Electric vehicles

Abstract

To restrain charge time from being prolonged when charging by using external equipment.SOLUTION: An ECU executes processing which includes: step (S102) of acquiring temperature, electrical current and voltage if there is possibility of charging after moving (YES at S100); step (S104) of acquiring ambient temperature; step (S106) of setting an offset amount α; step (S108) of calculating an average value of electrical current squared value; step (S110) of setting a threshold value β; step (S112) of setting an execution range of cooling control; step (S116) of executing the cooling control when battery temperature is within the execution range (YES at S114); and step (S118) of determining non-execution of the cooling control when the battery temperature is not within the execution range (NO at S114).SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to control of an electric vehicle. [Background technology]

[0002] Electric vehicles are equipped with a power storage device that supplies power to an electric motor, which is a drive source, and is charged using power generated by the electric motor. Because this power storage device generates heat during charging and discharging, a cooling device is also installed to control the temperature of the power storage device so that it remains within an appropriate temperature range.

[0003] For example, Japanese Patent Application Laid-Open No. 2012-104458 (Patent Document 1) discloses a technique for calculating a target temperature of a battery so that the target temperature decreases as the SOC increases. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-104458 Summary of the Invention [Problem to be solved by the invention]

[0005] In the above-described electric vehicle, the power storage device may be rapidly charged using external equipment. However, when the power storage device is rapidly charged from a low SOC state to a predetermined state of charge, a larger charging current flows than when the power storage device is rapidly charged from a high SOC state to the predetermined state of charge. This increases the amount of heat generated by the power storage device during charging. As a result, the temperature of the power storage device may rise above a temperature range suitable for charging during charging, which may limit the charging power and lengthen the charging time.

[0006] The present disclosure has been made to solve the above-mentioned problems, and its purpose is to provide an electric vehicle that prevents the charging time from becoming long when charging using external equipment. [Means for solving the problem]

[0007] According to an aspect of the present disclosure, an electric vehicle includes a power storage device that supplies electric power to a drive source, a temperature adjustment device that adjusts the temperature of the power storage device, and a control device that operates the temperature adjustment device when the temperature of the power storage device falls within a temperature range for performing the temperature adjustment. When the vehicle reaches a state where charging is predicted after traveling, the control device sets either an upper limit or a lower limit of the temperature range using a State of Charge (SOC) of the power storage device.

[0008] In this way, when it is predicted that charging will be performed after the vehicle has been driven, the temperature can be set to a temperature suitable for charging the power storage device after driving by setting either the upper or lower limit of the temperature range for performing temperature adjustment using the SOC of the power storage device. This makes it possible to prevent charging from being performed when the temperature of the power storage device is outside the temperature range suitable for charging.

[0009] In one embodiment, the temperature adjustment device includes a cooling device that cools the power storage device. When the vehicle enters a state where charging is predicted after driving, the control device sets a lower limit of the temperature range when the SOC of the power storage device is low compared to when the SOC is high.

[0010] In this way, when the SOC of the power storage device is low, the temperature of the power storage device can be lower than when the SOC is high. Therefore, when charging is performed after driving with the SOC low, even if the power storage device generates heat during charging, the temperature of the power storage device can be prevented from rising above a temperature range suitable for charging.

[0011] Furthermore, in one embodiment, when a facility where charging is possible is set as the destination of the vehicle, the control device determines that the state is such that charging is predicted to occur after the vehicle has been driven.

[0012] In this way, if a facility where charging is possible is set as the vehicle's destination, it is predicted that charging will occur after the vehicle has been driven.Therefore, if charging is performed after driving with a low SOC, even if the storage device generates heat during charging, the temperature of the storage device can be prevented from rising beyond a temperature range suitable for charging.

[0013] Furthermore, in one embodiment, the control device sets the lower limit of the temperature range lower when the SOC is low at the time the facility is set as a destination than when the SOC is high.

[0014] In this way, the SOC of the storage device will be further reduced when the vehicle arrives at the destination, so by setting the lower limit of the temperature range low, when charging is performed after the vehicle has been driven, the temperature of the storage device can be prevented from rising beyond the temperature range suitable for charging, even if the storage device generates heat during charging.

[0015] Furthermore, in one embodiment, the controller sets the lower limit of the temperature range lower when the SOC is low at the time the vehicle reaches its destination than when the SOC is high.

[0016] In this way, the SOC will be in a low state when the vehicle reaches its destination, so by setting the lower limit of the temperature range low, when charging is performed after the vehicle has been driven, the temperature of the storage device can be prevented from rising above the temperature range suitable for charging, even if the storage device generates heat during charging.

[0017] Additionally, in one embodiment, the controller sets the lower limit of the temperature range lower when the outside temperature is high than when the outside temperature is low.

[0018] In this way, when the outside temperature is high, the temperature of the power storage device is more likely to rise than when the outside temperature is low. Therefore, by setting the lower limit of the temperature range low, when charging is performed after the vehicle has been driven, it is possible to prevent the temperature of the power storage device from rising above the temperature range suitable for charging, even if the power storage device generates heat during charging.

[0019] Furthermore, in one embodiment, the control device sets the lower limit of the temperature range lower when the load on the drive source is high than when the load on the drive source is low.

[0020] In this way, when the load on the drive source is high, the temperature of the power storage device is more likely to rise than when the load on the drive source is low. Therefore, by setting the lower limit of the temperature range low, when charging is performed after the vehicle has been driven, it is possible to prevent the temperature of the power storage device from rising above the temperature range suitable for charging, even if the power storage device generates heat during charging.

