Battery cooling control device and battery cooling control method

Abstract

To provide a battery cooling control device capable of cooling a battery when an outside air temperature is equal to or less than a predetermined temperature.SOLUTION: A battery cooling control device includes: an air conditioning system 20 for a vehicle, including at least an outdoor condenser 21, a compressor 22, an accumulator 23, an indoor condenser 27 and a battery cooler 40, the air conditioning system circulating a refrigerant; and a controller for controlling the air conditioning in a cabin by the air conditioning system 20. The controller performs a battery cooling control to cool a battery 3 by the battery cooler 40 using the air conditioning system 20 when a battery temperature is higher than a predetermined battery temperature threshold even if an outside air temperature is equal to or less than a predetermined temperature.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a battery cooling control device and a battery cooling control method. [Background technology]

[0002] Vehicle battery cooling systems for cooling traction batteries installed in vehicles have been known for some time (for example, Patent Document 1). The vehicle battery cooling system described in Patent Document 1 comprises a battery installed in a vehicle and used for driving, a battery case covering at least the bottom side of the battery, a battery cooling line provided integrally with the battery case portion on the bottom side of the battery and serving as a passage for refrigerant, and a refrigerant line connecting to an air conditioning system to supply and recover refrigerant to the battery cooling line. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2008-44476 [Overview of the project] [Problems that the invention aims to solve]

[0004] However, the above-mentioned vehicle battery cooling system has a problem in that, at low ambient temperatures, such as below 0°C, the refrigerant does not vaporize, and therefore the battery cannot be cooled.

[0005] The problem that this invention aims to solve is to provide a battery cooling control device and a battery cooling control method that can cool a battery when the ambient temperature is below a predetermined temperature. [Means for solving the problem]

[0006] The present invention solves the above problem by performing battery cooling control, which uses the vehicle's air conditioning system to cool the battery with a battery cooler if the battery temperature is higher than a predetermined battery temperature threshold, even if the outside temperature is below a predetermined temperature. [Effects of the Invention]

[0007] According to the present invention, the battery can be cooled even when the ambient temperature is below a predetermined temperature. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a block diagram of a battery cooling system according to one embodiment of the present invention. [Figure 2] Figure 2 is a block diagram of the air conditioning system. [Figure 3] Figure 3 is a block diagram of the air conditioning system. [Figure 4] Figure 4 is a flowchart showing the control flow of the cooling controller. [Figure 5] Figure 5 is a graph illustrating the relationship between ambient temperature and the on / off state of battery cooling. [Figure 6] Figure 6 is a graph showing the battery's temperature characteristics, SOC characteristics, and driving range characteristics. [Modes for carrying out the invention]

[0009] Hereinafter, an embodiment of the battery cooling control device and battery cooling control method according to the present invention will be described with reference to the drawings. Figure 1 is a block diagram of a battery cooling system according to an embodiment of the present invention. The battery cooling system comprises a battery 3 including a plurality of cells (batteries) 1, an inverter 2, a relay switch 4, a motor 5, a total voltage sensor 6, a current sensor 7, a temperature sensor 8, an ambient temperature sensor 9, a lithium-ion battery controller (LBC) 100, a vehicle controller 200, and a cooling controller 300. The device including at least the battery controller 100 and / or the cooling controller 300 corresponds to the "battery cooling control device" of the present invention, and the control processing performed by the battery controller 100 and / or the cooling controller 300 corresponds to the "battery cooling control method" of the present invention.

[0010] Battery 3 has battery modules M1, M2, and M3, each consisting of n cells (batteries) 1 connected in series (n is any positive integer; in the example shown in Figure 1, n=4). For example, lithium-ion batteries are used for cell 1. Battery 3 is a rechargeable secondary battery that can be charged by an external charging device. When a charging cable is connected to the vehicle, battery 3 is electrically connected to the external charging device in a rechargeable state. Battery 3 is also connected to motor 5 via inverter 2. Battery 3 discharges when motor 5 is operating and charges when motor 5 is regenerating. The number of battery modules is not limited to three; it may be one, two, or four or more.

[0011] Three battery modules M1 to M3 are connected in series, and motors 5 for electric vehicles, etc., are connected to both ends of them via inverters 2. Inverter 2 is a power conversion circuit that converts power between the battery 3 and the motor 5.

