Battery temperature control system

Abstract

To provide a battery temperature control system that accurately regulates the temperature of an electric vehicle battery.SOLUTION: A temperature control system 10 for an electric vehicle 1 includes a motor 21, a battery 28 that stores electric energy to be supplied to the motor, a temperature regulator 4 that regulates the temperature of the battery, and a control device 35 that performs temperature regulation control using the temperature regulator such that the temperature of the battery at the start of charging becomes a target temperature suitable for charging. The control device performs temperature regulation control while the electric vehicle is heading to a charging spot. The control device also predicts a temperature rise due to self-heating of the battery until the electric vehicle arrives at the charging spot, and performs temperature regulation control taking the predicted temperature rise into consideration.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The technology disclosed herein relates to a battery temperature control system. [Background technology]

[0002] Patent Document 1 describes a conventional battery temperature control device. The battery temperature control device is installed in an electric vehicle or a plug-in hybrid vehicle. The vehicle is equipped with a secondary battery that stores driving power supplied to the electric motor. When a charger for charging is selected by the occupant while the vehicle is traveling, the battery temperature control device adjusts the battery temperature so that the battery temperature reaches a target battery temperature when the vehicle arrives at the selected charger. Because the battery temperature is at a predetermined temperature when charging begins, the battery charging time is prevented from becoming too long. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-100892 Summary of the Invention [Problem to be solved by the invention]

[0004] The conventional battery temperature control device does not take into account the fact that the battery temperature may increase due to self-heating of the battery before arriving at the charger. If self-heating of the battery is not taken into account, the battery temperature may deviate from the target battery temperature when the battery arrives at the charger. Furthermore, if self-heating of the battery is not taken into account, the battery may be heated or cooled unnecessarily.

[0005] The technology disclosed herein accurately regulates the temperature of the battery in an electric vehicle. [Means for solving the problem]

[0006] The technology disclosed herein relates to a battery temperature control system. a motor mounted on the electric vehicle and outputting a driving force for running the electric vehicle; a battery for storing electrical energy to be supplied to the motor; a temperature control device for controlling the temperature of the battery; a control device that performs temperature regulation control using the temperature regulation device so that the temperature at the start of charging of the battery becomes a target temperature suitable for charging, the control device performs the temperature adjustment control while the electric vehicle is heading to a charging spot where the battery is charged, The control device also predicts a temperature rise due to self-heating of the battery until the electric vehicle arrives at the charging spot, and performs the temperature adjustment control taking the predicted temperature rise into consideration.

[0007] An electric vehicle travels by having a motor supplied with electric energy from a battery output a driving force for traveling. As the traveling distance of an electric vehicle increases, the SOC of the battery decreases. If the SOC of the battery decreases while the electric vehicle is traveling, the user of the electric vehicle will stop the vehicle at a charging spot, for example, to charge the battery. The battery may be charged quickly. To shorten the charging time, it is preferable that the battery temperature be at a predetermined temperature when charging begins.

[0008] The control device uses the temperature regulator to regulate the temperature of the battery. Specifically, the control device regulates the temperature while the electric vehicle is heading to the charging spot so that the battery temperature will be a target temperature when the electric vehicle arrives at the charging spot and begins charging the battery.

[0009] As an electric vehicle travels to a charging spot, the battery supplies electrical energy to the motor until the electric vehicle arrives at the charging spot. Therefore, the battery temperature may rise due to self-heating of the battery until the electric vehicle arrives at the charging spot. The control device predicts the temperature rise due to self-heating of the battery and performs temperature regulation control taking the predicted temperature rise into consideration. The control device can accurately set the battery temperature to a target temperature when the electric vehicle arrives at the charging spot and begins charging the battery. As a result, the battery charging time is shortened.

[0010] the temperature control device consumes electrical energy from the battery to heat the battery; The control device may use the temperature adjustment device to heat the battery when heating is necessary to bring the battery temperature to a target temperature, taking into account temperature rise due to self-heating of the battery, and may not use the temperature adjustment device when heating is not necessary.

[0011] When the battery does not need to be heated due to self-heating of the battery, the control device does not use the temperature adjustment device, thereby reducing the wasteful consumption of the battery's electrical energy for adjusting the battery's temperature.

[0012] The temperature adjustment device may include an electric heater that contacts the battery, or an electric heater that heats a refrigerant in a temperature adjustment plate that contacts the battery.

[0013] When heating a battery using an electric heater, the battery is heated by the electric heater or the temperature control plate in contact with the battery, which can cause a temperature distribution in the battery. If a temperature distribution occurs in the battery at the start of charging, charging of the battery may be limited to prevent the temperature of the relatively hotter parts from becoming too high. The temperature distribution in the battery may result in a longer charging time.

[0014] When an electric heater is not used in the battery temperature regulation control, the occurrence of temperature distribution in the battery is suppressed. The temperature rise due to the battery's self-heating makes the temperature of the entire battery uniform or approximately uniform, so the temperature distribution of the battery at the start of charging is suppressed. The battery charging time is shortened.

