Thermal management control method for hybrid vehicle

Abstract

The present invention discloses a thermal management control method for a hybrid vehicle, and relates to the field of vehicle technology. The thermal management control method for the hybrid vehicle comprises the following steps: detecting the temperature of a battery; if the temperature of the battery is lower than a first set temperature, controlling the engine system to start, so as to increase the temperature of the circulating water in the engine, and heating the battery by the circulating water in the engine; when the temperature of the battery is heated to a temperature greater than or equal to the first set temperature, while the circulating water in the engine heats the battery, controlling the battery to charge or discharge, and using the heat generated by the battery charging or discharging to heat the battery. The thermal management control method for the hybrid vehicle can achieve rapid battery heating when the vehicle is started in a cold area, so that the battery temperature can quickly reach a temperature that can achieve a pure electric drive mode, thereby improving the economy and driving comfort of the vehicle.

Description

Technical Field

[0001] The present invention relates to the field of vehicle technology, and in particular to a thermal management control method for a hybrid vehicle. Background Art

[0002] The power system of a hybrid vehicle includes a motor, battery and engine. The battery, motor and engine are prone to overheating when the vehicle is under high load; in cold areas, the battery charging and discharging capacity is limited, which will affect the vehicle's economy and driving comfort.

[0003] At present, in order to reduce costs, the thermal management system of hybrid vehicles usually adopts an integrated thermal management system, which heats or cools the motor, battery and engine through the integrated thermal management system. However, in extremely cold areas, when the vehicle is started and started, the battery charging performance and discharge power will be greatly reduced due to the low activity of the battery at low temperatures. In the integrated thermal management system, the circulating water in the engine is the only heat source for the battery to heat the battery, resulting in a very slow battery heating speed, resulting in poor vehicle economy and driving comfort. Summary of the invention

[0004] The purpose of the present invention is to provide a thermal management control method for a hybrid vehicle, so as to solve the technical problem that when a hybrid vehicle is in extremely cold areas, the vehicle's economy and comfort are poor due to reduced battery charging performance and discharge power and slow battery heating speed, thereby improving the vehicle's economy and driving comfort.

[0005] To achieve this object, the present invention adopts the following technical solutions:

[0006] A thermal management control method for a hybrid vehicle, wherein the hybrid vehicle comprises an engine system and an electric drive system, wherein the engine system comprises an engine, and the electric drive system comprises a motor and a battery, wherein the battery provides electrical energy to the motor, and the engine system can provide negative torque to the motor to charge the battery, wherein the thermal management control method for the hybrid vehicle comprises the following steps:

[0007] Detect the temperature of the battery;

[0008] If the temperature of the battery is lower than a first set temperature, the engine system is controlled to start so as to increase the temperature of circulating water in the engine; the battery is heated by circulating water in the engine;

[0009] When the temperature of the battery is heated to a temperature greater than or equal to the first set temperature, the battery is controlled to be charged or discharged while the circulating water in the engine heats the battery, and the heat generated by the charging or discharging of the battery is used to heat the battery.

[0010] As an optional solution of the thermal management control method of the hybrid vehicle, the thermal management control method of the hybrid vehicle further includes the following steps:

[0011] Determine whether the vehicle is in a stationary state after starting;

[0012] If yes, the vehicle is controlled to enter a parking thermal management control mode. When the vehicle enters the parking thermal management control mode, the temperature of the battery is detected. If the temperature of the battery is lower than the first set temperature, the temperature of the circulating water in the engine is increased by controlling the engine speed, so that the battery is heated by the circulating water in the engine.

[0013] If not, the vehicle is controlled to enter the driving thermal management control mode. When the vehicle enters the driving thermal management control mode, the temperature of the battery is detected. If the temperature of the battery is lower than the first set temperature, the vehicle is controlled to enter the engine drive mode, the temperature of the circulating water in the engine is increased, and the battery is heated by the circulating water in the engine.

[0014] As an optional solution of the thermal management control method of the hybrid vehicle, when the vehicle enters the parking thermal management control mode, the temperature of the battery is detected. If the temperature of the battery is lower than the first set temperature, the temperature of the circulating water in the engine is increased by controlling the engine speed. The specific steps of heating the battery by the circulating water in the engine include:

[0015] While detecting the temperature of the battery, detect the temperature of the circulating water in the engine;

[0016] If the temperature of the battery is lower than the first set temperature, and the temperature of the circulating water in the engine is lower than the second set temperature, the engine is controlled to run at a first set speed, and the second set temperature is lower than the first set temperature;

[0017] When the temperature of the circulating water in the engine rises to be equal to the second set temperature, the engine is controlled to run at a second set speed, and the circulating water in the engine is controlled to start heating the battery, and the second set speed is less than the first set speed;

[0018] When the temperature of the circulating water in the engine continues to rise to be equal to the first set temperature, the engine is controlled to run at a third set speed, which is lower than the second set speed.

[0019] As an optional scheme for the thermal management control method of the hybrid vehicle, when the vehicle enters the parking thermal management control mode, when the temperature of the battery is heated to a temperature greater than a third set temperature, the third set temperature is greater than the first set temperature, and while controlling the circulating water in the engine to heat the battery, the vehicle is allowed to enter the parking power generation mode to charge the battery, and the heat generated by the battery charging is used to heat the battery.