[0012] The relay switch 4 controls the main power supply by switching it ON or OFF, and is connected between the battery 3, the motor 5, and the inverter 2.

[0013] The total voltage sensor 6 is a sensor connected between the terminals of both poles of the battery 3 to detect the voltage of the battery 3. The current sensor 7 is connected between the battery 3 and the inverter 2 to detect the current output from the battery 3. The temperature sensor 8 is provided on the battery 3 to detect the temperature of the battery 3. Note that the temperature sensor 8 is provided at multiple locations of the battery 3, and the average temperature of the detection values of the multiple temperature sensors is taken as the detected temperature of the battery 3. The total voltage sensor 6, the current sensor 7, and the temperature sensor 8 detect the total voltage, current, and temperature of the battery 3 according to commands from the LBC100 and / or the vehicle controller 200, and transmit the detection results to the cooling controller 300. The outside air temperature sensor 9 is a sensor that detects the outside temperature, and transmits the detection result to the LBC100, the vehicle controller 200, and / or the cooling controller 300.

[0014] The LBC100 is a controller (processor) that performs state management of the battery 3 and charge / discharge control of the battery 3, and includes cell controllers CC1, CC2, CC3, photocouplers PC1, PC2, and a battery controller (CPU) 10. The three cell controllers CC1, CC2, CC3 monitor the battery capacities of the corresponding battery modules M1, M2, M3 (specifically, the voltages VC1 to VC4 of each single cell). The input terminals VC1 to VC4 of each cell controller CC1 to CC3 are connected to each cell 1 of the battery modules M1 to M3, and the cell controllers CC1 to CC3 are cascade-connected.

[0015] The CPU 10 transmits a command to detect the voltage of each cell 1 to the cell controllers CC1 to CC3 at a predetermined timing, and the cell controllers CC1 to CC3 that receive this detect the voltage of each cell 1. The detected voltage is held by a memory (not shown) etc. that each cell controller CC1 to CC3 has.

[0016] Also, the CPU 10 transmits a command to read out the voltage of each cell 1 to the cell controllers CC1 to CC3 at a predetermined timing, and the cell controllers CC1 to CC3 that receive this read out the detected voltage held in the memory and transmit it to the CPU 10.

[0017] For the communication between the CPU 10 and the cell controllers CC1 to CC3, the photocouplers PC1 and PC2 having electrical insulation are used. The photocouplers PC1 and PC2 each have a photodiode PD1 and PD2 which are light emitting elements, and a phototransistor PT1 and PT2 which are light receiving elements.

[0018] For the communication between the cell controller CC2 and the CPU 10, no photocoupler is used, and the data transmitted from the CPU 10 to the cell controller CC3 is sent from the cell controller CC3 to the cell controller CC2, further sent from the cell controller CC2 to the cell controller CC1, and finally this data is sent from the cell controller CC1 to the CPU 10 via the photocoupler PC2, adopting a so-called cascade communication method.

[0019] The vehicle controller 200 is a controller (processor) that controls the entire vehicle, such as controlling the drive system including the motor 5 and controlling the accessory system such as lights. Also, the vehicle controller 200 controls the battery 3 together with the battery controller 100. For example, the vehicle controller 200 limits the output torque of the motor by controlling the inverter 2 in order to prevent over-discharge or charge-discharge of the battery 3 according to the SOC (State of Charge) of the battery 3. In the example of FIG. 1, the LBC 100 and the vehicle controller 200 are separated, but the LBC 100 and the vehicle controller 200 may be made into one controller. Also, the detection values of the total voltage sensor 6, the current sensor 7, and the temperature sensor 8 may be directly output to the battery controller 100.

[0020] The battery controller 100 and / or cooling controller 300 are controllers (processors) that control the air conditioning inside the vehicle cabin using the vehicle's air conditioning system and perform control (hereinafter also referred to as battery cooling control) that uses the air conditioning system 20 to cool the battery 3 with the battery cooler 40. The battery controller 100 and / or cooling controller 300 control the air conditioning system 20 to provide cooling and / or heating based on the user's operation inside the vehicle cabin or based on an auto setting. The battery controller 100 and / or cooling controller 300 also perform battery cooling control based on the temperature detected by the temperature sensor 8 and the temperature detected by the outside temperature sensor 9, even if the outside temperature is below a predetermined temperature, as long as the outside temperature is below a predetermined outside temperature threshold. In other words, even when the outside temperature is low, for example, below 0°C, if the battery temperature is high, the battery controller 100 and / or cooling controller 300 will cool the battery 3 with the battery cooler 40 using the air conditioning system 20 shown in Figures 2 and 3 below. Furthermore, the primary controller for these functions may be either the battery controller 100 or the cooling controller 300, or it may be the controller of both the battery controller 100 and the cooling controller 300.

