Heating control device of electric vehicle

Abstract

To provide a control device of a vehicle which can warm up a cabin in an early stage.SOLUTION: A heating control device of an electric vehicle comprises: a motor as a traveling power source; a battery which supplies the motor with electric power; a heater core for heating which transfers heat of the battery through cooling water; and a flow control mechanism which controls flow rate of cooling water passing through the battery to raise temperature of the battery to a target temperature. The heating control device of the electric vehicle includes: a prediction part which predicts, when heating is not used, whether the heating is used or not based on at least one of environment information around the electric vehicle, temperature information in a cabin, drive state information of auxiliary machines of the electric vehicle, and use history information of the heating; and a configuration part which sets, when use of the heating is predicted, the target temperature to be a higher value in comparison with a case that no use of the heating of predicted.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a heating control device for an electric vehicle. [Background technology]

[0002] BACKGROUND ART There is an electric vehicle that includes a motor as a driving power source, a battery that supplies power to the motor, and a heater core to which heat from the battery is transferred via coolant (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2015-191703 Summary of the Invention [Problem to be solved by the invention]

[0004] In engine vehicles, engine heat is transferred to the heater core via the coolant. Compared to engine vehicles, electric vehicles have lower heating capacity because they use heat from the battery. For this reason, it may take some time for the interior of an electric vehicle to warm up after starting the heater.

[0005] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a heating control device for an electric vehicle that can quickly warm the interior of the vehicle. [Means for solving the problem]

[0006] The above object can be achieved by a heating control device for an electric vehicle having a motor as a driving power source, a battery that supplies power to the motor, a heater core for heating to which heat from the battery is transferred via coolant, and a flow control mechanism that controls the flow rate of coolant passing through the battery so that the temperature of the battery reaches a target temperature, the heating control device including: a prediction unit that predicts whether heating will be used when heating is not in use based on at least one of environmental information around the electric vehicle, temperature information within the vehicle cabin, driving status information of accessories of the electric vehicle, and heating usage history information; and a setting unit that sets the target temperature to a higher value when heating is predicted to be used than when heating is predicted not to be used. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a control device for an electric vehicle that can quickly warm up the interior of the vehicle. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic configuration diagram of an electric vehicle. [Figure 2] FIG. 2 is a schematic diagram of a cooling system. [Figure 3] 10 is a flowchart illustrating a target battery temperature setting control. DETAILED DESCRIPTION OF THE INVENTION

[0009] [Outline of electric vehicle configuration] 1 is a schematic diagram of an electric vehicle 1. The electric vehicle 1 is an electric vehicle equipped with a motor 2 as a driving power source, but may also be a hybrid vehicle. The electric vehicle 1 is equipped with the motor 2, a transaxle 2a, a drive shaft 5, drive wheels 6, a PCU (Power Control Unit) 7, an ESU (Electricity Supply Unit) 7a, a battery 8, and an ECU (Electric Control Unit) 10.

[0010] The motor 2 functions as an electric motor that outputs torque when supplied with electric power. The motor 2 also functions as a generator that generates electricity when the electric vehicle 1 is braked. The stored electric power in the battery 8 is supplied to the motor 2 via the PCU 7. The generated electric power of the motor 2 is supplied to the battery 8 via the PCU 7. The ECU 10 controls the PCU 7 to adjust the electric power exchanged between the motor 2 and the battery 8.

[0011] The ESU 7a is mounted on the electric vehicle 1 so that the battery 8 can be charged using power from an AC power source such as a household power source or an external charging device such as a quick charger installed at a charging station. In other words, the battery 8 can be externally charged via a plug 9.

[0012] The motor 2 is provided in a transaxle 2a, which houses a reduction gear and a differential gear. The power of the motor 2 is transmitted to a drive shaft 5 via the reduction gear and the differential gear, causing the drive wheels 6 to rotate.

[0013] The ECU 10 includes a central processing unit (CPU), a random access memory (RAM), a read-only memory (ROM), and a storage device, and performs various controls by executing programs stored in the ROM and the storage device. The ECU 10 is an example of a control device for an electric vehicle, and functionally realizes a prediction unit and a setting unit, which will be described in detail later.