[0015] the temperature adjustment device includes the electric heater and a second heating device that consumes less energy than the electric heater, The control device may select the electric heater or the second heating device depending on the amount of heat required to raise the temperature of the battery to a target temperature.

[0016] By taking into account the self-heating of the battery, the amount of heating required to bring the battery temperature to the target temperature may be relatively reduced. For example, when the amount of heating required is small, the second heating device, which consumes relatively less energy, heats the battery, thereby saving the electrical energy required to regulate the battery temperature.

[0017] The temperature adjustment device includes a first cooling device that cools the battery by utilizing wind generated during running, and a second cooling device that cools the battery by consuming electrical energy of the battery, The control device may select the first cooling device or the second cooling device depending on the amount of cooling required to bring the temperature of the battery to a target temperature, taking into account temperature rise due to self-heating of the battery.

[0018] The first cooling device may use wind from the vehicle while it is running to air-cool the battery, or it may use a cooling circuit including a radiator to water-cool the battery. The second cooling device may be a refrigeration cycle including an electric compressor, for example. The first cooling device consumes less electrical energy to cool the battery than the second cooling device.

[0019] The control device determines the amount of cooling required to bring the battery temperature to a target temperature, taking into account the self-heating of the battery. For example, if the amount of cooling required is small, the first cooling device, which consumes relatively less energy, cools the battery, thereby saving the electrical energy required to regulate the battery temperature.

[0020] The control device may predict, based on information related to a traffic environment, the electric energy required for the electric vehicle to arrive at the charging spot, and may also predict, based on the electric energy, a temperature rise due to self-heating of the battery.

[0021] Here, the information about the traffic environment may include, for example, the distance to the charging spot, the road gradient along that road, the maximum vehicle speed along that road (i.e., the vehicle speed limited by signs), traffic congestion information along that road, and the outside air temperature. However, the information about the traffic environment is not limited to these.

[0022] The information about the traffic environment allows the control device to accurately predict the amount of electrical energy required for the electric vehicle to arrive at a charging spot. Based on the accurately predicted required electrical energy, the control device can accurately predict the temperature rise due to self-heating of the battery.

[0023] The control device may also predict the electrical energy required for the electric vehicle to arrive at the charging spot, based on information about a driving operation of a user of the electric vehicle.

[0024] By taking into account information about the user's driving operations, such as frequent sudden acceleration / deceleration or driving at relatively high speeds, the control device can more accurately predict the amount of electrical energy required for the electric vehicle to arrive at a charging spot.

[0025] The control device may also predict, based on information about the electric vehicle, the electric energy required for the electric vehicle to arrive at the charging spot.

[0026] Here, the information about the electric vehicle includes, for example, the battery temperature, SOC (State Of Charge), and SOH (State Of Health). The information about the electric vehicle also includes the weight of the electric vehicle, the number of occupants, and the weight of the luggage compartment. However, the information about the electric vehicle is not limited to these.

[0027] The information about the electric vehicle allows the control device to more accurately predict the amount of electrical energy required for the electric vehicle to arrive at a charging spot. Based on the accurately predicted required electrical energy, the control device can more accurately predict the temperature rise due to self-heating of the battery.

[0028] If the control device predicts that the SOC of the battery will fall below a predetermined tolerance upon arrival at the charging spot while performing the temperature adjustment control, the control device may reduce the amount of electrical energy consumed by the temperature adjustment control so that the SOC is equal to or greater than the tolerance.

[0029] If the battery's SOC drops too much before arriving at a charging spot, the user of the electric vehicle will feel uneasy. Therefore, if the control device predicts that the battery's SOC will fall below a predetermined tolerance when arriving at a charging spot while executing temperature regulation control, the control device reduces the amount of electrical energy consumed by temperature regulation control. The predetermined tolerance may be an SOC at which the user does not feel uneasy about running out of power. The temperature regulation control restriction prevents the battery's SOC from dropping too much before arriving at the charging spot, so the user will not feel uneasy. Note that as a result of the temperature regulation control restriction, the battery temperature may not have reached the target temperature when charging of the battery begins at the charging spot. [Effects of the Invention]

[0030] The above-described battery temperature control system can accurately regulate the temperature of the battery of an electric vehicle. [Brief explanation of the drawings]

[0031] [Figure 1] FIG. 1 is a block diagram of an electric vehicle. [Figure 2] FIG. 2 shows a battery temperature regulator. [Figure 3] FIG. 3 compares the changes in battery temperature and SOC between conventional control and the present control relating to battery temperature regulation. [Figure 4] FIG. 4 is a flowchart relating to prediction of temperature rise due to self-heating of the battery. [Figure 5] FIG. 5 is a part of a flowchart relating to the temperature regulation control of the battery. [Figure 6] FIG. 6 is a part of a flowchart relating to the temperature regulation control of the battery. DETAILED DESCRIPTION OF THE INVENTION

[0032] Hereinafter, an embodiment of a battery temperature control system will be described with reference to the drawings. The battery temperature control system described here is an example.