[0021] The air conditioning system installed in the vehicle will be described with reference to Figures 2 and 3. Figures 2 and 3 are block diagrams of the air conditioning system. Figure 2 shows the flow of refrigerant when the air conditioning system 20 is used for heating the interior of the vehicle. Figure 3 shows the flow of refrigerant when the air conditioning system 20 is used for battery cooling, and corresponds to the flow of refrigerant during battery cooling control. In Figures 2 and 3, thick lines, solid lines, and dotted lines represent refrigerant pipes 24, with thick lines indicating the flow of high-pressure refrigerant, solid lines indicating the flow of low-pressure refrigerant, and dotted lines indicating the flow of no refrigerant.

[0022] The air conditioning system 20 is installed in the vehicle and has a heating and cooling function for heating or cooling the interior of the vehicle, and a battery cooling function for cooling the battery. The air conditioning system 20 also switches between a heating and cooling method that circulates a refrigerant to heat and cool the interior of the vehicle, a battery cooling method that circulates a refrigerant to cool the battery 3, and a heating method that heats the interior of the vehicle using a method different from refrigerant circulation, thereby providing heating and cooling of the interior of the vehicle and battery cooling. In other words, the air conditioning system 20 has a heat pump air conditioning system and a heating system using a method other than the heat pump type.

[0023] As shown in Figures 2 and 3, the air conditioning system 20 includes an outdoor condenser 21, an electric compressor 22, an accumulator 23, a refrigerant pipe 24, a blower 25, an evaporator 26, an indoor condenser 27, expansion (EXP) valves 28a to 28c, a heating unit 30, a battery cooler 40, and a cooling plate 41. The blower 25, evaporator 26, and indoor condenser 27 are housed within the air conditioning unit case.

[0024] The outdoor condenser 21 exchanges heat between the refrigerant and the outside air (outside air). When heating or cooling the vehicle interior, if the refrigerant temperature is higher than the outside air temperature, the refrigerant in the outdoor condenser 21 dissipates heat to the outside. Conversely, if the refrigerant temperature is lower than the outside air temperature, the refrigerant in the outdoor condenser 21 absorbs heat from the outside. In addition, the outdoor condenser 21 functions as a heat exchanger when cooling the battery, dissipating heat from the refrigerant in the outdoor condenser 21 to the outside.

[0025] The electric compressor 22 compresses the refrigerant. The accumulator 23 separates the liquid and gaseous components of the refrigerant and supplies only the gaseous refrigerant to the electric compressor 22.

[0026] The refrigerant pipe 24 is a pipe that forms a circulation path for the refrigerant in the air conditioning system 20. As shown in Figure 2, when the air conditioning system is operating as a heating system for the vehicle interior, the refrigerant pipe 24 is configured so that the refrigerant compressed by the electric compressor 22 flows in the order of indoor condenser 27, outdoor condenser 21, accumulator 23, and then returns to the electric compressor 22. When the air conditioning system 20 is operating as a cooling system for the vehicle interior, the refrigerant pipe 24 is configured so that the refrigerant compressed by the electric compressor 22 flows in the order of indoor condenser 27, outdoor condenser 21, evaporator 26, accumulator 23, and then returns to the electric compressor 22. Furthermore, as shown in Figure 3, when the air conditioning system 20 is operating as a cooling system for the battery 3, the refrigerant pipe 24 is configured so that the refrigerant compressed by the electric compressor 22 flows in the order of indoor condenser 27, outdoor condenser 21, battery cooler 40, accumulator 23, and then returns to the electric compressor 22. In other words, when cooling the battery 3, the refrigerant pipe 24 becomes a circulation path that circulates the refrigerant to the outdoor condenser 21, compressor 22, accumulator 23, indoor condenser 27, and battery cooler 40.