[0020] As an optional scheme of the thermal management control method of the hybrid vehicle, when the temperature of the battery is heated to be greater than the third set temperature, the SOC of the battery is first detected; when the SOC of the battery is less than or equal to the maximum capacity allowed for charging, the vehicle is controlled to enter the parking power generation mode.

[0021] As an optional solution of the thermal management control method of the hybrid vehicle, the specific steps of controlling the vehicle to enter the parking power generation mode to charge the battery and using the heat generated by the battery charging to heat the battery include:

[0022] After the vehicle enters the parking power generation mode, the power generation of the motor in the negative torque state changes with the temperature of the battery. As the temperature of the battery gradually increases, the negative torque provided by the engine system to the motor is controlled to gradually increase, so that the power generation gradually increases;

[0023] When the temperature of the battery is heated to a temperature greater than a fourth set temperature, the vehicle is controlled to exit the parking power generation mode, and the fourth set temperature is greater than the third set temperature.

[0024] As an optional solution of the thermal management control method of the hybrid vehicle, when the vehicle enters the driving thermal management control mode, the temperature of the battery is detected. If the temperature of the battery is less than a first set temperature, the vehicle is controlled to enter the engine driving mode, and the temperature of the circulating water in the engine is increased. The specific steps of heating the battery by the circulating water in the engine include:

[0025] Detect the temperature of the battery;

[0026] If the temperature of the battery is lower than the first set temperature, the vehicle is controlled to enter an engine driving mode, in which the temperature of the circulating water in the engine is increased;

[0027] When the temperature of the circulating water in the engine rises to be equal to the first set temperature, the vehicle is controlled to enter a hybrid driving mode, and the battery is heated simultaneously by the heat generated by the circulating water in the engine and the discharge of the battery;

[0028] When the temperature of the battery is heated to be greater than the third set temperature, the vehicle is controlled to enter a pure electric driving mode, and the battery is heated by the heat generated by the discharge of the battery. The third set temperature is greater than the first set temperature.

[0029] As an optional solution of the thermal management control method of the hybrid vehicle, when the temperature of the circulating water in the engine rises to be equal to the first set temperature, the vehicle is controlled to enter the hybrid driving mode, and the specific steps of heating the battery by the heat generated by the circulating water in the engine and the discharge of the battery include:

[0030] When the temperature of the circulating water in the engine rises to be equal to the first set temperature, the circulating water in the engine is controlled to start heating the battery; at the same time, the battery is discharged at the maximum discharge power, and the battery uses the heat generated during discharge to heat the battery.

[0031] As an optional solution of the thermal management control method of the hybrid vehicle, when the temperature of the battery is heated to be greater than the third set temperature, the vehicle is controlled to enter a pure electric driving mode, and the specific steps of heating the battery by the heat generated by the discharge of the battery include:

[0032] When the temperature of the battery is heated to a temperature greater than the third set temperature, the clutch is controlled to be separated from the gearbox so that the vehicle enters a pure electric driving mode, while the engine remains in a started state;

[0033] When the temperature of the battery continues to heat up to be greater than a fourth set temperature, the engine is controlled to be shut down, and the fourth set temperature is greater than the third set temperature.

[0034] As an optional solution of the thermal management control method of the hybrid vehicle, when the engine remains in the started state, the speed of the engine is controlled so that the temperature of the water circulating in the engine remains unchanged.

[0035] As an optional scheme of the thermal management control method of the hybrid vehicle, when controlling the vehicle to enter the hybrid drive mode, the output power of the engine is equal to the difference between the total power required for the vehicle to run and the maximum discharge power of the electric drive system.

[0036] Beneficial effects of the present invention:

[0037] The thermal management control method of a hybrid vehicle provided by the present invention is a thermal management control method for the battery of a hybrid vehicle in a cold region. By detecting the temperature of the battery, if the temperature of the battery is less than a first set temperature, the engine system is controlled to start to increase the temperature of the circulating water in the engine, and then the heated circulating water in the engine is used to heat the battery, so that the battery temperature is rapidly increased; when the battery temperature is heated to a temperature greater than or equal to the first set temperature, while the circulating water in the engine heats the battery, the battery is controlled to charge or discharge, and the heat generated by the charging or discharging of the battery is used to heat the battery; thereby achieving rapid increase in battery temperature while reducing energy consumption. The thermal management control method of a hybrid vehicle can enable a vehicle in a cold region to achieve rapid battery heating when it is parked or moving after starting, so that the battery temperature can quickly reach a temperature that can achieve a pure electric drive mode, thereby improving the economy and driving comfort of the vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 is a schematic diagram of a transmission system of a hybrid vehicle provided by an embodiment of the present invention;

[0039] Figure 2 is a schematic diagram of a thermal management control system for a hybrid vehicle provided by an embodiment of the present invention;

[0040] Figure 3 The process of the thermal management control method of a hybrid vehicle provided by an embodiment of the present invention is Figure 1 ;

[0041] Figure 4 The process of the thermal management control method of a hybrid vehicle provided by an embodiment of the present invention is Figure 2 ;

[0042] Figure 5 is a flow chart of a parking thermal management control method provided by an embodiment of the present invention;

[0043] Figure 6 It is a flow chart of a vehicle thermal management control method provided by an embodiment of the present invention.

