Electric vehicle

Abstract

To suppress traveling performance (traveling possible distance) from deteriorating.SOLUTION: When a first temperature adjustment is requested as an operation request, operation of a temperature adjustment device is restricted more when a ratio of power storage in a power storage device or allowable output power is less than a first threshold, in comparison with when the ratio or the power is above the first threshold. When the first temperature adjustment is not requested as the operation request but a second temperature adjustment is requested, the operation of the temperature adjustment device is restricted more when the ratio of power storage or the allowable output power is less than a second threshold larger than the first threshold, in comparison with when the ratio or the power is equal to or larger than the second threshold.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to electric vehicles. [Background technology]

[0002] Conventionally, an electric vehicle of this type has been proposed in which the refrigerant from an air conditioning system that cools the passenger compartment is used to cool the battery, and when the air conditioning system is operating above a certain load, the battery is not cooled and at least one of the power input and output to the battery is limited (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2023-007581 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the electric vehicle described above, the air conditioning system does not stop cooling the battery unless the load exceeds a certain level. This means that a relatively large amount of power is consumed to cool the battery, reducing the amount of power required for driving, which may result in a decrease in driving performance (travel distance). The electric vehicle disclosed herein has a primary objective of suppressing the decrease in driving performance (travel distance). [Means for solving the problem]

[0005] The electric vehicle of the present disclosure employs the following means to achieve the above-mentioned main object. The electric vehicle of the present disclosure is an electric vehicle including a power storage device that exchanges electric power with a driving motor, a temperature adjustment device that operates by receiving a supply of electric power from the power storage device, and a control device that controls the temperature adjustment device to perform a first temperature adjustment that adjusts the temperature in the vehicle cabin and / or a second temperature adjustment that adjusts the temperature of the power storage device in response to an operation request of the temperature adjustment device, wherein, when the first temperature adjustment is requested as the operation request, the control device limits the operation of the temperature adjustment device when the power storage rate or the allowable output power of the power storage device is less than a first threshold value, compared to when the power storage rate or the allowable output power is equal to or greater than the first threshold value, and, when the first temperature adjustment is not requested but the second temperature adjustment is requested as the operation request, the control device limits the operation of the temperature adjustment device when the power storage rate or the allowable output power is less than a second threshold value that is greater than the first threshold value, compared to when the power storage rate or the allowable output power is equal to or greater than the second threshold value.

[0006] In the electric vehicle disclosed herein, by carrying out the above-mentioned process, when the power storage ratio decreases as the vehicle travels and the allowable output power becomes smaller, the operation of the temperature adjustment device for only the second temperature adjustment is restricted (at an early stage) in priority to the operation of the temperature adjustment device for the first temperature adjustment. This makes it possible to suppress the reduction in the amount of power for traveling by suppressing the consumption of the amount of power for adjusting the temperature of the battery, and suppress the reduction in the traveling performance (travelable distance). [Brief description of the drawings]

[0007] [Figure 1] 1 is a schematic configuration diagram of an electric vehicle 20 according to an embodiment of the present disclosure. [Diagram 2] 2 shows a schematic configuration of a temperature adjustment device 50 provided in an electric vehicle 20. [Diagram 3] 10 is a flowchart illustrating an example of a processing routine. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] An embodiment of the present disclosure will be described with reference to the drawings. Fig. 1 is a schematic diagram of an electric vehicle 20 according to an embodiment of the present disclosure, and Fig. 2 is a schematic diagram of a temperature adjustment device 50 provided in the electric vehicle 20. As shown in Fig. 1, the electric vehicle 20 according to the embodiment includes a motor 32, an inverter 34, a high-voltage battery (electricity storage device) 36, a low-voltage battery 40, a DC / DC converter 44, a charger 46, the temperature adjustment device 50, and an electronic control unit 80.

[0009] The motor 32 is configured as a synchronous generator motor, and a rotor of the motor 32 is connected to a drive shaft 26 which is connected to the drive wheels 22a, 22b via a differential gear 24. The inverter 34 is connected to a high-voltage power line 38 together with a high-voltage battery 36. The motor 32 is rotationally driven by an electronic control unit 80 controlling the switching of a plurality of switching elements of the inverter 34.

