Thermal management architecture and control method of hybrid commercial vehicle in low-temperature and low-SOC mode

Abstract

The invention relates to the technical field of new energy vehicle thermal management control, in particular to a thermal management architecture and control method of a hybrid commercial vehicle in a low-temperature and low-SOC mode, and the thermal management architecture comprises an extended-range engine, a CO clutch, a generator, a 12V starter normally-closed water valve, a Chiller heat exchanger, an electronic water pump, a power battery and the like. The range extender engine water circulation pipeline and the battery water circulation pipeline are connected through the Chiller heat exchanger, and the range extender engine water circulation pipeline is provided with an engine water temperature sensor, a mechanical water pump and a normally-closed water valve. The battery water circulation pipeline is provided with an electronic water pump and a battery inlet water temperature sensor. The power battery is provided with a heating film. The problems that in a low-temperature and low-SOC environment, a heating film of a power battery stops working, and a vehicle cannot be charged, cannot run and can only wait for rescue are solved.

Description

Technical Field

[0001] The present invention relates to the field of thermal management control technology for new energy vehicles, and in particular to a thermal management architecture and control method for a hybrid commercial vehicle in a low temperature and low SOC mode. Background Art

[0002] Pure electric new energy logistics light trucks have spread all over the country, and people are paying more and more attention to and accepting new energy light trucks. Extended-range new energy light trucks have also attracted much attention because they have all the advantages of pure electric vehicles. In terms of endurance, extended-range light trucks do not have the "range anxiety" of pure electric light trucks. The endurance of pure electric light trucks depends on battery capacity and operating conditions. Once the battery is insufficient, it takes a long time to charge. Extended-range light trucks can use fuel engines to generate electricity to supplement electricity and increase endurance. In terms of energy replenishment, pure electric light trucks take a long time to charge, especially at fast charging piles, which may take tens of minutes to hours to fully charge. Extended-range light trucks are more flexible in replenishing energy. When the battery is insufficient, they can be replenished with fuel and continue to generate electricity within a few minutes at gas stations, just like traditional fuel vehicles, saving time and improving transportation efficiency.

[0003] Although extended-range new energy light trucks have the above advantages over pure electric vehicles, they also have the disadvantages of pure electric vehicles. First, in extremely cold environments, the power battery SOC is lower than a certain threshold, the vehicle power is limited, and the battery's built-in heating film stops working. At this time, the vehicle is completely unable to operate and breaks down, and can only wait for rescue. Secondly, the vehicle is soaked overnight and the power battery is frozen through. At this time, due to its own characteristics, the power battery's discharge capacity decreases and its charging capacity also drops sharply. Although extended-range new energy light trucks have a range extender, it does not directly participate in driving, so in this scenario the range extender may fail to start. Even if it starts successfully, the battery's charging capacity is weak and the battery has anti-overcharge restrictions, resulting in the range extender being unable to provide the high-power electricity required by the vehicle. At the same time, if the power battery is overcharged, it will cause serious damage to the battery. Summary of the invention

[0004] The present invention provides a thermal management architecture and control method for hybrid commercial vehicles in low temperature and low SOC mode. The VCU controls the closing or opening of the CO clutch by judging the discharge capacity of the power battery at this time, and the engine is started in different ways (generator reverse drag or 12V starter reverse drag). The heat generated after the engine is started is transferred to the power battery through the heat exchanger for heating. When the battery is heated to a certain temperature, the battery overcharge prevention limit is released, and the range extender can follow the power demand of the whole vehicle. At this time, the vehicle can get out of trouble without rescue and run normally.