[0044] In the figure:

[0045] 1. Engine; 2. Clutch; 3. Motor; 4. Gearbox; 5. ECU; 6. MCU; 7. TCU / CCU; 8. Electric power steering pump; 9. Auxiliary machine controller; 10. Battery; 11. Instrument; 12. Shift handle; 13. CAN; 14. HCU; 15. Battery water pump; 16. Battery heat exchanger; 17. Motor water pump; 18. Motor controller; 19. First radiator; 20. Second radiator; 21. Third radiator; 22. First cooling fan group; 23. Second cooling fan group; 24. Engine heat exchanger; 25. Condenser; 26. Compressor; 27. Cab refrigeration circuit; 28. Cab heating circuit; 29. ​​Cab stop valve; 30. Cab warm water valve; 31. Battery warm water valve; 32. Normally closed two-position single-way valve; 33. Battery stop valve; 34. Engine thermostat. DETAILED DESCRIPTION

[0046] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0047] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance. Among them, the terms "first position" and "second position" are two different positions.

[0048] Unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0049] Unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include the first feature being in direct contact with the second feature, or may include the first feature being in contact with the second feature through another feature between them instead of being in direct contact. Moreover, a first feature being "above", "above" and "above" a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes the first feature being directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0050] The technical solution of the present invention is further described below with reference to the accompanying drawings and through specific implementation methods.

[0051] like Figure 1 As shown, the hybrid vehicle includes an engine system and an electric drive system. The engine system includes an engine 1, and the electric drive system includes a motor 3 and a battery 10. The battery 10 is a power battery with a BMS (Battery Management System). The battery 10 provides electrical energy for the motor 3, and the engine system can provide negative torque for the motor 3 to charge the battery 10. The ECU 5 (Electronic Control Unit) is used to control the engine 1. The engine 1 is connected to the input shaft of the gearbox 4 through the clutch 2. The output shaft of the gearbox 4 is connected to the drive shaft of the vehicle, and the drive shaft of the vehicle is used to drive the wheels to move. The clutch 2 is connected to the CAN 13 (Controller Area Network) through the CCU (Clutch Control Unit) in the TCU / CCU 7. The CCU mainly controls the speed and target position of the clutch 2 to be separated and engaged, and is achieved by controlling the intake and exhaust solenoid valves of the clutch 2. The gearbox 4 is connected to CAN13 through the TCU (Transmission Control Unit) in TCU / CCU7, the ECU5, the instrument 11 and the shift handle 12 are all connected to CAN13, and CAN13 is connected to HCU14 (Hybrid Control Unit, the main controller of the hybrid system). The motor 3 is mechanically connected to the gearbox 4, the battery 10 is connected to the MCU6 (Micro Control Unit, micro control unit) through a high-voltage wire harness, and the MCU6 is connected to the motor 3 through a high-voltage wire harness. The MCU6 controls the battery 10 to charge and discharge the motor 3. The battery 10 is connected to the auxiliary machine controller 9 through a high-voltage wire harness, and the auxiliary machine controller 9 is connected to the electric power steering pump 8 through a high-voltage wire harness, and is connected to the battery 10 through a low-voltage wire harness.

[0052] The driving modes of hybrid vehicles include pure electric driving mode, engine driving mode and hybrid driving mode. Among them, driving the vehicle solely by the electric drive system is called pure electric driving mode, driving the vehicle solely by the engine system is called engine driving mode, and driving the vehicle by both the electric drive system and the engine system is called hybrid driving mode.

[0053] In cold regions, the charging and discharging capacity of the battery 10 of a hybrid vehicle is limited, which will affect the vehicle's economy and driving comfort. Therefore, a thermal management system is required to achieve temperature control of the motor 3, the battery 10 and the engine 1 to ensure the normal operation of the engine system and the electric drive system. A distributed thermal management system in which each component is independently provided with a thermal management system has too many components, and the cooling or circulating water pipelines are complicated and costly.

[0054] like Figure 2As shown, the thermal management system of the current hybrid vehicle is an integrated thermal management system, which integrates the thermal management of the engine 1, the thermal management of the motor 3 and the motor controller 18, the thermal management of the battery 10, and the thermal management of the cab into a set of thermal management systems through a control valve group. The integrated thermal management system includes a cooling circuit, a heating circuit, a motor circuit, and a battery circuit. The cooling circuit is provided with a condenser 25 and a compressor 26. The condenser 25 is connected to the cab refrigeration circuit 27 through a cab stop valve 29, and is connected to the battery refrigeration circuit through a battery stop valve 33 to cool the battery 10. The refrigerant after flowing through the cab refrigeration circuit 27 and the battery refrigeration circuit is returned to the condenser 25 through the normally closed two-position one-way valve 32 and the compressor 26. When there is a cooling demand for the cab, the refrigerant passes through the cab refrigeration circuit 27 first. The engine heat exchanger 24 is connected between the normally closed two-position one-way valve 32 and the compressor 26. The engine heat exchanger 24 is connected to the engine 1. When the engine 1 has a cooling demand, the normally closed two-position one-way valve 32 is opened, so that the refrigerant after passing through the cab and the battery 10 passes through the engine heat exchanger 24 and then through the compressor 26 to return to the condenser 25. A first radiator 19 is provided in the heating circuit. The internal circulation water pipe of the engine 1 is connected to the first radiator 19 through the engine thermostat 34. The flow rate of the internal circulation water pipe of the engine 1 is controlled by the engine thermostat 34. The first radiator 19 is used to dissipate heat for the engine 1. The internal circulation water of the engine is connected to the cab heating circuit 28 through the cab warm water valve 30 to provide heat for the cab. The internal circulation water of the engine is connected to the battery heat exchanger 16 through the battery warm water valve 31 to heat the battery 10. Finally, the water passing through the cab heating circuit 28 and the battery heat exchanger 16 returns to the internal circulation water pipe of the engine 1. The motor circuit is provided with a motor 3, a motor controller 18, a motor water pump 17 and a second radiator 20. The motor water pump 17 provides power for the circulating water in the motor circuit, and the second radiator 20 is used to dissipate heat for the motor 3 and the motor controller 18. The battery circuit is provided with a battery 10, a battery water pump 15, a battery heat exchanger 16 and a third radiator 21. The battery water pump 15 provides power for the circulating water in the battery circuit, the battery heat exchanger 16 performs heat exchange with the heat in the cooling circuit and the heating circuit, thereby cooling or heating the battery 10, and the third radiator 21 is used to dissipate heat for the battery 10. The first radiator 19, the second radiator 20 and the third radiator 21 share a cooling fan group, and the cooling fan group includes a first cooling fan group 22 and a second cooling fan group 23. According to the heat dissipation requirements of the vehicle, one of the first cooling fan group 22 and the second cooling fan group 23 can be controlled to work, or both cooling fan groups can be controlled to work at the same time. The cooling fan group can be driven by the engine 1 or by the motor 3.