[0027] The blower 25 is a fan that generates airflow within the air conditioning unit case. The evaporator 26 is an evaporator located downstream of the airflow from the blower 25. The evaporator 26 cools the interior of the vehicle by removing heat from the air inside the vehicle through heat exchange between the refrigerant flowing inside and the air in the air passage.

[0028] The interior condenser 27 is located downstream of the evaporator 26 in the direction of airflow within the case. The interior condenser heats the vehicle interior by exchanging heat between the refrigerant flowing inside and the air blown into the case, thereby transferring heat to the air.

[0029] EXP valves 28a to 28c are installed in the refrigerant pipe 24 and are valves for adjusting the refrigerant pressure. Although not shown in Figures 2 and 3, the air conditioning system 20 is also equipped with solenoid valves in addition to the EXP valves 28a to 28c, and these solenoid valves are installed in the refrigerant pipe 24. The opening and closing of the EXP valves 28a to 28c and the solenoid valves switches the refrigerant circulation path. The opening and closing of the valves is controlled by the cooling controller 300.

[0030] The heating unit 30 is a PTC heater installed in the vehicle. The heating unit 30 uses the power from the battery 3 to supply electricity to the heater (electrical resistor) and generate heat. The heating unit 30 is a device for providing heating using a heating method other than a heat pump type that circulates a refrigerant (heater type).

[0031] The battery cooler 40 cools the battery 3 by exchanging heat between the coolant flowing inside and the cooling plate 41, thereby removing heat from the cooling plate 41. The cooling plate 41 is attached to the case that covers the battery 3. The cooling plate 41 is a metal component that transfers the heat from the battery 3 to the battery cooler 40.

[0032] The cooling controller 300 compares a preset battery temperature threshold with the temperature detected by the temperature sensor 8 to determine whether or not to cool the battery 3. The battery temperature threshold is a temperature threshold used to determine whether or not to cool the battery 3 by the air conditioning system 20. If the temperature of the battery 3 is higher than the battery temperature threshold, the cooling controller 300 turns on battery cooling by the air conditioning system 20. If the battery 3 has been cooled and its temperature is below the battery temperature threshold, the cooling controller 300 turns off battery cooling by the air conditioning system 20.

[0033] The air conditioning system 20 is a heating and cooling system using a heat pump. A cooling system using a heat pump cools by utilizing the heat of vaporization when a refrigerant, which is a mixture of gas and liquid, is vaporized. When using this cooling system to cool the battery 3, it is necessary to supply high-pressure refrigerant to the battery cooler 40. When cooling the battery 3, the cooling controller 300 turns on the battery cooling by the air conditioning system 20 and adjusts the EXP valves 28a to 28c, etc., so that the refrigerant circulates as shown in Figure 3. The cooling controller 300 also adjusts the opening of the EXP valve 28c to adjust the refrigerant pressure supplied from the outdoor condenser 21 to the battery cooler 40. In this way, by using a heat pump cooling system to cool the battery 3, the refrigerant can be vaporized even when the outside temperature is low (for example, below 0 degrees Celsius), and therefore the battery 3 can be cooled. In other words, the air conditioning system 20 has at least an outdoor condenser 21, a compressor 22, an accumulator 23, an indoor condenser 27, and a battery cooler 40, and is a system that circulates refrigerant to heat the vehicle interior and also cool the battery. When battery cooling is controlled, the refrigerant flow path is switched from a flow path that supplies refrigerant to the evaporator 26 to a flow path that supplies refrigerant to the battery cooler 40, forming a refrigerant circulation path that includes the battery cooler. To put it another way, when battery cooling is controlled, the cooling controller 300 switches from a refrigerant flow path in cooling mode that includes the evaporator 26 but does not include the battery cooler 40 to a refrigerant flow path in battery cooling mode that includes the battery cooler 40 but does not include the evaporator 26.

[0034] On the other hand, a heating system using a heat pump is a system that reduces the refrigerant pressure upstream of the outdoor condenser 21. Therefore, it is difficult to achieve both heating of the vehicle interior (cabin) and battery cooling with a heat pump. For this reason, the air conditioning system 20 has a heating system using a heating unit 30 in addition to the heating and cooling system using a heat pump. When the cooling controller 300 performs battery cooling control while the heating by the heat pump is in operation, it switches from heating by the heat pump to heater-type heating by the heating unit 30. This makes it possible to achieve both heating of the vehicle interior and battery cooling (especially battery cooling when the outside temperature is low).

