Electric vehicle

Abstract

A vehicle capable of traveling using electric power includes a battery including a single cell capable of accumulating electric power for traveling and a conductive member (for example, a terminal, a bus bar module, a bus bar) through which electric current flows outside the single cell; an MG that generates driving force using electric power of the battery; a cooling / warming device that cools the conductive member; and a CPU of an ECU. In a case where there is a request to cause the MG to operate at or above a prescribed output, the CPU controls the cooling / warming device to cool the conductive member at least during a period from when the request is received to when the prescribed output or more is generated. Thus, the conductive member of the battery is cooled in advance before being heated during a period from when the request to cause the MG to operate at or above the prescribed output is received to when the prescribed output or more is generated.

Description

Technical Field

[0001] This invention relates to an electric vehicle, and more particularly to an electric vehicle capable of operating on electricity. Background Technology

[0002] Previously, there were technologies that enabled vehicles to start quickly by controlling them to start rapidly (for example, see Japanese Patent Application Publication No. 2021-55842). Summary of the Invention

[0003] In electric vehicles such as battery electric vehicles (BEVs), hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), and fuel cell electric vehicles (FCEVs), the energized components around the battery reach high temperatures during rapid acceleration and high-output discharge from the battery. High temperatures in these components increase resistance, making it difficult to maximize battery output. Consequently, the vehicle's acceleration performance deteriorates.

[0004] The present invention was made to solve the above-mentioned problems, and its object is to provide an electric vehicle in which the resistance of the conductive components does not increase, thereby improving the output of the battery and preventing the deterioration of acceleration performance.

[0005] The present invention relates to an electric vehicle capable of operating on electricity, comprising: a battery including battery cells capable of storing power for operation and conductive components through which current flows on the exterior of the battery cells; an electric generator that uses the power from the battery to generate driving force; a cooling unit that cools the conductive components; and a processor. When there is a demand for the electric generator to operate at a specified output or higher, the processor controls the cooling unit to cool the conductive components at least from the time the demand is received until the specified output or higher is generated.

[0006] According to this structure, during the period from receiving a request to operate the electric generator at a specified output or higher until the specified output or higher is generated, the conductive components of the battery are pre-cooled before being heated. As a result, an electric vehicle can be provided that improves battery output without increasing the resistance of the conductive components and prevents acceleration performance degradation.

[0007] The cooling section can also serve as a cooling unit for the battery cells, and it provides stronger cooling to the conductive components than to the battery cells themselves. With this structure, the conductive components are cooled more effectively than the battery cells, thus preventing further increases in their resistance. Furthermore, it can suppress the increase in the internal resistance of the battery cells caused by over-cooling.

[0008] It can also include a sensor for detecting the battery temperature, and the cooling unit includes a cooling device for cooling the refrigerant. Alternatively, the processor can calculate the amount of heat required to cool the conductive components based on the temperature detected by the sensor and the temperature of the refrigerant, and control the cooling device to cool the conductive components using this heat.

[0009] Based on this structure, conductive components can be appropriately cooled using refrigerant cooled by a cooling device.

[0010] The cooling section can be configured to reduce the temperature of the conductive components more than that of the battery cells.

[0011] With this structure, the conductive components are cooled more effectively than the battery cells, thus preventing a further increase in the resistance of the conductive components. Furthermore, it suppresses the rise in the internal resistance of the battery cells caused by over-cooling.

[0012] According to the present invention, an electric vehicle is provided in which the resistance of a conductive component does not increase, thereby improving the output of the battery and preventing deterioration of acceleration performance. Attached Figure Description

[0013] Hereinafter, with reference to the accompanying drawings, the features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will be described, in which the same reference numerals denote the same elements, and wherein:

[0014] Figure 1 This is a schematic structural diagram of the vehicle involved in this embodiment.

[0015] Figure 2 This is a diagram illustrating an example of the cooling / heating device of this embodiment.

[0016] Figure 3 This is a schematic diagram showing the structure of a battery used to illustrate the cooling of the battery in the first embodiment.

[0017] Figure 4 This is a diagram illustrating the cooling of the conductive components of the battery in the start-up control of this embodiment.