[0033] (Electric vehicle configuration) 1 shows the configuration of an electric vehicle 1. The electric vehicle 1 is a so-called BEV (Battery Electric Vehicle). A battery temperature control system 10 is mounted on the electric vehicle 1.

[0034] The electric vehicle 1 is equipped with an electric motor 21. The electric motor 21 outputs driving force for running the electric vehicle 1. The electric motor 21 is connected to the left and right drive wheels 15 via a reduction gear 17 and an axle 16. The reduction gear 17 and the axle 16 transmit the output of the electric motor 21 to the drive wheels 15.

[0035] The electric vehicle 1 includes an inverter 25. The inverter 25 is connected to the electric motor 21. The inverter 25 supplies an AC current to the electric motor 21. The electric motor 21 receives the AC current from the inverter 25 and operates.

[0036] The electric vehicle 1 includes a battery 28. The battery 28 stores electric energy to be supplied to the electric motor 21. The battery 28 is connected to an inverter 25. The inverter 25 converts the direct current from the battery 28 into alternating current.

[0037] A charger 26 is connected to the battery 28. The charger 26 has a socket 261. A charging plug 262 is inserted into the socket 261. The charger 26 receives a current supply from an external power source and charges the battery 28.

[0038] A DC / DC converter 24 is also connected to the battery 28. The DC / DC converter 24 changes the voltage of the direct current from the battery 28. The DC / DC converter 24 supplies the stepped-down direct current to various electrical components 29 mounted on the electric automobile 1. The electrical components 29 include, for example, an air conditioning compressor or an air conditioning heater for the vehicle interior.

[0039] The temperature control system 10 includes a control device 35. As will be described later, the control device 35 executes temperature adjustment control to adjust the temperature of the battery 28 before charging the battery 28. The control device 35 receives a signal from a sensor 281 of the battery 28. The sensor 281 outputs a signal related to the temperature of the battery 28. The sensor 281 also outputs a signal related to the voltage and / or current of the battery 28. The control device 35 can determine the temperature of the battery 28 and the SOC of the battery 28 based on the signal from the sensor 281.

[0040] The temperature control system 10 has a navigation device 33. The navigation device 33 acquires information about the current location of the vehicle using a GPS (Global Positioning System) and provides route guidance to the destination using map data. The navigation device 33 is connected to a control device 35. As will be described later, the control device 35 acquires information about the traffic environment to a charging spot where the battery 28 is charged from the navigation device 33.

[0041] The temperature control system 10 has a communication device 37. The communication device 37 can receive road traffic information. The road traffic information is, for example, traffic congestion information. The communication device 37 may be capable of two-way communication. The communication device 37 is connected to the control device 35. As will be described later, the control device 35 obtains information from the communication device 37 about traffic congestion on the way to a charging spot where the battery 28 is to be charged.

[0042] The temperature control system 10 has a storage device 39. The storage device 39 stores a log related to the driving operations of the user of the electric vehicle 1. Examples of the user's driving operations include acceleration / deceleration of the electric vehicle 1 associated with operation of the accelerator pedal and / or brake pedal, and the relative driving speed of the electric vehicle 1 compared to the driving speed of surrounding vehicles. The input / output of the battery 28 associated with driving the electric vehicle 1 varies depending on the user's driving operations. The log related to the user's driving operations stored in the storage device 39 is used to predict self-heating of the battery 28, as described below. The storage device 39 also stores past driving data of the electric vehicle 1. The driving data is, for example, data related to the driving force of the electric vehicle 1 when traveling to a charging spot. The past driving data of the electric vehicle 1 is used to predict self-heating of the battery 28, as described below.

[0043] The temperature control system 10 has a temperature adjustment device 4 for the battery 28. The temperature adjustment device adjusts the temperature of the battery 28 using electrical energy from the battery 28. The temperature adjustment device 4 includes a first refrigerant circuit 5 and a second refrigerant circuit 6. The first refrigerant circuit 5 and the second refrigerant circuit 6 can adjust the temperature of the battery 28 by heating or cooling the battery 28. The first refrigerant and the second refrigerant may be the same refrigerant. The first refrigerant and the second refrigerant may be, for example, a hydrofluoroolefin (R1234yf, R1234ze). Alternatively, the first refrigerant and the second refrigerant may be different refrigerants. The first refrigerant may be, for example, water. The second refrigerant may be, for example, a hydrofluoroolefin.

[0044] (Configuration of temperature control device) 2 schematically shows the configuration of the temperature adjustment device 4. The temperature adjustment device 4 has a first refrigerant circuit 5 and a second refrigerant circuit 6. The first refrigerant circuit 5 has a PTC (Positive Temperature Coefficient) heater 51, a radiator 52 (first cooling device) that exchanges heat of the first refrigerant with airflow during travel, a refrigerant pump 53, and a refrigerant circuit 54 disposed inside the battery 28. The first refrigerant circuit 5 can heat the battery 28 with the PTC heater 51. The first refrigerant circuit 5 can also cool the battery 28 with the radiator 52.