[0055] In order to solve the problem of rapid heating of the battery 10 when the hybrid vehicle is in cold areas, this embodiment provides a thermal management control method for a hybrid vehicle, which uses the above-mentioned integrated thermal management system to improve the economy and driving comfort of the vehicle.

[0056] like Figure 3 As shown, the thermal management control method for a hybrid vehicle provided in this embodiment includes the following steps:

[0057] S1 . Detect the temperature of the battery 10 .

[0058] S2. If the temperature of the battery 10 is lower than the first set temperature, the engine system is controlled to start to increase the temperature of the circulating water in the engine, so as to heat the battery 10 through the circulating water in the engine.

[0059] S3. When the temperature of the battery 10 is heated to a temperature greater than or equal to the first set temperature, while circulating water in the engine heats the battery 10, the battery 10 is controlled to charge or discharge, and the heat generated by the charging or discharging of the battery 10 is used to heat the battery 10.

[0060] When the temperature of the battery 10 is lower than the first set temperature, the battery 10 is prohibited from charging and discharging. In cold regions, when the hybrid vehicle is just started, the engine system is the only heat source in the integrated thermal management system. At this time, the engine system can only be started by controlling the engine system. The engine system generates heat to increase the temperature of the circulating water in the engine, and the circulating water in the engine heats the battery 10.

[0061] When the temperature of the battery 10 is heated to a temperature greater than or equal to the first set temperature, the battery 10 can be controlled to charge or discharge while the circulating water in the engine heats the battery 10, and the heat generated by the electrochemical reaction inside the battery 10 when it is charged or discharged is used to heat the battery 10. Thus, the temperature of the battery 10 is quickly increased while reducing energy consumption. The thermal management control method of the hybrid vehicle can enable the battery 10 to quickly heat up when the vehicle is stationary or moving after starting in a cold area, so that the temperature of the battery 10 can quickly reach a temperature that can realize a pure electric drive mode, thereby improving the economy and driving comfort of the vehicle.

[0062] In cold regions, the operating conditions are different when the vehicle is stationary and in driving state after starting, and the thermal management control methods are not exactly the same. Therefore, after the vehicle is started, it is necessary to judge the state of the vehicle after starting and perform different thermal management controls for different states.

[0063] Therefore, if Figure 4 As shown, the thermal management control method for a hybrid vehicle provided in this embodiment includes the following steps:

[0064] S10, determining whether the vehicle is in a stationary state after starting; if so, executing S20; if not, executing S30.

[0065] The states of the vehicle after starting include stationary state and driving state. When the vehicle is in a stationary state, it means that after the engine 1 is started, the driver has not stepped on the clutch 2 and the accelerator, and the vehicle has not moved. At this time, due to the low ambient temperature, the temperature of the battery 10 is also relatively low. When the temperature of the battery 10 is lower than the first set temperature, charging and discharging are prohibited, so the electric drive system cannot drive the vehicle to move. When the vehicle is in a driving state, when the temperature of the battery 10 is lower than the first set temperature, the electric drive system cannot work normally and can only enter the engine drive mode, and all loads are borne by the engine 1. Rapid heating of the battery 10 is achieved by quickly increasing the temperature of the circulating water in the engine.

[0066] S20, controlling the vehicle to enter the parking thermal management control mode. When the vehicle enters the parking thermal management control mode, detecting the temperature of the battery 10, if the temperature of the battery 10 is less than the first set temperature, increasing the temperature of the circulating water in the engine by controlling the speed of the engine 1, and heating the battery 10 by the circulating water in the engine.

[0067] The temperature of the circulating water in the engine is increased by adjusting the rotation speed of the engine 1. The higher the rotation speed, the faster the temperature rises, and the faster the temperature of the circulating water in the engine is increased.

[0068] like Figure 5 As shown, the parking thermal management control method specifically includes the following steps:

[0069] S21 . While detecting the temperature of the battery 10 , the temperature of the circulating water in the engine is also detected.