[0018] Figure 5 This is a first schematic diagram showing the structure of a battery used to illustrate the cooling of the battery in the second embodiment.

[0019] Figure 6 This is a second schematic diagram showing the structure of a battery used to illustrate the cooling of the battery in the second embodiment. Detailed Implementation

[0020] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Furthermore, identical or corresponding parts in the drawings will be labeled with the same symbols, and their descriptions will not be repeated.

[0021] [First Implementation]

[0022] Figure 1 This is a schematic structural diagram of vehicle 1 according to this embodiment. In this embodiment, vehicle 1 is an electric vehicle, such as a battery electric vehicle (BEV). Vehicle 1 includes a motor generator (MG) 10, a power transmission gear 20, drive wheels 30, a power control unit (PCU) 40, a system main relay (SMR) 50, a battery 100, a monitoring unit 200, a battery control unit (ECU) 250, and a control ECU 300.

[0023] The MG10 functions as both an electric motor and a generator. The output torque of the MG10 is transmitted to the drive wheel 30 via a power transmission gear 20, which includes a reducer and a differential.

[0024] When vehicle 1 brakes, drive wheel 30 drives MG10, and MG10 acts as a generator. The regenerative power generated by the regenerative braking force in MG10 is stored in battery 100.

[0025] PCU40 is a power conversion device that bidirectionally converts power between MG10 and battery 100. PCU40 includes, for example, an inverter and a converter that operate according to control signals from control ECU300 to drive MG10.

[0026] SMR50 is electrically connected to the power line connecting battery 100 and PCU40. When SMR50 is ON according to a control signal from control ECU300, power can be transferred between battery 100 and PCU40. On the other hand, when SMR50 is OFF, the electrical connection between battery 100 and PCU40 is disconnected.

[0027] Battery 100 stores the power used to drive MG10. Battery 100 is a secondary battery, which is a battery pack composed of multiple individual cells (battery units) 110. The individual cells are, for example, lithium-ion batteries, nickel-metal hydride batteries, or all-solid-state batteries.

[0028] The monitoring unit 200 includes a voltage detection unit, a current sensor, and a temperature detection unit. The voltage detection unit detects the battery voltage VB. The current sensor detects the current IB input to and output to the battery 100. The temperature detection unit detects the temperature TB of the battery 100. The voltage VB, temperature TB, and current IB are input to the battery ECU 250. The battery ECU 250 calculates the state of charge (SOC) of the battery 100. SOC can be calculated, for example, using coulomb counting, SOC-OCV (Open Circuit Voltage) characteristics, or a combination thereof. The voltage VB, temperature TB, current IB, and SOC are output from the battery ECU 250 to the control ECU 300.

[0029] Vehicle 1 is equipped with a DC charging port 60 and an AC charging port 80, which can charge the battery 100 from an external DC power supply 400 or an external AC power supply 500 (EVSE: Electric Vehicle Supply Equipment) 2 (external charging). If the connector 420 at the front end of the charging cable 410 of the external DC power supply (EVSE) 400 is connected to the DC charging port 60, the charging relay 70 is controlled to be in the connected state, and external charging (fast charging) of the battery 100 is performed.

[0030] If the connector 520 at the front end of the charging cable 510 of the external AC power source (EVSE) 500 is connected to the AC charging port 80, the on-board charger 130 converts the AC power supplied from the external AC power source into DC power. The DC power output from the on-board charger 130 is supplied to the battery 100 via the charging relay 90 to perform external charging (normal charging) of the battery 100.

[0031] The control ECU 300 includes a central processing unit (CPU) 301 and a memory 302. The control ECU 300 controls various devices to achieve a desired state for the vehicle 1, based on signals received from the battery ECU 250, signals from various sensors (not shown) (e.g., throttle opening signal, vehicle speed signal, etc.), a mapping table stored in the memory 302, and other information. The control ECU 300 controls the cooling / heating device 800. The battery ECU 250 also includes a CPU and a memory, similar to the control ECU 300.