[0035] Next, the control method of the battery controller 100 will be explained with reference to Figure 4. Figure 4 is a flowchart of the control flow of the battery controller 100. The battery controller 100 manages the temperature of the battery 3 by repeatedly executing the control flow shown in Figure 4. In the following explanation, the battery temperature corresponds to the temperature detected by the temperature sensor 8. The ambient temperature corresponds to the temperature detected by the ambient temperature sensor 9. The battery controller 100 also transmits information to the cooling controller 300 to execute the following control flow, obtains information such as the pressure of the refrigerant managed by the cooling controller 300, and finally determines whether to turn the battery cooling on or off. The main controller for the following control flow may be the cooling controller 300, or it may be both the battery controller 100 and the cooling controller 300.

[0036] In step S1, the battery controller 100 determines whether battery cooling by the air conditioning system 20 is ON or OFF. If battery cooling is OFF, the air conditioning system 20 executes the control flow of step S2. If battery cooling is ON, the air conditioning system 20 executes the control flow of step S8.

[0037] In step S2, the battery controller 100 compares the ambient temperature (To) with a second ambient temperature threshold (To2) and determines whether the ambient temperature (To) is higher than the second ambient temperature threshold (To2). The battery controller 100 has ambient temperature thresholds as ambient temperature conditions for switching battery cooling on and off. The ambient temperature thresholds include a first ambient temperature threshold (To1) and a second ambient temperature threshold (To2) that is higher than the first ambient temperature threshold (To1). The ambient temperature thresholds are set to low temperatures, preferably to a value below 0 degrees. For example, the first ambient temperature threshold (To1) and the second ambient temperature threshold (To2) are set within the range of -10 degrees or higher and below 0 degrees.

[0038] If the ambient temperature (To) is below the second ambient temperature threshold (To2), in step S3, the battery controller 100 compares the battery temperature (Tb) with the second battery temperature threshold (Tb2) and determines whether the battery temperature (Tb) is higher than the second battery temperature threshold (Tb2). The battery controller 100 has a battery temperature threshold as a condition for switching battery cooling on and off. The battery temperature threshold includes a first battery temperature threshold (Tb1) and a second battery temperature threshold (Tb2) that is higher than the first battery temperature threshold (Tb1). The battery temperature threshold is a threshold for protecting the battery 3 from high temperatures, and for example, the first battery temperature threshold (Tb1) and the second battery temperature threshold (Tb2) are set within a range of 30°C or higher and less than 60°C.

[0039] If the battery temperature (Tb) is below the second battery temperature threshold (Tb2), in step S4, the battery controller 100 does not perform battery cooling control and maintains the battery cooling by the air conditioning system 20 in the off state. The control flow then ends.

[0040] In the determination flow of step S2, if it is determined that the ambient temperature (To) is higher than the second ambient temperature threshold (To2), the battery controller 100 compares the battery temperature (Tb) with the first battery temperature threshold (Tb1) and determines whether the battery temperature (Tb) is higher than the first battery temperature threshold (Tb1).

[0041] If, in the judgment flow of step S3, it is determined that the battery temperature (Tb) is higher than the second battery temperature threshold (Tb2), or if, in the judgment flow of step S5, it is determined that the battery temperature (Tb) is higher than the first battery temperature threshold (Tb1), the battery controller 100 executes battery cooling control and switches the battery cooling by the air conditioning system 20 from off to on. In other words, if the ambient temperature (To) is below the second ambient temperature threshold (To2), the cooling system is turned on when the battery temperature is higher than the higher threshold, the second battery temperature threshold (Tb2). On the other hand, if the ambient temperature (To) is higher than the second ambient temperature threshold (To2), the cooling system is turned on when the battery temperature is higher than the lower threshold, the first battery temperature threshold (Tb1). In this way, even when the ambient temperature is low, if the battery 3 is hot, battery cooling is turned on to protect the battery 3. Then the control flow ends.