[0021] In yet another embodiment, the temperature adjustment device includes a heating device that heats the power storage device. When charging is predicted after the vehicle has been driven, the control device sets the upper limit of the temperature range higher when the SOC of the power storage device is low than when the SOC is high.

[0022] In this way, when the SOC of the power storage device is low, the temperature of the power storage device can be made higher than when the SOC is high. Therefore, when charging is performed after driving with the SOC low, it is possible to prevent the temperature of the power storage device from being maintained below the temperature range suitable for charging during charging. [Effects of the Invention]

[0023] According to the present disclosure, it is possible to provide an electric vehicle that prevents the charging time from becoming long when charging using external equipment. [Brief explanation of the drawings]

[0024] [Figure 1] FIG. 1 is a diagram illustrating an example of a configuration of a vehicle. [Figure 2] FIG. 10 is a diagram showing an example of the relationship between charging current and SOC. [Figure 3] FIG. 10 is a diagram showing an example of a comparison result of the amount of heat generated when the SOC at the start of charging is different. [Figure 4] 4 is a flowchart illustrating an example of processing executed in an ECU. [Figure 5] FIG. 4 is a diagram showing an example of a map showing the relationship between the SOC of a battery and a lower limit temperature. [Figure 6] FIG. 4 is a diagram showing an example of a map showing the relationship between an offset amount α and an outside air temperature To. [Figure 7] FIG. 10 is a diagram showing an example of a map showing the relationship between a threshold value β and an average value of the square of the current. [Figure 8] FIG. 10 is a diagram showing an example of a comparison result of the cruising range with and without this control in an environment with high outside air temperature. [Figure 9] FIG. 10 is a diagram showing an example of a comparison result of charging time with and without this control in an environment with high outside air temperature. [Figure 10] FIG. 10 is a diagram showing an example of a comparison result of cruising range with and without this control in an environment with low outside air temperature. [Figure 11] FIG. 10 is a diagram showing an example of a comparison result of charging time with and without this control in an environment with low outside air temperature. [Figure 12] 10 is a flowchart showing an example of processing executed in an ECU in a modified example. [Figure 13] FIG. 10 is a diagram showing an example of a map showing the relationship between the SOC and the upper limit temperature of a battery in a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0025] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference numerals, and description thereof will not be repeated.

[0026] FIG. 1 is a diagram showing an example of the configuration of vehicle 1. Vehicle 1 is an electrically powered vehicle equipped with a power storage device that supplies power to a drive source. Vehicle 1 includes, for example, an electric vehicle, a plug-in hybrid vehicle, etc. In this embodiment, a case where vehicle 1 is an electric vehicle will be described as an example.

[0027] 1, the vehicle 1 includes an MG (Motor Generator) 10, a power transmission gear 20, drive wheels 30, a PCU (Power Control Unit) 40, an SMR (System Main Relay) 50, a charging device 60, an inlet 70, a cooling device 80, a battery 100, a monitoring unit 200, an ECU (Electronic Control Unit) 300, and a navigation system 400. The vehicle 1 is configured to run using the MG 10 as a drive source, and to supply electric power stored in the battery 100 to the MG 10 via the PCU 40.

[0028] The MG 10 is, for example, a three-phase AC rotating electric machine that functions as both an electric motor (motor) and a generator. The output torque of the MG 10 is transmitted to the drive wheels 30 via a power transmission gear 20 that includes a reduction gear, a differential gear, and the like.

[0029] When braking the vehicle 1, the MG 10 is driven by the drive wheels 30, and operates as a generator. The MG 10 can function as a braking device that performs regenerative braking to convert the kinetic energy of the vehicle 1 into electric power. The regenerative power generated by the regenerative braking force of the MG 10 is stored in the battery 100.

[0030] PCU 40 is a power conversion device that converts power bidirectionally between MG 10 and battery 100. PCU 40 includes, for example, an inverter and a converter that operate based on a control signal from ECU 300. When battery 100 is being discharged, the converter boosts the DC power supplied from battery 100 and supplies it to the inverter, and the inverter converts the DC power supplied from the converter into AC power to drive MG 10. When battery 100 is being charged, the inverter converts the AC power generated by MG 10 into DC power and supplies it to the converter, and the converter reduces the DC power supplied from the inverter to a voltage suitable for charging battery 100 and supplies it to battery 100.

[0031] PCU 40 suspends charging and discharging by stopping the operation of the inverter and converter based on a control signal from ECU 300. PCU 40 may be configured without the converter.

[0032] SMR 50 is electrically connected to a power line connecting battery 100 and PCU 40. When SMR 50 is closed (i.e., in a conductive state) in response to a control signal from ECU 300, power can be exchanged between battery 100 and PCU 40. On the other hand, when SMR 50 is opened (i.e., in a cut-off state) in response to a control signal from ECU 300, the electrical connection between battery 100 and PCU 40 is cut off.

[0033] When power is supplied from inlet 70, charging device 60 converts the power from inlet 70 into power that can charge battery 100. For example, charging device 60 may convert AC power supplied from inlet 70 into DC power, or may convert DC power supplied from inlet 70 into a DC voltage suitable for charging battery 100. Charging device 60 operates in response to a control signal from ECU 300.

[0034] Inlet 70 has a shape that can be fitted with a connector provided at the end of a charging cable (not shown) that is connected to a charging stand (for example, a quick charger). When the connector is attached to inlet 70, an electrical connection is established between inlet 70 and the connector. This allows power from the charging stand to be supplied to battery 100 via charging device 60.