[0032] Vehicle 1 also features a power switch (ignition switch) 350. The power switch 350 is operated by the user. For example, if the user operates the power switch 350 while pressing the brake pedal, the control ECU 300 will turn SMR50 ON (conducting state). With SMR50 ON, MG10 can be driven via PCU40 (drive system startup), allowing vehicle 1 to move. If the user operates the power switch 350 while vehicle 1 is in a driving state, SMR50 will turn OFF (disconnected state), PCU40 and other (drive system) mechanisms will stop, and vehicle 1 will come to a stop.

[0033] The Human Machine Interface (HMI) device 700 includes an input device and a display device. The input device and the display device may be a touch panel display.

[0034] Vehicle 1 is also equipped with a cooling / heating device 800. The cooling / heating device 800 cools the battery 100. Figure 2 This figure illustrates an example of the cooling / heating device 800 according to this embodiment. In this embodiment, the cooling / heating device 800 is composed of a thermal management circuit capable of cooling and heating the battery 100. The cooling / heating device 800 (thermal management circuit) includes a thermal circuit S and a refrigeration cycle R.

[0035] The refrigerant circulates in the refrigeration cycle R. The refrigeration cycle R includes a compressor R1 and a condenser R2. The compressor R1 compresses the refrigerant via a motor whose rotational speed is controlled by a control signal from the battery 100, which is controlled by a control signal from the control ECU 300. The power consumption of the compressor R1 is approximately proportional to the flow rate of the refrigerant discharged from the compressor R1, i.e., the rotational speed of the motor driving the compressor R1. The refrigerant compressed by the compressor R1 flows into the condenser R2. The high-pressure refrigerant discharged from the condenser R2 flows into the evaporator R3 via an electronic expansion valve, and then into the cooler Ch via another electronic expansion valve. The evaporator R3 serves as the cooling source for the air conditioning system of the vehicle 1. The cooler Ch exchanges heat with the heat medium circulating in the thermal circuit S, cooling the heat medium.

[0036] The heat transfer medium circulates in the thermal circuit S. The thermal circuit S includes a three-way valve S1, a battery 100, a reservoir (R / T), a Smart Power Unit (SPU), a PCU40, an oil cooler (O / C), and pumps W1 and W2. The oil cooler uses the heat transfer medium from the thermal circuit S to cool the oil cooling the transmission drive axle (T / A). EOP circulates the oil cooling the transmission drive axle. While pump W1 operates, ports P1 and P2 of the three-way valve S1 are connected, and the heat transfer medium cooled by the cooler circulates to the battery 100, thereby cooling the battery 100. While pump W2 operates, ports P2 and P3 of the three-way valve S1 are connected, and the heat transfer medium heated by waste heat from the SPU, PCU40, and O / C circulates to the battery 100, thereby heating the battery 100. Additionally, an electric heater can be installed between port P2 and the battery 100.

[0037] The heat transfer medium circulating in the thermal circuit S can be, for example, insulating oil or insulating antifreeze. The refrigeration cycle R and the thermal circuit S (compressor R1, pumps W1, W2, etc.) are driven by electricity stored in the battery 100.

[0038] In the aforementioned vehicle 1, a start-up control mechanism can be considered to enable rapid acceleration of vehicle 1. In electric vehicles such as BEVs, HEVs, PHEVs, and FCEVs (in this embodiment, vehicle 1 is a BEV), if high-output discharge occurs from the battery 100 during a rapid start, the energized components surrounding the battery 100 become hot. If these energized components become hot, resistance increases, making it difficult to increase the output of the battery 100. Therefore, the acceleration performance of vehicle 1 deteriorates.

[0039] Therefore, when there is a requirement for MG10 to operate at a specified output or higher, the CPU301 of the control ECU300 controls the cooling / heating device 800 to cool the conductive parts on the outside of the single cell 110 in the battery 100 through which current flows, at least from the time the requirement is received until the specified output or higher is generated.

[0040] Therefore, during the period from receiving a request to operate the MG10 at a specified output or higher until the specified output or higher is generated, the conductive components of the battery 100 are pre-cooled before being heated. As a result, the resistance of the conductive components does not increase, thereby improving the output of the battery 100 and preventing acceleration performance degradation.