[0010] The high-voltage battery 36 is configured as, for example, a lithium-ion secondary battery or a nickel-metal hydride secondary battery with a rated voltage of several hundred volts. The low-voltage battery 40 is configured as, for example, a lead-acid battery with a rated voltage of 12 volts, and is connected to the low-voltage power line 42. The DC / DC converter 44 is connected to the high-voltage power line 38 and the low-voltage power line 42, and steps down the power of the high-voltage power line 38 and supplies it to the low-voltage power line 42. The charger 46 is connected to the high-voltage power line 38, and is configured to be able to charge the high-voltage battery 36 using power from the external power source when a connector 48 is connected to an external power source such as a household power source or a commercial power source.

[0011] The temperature adjustment device 50 is configured to be able to perform a first temperature adjustment for adjusting the temperature inside the vehicle cabin and a second temperature adjustment for adjusting the temperature of the high-voltage battery 36. As shown in FIG. 2, the temperature adjustment device 50 has a first thermal circuit 52, a second thermal circuit 58, and a third thermal circuit 70. The first thermal circuit 52 has a flow path 54, an electric pump 55, a chiller 76, and a heat exchanger 78. The flow path 54 is a flow path for circulating the heat exchange medium (cooling water) between the electric pump 55 and the battery flow path of the high-voltage battery 36, the chiller 76, and the heat exchanger 78. The electric pump 55 is connected to the low-voltage power line 42, and pumps the heat exchange medium in the flow path 54.

[0012] The second thermal circuit 58 has a compressor 60, a condenser 61, an expansion valve 62, an evaporator 63, an expansion valve 66, and a chiller 76. The compressor 60 is connected to the high-voltage power line 38, and compresses the refrigerant from the evaporator 63 and the chiller 76 to make it a high-temperature, high-pressure gaseous refrigerant. The condenser 61 changes the refrigerant from the compressor 60 to a normal-temperature, high-pressure liquid refrigerant by heat exchange with air. The air warmed by this heat exchange is blown into the vehicle cabin from a set air outlet (an air outlet switched by an air outlet switching unit so as to correspond to the air outlet pattern) by a blower when heating the vehicle cabin. The air outlet switching unit and the blower are connected to the low-voltage power line 42. The expansion valve 62 decompresses the refrigerant from the condenser 61 to make it a low-temperature, low-pressure gas-liquid mixed refrigerant. The evaporator 63 changes the refrigerant from the expansion valve 62 into a low-temperature, low-pressure gaseous refrigerant by heat exchange with the air. The air cooled by this heat exchange is blown into the vehicle cabin from a set outlet by a blower when cooling the vehicle cabin. Therefore, the compressor 60, the condenser 61, the expansion valve 62, and the evaporator 63 function as a refrigeration cycle. The expansion valve 66 reduces the pressure of the refrigerant from the condenser 61 to a low-temperature, low-pressure gas-liquid mixed refrigerant. The chiller 76 exchanges heat between the refrigerant from the expansion valve 66 and the heat exchange medium in the flow path 54 of the first thermal circuit 52. As a result, the heat exchange medium in the flow path 54 of the first thermal circuit 52 is cooled when the second thermal circuit 58 is operating.

[0013] The third thermal circuit 70 has a flow path 72, an electric pump 73, a heater 74, and a heat exchanger 78. The flow path 72 is a flow path for circulating a heat exchange medium (cooling water) to the electric pump 73, the heater 74, and the heat exchanger 78. The electric pump 73 is connected to the low-voltage power line 42, and pumps the heat exchange medium in the flow path 72. The heater 74 is connected to the high-voltage power line 38, and heats the heat exchange medium in the flow path 72. The heat exchanger 78 exchanges heat between the heat exchange medium in the flow path 72 and the heat exchange medium in the flow path 54 of the first thermal circuit 52. As a result, when the third thermal circuit 70 is operating, the heat exchange medium in the flow path 54 of the first thermal circuit 52 is heated.