[0045] The PTC heater 51 is an example of an electric heater. Electric energy is supplied to the PTC heater 51 from the battery 28. The PTC heater 51 abuts against one side of the battery 28 and directly heats the battery 28. Because the PTC heater 51 applies heat to one side of the battery 28, heating the battery 28 by the PTC heater 51 may cause a temperature distribution in the battery 28 in which the temperature of a portion close to the PTC heater 51 is relatively high and the temperature of a portion far from the PTC heater 51 is relatively low. The PTC heater 51 may also heat the first refrigerant circulating through the first refrigerant circuit 5, and the first refrigerant may indirectly heat the battery 28 through the refrigerant circuit 54 (not shown). The PTC heater 51 may also heat the refrigerant of a temperature control plate abutting the battery 28.

[0046] Radiator 52 can exchange heat with the refrigerant using wind generated by running. The first refrigerant cooled by radiator 52 cools battery 28 through refrigerant circuit 54. Electric energy is supplied to refrigerant pump 53 from battery 28 through DC / DC converter 24.

[0047] The second refrigerant circuit 6 has a compressor 61, a condenser 62, an expansion valve 63, and a heat exchanger 64. The compressor 61 compresses the refrigerant. The condenser 62 condenses the high-temperature, high-pressure refrigerant from the compressor 61 by dissipating heat. The expansion valve 63 reduces the pressure of the refrigerant condensed in the condenser 62 and expands it. The heat exchanger 64 cools the battery 28 with the low-temperature, low-pressure refrigerant reduced in pressure and expanded in the expansion valve 63 (second cooling device). The compressor 61 is an electric compressor, and receives electrical energy from the battery 28 via the DC / DC converter 24. Cooling by the second refrigerant circuit 6 described above has a higher ability to lower the temperature of the battery 28 than cooling by the radiator of the first refrigerant circuit 5, but consumes more power.

[0048] Furthermore, the second refrigerant circuit 6 can be used as a heating means (second heating device) by reversing the circulation of the refrigerant. The refrigerant is decompressed and expanded in the expansion valve 63 to a low temperature and low pressure, and absorbs heat from the atmosphere in the condenser 62. The compressor 61 compresses the refrigerant, and the high temperature and high pressure refrigerant can heat the battery 28 via the heat exchanger 64. The second refrigerant circuit 6 can raise the temperature of the battery 28 by sending heat from the atmosphere to the battery 28 via the second refrigerant. Compared to the PTC heater 51, the PTC heater 51 has a higher ability to raise the temperature of the battery 28. Electrical energy is also supplied from the battery 28 via the DC / DC converter 24 for heating by the second refrigerant circuit 6, but the power consumption is lower than when heating is performed by the PTC heater 51.

[0049] (Battery temperature regulation control) If the SOC of the battery 28 drops while the electric vehicle 1 is traveling, the user of the electric vehicle 1 may stop the vehicle at a charging spot to charge the battery 28. In this case, it is preferable to shorten the charging time of the battery 28. The temperature control system 10 adjusts the temperature of the battery 28 to a predetermined temperature when charging of the battery 28 begins so as to shorten the charging time of the battery 28. The temperature control system 10 executes control to adjust the temperature of the battery 28 to a target temperature before the electric vehicle 1 arrives at the charging spot. The target temperature of the battery 28 may be a constant temperature or a temperature according to the state of the battery 28.

[0050] The upper diagram in Fig. 3 shows the change in temperature of battery 28 over time during temperature regulation control while electric vehicle 1 is heading to a charging spot (to the left of t0), and the change in temperature of battery 28 over time while battery 28 is being charged after arriving at the charging spot (to the right of t0). The lower diagram in Fig. 3 shows the change in SOC of battery 28 over time during temperature regulation control and during charging. Note that in the example in Fig. 3, the temperature of battery 28 is increased by temperature regulation control.

[0051] In conventional control, when the temperature of the battery 28 is raised to a target temperature, the PTC heater 51 is used to raise the temperature of the battery 28. The use of the PTC heater 51 has the advantage of being able to quickly raise the temperature of the battery 28. However, as mentioned above, raising the temperature of the battery 28 using the PTC heater 51 is likely to result in temperature distribution in the battery 28. The two-dot chain line in the upper diagram of Figure 3 illustrates the temperature of the high-temperature parts of the battery 28 under conventional control, and the one-dot chain line illustrates the temperature of the low-temperature parts of the battery 28. Under conventional control, temperature variations occurred in the battery 28 (see the arrows labeled "Temperature Variation"). The temperature of the high-temperature parts of the battery 28 significantly exceeded the target temperature.