[0041] Figure 3 This is a schematic diagram showing the structure of the battery 100 used for cooling the battery 100 in the first embodiment. (See reference) Figure 3The single cell 110 has a terminal 111. In addition to the single cell 110, the battery 100 also includes a bus module 112, heat insulation material 114, insulating resin 115, end plate 116, upper surface restraint band 118, lower surface restraint band 119, upper surface cooler 801, lower surface cooler 802 and delivery pipe 803.

[0042] Busbar module 112 is a module in which the busbar is connected to terminals 111 by connecting individual cells 110 in series. The busbar connects the positive and negative terminals 111 of two adjacent individual cells 110. Thermal insulation material 114 is a component that provides thermal insulation between the individual cells 110 and the end plate 116. Insulating resin 115 is a component that provides insulation between the individual cells 110 and the end plate 116. The end plate 116, the upper surface constraint band 118, and the lower surface constraint band 119 constrain the stacked individual cells 110.

[0043] The upper surface cooler 801 and the lower surface cooler 802 are connected via the conveying pipe 803 to Figure 2 Port P2 of the three-way valve S1 shown is connected. The heat medium cooled by the cooler Ch circulates inside the upper surface cooler 801 and the lower surface cooler 802 through the delivery pipe 803. As a result, the main body of the single cell 110, terminals 111, and bus module 112 are cooled. Terminals 111 and bus module 112 are conductive components of the battery 100. The conductive components of the battery 100, such as terminals 111 and bus module 112, are made of metals such as copper. Therefore, their thermal conductivity is higher than that of the main body of the single cell 110. As a result, the conductive components of the battery 100 are cooled more strongly by the upper surface cooler 801 and the lower surface cooler 802 compared to the main body of the single cell 110, except for the conductive components.

[0044] return Figure 1 Vehicle 1 also includes a start switch 360 for initiating start control in a start mode. The start switch 360 is operated by the user. If the start switch 360 is operated when the start mode is off, the start mode is set to on; if the start switch 360 is operated when the start mode is on, the start mode is set to off.

[0045] Figure 4 This is a diagram illustrating the cooling of the conductive components of the battery 100 in the start-up control of this embodiment. (Reference) Figure 4 At time t1, by operating the start switch 360, the CPU 301 of the ECU 300 is controlled to set the start mode to the on state.

[0046] After the CPU301 sets the start-up mode to the on state, it begins pre-cooling of the conductive components at time t2. During pre-cooling, the cooling / heating device 800 is controlled to cool the conductive components more intensely; for example, the speed of the compressor R1 in the refrigeration cycle R is increased, or the output of the pump W1 in the thermal circuit S is increased. Furthermore, based on the temperature of the battery 100 and the temperature of the heat transfer medium, the CPU301 calculates the minimum amount of cooling heat required to prevent the main body of the single battery 110 from being cooled to a minimum before the internal resistance of the single battery 110 rises above a predetermined value, and controls the cooling / heating device 800 to cool the battery 100 with this amount of cooling heat. Regarding the predetermined value as a threshold for internal resistance, if the internal resistance of the single battery 110 reaches or exceeds the predetermined value, it becomes a benchmark value for determining poor efficiency of the single battery.

[0047] At time t3, if the user operates the accelerator pedal, the CPU 301 controls the PCU 40 to initiate rapid acceleration via the MG10. Correspondingly, the battery output of the single battery 110 increases sharply, and the vehicle speed accelerates rapidly. As a result, a large amount of current flows through the conductive components, causing the temperature of terminal 111 (terminal temperature), one of the conductive components, to rise. Furthermore, the temperature of the main body of the battery 100 (battery temperature) also begins to rise. With pre-cooling of the conductive components, the temperature rise of terminal 111 can be suppressed compared to the case without pre-cooling.

[0048] At time t4, if the increase in battery output ends and the battery output decreases, the temperature of terminal 111 also decreases. CPU 301 continues pre-cooling while the specified conditions related to battery output are met. These specified conditions are, for example, conditions that extend from the time a requirement to set the start-up mode to the time when an output exceeding the rated maximum output Pmax (in the normal state when the start-up mode is not enabled) is generated. Figure 4 As shown, this is the condition from the time the start mode is enabled until the output exceeds the normal maximum output Pmax and then returns to the normal maximum output Pmax.