[0005] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a thermal management architecture of a hybrid commercial vehicle in a low-temperature and low-SOC mode, including a range-extended engine, a CO clutch, a generator, a 12V starter, and a power battery, etc. In a low-temperature and low-SOC environment, the VCU controls the closing or opening of the CO clutch by judging the discharge capacity of the power battery at this time, and the range-extended engine is started by reverse dragging of the generator or the reverse dragging of the 12V starter. A water circulation pipeline is arranged between the range-extended engine and the battery, and the range-extended engine water circulation pipeline and the battery water circulation pipeline are connected through a Chiller heat exchanger. The range-extended engine water circulation pipeline is provided with an engine water temperature sensor, a mechanical water pump and a normally closed water valve, and the battery water circulation pipeline is provided with an electronic water pump and a battery water inlet temperature sensor, and the power battery has a built-in heating film Further defined, a control method for a thermal management architecture of a hybrid commercial vehicle in a low temperature and low SOC mode, The specific steps are as follows: Step S1, in an extremely cold environment, the vehicle SOC is lower than a threshold value S%, and the vehicle is left standing overnight. The next day, the vehicle is powered on normally, and the vehicle enters a high-voltage READY state; Step S2, the vehicle VCU detects whether the battery SOC and the lowest temperature of the battery cell are lower than T1, where T1 is the temperature threshold at which the power battery allows the range extender to follow the power. If not, the vehicle can operate normally. If so, execute step S3; Step S3, the instrument ICM displays "Vehicle is warming up, do not drive", and the VCU detects whether the power battery discharge capacity is not less than the threshold value P1, which is the first threshold value for closing the CO clutch. If so, execute step S4; Step S4, the VCU controls the CO clutch to close, the EMS and the GCU receive the VCU start command, and the GCU controls the generator to start in reverse; Step S5, after the engine is successfully started, it runs in the idle state, and the CO clutch maintains the state at the time of starting. At the same time, the VCU detects whether the charging capacity of the power battery is not less than the threshold value P2, which is the second threshold value of the CO clutch closing. If so, execute step S6; Step S6, VCU controls the CO clutch to close, and GCU requests the engine speed to be R1; Step S7, VCU detects that the engine water temperature is not lower than the engine coolant temperature threshold T3 and the battery cell minimum temperature is not higher than T2, T2 is the temperature threshold for stopping heating of the power battery. If not, the engine speed is maintained at R1; Step S8, the VCU controls the normally closed water valve to open. Meanwhile, the battery water pump operates accordingly. The VCU detects whether the water inlet temperature of the battery pack is not less than T4, where T4 is the temperature threshold for closing the normally closed water valve. If not, the battery water pump continues to operate accordingly. If so, the VCU controls the normally closed water valve to close, and the water pump maintains its corresponding operation. Step S9, the VCU further detects whether the water inlet temperature of the battery pack is less than or equal to T4 - △T5, where △T5 represents the temperature hysteresis range of the water inlet temperature of the battery pack and is the temperature threshold for controlling the opening of the normally closed water valve. If not, the state where the VCU controls the normally closed water valve to close and the water pump operates accordingly is continued. If so, the VCU controls the normally closed water valve to open. Meanwhile, the battery water pump operates accordingly. Step S10, does the VCU detect that the minimum temperature of the power battery cells is greater than T1? If not, the previous state is maintained. If so, step S11 is executed. Step S11, the VCU switches to the driving mode. The instrument display ICM shows "Warming up completed, can drive". The vehicle drives normally. The extended-range power follows the vehicle's demand to meet driving requirements.

[0006] Further defined, it also includes step S12. After the vehicle drives normally, the VCU detects whether the minimum temperature of the battery cells is greater than T2. If so, the VCU controls the normally closed water valve to close and the battery water pump to turn off. If not, the VCU controls the normally closed water valve to open. Meanwhile, the battery water pump operates accordingly.

[0007] Further defined, step S4 also includes step S4.1. In step S3, the VCU detects whether the power discharge capacity of the power battery is not lower than the threshold P1. If not, step S4.1 is executed. In step S4.1, the VCU controls the CO clutch to open. The EMS receives the VCU start command. The VCU closes the 12V starter relay, and the 12V starter performs reverse drag start. In step S4.1, the VCU controls the CO clutch to open. The EMS receives the VCU start command. The VCU closes the 12V starter relay, and the 12V starter performs reverse drag start.