[0070] The temperature sensor of the battery 10 detects the temperature of the battery 10 and feeds it back to the MCU6, which then feeds back the temperature of the battery 10 to the HCU14; the temperature sensor in the circulating water pipe of the engine 1 detects the temperature of the circulating water in the engine and feeds it back to the ECU5, which then feeds back the temperature of the circulating water in the engine to the HCU14. Since the engine 1 has just been started at this time, the temperature of the circulating water in the engine is close to the ambient temperature and may be lower than the first set temperature.

[0071] S22: If the temperature of the battery 10 is lower than the first set temperature and the temperature of the circulating water in the engine is lower than the second set temperature, the engine 1 is controlled to run at the first set speed, and the second set temperature is lower than the first set temperature.

[0072] The HCU14 stores a first set temperature and a second set temperature. After receiving the temperature of the battery 10 and the temperature of the circulating water in the engine, the HCU14 compares the temperature of the battery 10 with the first set temperature, and compares the temperature of the circulating water in the engine with the second set temperature and the first set temperature, and controls the speed of the engine 1 according to the comparison result. Exemplarily, the first set temperature is 8°C and the second set temperature is -2°C. At this time, the temperature of the circulating water in the engine is extremely low, and the battery warm water valve 31 is kept closed. The engine 1 is controlled to run at a first set speed, which is a relatively high speed. Exemplarily, the first set speed is about 3000r / min. That is, the engine 1 is controlled to run at a relatively high speed to quickly increase the temperature of the circulating water in the engine.

[0073] S23. When the temperature of the circulating water in the engine rises to a second set temperature, the engine 1 is controlled to run at a second set speed, and the circulating water in the engine is controlled to start heating the battery 10. The second set speed is lower than the first set speed.

[0074] The second set speed is a medium speed. For example, the second set speed is about 2000r / min. When the engine 1 runs at a higher speed for a period of time, the temperature of the circulating water in the engine rises to -2°C. At this time, the battery warm water valve 31 can be opened so that the circulating water in the engine can exchange heat with the battery heat exchanger 16 through the heating circuit to heat the battery 10. At this time, the engine 1 runs at the second set speed, that is, the speed of the engine 1 is gradually reduced, the fuel consumption is reduced, and the economy of the vehicle is improved. Although the speed of the engine 1 is reduced, the temperature of the circulating water in the engine continues to rise. At the same time, the circulating water in the engine heats the battery 10, causing the temperature of the battery 10 to gradually rise.

[0075] S24. When the temperature of the circulating water in the engine continues to rise to be equal to the first set temperature, the engine 1 is controlled to run at a third set speed, which is lower than the second set speed.

[0076] The third set speed is idle speed, and illustratively, the third set speed is about 1000r / min. When the temperature of the circulating water in the engine is equal to 8°C, the temperature of the circulating water in the engine basically reaches the upper limit temperature value of the battery 10 that prohibits charging and discharging. Under the effect of heat transfer, the temperature of the battery 10 will gradually rise to 8°C. At this time, in order to reduce fuel consumption and improve the economy of the vehicle, the engine 1 can be controlled to run at idle speed. During the process of the engine 1 running at idle speed, the temperature of the circulating water in the engine will continue to rise, but the rising speed will slow down, and the temperature of the battery 10 will also rise slowly.

[0077] S25. When the temperature of the battery 10 is heated to a temperature greater than a third set temperature, the third set temperature is greater than the first set temperature, and while controlling the circulating water in the engine to heat the battery 10, the vehicle is allowed to enter the parking power generation mode to charge the battery 10, and the heat generated by the charging of the battery 10 is used to heat the battery 10.

[0078] Exemplarily, the third set temperature is 10°C. When the temperature of the battery 10 is heated to more than 10°C, the battery 10 can be charged. The third set temperature is the lowest temperature at which the battery 10 is allowed to be charged. At this time, the vehicle can be controlled to enter the parking power generation mode, that is, the engine 1 is connected to the motor 3 through the clutch 2, and outputs negative torque to the motor 3. At this time, the motor 3 acts as a generator and can charge the battery 10. During the charging process of the battery 10, the electrochemical reaction will generate heat, causing the temperature of the battery 10 to rise; at the same time, the circulating water in the engine continues to provide heat for the battery 10, and due to the increase in the load rate of the engine 1, the temperature rise rate of the circulating water in the engine is accelerated; thereby increasing the temperature rise rate of the battery 10 and improving the economy of the vehicle.

[0079] It should be noted that, in order to ensure the safety of the battery 10, when the temperature of the battery 10 is greater than the third set temperature, the SOC (State of Charge) of the battery 10 is first detected; when the SOC of the battery 10 is less than or equal to the maximum capacity allowed for charging, the vehicle is controlled to enter the parking power generation mode. That is, when the remaining power of the battery 10 is less than or equal to the maximum capacity allowed for charging, the battery 10 is charged again. If the remaining power of the battery 10 is greater than the maximum capacity allowed for charging, the battery 10 cannot be charged at this time, so the vehicle cannot be controlled to enter the parking power generation mode. At this time, the battery 10 can only be heated by the circulating water in the engine until the temperature of the battery 10 reaches the fourth set temperature that can pass the pure electric drive mode. For example, the fourth set temperature is 15°C.

[0080] Specifically, the specific steps of controlling the vehicle to enter the parking power generation mode to charge the battery 10 and using the heat generated by the battery 10 to heat the battery 10 include:

[0081] S251. After the vehicle enters the parking power generation mode, the power generation of the motor 3 when it is in the negative torque state varies with the temperature of the battery 10. As the temperature of the battery 10 gradually increases, the negative torque provided by the control engine system to the motor 3 gradually increases, so that the power generation power gradually increases.