[0049] However, this is not a limitation. The specified condition can also be a condition for the period from the time the requirement to set the start mode to the active state until a specified output, which exceeds the normal maximum output Pmax, is generated and then becomes less than the normal maximum output Pmax. It can also be a condition for the period from the time the requirement to set the start mode to the active state until the accelerator pedal is not operated or the amount of accelerator pedal operation reaches a specified amount (e.g., 50%). It can also be a condition for the period from the time the requirement to set the start mode to the active state until the requirement to set the start mode to the deactivated state. Alternatively, any one of these conditions can be met.

[0050] If the specified conditions related to battery output are not met at time t5, CPU301 terminates the pre-cooling of the conductive components. By terminating the pre-cooling, the intense cooling of the conductive components is ended, but the main body of the single battery 110, excluding the conductive components, continues to be cooled as needed.

[0051] [Second Implementation]

[0052] In the first embodiment, such as Figure 3 As shown, the conductive components such as the terminals 111 of the single battery 110 are cooled using the same components used to cool the conductive components other than the main body of the single battery 110 (upper surface cooler 801, lower surface cooler 802). In the second embodiment, the conductive components such as the terminals 111A of the single battery 110A are cooled using components different from those used to cool the conductive components (e.g., a dedicated component for cooling the conductive components).

[0053] Figure 5 This is a first schematic diagram showing the structure of the battery 100A used to illustrate the cooling of the battery 100A in the second embodiment. Figure 6 This is a second schematic diagram showing the structure of the battery 100A used to illustrate the cooling of the battery 100A in the second embodiment. (See reference) Figure 5 and Figure 6 , Figure 6 Indicates and Figure 5 The cross-section shown is perpendicular to the stacking direction of the single cell 110A.

[0054] The battery 100A in the second embodiment, in addition to the single cell 110A, also includes an upper surface cooler 801A, a lower surface cooler 802A, and a delivery pipe 803A. The upper surface cooler 801A and the lower surface cooler 802A are connected to the delivery pipe 803A... Figure 2Port P2 of the three-way valve S1 shown is connected. The heat medium cooled by the cooler Ch circulates inside the upper surface cooler 801A and the lower surface cooler 802A through the delivery pipe 803A. As a result, the main body, terminals 111A, and busbar 113A of the single cell 110A are cooled. The busbar 113A connects the positive and negative terminals 111A of two adjacent single cells 110A. Terminals 111A and busbar 113A are conductive components of the battery 100A. The conductive components of the battery 100A, such as terminals 111A and busbar 113A, are made of metals such as copper. Therefore, their thermal conductivity is higher than that of the main body of the single cell 110A. As a result, the conductive components of the battery 100A are cooled more strongly by the upper surface cooler 801A and the lower surface cooler 802A compared to the main body of the single cell 110A, except for the conductive components.

[0055] Furthermore, in this second embodiment, the upper surface cooler 801A is shaped to suit the cooling of conductive components of the battery, such as terminals 111A and busbar 113A, and is almost exclusively designed for cooling conductive components. Therefore, compared to the main body of the single battery 110A (excluding conductive components), the conductive components of the battery 100A, such as terminals 111A and busbar 113A, are cooled more effectively. Without the upper surface cooler 801A, the maximum temperature range of the single battery 110A is near section A. On the other hand, with the upper surface cooler 801A, the maximum temperature range of the single battery 110A becomes near section B, and the conductive components, such as terminals 111A, are cooled more effectively.

[0056] [Variation Example]

[0057] (1) In the foregoing embodiments, by setting as Figure 3 as well as Figure 5 and Figure 6 The structure shown allows conductive components such as terminals 111, 111A, bus module 112, and bus 113A to be cooled more effectively than other components. However, it is not limited to this; any structure that provides more effective cooling for conductive components compared to other components may be used.

[0058] (2) The foregoing embodiments can be understood as an invention of an electric vehicle such as vehicle 1. It can be understood as an invention of the battery 100, the cooling / heating device 800, and a battery system including its peripheral devices. It can be understood as an invention of a control method or control program executed in an electric vehicle or battery system.