[0008] Further defined, it also includes step S5.1. In step S5, the VCU detects whether the power charging capacity of the power battery is not lower than the threshold P2. If not, step S5.1 is executed. In step S5.1, the VCU controls the CO clutch to open. The GCU requests the engine speed to be R2. Meanwhile, the VCU detects whether the power charging capacity of the power battery is greater than or equal to ≥P2. If not, the current state is continued. If so, step S6 is executed.

[0009] The beneficial effects of adopting the above technical solutions are: The VCU controls the closing or opening of the CO clutch by judging the discharge capacity of the power battery at this time, and the engine is started in different ways (generator reverse drag or 12V starter reverse drag). The heat generated after the engine is started is transferred to the power battery through the heat exchanger for heating. When the battery is heated to a certain temperature, the battery overcharge protection limit is released, and the range extender can follow the power demand of the whole vehicle and replenish the battery at the same time. At this time, the vehicle can get out of trouble and run normally without rescue. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 Thermal management architecture for commercial vehicles in low temperature and low SOC mode Figure 2 The overall control flow chart of the present invention is The symbols in the figure correspond to: 1-extended-range engine, 2-CO clutch, 3-generator, 4-12V starter, 5-power battery, 6-Chiller heat exchanger, 7-engine water temperature sensor, 8-heating film, 9-mechanical water pump, 10-battery water pump, 11-battery water inlet temperature sensor, 12-normally closed water valve. DETAILED DESCRIPTION

[0011] The specific implementation methods of the present invention are further explained in detail below by describing the embodiments with reference to the accompanying drawings, with the aim of helping those skilled in the art to have a more complete, accurate and in-depth understanding of the concept and technical solution of the present invention and facilitating its implementation.

[0012] The present invention is a thermal management architecture and control method for hybrid commercial vehicles in low temperature and low SOC mode, which solves the problem that the heating film of the power battery stops working in a low temperature and low SOC environment, the vehicle cannot be charged, cannot drive, and can only wait for rescue. Secondly, the vehicle is left standing for a night and the power battery is frozen. At this time, due to its own characteristics, the discharge capacity of the power battery decreases, and the charging capacity also decreases sharply. Although the extended-range new energy light truck has an extender, it does not directly participate in the drive, so the range extender may fail to start in this scenario. Even if it starts successfully, the battery has a weak charging capacity and the battery has an overcharge prevention limit, which causes the range extender to be unable to provide the high-power electric energy required by the vehicle. At the same time, if the power battery is overcharged, it will cause serious damage to the battery.

[0013] like Figure 1 and Figure 2As shown in the figure, a thermal management architecture for a hybrid commercial vehicle in a low-temperature and low-SOC mode includes an extended-range engine 1, a CO clutch 2, a generator 3, and a 12V starter 4. The VCU controls the closing or opening of the CO clutch 2 by judging the discharge capacity of the power battery at this time. The extended-range engine 1 is started in the way of being dragged by the generator 3 in reverse or the 12V starter 4 in reverse. The water circulation pipeline of the extended-range engine 1 and the water circulation pipeline of the battery 5 are connected through a Chiller heat exchanger 6. The water circulation pipeline of the extended-range engine is provided with a water temperature sensor 7, a mechanical water pump 9, and a normally closed water valve 12. The water circulation pipeline of the battery 5 is provided with an electronic water pump 10 and a battery inlet water temperature sensor 11. The power battery is equipped with a self-heating film 8.