[0014] 1, the electronic control unit 80 includes a microcomputer having a CPU, ROM, RAM, flash memory, input / output ports, and communication ports, various drive circuits, and various logic ICs. The electronic control unit 80 receives inputs of a rotational position θm from a rotational position sensor 32a that detects the rotational position of the rotor of the motor 32, and phase currents Iu, Iv, and Iw from current sensors that detect the phase currents of the respective phases of the motor 32. The electronic control unit 80 also receives inputs of a voltage Vb from a voltage sensor 36v attached between the terminals of the high-voltage battery 36, a current Ib from a current sensor 36i attached to the output terminal of the high-voltage battery 36, and a temperature Tb from a temperature sensor 36t attached to the high-voltage battery 36. The electronic control unit 80 also receives inputs of a start signal from a start switch 90, a shift position SP from a shift sensor 92 that detects the operation position of a shift lever 91, an accelerator opening Acc from an accelerator sensor 94 that detects the depression amount of an accelerator pedal 93, a brake pedal position from a brake sensor 96 that detects the depression amount of a brake pedal 95, and a vehicle speed V from a vehicle speed sensor 97. The electronic control unit 80 also receives inputs of an interior temperature Tc from an interior temperature sensor 98, an on / off signal, a set temperature (target temperature) Tc*, and an air outlet pattern from an air conditioning switch 99. The electronic control unit 80 outputs control signals to the inverter 34, control signals to the DC / DC converter 44, and control signals to the temperature adjustment device 50 (electric pumps 55, 73, compressor 60, heater 74, air outlet switching unit, and blower). The electronic control unit 80 calculates the rotation speed Nm of the motor 32 based on the rotation position θm of the rotor of the motor 32 from the rotation position sensor 32a. The electronic control unit 80 calculates the power storage rate SOC of the high-voltage battery 36 based on the integrated value of the current Ib of the high-voltage battery 36. The electronic control unit 80 calculates the output limit Wout, which is the allowable output power of the high-voltage battery 36, based on the power storage rate SOC and the temperature Tb of the high-voltage battery 36. The output limit Wout is calculated to be smaller as the power storage rate SOC becomes lower.

[0015] Next, the operation of the electric vehicle 20 of the embodiment, particularly the control of the temperature adjustment device 50, will be described. FIG. 3 is a flowchart showing an example of a processing routine repeatedly executed by the electronic control unit 80. When this routine is executed, the electronic control unit 80 first determines whether or not temperature adjustment in the vehicle cabin is required (step S100), and when it determines that temperature adjustment in the vehicle cabin is required, compares the output limit Wout of the high-voltage battery 36 with a threshold value Wref1 (step S110). Here, the determination of whether or not temperature adjustment in the vehicle cabin is required can be made based on an on / off signal from the air conditioning switch 99. The threshold value Wref1 is determined as the value of the output limit Wout at which the vehicle should be ready-off (traveling should be terminated).