[0059] [Summarize]

[0060] (1) such as Figures 1 to 6As shown, a vehicle 1 capable of operating on electricity includes: a battery 100 comprising a single battery 110 capable of storing power for driving and conductive components (e.g., terminals 111, 111A, bus module 112, bus 113A) through which current flows outside the single battery 110; an MG 10 that uses the power from the battery 100 to generate driving force; a cooling / heating device 800 that cools the conductive components; and a CPU 301 that controls an ECU 300. Figure 4 As shown, when there is a requirement for MG10 to operate at a specified output (e.g., normally the highest output Pmax), CPU301 controls cooling / heating device 800 to cool the conductive components at least from the time the requirement is received until the specified output is generated.

[0061] Therefore, during the period from receiving a request to operate the MG10 at a specified output or higher until the specified output or higher is generated, the conductive components of the battery 100 are pre-cooled before being heated. As a result, the resistance of the conductive components does not increase, thus improving the output of the battery 100 and preventing acceleration performance degradation. Furthermore, malfunctions caused by heating of the conductive components can be prevented. Output limitations of the MG10 used to prevent malfunctions can be avoided.

[0062] (2) For example Figure 3 , Figure 5 and Figure 6 As shown, the upper surface coolers 801 and 801A and the lower surface cooler 802 of the cooling / heating device 800 can provide stronger cooling to the conductive components than to other components such as the main body of the single cell 110. Therefore, the conductive components are cooled more effectively than other components, thus preventing further increase in the resistance of the conductive components. Furthermore, it can suppress the increase in the internal resistance of the single cell 110 caused by over-cooling.

[0063] (3) such as Figure 1 and Figure 2 As shown, it may also include a sensor for detecting the temperature of the battery 100 (e.g., a temperature detection unit of the monitoring unit), and the cooling / heating device 800 includes a cooling device (e.g., a cooler Ch, a refrigeration cycle R) for cooling the refrigerant (e.g., a heat transfer medium). Figure 4 As shown, the CPU301 controlling the ECU300 can calculate the cooling heat of the conductive components based on the temperature detected by the sensor and the temperature of the refrigerant, and control the cooling equipment so that the conductive components are cooled by the cooling heat.

[0064] Therefore, it is possible to properly cool conductive components using refrigerant cooled by cooling equipment.

[0065] (4) such as Figure 3As shown, the upper surface cooler 801 and lower surface cooler 802 of the cooling / heating device 800 can also be used for cooling the single cell 110, and can be configured to reduce the temperature of the conductive components more than that of the single cell 110.

[0066] As a result, the conductive components are cooled more effectively than the single cell 110, thus preventing a further increase in the resistance of the conductive components. Furthermore, it is possible to suppress the increase in the internal resistance of the single cell 110 caused by over-cooling.

[0067] It should be considered that the embodiments disclosed herein are illustrative in all respects and not restrictive. The scope of the invention is not shown by the description of the above embodiments, but by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

Claims

1. An electric vehicle capable of operating on electricity, characterized in that it comprises: A battery, comprising a battery cell capable of storing power for driving and a conductive component through which current flows on the exterior of the battery cell; An electric generator that uses the power from the battery to generate driving force; A cooling section for cooling the conductive components; and processor, When there is a requirement for the electric generator to operate at a specified output or higher, the processor controls the cooling unit to cool the conductive components at least from the time the requirement is received until the specified output or higher is generated.

2. The electric vehicle according to claim 1, characterized in that, The cooling section also serves to cool the battery cell, and provides stronger cooling to the conductive components than to the battery cell.

3. The electric vehicle according to claim 1, characterized in that, It also has: A sensor that detects the temperature of the battery. The cooling section includes a cooling device for cooling the refrigerant. The processor performs the following processing: The cooling heat of the conductive component is calculated based on the temperature detected by the sensor and the temperature of the refrigerant; and The cooling device is controlled so that the conductive component is cooled by the cooling heat.

4. The electric vehicle according to claim 2, characterized in that, The cooling section is configured to reduce the temperature of the conductive component more than the temperature of the battery cell.

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