[0035] Cooling device 80 may, for example, include a cooling fan that operates in response to a control signal from ECU 300, and causes or stops the circulation of a refrigerant (for example, cooling air) in a battery case (not shown) that houses battery 100. Cooling device 80 may, for example, be configured to use cooling water as the refrigerant, and to cool battery 100 by circulating the cooling water through a cooling water passage provided in the battery case using a water pump to exchange heat with battery 100. Cooling device 80 is an example of a "temperature adjustment device" that adjusts the temperature of battery 100 in this embodiment.

[0036] Battery 100 is a power storage device that stores power for driving MG 10 (i.e., power for driving). Battery 100 is a chargeable and dischargeable DC power supply, and may be configured, for example, by connecting a plurality of cells (battery elements) in series, or by connecting a plurality of parallel battery blocks in series, each of which connects a plurality of cells in parallel. For example, a lithium-ion secondary battery can be used as the cell. Note that the cell is not limited to a lithium-ion secondary battery, and may be another secondary battery (for example, a nickel-metal hydride secondary battery). Furthermore, the cell may be an all-solid-state battery including a solid electrolyte.

[0037] The monitoring unit 200 includes a voltage sensor 202 that detects the voltage VB of the battery 100, a current sensor 204 that detects the current IB of the battery 100, and a temperature sensor 206 that detects the temperature TB of the battery 100 (hereinafter also referred to as battery temperature). The monitoring unit 200 calculates the SOC (State of Charge) of the battery 100 using the voltage VB, the current IB, and the temperature TB. The SOC can be calculated by various known methods, such as a current value integration method (coulomb counting) or an open circuit voltage (OCV) estimation method. The monitoring unit 200 transmits the detection results of the voltage sensor 202, the current sensor 204, and the temperature sensor 206, as well as the SOC calculation result, to the ECU 300. The SOC calculation may be performed by the ECU 300 instead of the monitoring unit 200.

[0038] The ECU 300 includes a CPU (Central Processing Unit) 301 and a memory 302. The memory 302 includes various types of memory such as a ROM (Read Only Memory) and a RAM (Random Access Memory). The ECU 300 controls on-board devices (for example, the PCU 40, the SMR 50, the charging device 60, the cooling device 80, or the navigation system 400) based on signals received from the monitoring unit 200 and the outside air temperature sensor 304 and information (for example, maps and programs) stored in the memory 302, so that the vehicle 1 is in a desired state.

[0039] An outside air temperature sensor 304 is connected to the ECU 300. The outside air temperature sensor 304 detects the temperature outside the vehicle 1 (hereinafter referred to as the outside air temperature) To. The outside air temperature sensor 304 transmits a signal indicating the detected outside air temperature To to the ECU 300.

[0040] Navigation system 400 includes a control unit 410, a touch panel display 420, an interface 430, and a position detection device 440. Information relating to an image displayed on touch panel display 420 from ECU 300 is transmitted to navigation system 400 via interface 430.

[0041] Control unit 410 includes a CPU 411 and a memory 412. Control unit 410 is configured to be able to communicate with ECU 300. Control unit 410 receives an operation signal based on a user's operation from touch panel display 420. Furthermore, control unit 410 executes display control of touch panel display 420, whereby various information is displayed on the display unit of touch panel display 420.

[0042] In the control unit 410, the CPU 411 executes a program stored in the memory 412, thereby performing display control of the touch panel display 420. However, the means for performing the display control is not limited to software, and the display control can also be performed by dedicated hardware (electronic circuitry).

[0043] The touch panel display 420 includes an input device (touch panel) that accepts input from a user. The control unit 410 receives signals generated by user operations on the input device. The user can input predetermined instructions or requests to the input device. As the input device, various switches, various pointing devices, a keyboard, etc. may be used instead of or in addition to the touch panel.

[0044] The position detection device 440 detects the position of the vehicle 1 using, for example, a GPS (Global Positioning System) satellite, a wireless LAN (Local Area Network), etc. The position detection device 440 transmits information about the position detection result of the vehicle 1 to the control unit 410.

[0045] For example, map information is stored in the memory 412 of the control unit 410. The control unit 410 identifies a travel route on a map from the current position of the vehicle 1 to a destination set by a user operation, and provides guidance to guide the vehicle 1 traveling along the travel route to the destination.

[0046] The control unit 410 displays map information and guidance information on the touch panel display 420, identifies a destination input by a user operation, and displays multiple options for driving routes to the identified destination. The guidance information includes, for example, information about the location of facilities where quick charging devices capable of charging the battery 100 mounted on the vehicle 1 are installed.

[0047] In vehicle 1 having the above-described configuration, external equipment may be used to rapidly charge battery 100. However, when rapid charging is performed from a low SOC state until battery 100 reaches a predetermined charge state (for example, a fully charged state), the charging current may be larger than when rapid charging is performed from a high SOC state until battery 100 reaches the predetermined charge state.

[0048] Fig. 2 is a diagram showing an example of the relationship between charging current and SOC. The vertical axis of Fig. 2 represents the charging current when charging battery 100. The horizontal axis of Fig. 2 represents the SOC of battery 100. LN1 in Fig. 2 represents an example of the change in charging current with respect to the change in SOC of battery 100.

[0049] 2, when the SOC of the battery 100 is in a range equal to or less than SOC(2), the charging current is constant at IB(0). On the other hand, when the SOC of the battery 100 is in a range greater than SOC(2), the charging current decreases as the SOC increases from IB(0).