[0016] When it is determined in step S110 that the output limit Wout of the high-voltage battery 36 is equal to or greater than the threshold value Wref1, the routine is terminated without prohibiting the operation of the temperature adjustment device 50. Since it is assumed that temperature adjustment in the vehicle cabin is required, the second thermal circuit 58, the outlet switching unit, and the blower of the temperature adjustment device 50 are operated. When the vehicle cabin temperature Tc is higher than the set temperature Tc*, it is determined that cooling of the vehicle cabin is required, and air cooled by heat exchange with the evaporator 63 is blown into the vehicle cabin from the set outlet (the outlet corresponding to the outlet pattern). When the vehicle cabin temperature Tc is lower than the set temperature Tc*, it is determined that heating of the vehicle cabin is required, and air warmed by heat exchange with the condenser 61 is blown into the vehicle cabin from the set outlet. When the second thermal circuit 58 and the blower are operated, when the temperature Tb of the high-voltage battery 36 is higher than the upper limit of the predetermined temperature range Rt, it is determined that cooling of the high-voltage battery 36 is required, and the first thermal circuit 52 is operated. As a result, the heat exchange medium in the flow path 54 of the first thermal circuit 52 is cooled by heat exchange in the chiller 76 and supplied to the battery flow path of the high-voltage battery 36. When the second thermal circuit 58 and the blower are operated, if the temperature Tb of the high-voltage battery 36 is lower than the lower limit of the predetermined temperature range Rt, it is determined that heating of the high-voltage battery 36 is required, and the first thermal circuit 52 and the third thermal circuit 70 are operated. As a result, the heat exchange medium in the flow path 54 of the first thermal circuit 52 is heated by heat exchange in the heat exchanger 78 and supplied to the battery flow path of the high-voltage battery 36. Note that the second thermal circuit 58 is also operated, and the heat exchange medium in the flow path 54 is cooled by heat exchange in the chiller 76, and the thermal efficiency is reduced. In the embodiment, the heater 74 is operated so that the degree of heating by heat exchange in the heat exchanger 78 is greater than the degree of cooling by heat exchange in the chiller 76 for the heat exchange medium in the flow path 54 of the first thermal circuit 52. When it is determined in step S110 that the output limit Wout of the high-voltage battery 36 is less than the threshold value Wref1, the operation of the temperature adjustment device 50 is prohibited (step S120), the ready-off state is established (step S130), and this routine is terminated.

[0017] When it is determined in step S100 that the temperature adjustment in the vehicle interior is not required, it is determined whether or not the temperature adjustment of the high-voltage battery 36 is required (step S140). When it is determined that the temperature adjustment of the high-voltage battery 36 is not required, this routine is terminated. When it is determined in step S140 that the temperature adjustment of the high-voltage battery 36 is required, the output limit Wout of the high-voltage battery 36 is compared with the threshold value Wref2 (step S150). Here, the threshold value Wref2 is set as a value somewhat larger than the threshold value Wref1. When it is determined in step S150 that the output limit Wout of the high-voltage battery 36 is equal to or greater than the threshold value Wref2, this routine is terminated without inhibiting the operation of the temperature adjustment device 50. In this case, when the temperature Tb of the high-voltage battery 36 is higher than the upper limit of the predetermined temperature range Rt, it is determined that the cooling of the high-voltage battery 36 is required, and the first thermal circuit 52 and the second thermal circuit 58 are operated. As a result, the heat exchange medium in the flow path 54 of the first thermal circuit 52 is cooled by heat exchange in the chiller 76 and supplied to the battery flow path of the high-voltage battery 36. On the other hand, when the temperature Tb of the high-voltage battery 36 is lower than the lower limit of the predetermined temperature range Rt, it is determined that heating of the high-voltage battery 36 is required, and the first thermal circuit 52 and the third thermal circuit 70 are operated. As a result, the heat exchange medium in the flow path 54 of the first thermal circuit 52 is heated by heat exchange in the heat exchanger 78 and supplied to the battery flow path of the high-voltage battery 36. When it is determined in step S150 that the output limit Wout of the high-voltage battery 36 is less than the threshold value Wref2, the operation of the temperature adjustment device 50 is prohibited (step S160), and this routine is terminated.

[0018] As the electric vehicle 20 travels, the power storage ratio SOC of the high-voltage battery 36 decreases, and the output limit Wout decreases. Therefore, in the embodiment, the operation of the temperature adjustment device 50 for adjusting the temperature of the high-voltage battery 36 is prohibited (at an early stage) in preference to the operation of the temperature adjustment device 50 for adjusting the temperature in the vehicle interior. This suppresses the consumption of the power amount for adjusting the temperature of the high-voltage battery 36, thereby suppressing a decrease in the power amount for traveling, and suppressing a decrease in the traveling performance (travelable distance). In addition, since the temperature adjustment in the vehicle interior includes a defroster that removes fogging from the windshield, the operation of the temperature adjustment device 50 for adjusting the temperature in the vehicle interior is not prohibited until the ready-off state, so that the anti-fogging performance is more sufficiently ensured.