[0042] If the determination flow in step S5 determines that the battery temperature (Tb) is below the first battery temperature threshold (Tb1), the battery controller 100 does not perform battery cooling control and maintains the battery cooling by the air conditioning system 20 in the off state. The control flow then ends.

[0043] If battery cooling is ON in the control flow of step S1, in step S8 the battery controller 100 compares the ambient temperature (To) with the first ambient temperature threshold (To1) and determines whether the ambient temperature (To) is higher than the first ambient temperature threshold (To1). If the ambient temperature (To) is less than or equal to the first ambient temperature threshold (To1), the battery controller 100 does not perform battery cooling control and switches the battery cooling by the air conditioning system 20 from ON to OFF. That is, if the ambient temperature falls below the first ambient temperature threshold (To1) while the battery 3 is being cooled by the air conditioning system 20, the battery controller 100 stops the cooling of the battery 3 by the air conditioning system 20. Then the control flow ends.

[0044] If the ambient temperature (To) is higher than the first ambient temperature threshold (To1), the battery controller 100 performs battery cooling control and maintains the battery cooling by the air conditioning system 20 in the ON state. Then the control flow ends.

[0045] Figure 5 is a graph illustrating the relationship between ambient temperature and the on / off state of battery cooling. In this embodiment, a hysteresis is introduced between the ambient temperature conditions when battery cooling switches from on to off and the ambient temperature conditions when battery cooling switches from off to on. As shown in Figure 5, when battery cooling by the air conditioning system 20 is on, if the ambient temperature drops below the first ambient temperature threshold (To1), the battery controller 100 switches the battery cooling by the air conditioning system 20 from on to off. Also, when battery cooling by the air conditioning system 20 is off, if the ambient temperature rises above the second ambient temperature threshold (To2), the battery controller 100 switches the battery cooling by the air conditioning system 20 from off to on.

[0046] Next, referring to FIG. 6, the case where the battery cooling system in the present embodiment is applied to a vehicle is compared with the case where it is not applied to the vehicle (hereinafter also referred to as "comparative example"), and the temperature, SOC (State of Charge), and driving distance of the battery 3 will be described. In FIG. 6, the solid line indicates the characteristics when the battery cooling system is applied, and the dotted line indicates the characteristics when the battery cooling system is not applied (comparative example). The characteristics in FIG. 6 are the characteristics when the vehicle driving and the charging of the battery 3 are repeated. Regarding the vehicle driving, the vehicle runs until the SOC reaches a predetermined lower limit SOC L When the vehicle reaches. Also, regarding the charging of the battery 3, it is assumed that the vehicle is charged while being stopped. Note that when the SOC reaches a predetermined upper limit SOC H When reached, or when the charging time reaches a predetermined charging time, the charging of the battery 3 ends.

[0047] After the first driving, the battery 3 is charged. During the first charging, the temperature of the battery 3 rises. In the present embodiment, at the time point of time t1, the battery cooling system is turned on, and the rise in battery temperature is suppressed. On the other hand, in the comparative example, the rise in battery temperature continues. Then, during the second charging, in the comparative example, before the SOC reaches the upper limit SOC H When reached, since the battery temperature reaches the upper limit temperature T H When reached, the charging power is reduced (time t2) so that the battery temperature does not rise too much. In the comparative example, during the third charging and the fourth charging, the charging power is reduced so that the battery temperature does not rise too much above the upper limit temperature T H When reached. And in the second to fourth chargings, the charging ends when the charging time has passed a predetermined time. On the other hand, in the present embodiment, during the second to fourth chargings, the battery cooling system is also turned on and the rise in battery temperature is suppressed, so that the battery temperature does not reach the upper limit temperature T H When reached, until the SOC reaches the upper limit SOC H When reached, the battery 3 can be charged.

[0048] In the comparative example, since the charging ends before the SOC reaches the upper limit SOC H When reached, the battery 3 cannot be fully charged, and the driving time (t аThe driving range per charge will be shorter. Similarly, on the 2nd and 4th charges, the SOC will be at its upper limit. H Because charging ends before reaching this point, battery 3 cannot be fully charged, resulting in shorter running times during the 4th and 5th runs (t b or t c The distance traveled per unit is reduced. And the total distance traveled in this embodiment is longer than in the comparative example.