[0052] Furthermore, while the electric vehicle 1 is traveling until it arrives at the charging spot, the battery 28 outputs electric energy, and the temperature of the battery 28 rises due to self-heating. Conventional control does not take into account the rise in temperature due to self-heating, and therefore the PTC heater 51 unnecessarily heats the battery 28. As a result, the temperature of the low-temperature parts of the battery 28 also exceeds the target temperature when charging of the battery 28 begins (see the arrows indicating "unnecessary heating").

[0053] As a result, after charging of the battery 28 begins, the temperature of the hot parts of the battery 28 becomes too high and quickly reaches the "degeneration start temperature." In other words, as shown by the dashed line in the lower diagram of Figure 3, the charging current is suppressed after t1 to prevent the temperature of the battery 28 from rising any further. As a result, with conventional control, even if the temperature of the battery 28 is adjusted before charging, the charging time may be long.

[0054] Furthermore, in conventional temperature regulation control, the use of the PTC heater 51 consumes electrical energy from the battery 28, which makes it easy for the SOC of the battery 28 to decrease during temperature regulation control. Before the electric vehicle 1 arrives at a charging spot, the SOC of the battery 28 may fall below a predetermined SOC, for example, an SOC at which the user feels anxious about running out of power.

[0055] To address these issues, the battery 28 temperature control system 10 disclosed herein reduces unnecessary heating during temperature regulation control and reduces temperature variations in the battery 28, thereby shortening the charging time of the battery 28. The battery temperature control system 10 disclosed herein also prevents the SOC of the battery 28 from falling below an SOC that would cause anxiety to the user due to temperature regulation control before the electric vehicle 1 arrives at a charging spot.

[0056] Specifically, when a charging spot is specified as the destination by the user of the electric vehicle 1, the temperature control system 10 predicts the temperature rise due to self-heating of the battery 28 until the vehicle arrives at the charging spot, and performs temperature adjustment control of the battery 28 taking into account the predicted temperature rise.

[0057] In this control, unnecessary heating is suppressed, so that the temperature of the battery 28 reaches or nearly reaches the target temperature when charging of the battery 28 starts, as shown by the solid line in the upper graph of FIG.

[0058] Furthermore, in order to prevent unnecessary heating, the temperature control system 10 may not use heating by the PTC heater 51. By allowing the temperature of the battery 28 to rise due to self-heating without using the PTC heater 51, temperature variations in the battery 28 are reduced.

[0059] As a result, in this control, as shown by the solid line in the upper graph of Figure 3, the temperature of the battery 28 does not exceed the degeneration start temperature after charging starts, and rapid charging of the battery 28 is continuously performed, thereby shortening the charging time of the battery 28.

[0060] Non-use of the PTC heater 51 also suppresses a decrease in the SOC of the battery 28, so that the SOC of the battery 28 does not fall below an SOC that would cause anxiety to the user, as shown by the solid line in the lower diagram of FIG.

[0061] Note that the temperature regulation control may also cool the battery 28 so that the temperature of the battery 28 reaches a target temperature. When cooling of the battery 28 is required, the temperature regulation control is reversed from that shown in FIG.

[0062] (Temperature control procedure) Next, the control procedure by the temperature control system 10 will be described with reference to the flowcharts of Figs. 4-6. Figs. 4-6 show the procedure for temperature adjustment control. Fig. 4 shows the procedure for predicting the temperature rise due to self-heating of the battery 28 until the electric vehicle 1 reaches the charging spot after a charging spot is specified as the destination. Fig. 5 shows the procedure for determining the need for heating or cooling of the battery 28 based on the predicted temperature of the battery 28, and for selecting a heating means if heating is required. Fig. 6 shows the procedure for selecting a cooling means if cooling is required.

[0063] 4 starts when the user of the electric vehicle 1 specifies the charging spot to which the user is heading. The user may specify the charging spot using the navigation device 33, for example.

[0064] In step S41, the control device 35 checks the route to the charging spot. Information about the route to the charging spot can be obtained from map information of the navigation device 33. In step S41, the control device 35 also obtains information about the gradient of the road surface on the route to the charging spot and information about the maximum vehicle speed on the route to the charging spot (i.e., the vehicle speed limited by signs). The information about the route, gradient, or maximum vehicle speed is related to the driving force required for the electric vehicle 1 to arrive at the charging spot. This driving force corresponds to the electrical energy of the battery 28 consumed by the electric vehicle 1 until it arrives at the charging spot. The control device 35 may obtain this information from the navigation device 33. The control device 35 may also obtain the information to be obtained in step S41 from outside the electric vehicle 1 using the communication device 37.

[0065] In step S42, the control unit 35 predicts the driving force required for the electric vehicle 1 to arrive at the charging spot based on the information acquired in step S41 and the weight of the electric vehicle 1 (step S411). Here, the weight of the electric vehicle 1 is the sum of the weight of the vehicle itself, the current number of passengers, and the load weight of the luggage compartment. The weight of the vehicle itself may be stored in, for example, the storage device 39. The current number of passengers and the load weight of the luggage compartment may be detected by a sensor. For example, the control device 35 may acquire information about the current number of passengers based on the number of seat belt devices fastened.

