat from the ePT 11 is used as a heat source for the air conditioning system 7 (heat pump) to drive the air conditioning system 7 (heat pump), the heat absorbed by the refrigerant is absorbed by the cooling water by the water-cooled condenser 41, and supplied to the battery 31, the control is not limited to this embodiment.

[0110] Furthermore, the configuration of the cooling system 100 described in this embodiment is merely an example, and it is not necessary to use the same configuration. That is, when there is a need to warm up the battery 31, the waste heat from the ePT 11 is used as a heat source to drive the air conditioning system 7 (heat pump), the heat absorbed by the refrigerant is absorbed into the cooling water by the water-cooled condenser 41, and supplied to the battery 31. In any case, the configuration of the cooling system 100 can be changed as needed. For example, the cooling system 100 may have a configuration without the fifth waterway 50 and the sixth waterway 60. Even in this case, the waste heat from the ePT 11 is used as a heat source to drive the air conditioning system 7 (heat pump), the heat absorbed by the refrigerant is absorbed into the cooling water by the water-cooled condenser 41, and supplied to the battery 31.

[0111] Although embodiments of the present invention have been described above, these embodiments only represent a part of the application examples of the present invention, and are not intended to limit the technical scope of the present invention to the specific configurations of the above embodiments. [Explanation of Symbols]

[0112] 1: Cooling water channel, 7: Air conditioning system, 9: Controller, 10: First water channel, 11: Electric powertrain (ePT), 20: Second water channel, 21: Chiller, 30: Third water channel, 31: Battery, 40: Fourth water channel, 41: Condenser (water-cooled condenser), 70: Refrigerant flow path, 80: Switching valve, 100: Cooling system

Claims

1. A control method for an electric vehicle comprising an air conditioning system having a cooling water passage through which cooling water for cooling a battery flows, and a refrigerant passage through which a refrigerant flows, The cooling water passage includes a first water passage in which an electric powertrain including a motor and inverter is arranged, a second water passage in which a cooling device capable of heat exchange between the cooling water and the refrigerant is arranged, a third water passage in which a battery is arranged, and a fourth water passage in which a condenser capable of heat exchange between the refrigerant and the cooling water is arranged. Switching valves are provided on the cooling water channels to connect or disconnect each of the first to fourth channels, respectively. When warming up the battery, the waste heat from the electric powertrain is absorbed by the refrigerant via the cooling device, the refrigerant and the cooling water are heat-exchanged via the condenser to heat the cooling water, and the switching valve is controlled to supply the heated cooling water to the battery. A method for controlling electric vehicles.

2. A control method for an electric vehicle according to claim 1, When warming up the battery, the switching valve is controlled so that the cooling water flows in the order of the motor and then the inverter. A method for controlling electric vehicles.

3. A control method for an electric vehicle according to claim 2, When warming up the aforementioned battery, If the battery is being charged or the electric vehicle is running and the temperature of the coolant at the outlet of the electric powertrain is above a predetermined value, or If the electric vehicle is in motion and the losses of the inverter are less than or equal to the losses of the motor, The switching valve is controlled so that the cooling water flows in the order of the inverter and the motor. A method for controlling electric vehicles.

4. A method for controlling an electric vehicle according to any one of claims 1 to 3, The cooling water passage further includes a fifth water passage in which a radiator is located, The aforementioned switching valve connects or disconnects each of the first to fifth waterways, If there is no request for the aforementioned battery to warm up, and there is a request for heating inside the vehicle, When the temperature of the cooling water at the outlet of the cooling device is lower than the ambient temperature, the switching valve is controlled to supply the cooling device with the cooling water heated by the ambient air taken in through the radiator and the waste heat from the electric powertrain, thereby exchanging heat with the refrigerant. When the temperature of the cooling water at the outlet of the cooling device is higher than or equal to the ambient temperature, and when the temperature of the cooling water at the outlet of the electric powertrain is higher than or equal to the temperature of the battery, the switching valve is controlled to supply the cooling device with the cooling water heated by the waste heat of the electric powertrain to exchange heat with the refrigerant, and when the temperature of the cooling water at the outlet of the electric powertrain is lower than the temperature of the battery, the switching valve is controlled to supply the cooling device with the cooling water heated by the waste heat of the battery and the waste heat of the electric powertrain to exchange heat with the refrigerant. A method for controlling electric vehicles.

5. A control method for an electric vehicle according to claim 4, When cooling the aforementioned battery, If the temperature of the coolant at the outlet of the radiator is equal to or higher than the temperature of the battery, the switching valve is controlled to supply the coolant cooled by the cooling device to the battery. If the temperature of the coolant at the outlet of the radiator is lower than the temperature of the battery, the switching valve is controlled to supply the coolant cooled by the outside air taken in through the radiator to the battery. A method for controlling electric vehicles.

6. An electric vehicle comprising an air conditioning system having a cooling water passage through which cooling water for cooling the battery flows, a refrigerant passage through which refrigerant flows, and a controller, The cooling water passage includes a first water passage in which an electric powertrain including a motor and inverter is arranged, a second water passage in which a cooling device capable of heat exchange between the cooling water and the refrigerant is arranged, a third water passage in which a battery is arranged, and a fourth water passage in which a condenser capable of heat exchange between the refrigerant and the cooling water is arranged. Switching valves are provided on the cooling water channels to connect or disconnect each of the first to fourth channels, respectively. The controller controls the switching valve to warm up the battery, thereby absorbing the waste heat from the electric powertrain into the refrigerant via the cooling device, heating the cooling water through heat exchange between the refrigerant and the cooling water via the condenser, and supplying the heated cooling water to the battery. Electric vehicle.

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