[0049] As described above, in this embodiment, the air conditioning system includes at least an outdoor condenser 21, a compressor 22, an accumulator 23, an indoor condenser 27, and a battery cooler 40, and is a system that circulates a refrigerant. The battery controller 100 and / or cooling controller 300 control the air conditioning inside the vehicle cabin using the air conditioning system 20, and even if the outside temperature is below a predetermined temperature, if the battery temperature is higher than a predetermined battery temperature threshold, battery cooling control is performed. This allows the battery 3 to be cooled even when the outside temperature is low. As a result, deterioration of the battery 3 can be prevented, and restrictions on vehicle operation can be avoided.

[0050] Furthermore, in this embodiment, when the battery controller 100 and / or cooling controller 300 perform battery cooling control while heating is being operated by the indoor condenser 27, they switch from heating by the indoor condenser 27 to heating by the heating unit 30. This makes it possible to achieve both battery cooling and heating inside the vehicle.

[0051] In this embodiment, the battery controller 100 and / or cooling controller 300 perform battery cooling control when the ambient temperature is higher than the ambient temperature threshold (corresponding to the second ambient temperature threshold To2) and the battery temperature is higher than the first battery temperature threshold (Tb1) while battery cooling is off. Furthermore, the battery controller 100 and / or cooling controller 300 perform battery cooling control when the ambient temperature is below the ambient temperature threshold (corresponding to the second ambient temperature threshold To2) and the battery temperature is higher than the second battery temperature (Tb2) while battery cooling is off. This allows the battery 3 to be cooled even when the ambient temperature is low. Additionally, the temperature range over which battery cooling can be turned on can be widened depending on the ambient temperature.

[0052] In this embodiment, the battery controller 100 and / or cooling controller 300 switch the battery cooling off when the ambient temperature falls below a first ambient temperature threshold (To1) while the battery cooling is on, and when the ambient temperature rises above a second ambient temperature threshold (To2) while the battery cooling is off, and the battery temperature rises above a battery temperature threshold (corresponding to the first battery temperature threshold Tb1), the battery cooling is switched on. This allows for hysteresis in the switching between battery cooling on and off.

[0053] The battery controller 100 and / or the cooling controller 300 correspond to the "controller" or "processor" of the present invention, and the electric compressor 22 corresponds to the "compressor" of the present invention.

[0054] The embodiments described above are provided to facilitate understanding of the present invention and are not intended to limit it. Therefore, each element disclosed in the above embodiments is intended to include all design modifications and equivalents that fall within the technical scope of the present invention. [Explanation of symbols]

[0055] 1 cell 2 Inverters 3 Batteries 4. Relay switch 5 Motors 6. Total voltage sensor 7 Current Sensor 8. Temperature sensor 9. Outdoor temperature sensor 20 Air conditioning systems 21 Outdoor condenser 22 Electric Compressor 23 Accumulator 24 Refrigerant pipes 25 Blower 26 Evaporator 27 Indoor capacitor 28 EXP valve 28 Expansion (EXP) Valve 28c EXP valve 30 Heating section 40 Battery Cooler 41 Cooling Plate 100 Battery Controllers 200 Vehicle Controller 300 Cooling Controller

Claims

1. A vehicle air conditioning system having at least an outdoor condenser, compressor, accumulator, indoor condenser, and battery cooler, and circulating a refrigerant, The aforementioned air conditioning system includes a controller that controls the air conditioning inside the vehicle, The aforementioned air conditioning system has a heating unit that heats the interior of the vehicle in a manner different from heat exchange using the aforementioned refrigerant, The aforementioned controller, Even if the outside temperature is below a predetermined temperature, if the battery temperature is higher than a predetermined battery temperature threshold, the air conditioning system will be used to perform battery cooling control, which involves cooling the battery with the battery cooler. A battery cooling control device that switches from heating by the indoor condenser to heating by the heating unit when the battery cooling control is performed while heating by the indoor condenser is in operation.