[0014] The ECU 10 is connected to a heating switch 11 and a navigation device 12. The heating switch 11 is operated by a user. When the heating switch 11 is turned on, the ECU 10 causes a cooling system 30, which will be described later, to perform a heating operation. The navigation device 12 has a built-in GPS (Global Positioning System) receiver that acquires vehicle position information. Map data, the past driving history of the electric vehicle 1, etc. are stored in a storage device of the navigation device 12.

[0015] The ECU 10 has a communication interface and is capable of wireless communication with an external server via a network NW. The communication interface uses a communication standard such as LTE or Wi-Fi (registered trademark).

[0016] [Cooling system] The battery 8 is cooled by a cooling system 30, which will be described below, and the heat of the coolant that cools the battery 8 is transferred to a heater core 92 via the cooling system 30. Figure 2 is a schematic diagram of the cooling system 30. The cooling system 30 has a low-temperature radiator circuit 30a, a heat pump circuit 30b, and a high-temperature radiator circuit 30c. These circuits are thermally connected, but the paths through which the coolant flows are independent of each other.

[0017] The low-temperature radiator circuit 30a includes paths 33a, 34a, 37a, 38a, and 39a. The path 33a includes a heater 64, a battery 8, and a temperature sensor T1. The temperature sensor T1 detects the temperature of the coolant at the outlet side of the battery 8 and is connected to the ECU 10. The battery 8 supplies power to the motor 2 via the ESU 7a and the PCU 7. The battery 8 is cooled by the coolant flowing through the path 33a. The heater 64 can warm the battery 8 by heating the coolant through the path 33a as needed.

[0018] The path 34a is equipped with a water pump 68 and a chiller 70. The upstream end of the path 33a and the downstream end of the path 34a are connected via a switching valve 40. The downstream end of the path 33a and the upstream end of the path 34a are connected via a reservoir tank 69.

[0019] The upstream end of path 37a and the downstream end of path 38a are connected via a switching valve 40. The downstream end of path 37a and the upstream end of path 38a are connected via a reservoir tank 69. Path 37a includes a low-temperature radiator 42 and a temperature sensor T3. Path 38a includes an ESU 7a, a temperature sensor T2, a PCU 7, a water pump 60, and an oil cooler 54. Circulation path 50a circulates oil between the oil cooler 54 and the transaxle 2a by an oil pump 52. The temperature sensors T2 and T3 are connected to the ECU 10.

[0020] Path 39a bypasses low-temperature radiator 42. Path 39a branches at a switching valve 40 located at the junction of paths 37a and 38a, bypasses low-temperature radiator 42, and merges with reservoir tank 69 located at the downstream end of path 37a. Switching valve 40 is a five-way flow control valve, and connects paths 33a, 34a, 37a, 38a, and 39a. The operation of switching valve 40 is controlled by ECU 10.

[0021] The heat pump circuit 30b has paths 32b and 34b. The path 32b circulates coolant through the chiller 70 and the condenser 84. The path 32b has an expansion valve 72 and a compressor 82, and forms a refrigeration cycle. The path 32b transfers heat from the low-temperature radiator circuit 30a to the high-temperature radiator circuit 30c. The path 34b bypasses the chiller 70. The path 34b has an expansion valve 78, an evaporator 76, and an EPR (Evaporator Pressure Regulator) 74. A switching valve 80 is provided at the upstream end of the path 34b. The evaporator 76 absorbs heat from the surrounding air into the coolant. The heat absorbed by the evaporator 76 is transferred from the condenser 84 to the high-temperature radiator circuit 30c.

[0022] The high-temperature radiator circuit 30c has paths 32c and 34c. Path 32c circulates coolant through a condenser 84 and a high-temperature radiator 94. A water pump 88 is provided in path 32c. Heat transferred from the heat pump circuit 30b is released to the outside air from the high-temperature radiator 94. A heater 86 is provided in path 32c. Path 34c bypasses the high-temperature radiator 94. A heater core 92 is provided in path 34c. A switch valve 90 is provided at the upstream end of path 34c.