[0050] FIG. 3 is a diagram showing an example of a comparison result of the amount of heat generated when the SOC at the start of charging is different. The vertical axis of FIG. 3 represents the amount of heat generated. (A) of FIG. 3 shows a bar graph of an example of the amount of heat generated when the SOC at the start of charging is SOC(0) and charging is continued until it reaches SOC(4). (B) of FIG. 3 shows a bar graph of an example of the amount of heat generated when the SOC at the start of charging is SOC(1) (>SOC(0)) and charging is continued until it reaches SOC(4). (C) of FIG. 3 shows a bar graph of an example of the amount of heat generated when the SOC at the start of charging is SOC(2) (>SOC(1)) and charging is continued until it reaches SOC(4). (D) of FIG. 3 shows a bar graph of an example of the amount of heat generated when the SOC at the start of charging is SOC(3) (>SOC(2)) and charging is continued until it reaches SOC(4).

[0051] 3A to 3D, the lower the SOC at the start of charging, the more heat is generated during charging. During rapid charging, in particular, the amount of heat generated increases in a shorter time than during normal charging, which can cause the temperature of battery 100 to rise above the temperature range suitable for charging. As a result, charging power may be limited, and charging time may become longer.

[0052] Therefore, in this embodiment, when vehicle 1 reaches a state where charging is predicted to be performed after traveling, ECU 300 sets either the upper limit or the lower limit of the temperature range where temperature adjustment is performed using the SOC (State Of Charge) of the power storage device. In this embodiment, when vehicle 1 reaches a state where charging is predicted to be performed after traveling, for example, if the SOC of battery 100 is low, ECU 300 sets the lower limit of the temperature range where cooling of battery 100 is performed lower than when the SOC is high.

[0053] In this way, when the SOC of the battery 100 is low, the temperature TB of the battery 100 can be made lower than when the SOC is high. Therefore, when charging is performed after driving with the SOC low, even if the battery 100 generates heat during charging, the temperature TB of the battery 100 can be prevented from rising beyond the temperature range suitable for charging.

[0054] An example of processing executed by ECU 300 will be described below with reference to Fig. 4. Fig. 4 is a flowchart showing an example of processing executed by ECU 300. A series of processing shown in this flowchart is repeatedly executed by ECU 300 at predetermined intervals.

[0055] In step (hereinafter, step will be abbreviated as S) 100, ECU 300 determines whether or not there is a possibility of charging after moving. For example, when a facility capable of rapid charging of battery 100 mounted on vehicle 1 is set as the destination of vehicle 1, ECU 300 determines that charging is predicted to occur after traveling, that is, that there is a possibility of charging after moving. If it is determined that there is a possibility of charging after moving (YES in S100), the process proceeds to S102.

[0056] In S102, ECU 300 acquires temperature TB, current IB, and voltage VB of battery 100. ECU 300 acquires information indicating the detection results of temperature TB, current IB, and voltage VB from monitoring unit 200. Thereafter, the process proceeds to S104.

[0057] In S104, ECU 300 acquires outside air temperature To. ECU 300 acquires information indicating the detection result of outside air temperature To from outside air temperature sensor 304. Thereafter, the process proceeds to S106.

[0058] In S106, ECU 300 sets an offset amount α. Offset amount α indicates an offset amount in the axial direction of the temperature in a map indicating the relationship between the SOC and the lower limit value of the temperature at which cooling device 80 is activated (hereinafter referred to as the lower limit temperature).

[0059] Fig. 5 is a diagram showing an example of a map showing the relationship between the SOC and the lower limit temperature of the battery 100. The vertical axis of Fig. 5 represents the temperature TB of the battery 100. The horizontal axis of Fig. 5 represents the SOC of the battery 100. LN2 (solid line) in Fig. 5 represents a reference line showing the change in the lower limit temperature relative to the change in the SOC of the battery 100. LN3 (dashed line) in Fig. 5 represents the change in the lower limit temperature relative to the change in the SOC of the battery 100 after offset.

[0060] As shown by LN2 in Fig. 5, for example, when the SOC of battery 100 is 15% or less, the lower limit temperature is set to 30°C. Furthermore, when the SOC of battery 100 is 100%, the lower limit temperature is set to 50°C. Then, when the SOC of battery 100 is greater than 15% and less than 100%, the lower limit temperature is set to change linearly from 30°C to 50°C while the SOC changes from 15% to 100%. LN3 (dashed line) in Fig. 5 is set by moving LN2 in Fig. 5 by α in the direction in which the temperature increases.

[0061] The ECU 300 sets the offset amount α using the acquired outside air temperature To and a map showing the relationship between the offset amount α and the outside air temperature To. Fig. 6 is a diagram showing an example of a map showing the relationship between the offset amount α and the outside air temperature To. The vertical axis of Fig. 6 represents the offset amount α. The horizontal axis of Fig. 6 represents the outside air temperature To. LN5 in Fig. 6 represents the change in the offset amount α with respect to the change in the outside air temperature To.

[0062] As shown in LN5 of Fig. 6, for example, when the outside air temperature To is equal to or higher than To(2), the relationship between the offset amount α and the outside air temperature To is set so that the offset amount α becomes α(0). Also, when the outside air temperature To is equal to or lower than To(0), the relationship between the offset amount α and the outside air temperature To is set so that the offset amount α becomes α(2). Furthermore, as shown in LN5 of Fig. 6, in the section of the outside air temperature To from To(0) to To(2), the relationship between the outside air temperature To and the offset amount α is set so that the offset amount α becomes linear with respect to the outside air temperature To from α(2) to α(1).