[0014] A control method for the thermal management architecture of a hybrid commercial vehicle in a low-temperature and low-SOC mode is as follows: Step S1, in an extremely cold environment, when the vehicle's SOC is lower than the threshold S%, after standing overnight, the vehicle is normally energized with high voltage, and the whole vehicle enters the high-voltage READY state; Step S2, the vehicle's VCU detects whether the battery SOC and the lowest temperature of the battery cells are lower than T1. T1 is the temperature threshold at which the power battery allows the extended-range engine power to follow. If not, the vehicle can run normally. If so, step S3 is executed; Step S3, the instrument ICM displays "Vehicle warming up, do not drive". At the same time, the VCU detects whether the discharge capacity of the power battery is not lower than the threshold P1. P1 is the first threshold for closing the CO clutch. If so, step S4 is executed. If not, step S4.1 is executed. Step S4, the VCU controls the CO clutch to close. The EMS and GCU receive the VCU start command, and the GCU controls the generator to start by reverse dragging; Step S4.1, the VCU controls the CO clutch to open. The EMS receives the VCU start command, and the VCU closes the 12V starter relay, and the 12V starter starts by reverse dragging; Step S5, after the engine is successfully started, it runs in the idle state. The CO clutch maintains the state at startup. At the same time, the VCU detects whether the charging capacity of the power battery is not lower than the threshold P2. P2 is the second threshold for closing the CO clutch. If so, step S6 is executed. If not, step S5.1 is executed; Step S5.1, the VCU controls the CO clutch to open. The GCU requests the engine speed to be R2. At the same time, the VCU detects whether the charging capacity of the power battery is greater than or equal to ≥P2. If not, the current state is maintained. If so, step S6 is executed; Step S6, the VCU controls the CO clutch to close, and the GCU requests the engine speed to be R1; Step S7, the VCU detects that the engine water temperature is not lower than the engine coolant temperature threshold T3 and the battery cell minimum temperature is not higher than T2, where T2 is the temperature threshold for stopping heating of the power battery. If not, the engine speed is maintained at R1; Step S8, VCU controls the normally closed water valve to open, and at the same time, the battery water pump operates accordingly. VCU detects whether the water inlet temperature of the battery pack is not less than T4, T4 is the temperature threshold for closing the normally closed water valve. If not, the battery water pump is kept running accordingly. If so, VCU controls the normally closed water valve to close, and the water pump keeps running accordingly. Step S9, the VCU further detects whether the battery pack water inlet temperature is less than or equal to T4-△T5, where △T5 represents the battery pack water inlet temperature hysteresis interval, and controls the temperature threshold of the normally closed water valve to open. If not, the VCU continues to control the normally closed water valve to close, and the water pump operates accordingly. If so, the VCU controls the normally closed water valve to open, and the battery water pump operates accordingly. Step S10, VCU detects whether the lowest temperature of the power battery cell is greater than T1? If not, keep the previous state; if yes, execute step S11; Step S11, the VCU switches to the driving mode, the instrument display ICM shows "Warm-up completed, ready to drive", the vehicle drives normally, and the extended-range power follows the vehicle demand to meet driving needs; Step S12, after the vehicle is running normally, the VCU detects whether the minimum temperature of the battery cell is greater than T2. ​​If so, the VCU controls the normally closed water valve to close and the battery water pump to turn off. If not, the VCU controls the normally closed water valve to open and the battery water pump to operate accordingly.

[0015] The present invention is described above by way of example in conjunction with the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-mentioned method. As long as various non-substantial improvements are made using the method concept and technical solution of the present invention; or the above-mentioned concept and technical solution of the present invention are directly applied to other occasions without improvement, they are all within the protection scope of the present invention.

Claims

1. A thermal management architecture for a hybrid commercial vehicle in a low temperature and low SOC mode, characterized by: It includes a range-extended engine, a CO clutch, a generator, a 12V starter, a power battery, etc. In a low-temperature and low-SOC environment, the VCU controls the closing or opening of the CO clutch by judging the discharge capacity of the power battery at this time. The range-extended engine is started by reverse dragging of the generator or the 12V starter. A water circulation pipeline is arranged between the range-extended engine and the battery. The range-extended engine water circulation pipeline and the battery water circulation pipeline are connected through a Chiller heat exchanger. The range-extended engine water circulation pipeline is provided with an engine water temperature sensor, a mechanical water pump and a normally closed water valve. The battery water circulation pipeline is provided with an electronic water pump and a battery water inlet temperature sensor. The power battery has a heating film.