[0082] Ignoring power generation losses, the power generation is equal to the charging power of the battery 10. The lower the temperature of the battery 10, the smaller the allowed charging power; the higher the temperature of the battery 10, the larger the allowed charging power. When controlling the power generation of the generator, the allowed charging power of the battery 10 is obtained by looking up the table according to the temperature of the battery 10, and then the allowed charging power of the battery 10 is compared with the maximum power generation of the generator, and the generator is controlled to use the smaller value of the two as the power generation of the generator, that is, the negative torque provided by the engine system to the motor 3 is controlled to achieve the control of the power generation of the generator. In the process of charging the battery 10 through the generator, as the temperature of the battery 10 increases, the power generation of the generator is controlled to gradually increase, so as to quickly increase the temperature of the battery 10 and improve the economy of the vehicle.

[0083] It should be noted that the correspondence table between the temperature of the battery 10 and the charging power allowed by the battery 10 is already a prior art and will not be described in detail here.

[0084] S252: When the temperature of the battery 10 is heated to a temperature greater than a fourth set temperature, the vehicle is controlled to exit the parking power generation mode, and the fourth set temperature is greater than the third set temperature.

[0085] When the temperature of the battery 10 is greater than 15°C, the temperature of the battery 10 has reached a temperature at which the vehicle can be driven by the electric drive system alone, so there is no need to heat the battery 10. The vehicle can be controlled to exit the parking power generation mode and enter the pure electric drive mode to drive the vehicle, thereby improving the vehicle's economy and driving comfort.

[0086] The parking thermal management control method provided in this embodiment realizes a rapid increase in the temperature of the battery 10 by controlling the speed of the engine 1, the opening of the battery warm water valve 31 and the vehicle entering the parking charging mode. When the temperature of the circulating water in the engine is extremely low, the engine 1 is controlled to run at a higher speed to achieve the purpose of quickly increasing the temperature of the circulating water in the engine; when the temperature of the circulating water in the engine reaches a temperature that can heat the battery 10, the battery warm water valve 31 is controlled to open, and the battery 10 is heated by the circulating water in the engine. At the same time, the engine 1 is controlled to run at a medium speed to wait for the temperature of the battery 10 to increase. When the temperature of the battery 10 is increased to a temperature that can be charged, the vehicle is controlled to enter the parking power generation mode, the load rate of the engine 1 is increased, and the heat generated by the electrochemical reaction of the battery 10 is used to heat the battery 10, which accelerates the increase in the temperature of the battery 10, and the load of the engine 1 is used to generate electricity, thereby improving the economy of the vehicle.

[0087] S30, controlling the vehicle to enter a driving thermal management control mode. When the vehicle enters the driving thermal management control mode, detecting the temperature of the battery 10, if the temperature of the battery 10 is less than a first set temperature, controlling the vehicle to enter an engine drive mode, increasing the temperature of circulating water in the engine, and heating the battery 10 through the circulating water in the engine.

[0088] The vehicle enters the driving state as soon as it is started. Due to the low ambient temperature, the battery 10 needs to be heated, and the engine 1 is the only heat source of the integrated thermal management system. Therefore, the vehicle is first controlled to enter the engine driving mode, and the entire load is borne by the engine 1, so as to quickly increase the temperature of the circulating water in the engine.

[0089] Specifically, Figure 6 As shown, the driving thermal management control method includes the following steps:

[0090] S31 : Detect the temperature of the battery 10 .

[0091] The temperature of the battery 10 is detected by a battery temperature sensor and fed back to the MCU 6 , and the MCU 6 then feeds back the temperature of the battery 10 to the HCU 14 .

[0092] S32: If the temperature of the battery 10 is lower than the first set temperature, the vehicle is controlled to enter the engine driving mode. In the engine driving mode, the temperature of the circulating water in the engine increases.

[0093] The HCU 14 compares the received temperature of the battery 10 with the first set temperature. If the temperature of the battery 10 is lower than the first set temperature, the HCU 14 controls the vehicle to enter the engine driving mode to quickly increase the temperature of the circulating water in the engine.

[0094] It should be noted that the first set temperature in the driving thermal management control mode is the same temperature as the first set temperature in the parking thermal management control mode, the third set temperature in the driving thermal management control mode is the same temperature as the third set temperature in the parking thermal management control mode, and the fourth set temperature in the driving thermal management control mode is the same temperature as the fourth set temperature in the parking thermal management control mode.

[0095] S33. When the temperature of the circulating water in the engine rises to a first set temperature, the vehicle is controlled to enter a hybrid driving mode, and the battery 10 is heated simultaneously by the heat generated by the circulating water in the engine and the discharge of the battery 10 itself.

[0096] Specifically, when the temperature of the circulating water in the engine rises to a first set temperature, the battery warm water valve 31 is opened to control the circulating water in the engine to start heating the battery 10; at the same time, the battery 10 discharges at the maximum discharge power, and the battery 10 uses the heat generated during discharge to heat the battery 10.

[0097] When the temperature of battery 10 is equal to 8°C, battery 10 cannot be charged but has a certain discharge capacity. At this time, the vehicle is controlled to enter the hybrid drive mode, and the vehicle is driven by the engine system and the electric drive system. Battery 10 begins to discharge at maximum capacity to provide electric energy for motor 3 to drive the vehicle. At the same time, the engine system also drives the vehicle and continues to increase the temperature of the circulating water in the engine to heat battery 10.

