Heating control method for passenger compartment of new energy automobile

Abstract

The invention relates to the technical field of whole vehicle control of new energy vehicles, in particular to a new energy vehicle passenger compartment heating control method which comprises the following steps: 1, a whole vehicle is in a gun insertion charging working condition, and whether a driver has a heating demand or not is judged; step 2, the VCU awakens the GCU and the EMS, and synchronously enables fault diagnosis monitoring of the EMS and the GCU; step 3, the VCU sends an APU starting instruction to the APU, and sends a constant low-power generation request to the APU at the same time; s4, the VCU synchronously monitors the running time of the APU and the actual power generation power of the GCU, calculates the compensation current of battery charging, and sends a calculation result to a battery management unit BMS to calculate the requested charging pile charging current; and 5, the BMS calculates the charging current of the charging pile according to the compensation current provided by the VCU, and the problems that the cost of the whole vehicle is increased and the heating efficiency is low due to the fact that a PTC heating system is independently additionally arranged on the whole vehicle and a heat source is provided for heating of a passenger compartment through PTC when a gun is inserted for charging are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of whole vehicle control of new energy vehicles, and in particular to a method for controlling heating of a passenger compartment of a new energy vehicle. Background Art

[0002] The passenger compartment heating of new energy vehicles generally uses air PTC or water PTC as the heating heat source according to the different thermal management architectures. However, PTC uses the principle of resistance heat generation to generate heat, and its working efficiency is low. The lower the cab temperature, the greater the PTC resistance. In order to achieve the same heating effect, more electricity will be consumed. The power consumption of PTC is related to the blower inlet temperature. The lower the blower inlet temperature, the greater the PTC power. The greater the PTC power, the more electricity it consumes. Therefore, the PTC efficiency is relatively poor at low temperatures.

[0003] In order to solve the problem of high energy consumption for low-temperature heating in winter, which leads to a significant reduction in vehicle range, some users will install a diesel heater on the vehicle. A diesel heater is equivalent to a small diesel engine, which generates heat by burning diesel, and then transfers the heat to the cab for heating. Installing a diesel heater separately not only increases costs for users, but also poses certain safety risks.

[0004] The extended-range electric vehicle has an engine, which is part of the range extender, and the engine is decoupled from the drive end, which means that the engine can work independently. For the passenger compartment heating control scheme that uses the engine's waste heat for heating, the engine is usually in a shutdown state when the user plugs in the gun to charge, and the passenger compartment will not be able to be heated at this time. The conventional design scheme is to install a separate PTC heating system on the whole vehicle, and use PTC to provide a heat source for heating the passenger compartment when the gun is plugged in to charge. This not only increases the cost of the whole vehicle and increases the cost pressure of the whole vehicle, but also has the same problem of low heating efficiency. Summary of the invention

[0005] The present invention provides a method for controlling heating of a passenger compartment of a new energy vehicle, which solves the problem that at present, a PTC heating system is separately installed on the whole vehicle, and PTC is used to provide a heat source for heating the passenger compartment when the charging gun is plugged in, which increases the cost of the whole vehicle and still has the problem of low heating efficiency.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is: a method for controlling heating of a passenger compartment of a new energy vehicle, which specifically comprises the following steps: Step S1, the vehicle is in a plug-in charging state, and it is determined whether the driver has a heating demand, if so, step S2 is executed; Step S2, VCU wakes up the generator controller GCU and the engine controller EMS, synchronously enables the fault diagnosis monitoring of EMS and GCU, and determines whether EMS and GCU report a high-level fault. If so, VCU will not send an APU start instruction to APU. If not, execute step S3; Step S3, the VCU sends an APU start instruction to the APU, and at the same time sends a constant low-power power generation request to the APU; Step S4, VCU will synchronously monitor the APU operation time. When the APU operation time exceeds the threshold, it will control the APU to shut down. At the same time, it will monitor the actual power generation of GCU in real time, calculate the compensation current of battery charging, and send the calculation result to the battery management unit BMS to calculate the requested charging current of the charging pile to protect the battery from overcharging; Step S5: The BMS calculates the charging current of the charging pile according to the compensation current provided by the VCU.

[0007] It is further defined that in step S3, the method used to realize the issuance of a constant low-power power generation request to the APU is: a separate map should be set for the power generation control of the APU to ensure that in the scenario of plug-in charging and passenger compartment heating request, the APU power generation value calculated by the VCU will not be affected by the energy management control of the whole vehicle, thereby affecting the user's vehicle economy.