2. The control method of the thermal management architecture of a hybrid commercial vehicle in a low temperature and low SOC mode according to claim 1, characterized in that: The specific steps are as follows: Step S1: In an extremely cold environment, the vehicle SOC is lower than the threshold value S%, and the vehicle is left standing overnight. The next day, the vehicle is normal. After high voltage is applied, the vehicle enters high voltage READY state; Step S2, the vehicle VCU detects whether the battery SOC and the lowest temperature of the battery cell are lower than T1, where T1 is the temperature threshold at which the power battery allows the range extender to follow the power. If not, the vehicle can operate normally. If so, execute step S3; Step S3, the instrument ICM displays "Vehicle is warming up, do not drive", and the VCU detects whether the power battery discharge capacity is not less than the threshold value P1, which is the first threshold value for closing the CO clutch. If so, execute step S4; Step S4, the VCU controls the CO clutch to close, the EMS and the GCU receive the VCU start command, and the GCU controls the generator to start in reverse; Step S5: After the engine is successfully started, it runs in the idle state, and the CO clutch maintains the state at the time of starting. At the same time, the VCU detects whether the charging capacity of the power battery is not less than the threshold value P2, which is the second threshold value of the CO clutch closing. If so, execute step S6; Step S6, VCU controls the CO clutch to close, and GCU requests the engine speed to be R1; Step S7, the VCU detects that the engine water temperature is not lower than the engine coolant temperature threshold T3 and the battery cell minimum temperature is not higher than T2, where T2 is the temperature threshold for stopping heating of the power battery. If not, the engine speed is maintained at R1; Step S8, VCU controls the normally closed water valve to open, and at the same time, the battery water pump operates accordingly. VCU detects whether the water inlet temperature of the battery pack is not less than T4, T4 is the temperature threshold for closing the normally closed water valve. If not, the battery water pump is kept running accordingly. If so, VCU controls the normally closed water valve to close, and the water pump keeps running accordingly. Step S9, the VCU further detects whether the battery pack water inlet temperature is less than or equal to T4-△T5, where △T5 represents the battery pack water inlet temperature hysteresis interval, and controls the temperature threshold of the normally closed water valve to open. If not, the VCU continues to control the normally closed water valve to close, and the water pump operates accordingly. If so, the VCU controls the normally closed water valve to open, and the battery water pump operates accordingly. Step S10, VCU detects whether the lowest temperature of the power battery cell is greater than T1? If not, keep the previous state; if yes, execute step S11; Step S11, the VCU switches to driving mode, the instrument display ICM shows "Warm-up completed, ready to drive", the vehicle drives normally, and the extended-range power follows the vehicle's needs to meet driving requirements.

3. The control method of the thermal management architecture of a hybrid commercial vehicle in a low temperature and low SOC mode according to claim 2, characterized in that: The step S12 is also included. Step S12, after the vehicle is running normally, the VCU detects whether the minimum temperature of the battery cell is greater than T2. ​​If so, the VCU controls the normally closed water valve to close and the battery water pump to turn off. If not, the VCU controls the normally closed water valve to open and the battery water pump to operate accordingly.

4. The control method of the thermal management architecture of a hybrid commercial vehicle in a low temperature and low SOC mode according to claim 2, characterized in that: Step S4 also includes step S4.

1. In step S3, the VCU detects whether the power battery discharge capacity is not less than the threshold value P1. If not, step S4.1 is executed. Step S4.1: VCU controls the CO clutch to open, EMS receives the VCU start command, and VCU closes the 12V Starter relay, 12V starter for reverse starting.

5. The control method of the thermal management architecture of a hybrid commercial vehicle in a low temperature and low SOC mode according to claim 2, characterized in that: The method further includes step S5.

1. In step S5, the VCU detects whether the charging capacity of the power battery is not less than a threshold value P2. If not, step S5.1 is executed. Step S5.1, VCU controls the CO clutch to open, GCU requests the engine speed to be R2, and VCU detects whether the power battery charging capacity is ≥ P2. If not, the current state is maintained. If yes, step S6 is executed.

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