[0063] As shown in Fig. 6, for example, when the acquired outside air temperature To is To(1), ECU 300 sets the offset amount α to the value α(1) obtained using LN5 in Fig. 6. After the offset amount α is set, the process proceeds to S108.

[0064] In S108, ECU 300 calculates the average value of the squared value of current IB. ECU 300 calculates the average value of the squared value of current IB acquired during a predetermined period immediately preceding the acquired current IB. The predetermined period is not particularly limited and may be determined through experiments or the like. After the average value of the squared value of current IB is calculated, the process proceeds to S110.

[0065] In S110, ECU 300 sets threshold value β. Threshold value β indicates the lower limit value of the SOC range in which the lower limit temperature is the same as the lower limit temperature when the SOC is 100%. That is, the same value of the lower limit temperature is set while the SOC is between threshold value β and 100%. In this case, the relationship between the SOC and the lower limit temperature is set such that, while the SOC is between 15% and threshold value β, the lower limit temperature changes linearly with the SOC from the lower limit temperature when the SOC is 15% to the lower limit temperature corresponding to threshold value β.

[0066] LN4 (dotted line) in Figure 5 shows the relationship between the SOC and the lower limit temperature, which is set using the offset amount α and threshold value β. As shown in LN4 in Figure 5, the lower limit temperature is set to be 30°C + α until the SOC reaches 15%. On the other hand, while the SOC is between 15% and threshold value β, the lower limit temperature is set to have a linear relationship with the SOC from 30°C + α to 50°C + α. Then, when the SOC is equal to or greater than threshold value β, the lower limit temperature is set to be 50°C + α.

[0067] ECU 300 sets threshold value β using the average value of the squared value of current IB and a map showing the relationship between threshold value β and the average value. FIG. 7 is a diagram showing an example of the map showing the relationship between threshold value β and the average value of the squared value of current. The vertical axis of FIG. 7 represents threshold value β. The horizontal axis of FIG. 7 represents the average value of the squared value of current IB. LN6 in FIG. 7 shows the change in threshold value β with respect to the change in the average value of the squared value of current IB.

[0068] As shown in LN6 of Fig. 7, for example, when the average value of the squared values ​​of current IB is smaller than A(0), the relationship between threshold value β and the average value is set so that threshold value β is β(0). Also, in the section from A(1) to A(2) of the average value of the squared values ​​of current IB, the relationship between the average value and threshold value β is set so that threshold value β is linear with the average value from β(0) to β(1). Then, when the average value of the squared values ​​of current IB is greater than A(2), the relationship between threshold value β and the average value is set so that threshold value β is β(2).

[0069] 7, for example, when the average value of the calculated squared value of current IB is A(1), ECU 300 sets the value β(1) obtained using LN6 in FIG. 7 as threshold value β. After threshold value β is set, the process proceeds to S112.

[0070] In S112, ECU 300 sets the execution range of cooling control. That is, ECU 300 sets the line shown in LN4 in Fig. 5, which is set using the reference line shown in LN2 in Fig. 5, offset amount α, and threshold value β, as the lower limit of the execution range, with the lower limit temperature being the line shown in LN4 in Fig. 5.

[0071] In S114, ECU 300 determines whether the battery temperature is within the performance range. Specifically, if temperature TB is equal to or higher than the lower limit temperature corresponding to the current SOC, ECU 300 determines that the battery temperature is within the performance range. If it is determined that the battery temperature is within the performance range (YES in S114), the process proceeds to S116.

[0072] In S116, ECU 300 executes cooling control. ECU 300 executes cooling control to cool battery 100 by operating a device that circulates a coolant, such as a fan or a pump. If it is determined that the battery temperature is not within the execution range (NO in S114), the process proceeds to S118.

[0073] In S118, ECU 300 does not execute cooling control. If cooling device 80 is in an operating state, ECU 300 stops the operation of cooling device 80. If cooling device 80 is in an inoperating state, ECU 300 maintains the inoperating state. Note that if it is determined that there is no possibility of charging after vehicle 1 is moved (NO in S100), this process ends.

[0074] An example of the operation of the vehicle 1 based on the above-described structure and flowchart will now be described.

[0075] For example, if the user selects a facility (charging station) that allows rapid charging as a destination when starting to drive vehicle 1, it is determined that there is a possibility of charging after moving vehicle 1 (YES in S100), and temperature TB, current IB, and voltage VB are acquired (S102), and outside air temperature To is acquired (S104). Then, an offset amount α is set using the acquired outside air temperature To and a map showing the relationship between the outside air temperature To and offset amount α (S106). Then, an average value of the squared values ​​of current IB over the most recent predetermined period is calculated (S108), and threshold value β is set using the calculated average value of the squared values ​​of current IB and a map showing the relationship between threshold value β and the average value and threshold value β (S110). A lower limit temperature for each SOC is set using the set offset amount α, threshold value β, and the reference line shown in LN2 of FIG. 5, thereby setting the execution range of cooling control (S112).

[0076] Therefore, if the temperature TB is within the set execution range, the cooling control is executed (S116). On the other hand, if the temperature TB is not within the set execution range, the cooling control is not executed (S118).

[0077] In particular, when the SOC is low, the lower limit of the execution range is set lower than when the SOC is high. Furthermore, when the outside temperature is high, the lower limit of the execution range is set lower than when the outside temperature is low.