[0066] In the next step S43, the control device 35 checks real-time traffic conditions. The control device 35 obtains congestion information on the route to the charging spot, for example, using the communication device 37. Whether or not there is congestion on the route to the charging spot affects the average vehicle speed of the electric vehicle 1, and is therefore related to the driving force required for the electric vehicle 1 to arrive at the charging spot. The control device 35 also obtains information on the outside air temperature. The outside air temperature information is related to the temperature drop of the battery 28. The control device 35 uses the congestion information to correct the required driving force predicted in step S42.

[0067] In step S44, the control device 35 analyzes the driving style of the user (i.e., the driver) of the electric vehicle 1. The driving style is information about driving operations specific to the user, such as frequent sudden acceleration / deceleration or driving at a relatively high speed. The user's driving style affects the driving force required for the electric vehicle 1 to arrive at a charging spot. The user's driving style is based on past information. Information about each user's past driving style is stored in the storage device 39. The control device 35 uses the information stored in the storage device 39 to further modify the required driving force modified in step S43.

[0068] In this way, in step S42, the control device 35 predicts the general driving force of the electric vehicle 1 required to arrive at the charging spot from the current position, based on the road environment from the current position to the charging spot.

[0069] In step S43, the control device 35 corrects the general driving force predicted in step S42 to suit the current traffic situation. Then, in step S44, the control device 35 further corrects the driving force of the electric vehicle 1 corrected in step S43 to suit the driving style of the user.

[0070] In step S45, the control device 35 reads the previous driving data. Here, the previous driving data is driving data from when the user previously drove the route to the charging spot. For example, when commuting to work, it is possible that the user will drive the same route multiple times. If the previous driving data exists in the storage device 39, the control device 35 corrects the driving force corrected in step S44 based on the previous driving data. For example, the control device 35 corrects the driving force so that the previous driving data takes priority. This is because the previous driving data is actual data and is therefore more reliable than the predictions in steps S42-S45.

[0071] In this way, steps S41-S45 allow the control device 35 to accurately predict the driving force required for the electric vehicle 1 to arrive at the charging spot.

[0072] In step S46, the control device 35 predicts the power consumption of the electrical components 29. The power consumption of the electrical components 29 includes, for example, the power consumption of an air conditioner.

[0073] In step S47, the control device 35 predicts the average input / output (kW) of the battery 28 over time until the electric vehicle 1 arrives at the charging spot, based on the sum of the driving force (kW) required to run the electric vehicle 1 and the power (kW) consumed by the electrical equipment 29, which were calculated in steps S41-S45.

[0074] In step S48, the control device 35 predicts the temperature that will rise due to self-heating of the battery 28 until the vehicle arrives at the charging spot, based on the average input / output predicted in step S47 and the state of the battery 28 (step S412). The state of the battery 28 includes the temperature, SOC, or SOH of the battery 28.

[0075] In step S413, the control device 35 also predicts a temperature drop of the battery 28 until the electric vehicle 1 arrives at the charging spot. The control device 35 may predict the temperature drop of the battery 28, for example, based on the outside air temperature and the predicted running state of the electric vehicle 1 until the electric vehicle 1 arrives at the charging spot. In step S49, the control device 35 predicts the temperature of the battery 28 when the electric vehicle 1 arrives at the charging spot from the predicted temperature rise and temperature drop due to self-heating of the battery 28.

[0076] Then, the control device 35 executes temperature regulation control of the battery 28 in consideration of the predicted temperature of the battery 28 when the electric vehicle 1 arrives at the charging spot (step S410).

[0077] 5 shows the procedure for temperature regulation control of the battery 28. In step S50, the control device 35 reads the target temperature of the battery 28. The target temperature of the battery 28 may be a predetermined constant value, or may be a value according to the state (SOC or temperature) of the battery 28. Information regarding the target temperature of the battery 28 may be stored in the storage device 39.

[0078] In step S51, the control device 35 determines whether the battery 28 needs to be heated before arriving at the charging spot, based on the temperature of the battery 28 predicted in step S49 when the vehicle arrives at the charging spot and the target temperature read in step S50. If the battery 28 does not need to be heated, in step S511, the control device 35 determines whether the battery 28 needs to be cooled before arriving at the charging spot, based on the temperature of the battery 28 predicted in step S49 when the vehicle arrives at the charging spot and the target temperature read in step S50. If the battery 28 does not need to be cooled, the process ends. In this case, the temperature of the battery 28 reaches the target temperature by self-heating when the vehicle arrives at the charging spot. Since heating and cooling of the battery 28 using the temperature adjustment device 4 is omitted, unnecessary energy consumption is avoided. Furthermore, there is no temperature variation in the battery 28. As described above, the battery 28 is quickly charged.