2. A vehicle air conditioning system having at least an outdoor condenser, compressor, accumulator, indoor condenser, and battery cooler, and circulating a refrigerant, The aforementioned air conditioning system includes a controller that controls the air conditioning inside the vehicle, The aforementioned controller, Even if the outside temperature is below a predetermined temperature, if the battery temperature is higher than a predetermined battery temperature threshold, the air conditioning system will be used to perform battery cooling control, which involves cooling the battery with the battery cooler. The battery temperature threshold includes a first battery temperature threshold and a second battery temperature threshold that is higher than the first battery temperature threshold. The aforementioned controller, Switching the battery cooling by the aforementioned air conditioning system on and off, When the battery cooling is turned off, if the ambient temperature is higher than the ambient temperature threshold and the battery temperature is higher than the first battery temperature threshold, the battery cooling control is executed. A battery cooling control device that, when the battery cooling is turned off, executes the battery cooling control when the ambient temperature is below the ambient temperature threshold and the battery temperature is higher than the second battery temperature threshold.

3. A vehicle air conditioning system having at least an outdoor condenser, compressor, accumulator, indoor condenser, and battery cooler, and circulating a refrigerant, The aforementioned air conditioning system includes a controller that controls the air conditioning inside the vehicle, The aforementioned controller, Even if the outside temperature is below a predetermined temperature, if the battery temperature is higher than a predetermined battery temperature threshold, the air conditioning system will be used to perform battery cooling control, which involves cooling the battery with the battery cooler. Switching the battery cooling on and off using the aforementioned battery cooling control, When the battery cooling is turned on, if the ambient temperature falls below the first ambient temperature threshold, the battery cooling is switched off. A battery cooling control device that, while the battery cooling is off, switches the battery cooling on when the ambient temperature rises above a second ambient temperature threshold which is higher than the first ambient temperature threshold, and the battery temperature is higher than the battery temperature threshold.

4. A battery cooling control method performed by a processor, The aforementioned processor, The vehicle's air conditioning system, which includes at least an outdoor condenser, compressor, accumulator, and indoor condenser and battery cooler, and circulates a refrigerant, controls the air conditioning inside the vehicle. Even if the outside temperature is below a predetermined temperature, if the battery temperature is higher than a predetermined battery temperature threshold, the air conditioning system is used to circulate the refrigerant to the battery cooler to cool the battery, thereby executing battery cooling control. The air conditioning system of the aforementioned vehicle is It has a heating unit that heats the interior of the vehicle using a method different from the heat exchange using the aforementioned refrigerant, The aforementioned processor, A battery cooling control method that switches from heating by the indoor condenser to heating by the heating unit when the battery cooling control is performed while heating by the indoor condenser is in operation.

5. A battery cooling control method performed by a processor, The aforementioned processor, The vehicle's air conditioning system, which includes at least an outdoor condenser, compressor, accumulator, and indoor condenser and battery cooler, and circulates a refrigerant, controls the air conditioning inside the vehicle. Even if the outside temperature is below a predetermined temperature, if the battery temperature is higher than a predetermined battery temperature threshold, the air conditioning system is used to circulate the refrigerant to the battery cooler to cool the battery, thereby executing battery cooling control. The battery temperature threshold includes a first battery temperature threshold and a second battery temperature threshold that is higher than the first battery temperature threshold. The aforementioned processor, Switching the battery cooling by the aforementioned air conditioning system on and off, When the battery cooling is turned off, if the ambient temperature is higher than the ambient temperature threshold and the battery temperature is higher than the first battery temperature threshold, the battery cooling control is executed. A battery cooling control method that, when the battery cooling is turned off, the ambient temperature is below the ambient temperature threshold and the battery temperature is higher than the second battery temperature threshold, executes the battery cooling control.

6. A battery cooling control method performed by a processor, The aforementioned processor, The vehicle's air conditioning system, which includes at least an outdoor condenser, compressor, accumulator, and indoor condenser and battery cooler, and circulates a refrigerant, controls the air conditioning inside the vehicle. Even if the outside temperature is below a predetermined temperature, if the battery temperature is higher than a predetermined battery temperature threshold, the air conditioning system is used to circulate the refrigerant to the battery cooler to cool the battery, thereby executing battery cooling control. Switching the battery cooling on and off using the aforementioned battery cooling control, When the battery cooling is turned on, if the ambient temperature falls below the first ambient temperature threshold, the battery cooling is switched off. A battery cooling control method that, while the battery cooling is off, switches the battery cooling on when the ambient temperature rises above a second ambient temperature threshold that is higher than a first ambient temperature threshold, and the battery temperature is higher than the battery temperature threshold.

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