[0098] Specifically, when the vehicle is controlled to enter the hybrid drive mode, the output power of engine 1 is equal to the difference between the total power required for the vehicle to travel and the maximum discharge power of the electric drive system. Since the electric drive system needs to exert its maximum capacity to provide power for the vehicle at this time, engine 1 performs power supplement. According to the depth of the driver's accelerator pedal, the required vehicle speed is calculated, and the total power required for the vehicle to travel is calculated according to the product of the driving force required for the vehicle to travel and the vehicle speed, and then the maximum discharge power of the electric drive system is calculated to obtain the output power of engine 1. The torque and speed of engine 1 are controlled according to the calculated output power of engine 1.

[0099] S34. When the temperature of the battery 10 is heated to a temperature greater than a third set temperature, the vehicle is controlled to enter a pure electric driving mode, and the heat generated by the discharge of the battery 10 is used to heat the battery 10. The third set temperature is greater than the first set temperature.

[0100] When the temperature of the battery 10 is equal to 10° C., the electric drive system has a certain discharge capacity, and controls the vehicle to switch to a pure electric drive mode, and heats itself through the heat generated by the electrochemical reaction during the discharge of the battery 10 .

[0101] Specifically, the steps include:

[0102] S341, when the temperature of the battery 10 is heated to a temperature greater than a third set temperature, the clutch 2 is controlled to be separated from the gearbox 4, so that the vehicle enters a pure electric driving mode, and the engine 1 remains in a started state;

[0103] When the temperature of the battery 10 is heated to more than 10°C, the clutch 2 is controlled to be separated from the gearbox 4, that is, the engine system does not provide driving force for the vehicle, and the driving force of the vehicle is provided entirely by the electric drive system. At this time, in order to achieve rapid heating of the battery 10, the engine 1 is not shut down, but remains in the started state, so that the temperature of the circulating water in the engine remains unchanged and the battery 10 can continue to be heated.

[0104] Furthermore, when the engine 1 remains in the started state, the temperature of the circulating water in the engine is kept constant by controlling the rotation speed of the engine 1 .

[0105] Since the temperature of the circulating water in the engine will drop after exchanging heat with the battery 10, in order to prevent the temperature of the circulating water in the engine from dropping, when the temperature of the circulating water in the engine drops, the speed of the engine 1 is controlled to increase. When the temperature of the circulating water in the engine increases to a higher temperature, the speed of the engine 1 is controlled to decrease, thereby ensuring that the temperature of the circulating water in the engine remains unchanged at the temperature before the clutch 2 is separated from the gearbox 4, thereby achieving the continuous heating of the battery 10 by the circulating water in the engine.

[0106] S342: When the temperature of the battery 10 continues to heat up to be greater than the fourth set temperature, the engine 1 is controlled to be shut down, and the fourth set temperature is greater than the third set temperature.

[0107] When the temperature of the battery 10 is greater than 15°C, the temperature of the battery 10 has reached a temperature at which the vehicle can be driven by the electric drive system alone, so there is no need to heat the battery 10. At this time, the engine 1 can be turned off and the vehicle can be driven completely by the electric drive system.

[0108] The driving thermal management control method provided in this embodiment realizes the rapid increase of the temperature of the battery 10 by controlling the speed of the engine 1 and the driving mode of the vehicle. When the temperature of the circulating water in the engine is extremely low, the vehicle is controlled to be in the engine driving mode, and the temperature of the circulating water in the engine is rapidly increased. After the temperature of the circulating water in the engine is increased to a level that can heat the battery 10, the vehicle is controlled to enter the hybrid driving mode, and the battery 10 is discharged at the maximum capacity. The heat generated by the electrochemical reaction between the circulating water in the engine and the battery 10 is used to heat the battery 10, and the temperature of the battery 10 is rapidly increased. When the electric drive system has a certain discharge capacity, the vehicle is controlled to switch to the pure electric driving mode to achieve energy saving; at the same time, the speed of the engine 1 is adjusted according to the temperature of the battery 10 to ensure that the temperature of the circulating water in the engine remains unchanged and can continuously heat the battery 10. When the temperature of the battery 10 is heated to more than 15°C, the engine 1 is turned off, which improves the economy and driving comfort of the vehicle.

[0109] The above contents are only preferred embodiments of the present invention. For ordinary technicians in this field, according to the concept of the present invention, there will be changes in the specific implementation methods and application scopes. The content of this specification should not be understood as limiting the present invention.

Claims

1. A thermal management control method for a hybrid vehicle, wherein the hybrid vehicle comprises an engine system and an electric drive system, wherein the engine system comprises an engine (1), the electric drive system comprises a motor (3) and a battery (10), the battery (10) provides electrical energy for the motor (3), and the engine system can provide negative torque for the motor (3) to charge the battery (10), wherein: The thermal management control method of the hybrid vehicle comprises the following steps: Determine whether the vehicle is in a stationary state after starting; If not, the vehicle is controlled to enter a driving thermal management control mode. When the vehicle enters the driving thermal management control mode, the temperature of the battery (10) is detected. If the temperature of the battery (10) is less than a first set temperature, the vehicle is controlled to enter an engine driving mode, the temperature of the circulating water in the engine is increased, and the battery (10) is heated by the circulating water in the engine; The specific steps include: detecting the temperature of the battery (10); If the temperature of the battery (10) is lower than the first set temperature, the vehicle is controlled to enter an engine driving mode, in which the temperature of circulating water in the engine increases; When the temperature of the circulating water in the engine rises to be equal to the first set temperature, the vehicle is controlled to enter a hybrid driving mode, and the battery (10) is heated simultaneously by the heat generated by the circulating water in the engine and the discharge of the battery (10); When the temperature of the battery (10) is heated to a temperature greater than a third set temperature, the vehicle is controlled to enter a pure electric drive mode, and the battery (10) is heated by heat generated by discharge of the battery (10), and the third set temperature is greater than the first set temperature.