[0079] Returning to step S51, if it is necessary to heat the battery 28, in step S52, the control device 35 calculates the power (kW) required to heat the battery 28 from the energy (kWh) required to heat the battery 28, which is calculated from the difference between the predicted temperature of the battery 28 when the vehicle arrives at the charging spot and the target temperature, and the time required to reach the charging spot. Information on the time required to reach the charging spot can be obtained from the navigation device 33.

[0080] In step S53, the control device 35 determines whether heating by the PTC heater 51 is necessary based on the required power calculated in step S52, in other words, the amount of heat required to raise the battery 28 to the target temperature before arriving at the charging spot. If the required power is high and heating by the PTC heater 51 is necessary, the process proceeds to step S55. If the required power is low and heating by the PTC heater 51 is not necessary, the process proceeds to step S58.

[0081] In step S55, the control device 35 determines whether the SOC of the battery 28 upon arrival at the charging spot is equal to or greater than a tolerance value. The tolerance value is determined based on the frequency of charging by the user (step S54). In other words, the SOC of the battery 28 at which the user wishes to start charging, in other words, the SOC of the battery 28 at which the user feels anxious about running out of power, can be predicted from distribution information of the remaining SOC of the battery 28 when the user started charging in the past. The tolerance value corresponds to the SOC of the battery 28 at which the user feels anxious about running out of power. In step S55, the control device 35 determines whether the SOC of the battery 28 will fall below the SOC at which the user feels anxious about running out of power while consuming the electrical energy of the battery 28 by adjusting the temperature of the battery 28 until the battery 28 reaches the charging spot. If the SOC of the battery 28 is equal to or greater than the tolerance value, the control device 35 heats the battery 28 using the PTC heater 51 in step S56.

[0082] On the other hand, if the SOC of the battery 28 is below the allowable value, the control device 35 calculates the power consumption of the PTC heater 51 so that the SOC is equal to or greater than the allowable value in step S57, and then heats the battery 28 with the PTC heater 51 in step S56. Because power consumption is suppressed, the SOC of the battery 28 does not fall below the allowable value by the time the electric vehicle 1 arrives at the charging spot. However, there are cases where the temperature of the battery 28 does not reach the target temperature when the electric vehicle 1 arrives at the charging spot.

[0083] When the process proceeds to step S58, the control device 35 heats the battery 28 using the second refrigerant circuit 6. Compared to when the PTC heater 51 is used, the power consumption required to heat the battery 28 can be reduced.

[0084] In step S58, the control device 35 determines whether the SOC of the battery 28 when the electric vehicle 1 arrives at the charging spot is equal to or greater than the allowable value, as in step S55. If the determination in step S58 is Yes, the control device 35 heats the battery 28 using the second refrigerant circuit 6 in step S59. If the determination in step S58 is No, the control device 35 calculates the power consumption for heating using the second refrigerant circuit 6 so that the SOC is equal to or greater than the allowable value in step S510, and then heats the battery 28 using the second refrigerant circuit 6 in step S59. In this case, the temperature of the battery 28 may not reach the target temperature when the electric vehicle 1 arrives at the charging spot. On the other hand, the SOC of the battery 28 does not fall below the allowable value by the time the electric vehicle 1 arrives at the charging spot.

[0085] 6 is a flow chart of the cooling control in step S512. In step S61, the control device 35 calculates the power (kW) required to cool the battery 28 from the energy (kWh) required to cool the battery 28, which is calculated from the difference between the predicted temperature of the battery 28 when the vehicle arrives at the charging spot and the target temperature, and the time required to reach the charging spot.

[0086] In step S62, the control device 35 determines whether cooling by the second refrigerant circuit 6 is necessary based on the required power calculated in step S61, in other words, the amount of cooling required to bring the battery 28 to the target temperature before arriving at the charging spot. If the required power is high and cooling by the second refrigerant circuit 6 is necessary, the process proceeds to step S64. If the required power is low and cooling by the second refrigerant circuit 6 is not necessary, the process proceeds to step S67.

[0087] In step S64, the control device 35 determines whether the SOC of the battery 28 upon arrival at the charging spot is equal to or greater than the allowable value. As described above, the allowable value is determined based on the charging frequency by the user (step S63). If the SOC of the battery is equal to or greater than the allowable value, that is, if the SOC of the battery 28 does not fall below the SOC at which the user feels anxious about running out of power, the control device 35 cools the battery 28 using the second refrigerant circuit 6 in step S65.

[0088] On the other hand, if the SOC of the battery 28 is below the allowable value, the control device 35 calculates the power consumption for cooling by the second refrigerant circuit 6 so that the SOC is equal to or greater than the allowable value in step S66, and then cools the battery 28 by the second refrigerant circuit 6 in step S65. Because the power consumption is suppressed, the SOC of the battery 28 does not fall below the allowable value by the time the electric vehicle 1 arrives at the charging spot. However, the temperature of the battery 28 when the electric vehicle 1 arrives at the charging spot may deviate from the target temperature.