[0078] Therefore, when there is a possibility of charging the battery 100 after moving the vehicle 1, cooling control is executed so that the temperature of the battery 100 becomes lower than when the SOC is high. As a result, it is possible to suppress a temperature rise of the battery 100 before the vehicle 1 reaches the destination. Therefore, it is possible to suppress a limitation on the charging power caused by a temperature rise of the battery 100 while the battery 100 is being charged.

[0079] FIG. 8 is a diagram showing an example of the results of comparing the cruising range with and without this control in an environment with high outside air temperature. Note that this control is control performed by the processing of the flowchart in FIG. 4. The vertical axis in FIG. 8 represents the cruising range. The bar graph on the left side of FIG. 8 represents the cruising range when this control is not performed (for example, 277 km). The bar graph on the right side of FIG. 8 represents the cruising range when this control is performed (for example, 264 km).

[0080] 8, in an environment where the outside air temperature is high, the offset amount α is smaller than in an environment where the outside air temperature is low, and therefore the lower limit temperature for the same SOC is set lower. Therefore, the cooling device 80 operates earlier than in an environment where the outside air temperature is low. As a result, although the cruising range is shortened by the amount that the cooling device 80 operates earlier, the temperature of the battery 100 can be lowered when the vehicle arrives at the destination (i.e., a facility where rapid charging is possible).

[0081] Fig. 9 is a diagram showing an example of the results of comparing charging times with and without this control in an environment with high outside air temperature. The vertical axis in Fig. 9 represents charging time. The bar graph on the left side of Fig. 9 represents charging time when this control is not executed (for example, 40 minutes). The bar graph on the right side of Fig. 9 represents charging time when this control is executed (for example, 25 minutes).

[0082] As shown in Fig. 9, when this control is not executed, the temperature of battery 100 at the time of arrival at a facility where rapid charging is possible is higher than when this control is executed. As a result, when rapid charging is started and the temperature of battery 100 rises, if the charging power is limited due to the temperature rise of battery 100, the charging time may become longer. On the other hand, when this control is executed, the temperature of battery 100 at the time of arrival at a facility where rapid charging is possible is controlled to be lower than when this control is not executed. As a result, even if rapid charging is started and the temperature of battery 100 rises, if the temperature does not rise to the temperature at which the charging power is limited, the charging time is prevented from becoming longer.

[0083] Fig. 10 is a diagram showing an example of the results of comparing the cruising range with and without this control in an environment with low outside air temperature. The vertical axis in Fig. 10 represents the cruising range. The bar graph on the left in Fig. 10 shows the cruising range (277 km, as an example) when this control is not executed. The bar graph on the right in Fig. 10 shows the cruising range (277 km) when this control is executed.

[0084] 10, in an environment where the outside air temperature is low, the offset amount α is larger than in an environment where the outside air temperature is high, and therefore the lower limit of the temperature at which the cooling device 80 operates at the same SOC becomes higher. Therefore, unlike in an environment where the outside air temperature is high, the cooling device 80 remains stopped. When the cooling device 80 remains stopped, no power is consumed to operate the cooling device 80, and therefore the cruising range remains the same regardless of whether or not this control is performed.

[0085] Fig. 11 shows an example of the results of comparing charging times with and without this control in a low outside air temperature environment. The vertical axis in Fig. 11 represents charging time. The bar graph on the left side of Fig. 11 shows the charging time (25 minutes, as an example) when this control is not executed. The bar graph on the right side of Fig. 11 shows the charging time (25 minutes) when this control is executed.

[0086] 11, in an environment where the outside air temperature is low, the cooling device 80 remains stopped regardless of whether this control is performed, so the temperature of the battery 100 when it arrives at a facility where rapid charging is possible will be the same, and as a result, the charging time will also be the same.

[0087] As described above, in vehicle 1, which is an electric vehicle according to the present embodiment, when the SOC of battery 100 is low, the temperature of battery 100 can be lower than when the SOC is high. Therefore, when charging is performed after traveling with a low SOC, even if battery 100 generates heat during charging, the temperature of battery 100 can be prevented from rising above a temperature range suitable for charging. Therefore, it is possible to provide an electric vehicle that prevents the charging time from becoming long when charging using external equipment.

[0088] Furthermore, if a facility where charging is possible is set as the destination of vehicle 1, it is predicted that charging will be performed after vehicle 1 has traveled. Therefore, by setting the lower limit of the temperature range (execution range) lower when the SOC of battery 100 is low than when the SOC is high, it is possible to prevent the temperature of battery 100 from rising above the temperature range suitable for charging when charging is performed after traveling, even if battery 100 generates heat during charging.

[0089] Furthermore, if the SOC is low at the time when the facility where vehicle 1 can be charged is set as the destination, the SOC of battery 100 will be even lower when vehicle 1 arrives at the destination. Therefore, by setting the lower limit of the temperature range low, when charging is performed after vehicle 1 has been driven, the temperature of battery 100 can be prevented from rising above the temperature range suitable for charging, even if battery 100 generates heat during charging.

[0090] Furthermore, when the outside air temperature is high, the temperature of battery 100 is more likely to rise than when the outside air temperature is low. Therefore, by setting the lower limit of the temperature range low, even if battery 100 generates heat during charging after driving, the temperature of battery 100 can be prevented from rising above the temperature range suitable for charging.

[0091] Furthermore, when the load on MG10, which is the drive source (i.e., the average value of the square of the current IB), is high, the lower limit of the temperature range is set lower than when the load on the drive source is low. Therefore, when there is a possibility of charging after the vehicle 1 moves, cooling control is executed to lower the temperature of the battery 100. As a result, it is possible to suppress a temperature rise in the battery 100 before the vehicle reaches the destination. Therefore, it is possible to suppress a limitation on the charging power due to a temperature rise in the battery 100 while the battery 100 is being charged.