[0023] In the cooling system 30 configured as described above, when heating is requested by the heating switch 11, the ECU 10 controls the switching valve 40 to restrict the flow of coolant to the low-temperature radiator 42, and controls the switching valve 90 to restrict the flow of coolant to the high-temperature radiator 94. Furthermore, the coolant that has passed through the battery 8 flows to the chiller 70 via paths 33a and 34a. In this manner, the high-temperature coolant is transferred to the coolant in the heat pump circuit 30b via the chiller 70. Heat from the coolant in the heat pump circuit 30b is transferred to the coolant in the high-temperature radiator circuit 30c via the condenser 84. The coolant in the high-temperature radiator circuit 30c flows to the heater core 92 via path 34c. The heater core 92 dissipates heat from the coolant into the vehicle interior. In this manner, the vehicle interior is heated.

[0024] The ECU 10 controls the temperature of the battery 8 to a target temperature. Specifically, the ECU 10 controls the switching valve 40 and the water pump 68 to control the flow rate of the coolant passing through the battery 8, thereby controlling the temperature of the battery 8 to the target temperature. For example, when the switching valve 40 increases the opening of the path 33a, the flow rate of the coolant passing through the battery 8 increases. Furthermore, when the driving force of the water pump 68 increases, the flow rate of the coolant flowing from the path 34a to the path 33a increases, and the flow rate of the coolant passing through the battery 8 increases. The switching valve 40 and the water pump 68 are examples of a flow rate control mechanism. For example, when the temperature of the battery 8 is lower than the target temperature, the flow rate of the coolant flowing into the battery 8 is reduced, thereby increasing the temperature of the battery 8. Furthermore, when the temperature of the battery 8 is higher than the target temperature, the flow rate of the coolant flowing into the battery 8 is increased, thereby decreasing the temperature of the battery 8. The ECU 10 also controls the heater 64 to control the temperature of the battery 8 to the target temperature. The ECU 10 regards the temperature of the coolant detected by the temperature sensor T1 as the temperature of the battery 8. The ECU 10 sets the target temperature of the battery 8 as follows.

[0025] [Battery target temperature setting control] 3 is a flowchart illustrating the battery target temperature setting control. The ECU 10 determines whether the heater is not in use (step S1). If the answer is No in step S1, this control ends. If the answer is Yes in step S1, the ECU 10 determines whether the battery 8 is being plugged in and charged (step S2).

[0026] If the answer is Yes in step S2, the ECU 10 predicts whether or not the heater will be used (step S3). Specifically, it predicts whether or not the heater will be used within a predetermined time based on at least one of environmental information around the electric vehicle 1, temperature information inside the vehicle cabin, driving state information of the accessories of the electric vehicle 1, and heater use history information. Step S3 is an example of processing executed by the prediction unit.

[0027] The environmental information is, for example, weather information and outside temperature information around the electric vehicle 1. The environmental information is acquired, for example, via a network NW. For example, if it is predicted that the weather will worsen or the outside temperature will drop within a predetermined time period, it may be predicted that the heater will be used. The temperature information inside the vehicle cabin is the temperature inside the vehicle cabin and the degree of temperature drop inside the vehicle cabin. The temperature inside the vehicle cabin is acquired by a temperature sensor that detects the temperature inside the vehicle cabin. For example, it may be predicted that the heater will be used if the temperature inside the vehicle cabin drops below a predetermined temperature or if the degree of temperature drop is equal to or greater than a predetermined value. The driving status information of the accessories of the electric vehicle 1 is, for example, information indicating the driving status of the headlights and wipers. For example, it may be predicted that the heater will be used if the headlights and wipers are driving. The heating usage history information is, for example, the time period during which the heater will be used. For example, it may be predicted that the heater will be used if the time period during which the heater will be used falls within a predetermined time period. Furthermore, these pieces of information may be combined to predict the use of the heater.

[0028] If the answer to step S3 is Yes, the ECU 10 sets the target temperature of the battery 8 to (X+A) degrees (step S4). If the answer to step S3 is No, the ECU 10 sets the target temperature of the battery 8 to X degrees (step S5). Here, X degrees is a temperature at which the battery 8 can fully perform. X degrees is, for example, a temperature higher than 0 degrees. The added temperature A is a positive value. In this way, when it is predicted that the heating will be used, the target temperature of the battery 8 is set to a higher value than when it is predicted that the heating will not be used. This increases the temperature of the coolant that has passed through the battery 8. As a result, the temperature of the coolant flowing through the heater core 92 also increases. That is, before the heating is used, high-temperature coolant flows through the heater core 92. Therefore, when the heating starts to be used, the heater core 92 dissipates heat from the high-temperature coolant into the vehicle interior. This allows the vehicle interior to be warmed up quickly after the heating starts to be used. Steps S4 and S5 are an example of processing executed by the setting unit.