[0089] When the process proceeds to step S67, the control device 35 cools the battery 28 using the radiator 52 of the first refrigerant circuit 5. Compared to using the second refrigerant circuit 6, the power consumption required to cool the battery 28 can be reduced.

[0090] In step S67, the control device 35 determines whether the SOC of the battery 28 when the electric vehicle 1 arrives at the charging spot is equal to or greater than the allowable value, as in step S64. If the determination in step S67 is Yes, the control device 35 cools the battery 28 using the first refrigerant circuit 5 in step S68. If the determination in step S67 is No, the control device 35 calculates the power consumption of the first refrigerant circuit 5 so that the SOC is equal to or greater than the allowable value in step S69, and then cools the battery 28 using the first refrigerant circuit 5 in step S68. In this case, the temperature of the battery 28 when the electric vehicle 1 arrives at the charging spot may deviate from the target temperature. On the other hand, the SOC of the battery 28 does not fall below the allowable value until the electric vehicle 1 arrives at the charging spot.

[0091] (Variation) The heating means is not limited to including both the PTC heater 51 and heating by the second refrigerant circuit 6. The heating means may be the PTC heater 51 alone. If heating by the PTC heater 51 is omitted in consideration of the temperature rise due to self-heating of the battery 28, it is possible to accurately adjust the temperature of the battery 28 to a target temperature, while suppressing unnecessary consumption of electrical energy and suppressing the occurrence of temperature distribution in the battery 28 due to heating by the PTC heater 51.

[0092] The temperature control system 10 disclosed herein is not limited to application to BEVs, but can also be applied to PHEVs (Plug-in Hybrid Vehicles) that are equipped with an internal combustion engine together with a battery 28. [Explanation of symbols]

[0093] 1 Electric vehicle 21 Electric motor 28 Battery 35 Control device 4 Temperature control device 5 1st refrigerant circuit 51 PTC heater (electric heater) 52 Radiator (first cooling device) 53 Refrigerant pump 54 Refrigerant circuit 6 Second refrigerant circuit 61 Compressor 62 Capacitor 63 Expansion valve 64 Heat exchanger (second cooling device)

Claims

1. a motor mounted on the electric vehicle and outputting a driving force for running the electric vehicle; a battery for storing electrical energy to be supplied to the motor; a temperature control device for controlling the temperature of the battery; a control device that performs temperature regulation control using the temperature regulation device so that the temperature at the start of charging of the battery becomes a target temperature suitable for charging, the control device performs the temperature adjustment control while the electric vehicle is heading to a charging spot where the battery is charged, The control device also predicts a temperature rise due to self-heating of the battery until the electric vehicle arrives at the charging spot, and performs the temperature adjustment control taking the predicted temperature rise into consideration. Battery temperature control system.

2. 2. The battery temperature control system according to claim 1, the temperature control device consumes electrical energy from the battery to heat the battery; the control device uses the temperature adjustment device to heat the battery when heating is necessary to set the temperature of the battery to a target temperature after taking into consideration a temperature rise due to self-heating of the battery, and does not use the temperature adjustment device when heating is not necessary; Battery temperature control system.

3. 3. The battery temperature control system according to claim 2, The temperature adjustment device includes an electric heater that contacts the battery or an electric heater that heats a refrigerant in a temperature adjustment plate that contacts the battery. Battery temperature control system.

4. 4. The battery temperature control system according to claim 3, the temperature adjustment device includes the electric heater and a second heating device that consumes less energy than the electric heater, the control device selects the electric heater or the second heating device depending on the amount of heating required to raise the temperature of the battery to a target temperature. Battery temperature control system.

5. 2. The battery temperature control system according to claim 1, the temperature adjustment device includes a first cooling device that cools the battery by utilizing wind generated when the vehicle is running, and a second cooling device that cools the battery by consuming electrical energy from the battery, the control device selects the first cooling device or the second cooling device according to a cooling amount required to bring the temperature of the battery to a target temperature, taking into consideration a temperature rise due to self-heating of the battery. Battery temperature control system.

6. 2. The battery temperature control system according to claim 1, the control device predicts the electric energy required for the electric vehicle to arrive at the charging spot based on information related to a traffic environment, and predicts a temperature increase due to self-heating of the battery based on the electric energy. Battery temperature control system.

7. 7. The battery temperature control system according to claim 6, The control device also predicts the electric energy required for the electric vehicle to arrive at the charging spot based on information about a driving operation of a user of the electric vehicle. Battery temperature control system.

8. 8. The battery temperature control system according to claim 6, The control device also predicts, based on information about the electric vehicle, electric energy required for the electric vehicle to arrive at the charging spot. Battery temperature control system.

9. 2. The battery temperature control system according to claim 1, When the control device predicts that the SOC of the battery will fall below a predetermined allowable value when the vehicle arrives at the charging spot while performing the temperature adjustment control, the control device reduces the amount of electrical energy consumed by the temperature adjustment control so that the SOC becomes equal to or greater than the allowable value. Battery temperature control system.

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