[0092] Modifications will be described below. In the above embodiment, the outside air temperature To is described as being obtained using the outside air temperature sensor 304 provided in the vehicle 1, but it may also be obtained, for example, from a server or the like via a communication network external to the vehicle 1 (such as the Internet), or it may be obtained directly from another vehicle traveling near the vehicle 1 or via a communication network.

[0093] Furthermore, in the above embodiment, it has been described that the lower limit of the temperature range is set lower when the SOC is low at the time when the destination of vehicle 1 is set than when the SOC is high, but for example, when the SOC is low at the time when vehicle 1 reaches the destination instead of when the destination of vehicle 1 is set, the lower limit of the temperature range may be set lower than when the SOC is high. ECU 300 may, for example, estimate the SOC at the time when the destination is reached taking into account the SOC of battery 100 before travel and the length of the travel route, and set the lower limit of the temperature range using the estimated SOC.

[0094] In this way, when charging is performed after the vehicle 1 has reached its destination, even if the battery 100 generates heat during charging, the temperature of the battery 100 can be prevented from rising above a temperature range suitable for charging.

[0095] Furthermore, in the above-described embodiment, ECU 300 has been described as determining that there is a possibility that vehicle 1 will be charged after moving when a charging facility is selected as the destination. However, for example, ECU 300 may determine that there is a possibility that vehicle 1 will be charged after moving when home is selected as the destination, or may determine that there is a possibility that vehicle 1 will be charged after moving when the SOC is below a threshold, or may determine that there is a possibility that vehicle 1 will be charged after moving when the current time is within a preset time period or within a charging time period identified using a charging history, etc.

[0096] Furthermore, in the above embodiment, the cooling device 80 has been described as an example of a temperature adjustment device that adjusts the temperature of the battery 100, but the temperature adjustment device that adjusts the temperature of the battery 100 may also be, for example, a heating device (not shown) that heats the battery 100. The heating device may also be, for example, a heater that operates using the power of the battery 100.

[0097] For example, when the vehicle 1 reaches a state where charging is predicted to occur after the vehicle 1 has been driven, the ECU 300 may set the upper limit of the temperature range in which heating is performed higher if the SOC of the battery 100 is low than if the SOC is high.

[0098] 12 is a flowchart showing an example of a process executed in the modified ECU 300. The series of processes shown in this flowchart are repeatedly executed by the ECU 300 at predetermined intervals.

[0099] The same step numbers are assigned to the processes shown in the flowchart of Fig. 12 that are similar to the processes shown in the flowchart of Fig. 4. Therefore, the contents of those processes are the same except as described below, and therefore detailed description thereof will not be repeated.

[0100] After threshold value β is set in S110, the process proceeds to S200. In S200, ECU 300 sets an execution range for temperature rise control.

[0101] In this modified example, the offset amount α set in S106 indicates the offset amount in the axial direction of the temperature in a map showing the relationship between the SOC and the upper limit value of the temperature at which the heating device is operated (hereinafter referred to as the upper limit temperature).

[0102] Fig. 13 is a diagram showing an example of a map showing the relationship between the SOC and upper limit temperature of battery 100 in a modified example. The vertical axis of Fig. 13 represents the temperature TB of battery 100. The horizontal axis of Fig. 13 represents the SOC of battery 100. LN7 (solid line) in Fig. 13 represents a reference line showing the change in the upper limit temperature relative to the change in the SOC of battery 100. LN8 (dashed line) in Fig. 13 represents the change in the upper limit temperature relative to the change in the SOC of battery 100 after offset.

[0103] As shown by LN7 in Fig. 13, for example, when the SOC of battery 100 is 15% or less, the upper limit temperature is set to 15°C. Furthermore, when the SOC of battery 100 is 100%, the upper limit temperature is set to -20°C. Then, when the SOC of battery 100 is greater than 15% and less than 100%, the upper limit temperature is set to change linearly from 15°C to -20°C while the SOC changes from 15% to 100%. LN8 (dashed line) in Fig. 13 is set by moving LN7 in Fig. 13 by α in the direction in which the temperature increases.

[0104] ECU 300 sets offset amount α using outside air temperature To acquired in S104 and a map showing the relationship between offset amount α and outside air temperature To. The map showing the relationship between offset amount α and outside air temperature To is as described with reference to FIG. 6, and therefore detailed description thereof will not be repeated.

[0105] ECU 300 sets threshold value β using the average value of the squared value of current IB calculated in S108 and a map showing the relationship between threshold value β and the average value. Threshold value β indicates the lower limit of the SOC range in which the upper limit temperature is the same as the upper limit temperature when the SOC is 100%. That is, the same value of the upper limit temperature is set while the SOC is between threshold value β and 100%. In this case, the relationship between the SOC and the upper limit temperature is set such that the upper limit temperature changes linearly with the SOC from the upper limit temperature when the SOC is 15% to the upper limit temperature corresponding to threshold value β while the SOC is between 15% and threshold value β. The map showing the relationship between threshold value β and the average value has been described using FIG. 7, and therefore detailed description thereof will not be repeated.