2. The thermal management control method of a hybrid vehicle according to claim 1, characterized in that: The thermal management control method of the hybrid vehicle further comprises the following steps: If the vehicle is in a stationary state after starting, the vehicle is controlled to enter a parking thermal management control mode. When the vehicle enters the parking thermal management control mode, the temperature of the battery (10) is detected. If the temperature of the battery (10) is lower than the first set temperature, the temperature of the water circulating in the engine is increased by controlling the rotation speed of the engine (1), and the battery (10) is heated by the water circulating in the engine.

3. The thermal management control method of a hybrid vehicle according to claim 2, characterized in that: When the vehicle enters the parking thermal management control mode, the temperature of the battery (10) is detected. If the temperature of the battery (10) is lower than the first set temperature, the temperature of the water circulating in the engine is increased by controlling the rotation speed of the engine (1). The specific steps of heating the battery (10) by the water circulating in the engine include: While detecting the temperature of the battery (10), the temperature of the circulating water in the engine is also detected; If the temperature of the battery (10) is lower than the first set temperature and the temperature of the circulating water in the engine is lower than a second set temperature, the engine (1) is controlled to run at a first set speed, and the second set temperature is lower than the first set temperature; When the temperature of the circulating water in the engine rises to be equal to the second set temperature, the engine (1) is controlled to run at a second set speed, and the circulating water in the engine is controlled to start heating the battery (10), the second set speed being lower than the first set speed; When the temperature of the circulating water in the engine continues to rise to be equal to the first set temperature, the engine (1) is controlled to run at a third set speed, which is lower than the second set speed.

4. The thermal management control method for a hybrid vehicle according to claim 3, characterized in that: When the vehicle enters the parking thermal management control mode, when the temperature of the battery (10) is heated to a temperature greater than a third set temperature, the third set temperature is greater than the first set temperature, and while controlling the circulating water in the engine to heat the battery (10), the vehicle is allowed to enter the parking power generation mode to charge the battery (10), and the heat generated by the charging of the battery (10) is used to heat the battery (10).

5. The thermal management control method of a hybrid vehicle according to claim 4, characterized in that: When the temperature of the battery (10) is heated to a temperature greater than the third set temperature, the SOC of the battery (10) is first detected; when the SOC of the battery (10) is less than or equal to the maximum capacity allowed for charging, the vehicle is controlled to enter a parking power generation mode.

6. The thermal management control method of a hybrid vehicle according to claim 5, characterized in that: The specific steps of controlling the vehicle to enter a parking power generation mode to charge the battery (10), and utilizing the heat generated by the charging of the battery (10) to heat the battery (10) include: After the vehicle enters the parking power generation mode, the power generation of the motor (3) when in a negative torque state changes with the temperature of the battery (10), and as the temperature of the battery (10) gradually increases, the negative torque provided by the engine system to the motor (3) is controlled to gradually increase, so that the power generation gradually increases; When the temperature of the battery (10) is heated to a temperature greater than a fourth set temperature, the vehicle is controlled to exit the parking power generation mode, and the fourth set temperature is greater than the third set temperature.

7. The thermal management control method of a hybrid vehicle according to claim 1, characterized in that: When the temperature of the circulating water in the engine rises to be equal to the first set temperature, the vehicle is controlled to enter a hybrid driving mode, and the specific steps of heating the battery (10) by heat generated by the circulating water in the engine and the discharge of the battery (10) include: When the temperature of the circulating water in the engine rises to be equal to the first set temperature, the circulating water in the engine is controlled to start heating the battery (10); at the same time, the battery (10) is discharged at the maximum discharge power, and the battery (10) uses the heat generated during discharge to heat the battery (10).

8. The thermal management control method of a hybrid vehicle according to claim 1, characterized in that: When the temperature of the battery (10) is heated to a temperature greater than the third set temperature, the vehicle is controlled to enter a pure electric driving mode, and the specific steps of heating the battery (10) by heat generated by discharge of the battery (10) include: When the temperature of the battery (10) is heated to a temperature greater than the third set temperature, the clutch (2) is controlled to separate from the gearbox (4) so ​​that the vehicle enters a pure electric driving mode, while the engine (1) remains in a started state; When the temperature of the battery (10) continues to heat up to a temperature greater than a fourth set temperature, the engine (1) is controlled to be shut down, and the fourth set temperature is greater than the third set temperature.

9. The thermal management control method for a hybrid vehicle according to claim 8, characterized in that: When the engine (1) remains in the started state, the temperature of the circulating water in the engine is kept constant by controlling the rotation speed of the engine (1).

10. The thermal management control method of a hybrid vehicle according to claim 1, characterized in that: When the vehicle is controlled to enter a hybrid power driving mode, the output power of the engine (1) is equal to the difference between the total power required for the vehicle to travel and the maximum discharge power of the electric drive system.

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