[0029] Furthermore, if the answer to step S2 is Yes, that is, if the battery 8 is being plugged in for charging, the temperature of the battery 8 rises. In such a case, the target temperature of the battery 8 is set to a high value. Therefore, the waste heat generated by the charging of the battery 8 is effectively used for heating. Furthermore, during plugged in charging, the electric vehicle 1 is stopped and the motor 2 is stopped. Therefore, power from the battery 8 is not being supplied to the motor 2. In such a state, there is little need to strictly manage the temperature of the battery 8 in order to ensure the performance of the battery 8. Therefore, ensuring the heating performance takes priority over managing the temperature of the battery 8.

[0030] If the answer is No in step S2, the ECU 10 predicts whether or not the heater will be used (step S6). The prediction method is the same as in step S3. If the answer is No in step S6, the target temperature of the battery 8 is set to X degrees (step S5). In this way, if the heater will not be used, the temperature management of the battery 8 takes priority over the heating performance.

[0031] If the answer is Yes in step S6, the ECU 10 determines whether the temperature of the battery 8 is within a range requiring cooling (step S7). The range requiring cooling is a high temperature range in which the performance of the battery 8 may be reduced. If the answer is Yes in step S7, the target temperature of the battery 8 is set to X degrees (step S5). In such a case, temperature management of the battery 8 takes priority over heating performance, and cooling of the battery 8 is promoted.

[0032] If the answer is No in step S7, the ECU 10 predicts whether or not the vehicle will be parked (step S8). Specifically, the ECU 10 predicts whether the vehicle will be parked based on the position information of the electric vehicle 1 and the map information of the navigation device 12. For example, if the position of the electric vehicle 1 is within a predetermined distance from a parking lot, it is predicted that the vehicle will be parked.

[0033] If the answer is Yes in step S8, the ECU 10 sets the target temperature of the battery 8 to (X+B) degrees (step S9). The added temperature B is a temperature lower than the added temperature A described above. That is, the target temperature set in step S9 is lower than the target temperature set in step S4. Even when parking is predicted, there may be cases where driving is resumed immediately after parking. This is to ensure the performance of the battery 8 when driving is resumed in such a case.

[0034] If the answer is No in step S8, the ECU 10 sets the target temperature of the battery 8 to (X+C) degrees (step S10). The added temperature C is a temperature lower than the added temperature B. That is, the target temperature set in step S10 is lower than the target temperatures set in steps S4 and S9. This is to achieve both the performance of the battery 8 and the heating performance when it is predicted that the electric vehicle 1 will not be parked, that is, when it is predicted that the electric vehicle 1 will continue to run and when it is predicted that the heater will be used.

[0035] Although the embodiments of the present invention have been described in detail above, the present invention is not limited to such specific embodiments, and various modifications and variations are possible within the scope of the gist of the present invention as defined in the claims. [Explanation of symbols]

[0036] 1 Electric vehicles 2 motors 8 Battery 10 ECU (heating control unit, prediction unit, setting unit) 12 Navigation devices 30 Cooling System 92 heater core

Claims

[Claim 1] a motor that is a driving power source; a battery for supplying power to the motor; a heater core for heating to which heat from the battery is transferred via coolant; a flow rate control mechanism that controls the flow rate of cooling water passing through the battery so that the temperature of the battery reaches a target temperature; A heating control device for an electric vehicle having a prediction unit that predicts whether or not a heater will be used when the heater is not in use, based on at least one of environmental information around the electric vehicle, temperature information within the vehicle cabin, driving state information of an accessory of the electric vehicle, and heater use history information; A heating control device for an electric vehicle, comprising: a setting unit that sets the target temperature to a higher value when it is predicted that heating will be used than when it is predicted that heating will not be used.

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