[0106] LN9 (dotted line) in Fig. 13 shows the relationship between the SOC and the upper limit temperature, which is set using the offset amount α and the threshold value β. As shown in LN9 in Fig. 13, the upper limit temperature is set to be 15°C + α until the SOC reaches 15%. On the other hand, while the SOC is between 15% and the threshold value β, the upper limit temperature is set to have a linear relationship with the SOC from 15°C + α to -20°C + α. Then, when the SOC is equal to or greater than the threshold value β, the upper limit temperature is set to be -20°C + α.

[0107] If temperature TB is equal to or lower than the upper limit temperature corresponding to the current SOC, ECU 300 determines that the battery temperature is within the performance range. If it is determined that the battery temperature is within the performance range (YES in S114), the process proceeds to S202.

[0108] In S202, ECU 300 executes temperature increase control. ECU 300 executes temperature increase control, for example, by operating a heater to heat battery 100. Thereafter, this process ends. Note that if it is determined that the battery temperature is not within the execution range (NO in S114), the process proceeds to S204.

[0109] In S204, ECU 300 does not execute temperature increase control. If the heating device is in an operating state, ECU 300 stops the operation of the heating device. If the heating device is in an inoperating state, ECU 300 maintains the inoperating state. Thereafter, this process ends.

[0110] An example of the operation of the vehicle 1 in this modified example based on the above-described structure and flowchart will now be described.

[0111] For example, if the user selects a facility (charging station) that allows rapid charging as a destination when starting to drive vehicle 1, it is determined that there is a possibility of charging after moving vehicle 1 (YES in S100), and temperature TB, current IB, and voltage VB are acquired (S102), and outside air temperature To is acquired (S104). Then, an offset amount α is set using the acquired outside air temperature To and a map showing the relationship between the outside air temperature To and offset amount α (S106). Then, an average value of the squared values ​​of current IB over the most recent predetermined period is calculated (S108), and threshold value β is set using the calculated average value of the squared values ​​of current IB and a map showing the relationship between threshold value β and the average value and threshold value β (S110). An upper limit temperature for each SOC is set using the set offset amount α, threshold value β, and the reference line shown in LN7 of FIG. 13, thereby setting the execution range of temperature rise control (S200).

[0112] Therefore, if the temperature TB is within the set execution range, the temperature increase control is executed (S202). On the other hand, if the temperature TB is not within the set execution range, the temperature increase control is not executed (S204).

[0113] In particular, when the SOC is low, the upper limit of the execution range is set higher than when the SOC is high. Furthermore, when the outside temperature is low, the upper limit of the execution range is set higher than when the outside temperature is high.

[0114] Therefore, when there is a possibility of charging after moving the vehicle 1, the temperature increase control is executed so that the temperature of the battery 100 becomes higher than when the SOC is high. As a result, the temperature of the battery 100 can be increased by the time the vehicle 1 reaches the destination, particularly in an environment with a low outside air temperature. Therefore, it is possible to prevent the temperature of the battery 100 from remaining lower than the temperature range suitable for charging while the battery 100 is being charged.

[0115] In addition, although the map for setting the offset amount α and threshold value β used in the temperature rise control is the same as the map for setting the offset amount α and threshold value β used in the cooling control, the offset amount α and threshold value β used in the temperature rise control may be set using a map different from the map used in the cooling control.

[0116] The above-described modifications may be implemented in whole or in part in appropriate combination. The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0117] 1 Vehicle, 10 MG, 20 power transmission gear, 30 drive wheel, 40 PCU, 50 SMR, 60 charging device, 70 inlet, 80 cooling device, 100 battery, 200 monitoring unit, 202 voltage sensor, 204 current sensor, 206 temperature sensor, 300 ECU, 301, 411 CPU, 302, 412 memory, 304 outside air temperature sensor, 400 navigation system, 410 control unit, 420 touch panel display, 430 interface, 440 position detection device.

Claims

1. a power storage device that supplies power to the drive source; a temperature adjustment device that adjusts the temperature of the power storage device; a control device that operates the temperature adjustment device when the temperature of the power storage device falls within a temperature range for performing the temperature adjustment; When the vehicle reaches a state where charging is predicted to be performed after traveling, the control device sets either an upper limit or a lower limit of the temperature range using an SOC (State of Charge) of the power storage device.

2. the temperature adjustment device includes a cooling device that cools the power storage device, 2. The electric vehicle according to claim 1, wherein, when the vehicle enters a state in which charging is predicted to be performed after traveling, the control device sets the lower limit of the temperature range lower when the SOC of the power storage device is low than when the SOC is high.

3. 3. The electric vehicle according to claim 2, wherein the control device determines that the vehicle is in a state in which charging is predicted to be performed after the vehicle has been driven when a facility where charging is possible is set as a destination of the vehicle.

4. The electric vehicle according to claim 3 , wherein the control device sets the lower limit of the temperature range lower when the SOC is low at the time the facility is set as the destination than when the SOC is high.

5. The electric vehicle according to claim 3 , wherein the control device sets the lower limit of the temperature range lower when the SOC is low at the time the vehicle reaches the destination than when the SOC is high.

6. The electric vehicle according to claim 2 , wherein the control device sets the lower limit of the temperature range lower when the outside air temperature is high than when the outside air temperature is low.

7. The electric vehicle according to claim 2 , wherein the control device sets the lower limit of the temperature range lower when the load on the drive source is high than when the load on the drive source is low.

8. the temperature adjustment device includes a heating device that increases the temperature of the power storage device, 2. The electric vehicle according to claim 1, wherein, when the vehicle enters a state in which charging is predicted to be performed after traveling, the control device sets the upper limit of the temperature range higher when the SOC of the power storage device is low than when the SOC is high.

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