[0019] In the electric vehicle 20 of the present embodiment described above, when temperature adjustment in the vehicle interior is requested, operation of the temperature adjustment device 50 is prohibited when the output limit Wout of the high-voltage battery 36 is less than the threshold value Wref1, and when temperature adjustment in the vehicle interior is not requested and temperature adjustment of the high-voltage battery 36 is requested, operation of the temperature adjustment device 50 is prohibited when the output limit Wout is less than a threshold value Wref2 that is greater than the threshold value Wref1. This suppresses consumption of the amount of power required for temperature adjustment of the high-voltage battery 36, thereby suppressing a decrease in the amount of power required for driving and suppressing a decrease in driving performance (travel distance).

[0020] In the above embodiment, when heating is required for temperature adjustment in the vehicle interior, air warmed by heat exchange with the condenser 61 of the second thermal circuit 58 is blown into the vehicle interior from the set air outlet, but in addition to or instead of this, air warmed by heat exchange with the heat exchange medium in the flow path 72 heated by the heater 74 of the third thermal circuit 70 may be blown into the vehicle interior from the set air outlet. This is particularly effective when the allowable degree of heating possible with the heater 74 is high.

[0021] In the above embodiment, when the temperature adjustment in the vehicle interior is requested in step S100, the process proceeds to step S110, but when the defroster is requested as part of the temperature adjustment in the vehicle interior, the process proceeds to step S110, and when something other than the defroster is requested, the process proceeds to step S150. The determination of whether the defroster is requested can be made based on the air outlet pattern from the air conditioning switch 99.

[0022] In the above embodiment, the output limit Wout of the high-voltage battery 36 is compared with the threshold value Wref1 or the threshold value Wref2 in steps S110 and S150, but the power storage rate SOC of the high-voltage battery 36 may be compared with the threshold value Sref1 or a threshold value Sref2 that is larger than the threshold value Sref1.

[0023] In the above-described embodiment, when the output limit Wout of the high-voltage battery 36 is equal to or greater than the threshold value Wref1 in step S110, operation of the temperature adjustment device 50 is not prohibited. However, when the output limit Wout of the high-voltage battery 36 is equal to or greater than the threshold value Wref1 and less than the threshold value Wref2, operation of the parts of the temperature adjustment device 50 related only to temperature adjustment of the high-voltage battery 36 (the first thermal circuit 52 and the third thermal circuit 70) may be prohibited.

[0024] In the above embodiment, operation of the temperature adjustment device 50 is prohibited in step 160, but it is sufficient to limit the operation of the temperature adjustment device 50 compared to when the output limit Wout of the high-voltage battery 36 is equal to or greater than the threshold value Wref2, and for example, the operating power of the temperature adjustment device 50 may be limited.

[0025] In the above embodiment, the high voltage battery 36 is used as the power storage device, but a capacitor or the like may also be used.

[0026] The above describes embodiments for implementing the present disclosure, but the present disclosure is not limited to these embodiments, and it goes without saying that the present disclosure can be implemented in various forms without departing from the gist of the present disclosure. [Industrial Applicability]

[0027] The present disclosure can be used in the electric vehicle manufacturing industry and the like. [Explanation of symbols]

[0028] 20 Electric vehicles, 36 High voltage batteries, 50 Temperature regulators, 80 Electronic control units.

Claims

[Claim 1] An electric vehicle including: a power storage device that exchanges electric power with a driving motor; a temperature adjustment device that operates by receiving a supply of electric power from the power storage device; and a control device that controls the temperature adjustment device to perform a first temperature adjustment that adjusts a temperature in a vehicle cabin and / or a second temperature adjustment that adjusts a temperature of the power storage device in response to an operation request of the temperature adjustment device, When the first temperature adjustment is requested as the operation request, the control device limits the operation of the temperature adjustment device when the power storage rate or the allowable output power of the power storage device is less than a first threshold value, compared to when it is equal to or greater than the first threshold value, and when the first temperature adjustment is not requested as the operation request and the second temperature adjustment is requested, limits the operation of the temperature adjustment device when the power storage rate or the allowable output power is less than a second threshold value that is greater than the first threshold value, compared to when it is equal to or greater than the second threshold value. Electric car.

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