[0008] It is further defined that for the mode management and control of the VCU, the whole vehicle should be allowed to enter the SHEV mode when plugging in for charging, so that the whole vehicle can actually enter the SHEV mode. When the VCU determines that the plugging in is for charging and there is a heating request, the driving mode is controlled to enter the SHEV mode. Only when the mode management can enter the SHEV mode normally can the mode management normally issue the start APU command.

[0009] It is further specified that after the APU is started by plugging in the charging gun for heating, if the driver cancels the heating request, the VCU will control the APU to stop running. If the heating request is maintained, the BMS will control the charging to stop after the plug-in charging is completed. The VCU side's operation control of the APU is based on the logical judgment that the driver has a heating request and is in the plug-in charging state. After the plug-in charging is completed, the GCU should be controlled to run at 0 power. When the APU is running at 0 power, the engine only outputs the torque to maintain idle operation and executes idle control of the speed closed loop. It will not output additional torque for power generation, and the generator simply runs.

[0010] It is further limited that when the vehicle is plugged in for charging and there is a heating request, the vehicle is prohibited from being ready after the APU starts the engine.

[0011] It is further specified that when the VCU recognizes that the vehicle is in the plug-in charging condition, the VCU will prohibit the power system from being enabled and the range extender cannot be started and run. When the air-conditioning control panel forwards the passenger compartment heating request to the VCU through the central gateway, the VCU will enable the APU, and then further judge the vehicle status to decide whether to start the APU.

[0012] It is further specified that the VCU needs to be allowed to issue the APU start command when it is not in the ON position, so that the engine can be started normally for heating when the remote air conditioning and heating are started.

[0013] The beneficial effects of adopting the above technical solution are: The present invention aims at heating control during charging with a plug-in charger. There is no need to add a separate PTC component for heating. By starting the APU to provide a heating source for the passenger compartment, the cost of the entire vehicle is not increased, and the thermal management efficiency of the passenger compartment of the entire vehicle can be ensured, thereby reducing the cost pressure of the entire vehicle.

[0014] 2. In the present invention, for the plug-in charging condition, the residual heat after the engine is started is used directly for heating, and the engine is regarded as a diesel heater. However, its thermal efficiency is much higher than that of a diesel heater, and there is no need to add components such as a diesel heater or PTC separately, which reduces the hardware cost of the whole vehicle. The heating control of the plug-in charging is realized through the software control strategy, which meets the heating needs of the passenger compartment when the plug-in charging is carried out. It is necessary to redesign the control strategy of the power system and the APU to allow the APU to be started when the plug-in charging is carried out to meet the heating needs of the passenger compartment, while taking into account the heating efficiency and high-voltage safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is the heating APU flow chart after charging of the present invention Figure 2 The overall control flow chart of the present invention is DETAILED DESCRIPTION

[0016] 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.

[0017] The present invention is a method for controlling the heating of the passenger compartment of a new energy vehicle. For the heating control during charging with a charging gun, there is no need to add a separate PTC component for heating. By starting the APU, a heating heat source is provided for the passenger compartment, which does not increase the cost of the entire vehicle and can ensure the thermal management efficiency of the passenger compartment of the entire vehicle, thereby reducing the cost pressure of the entire vehicle, improving the market competitiveness of the product, reducing the user's vehicle purchase cost, and improving the user's vehicle use income and driving experience.

[0018] Specifically, Figure 1and Figure 2 As shown, the specific steps include: Step S1, VCU identifies whether the vehicle is in the plug-in charging condition. If so, VCU will prohibit the power system from being enabled, and the range extender cannot be started. The air conditioning control panel forwards the passenger compartment heating request to VCU through the central gateway. VCU will enable APU, and then further judge the vehicle status to decide whether to start APU. According to the national standard electric vehicle safety requirements and the actual safety considerations of the vehicle, after the engine is started, VCU will usually think that the power system is ready, so it will enable the drive control of the electric drive system. At this time, if the driver accidentally steps on the accelerator pedal during plug-in charging, it will cause a safety risk. Therefore, for the plug-in charging and heating request conditions, the vehicle should be prohibited from being ready after the APU starts the engine; Step S2, VCU should wake up GCU and EMS synchronously. VCU will determine whether the conditions for starting APU are met according to the status of EMS and GCU, and synchronously enable the fault diagnosis monitoring of EMS and GCU to determine whether EMS and GCU report high-level faults. If so, even if there is a heating request, VCU will not issue an APU start instruction to APU. For the mode management control of VCU, the whole vehicle should be allowed to enter SHEV mode when plugging in for charging, so that the whole vehicle can actually enter SHEV mode. When VCU determines that the plug-in is charging and there is a heating request, it controls the drive mode to enter SHEV mode. Only when the mode management can enter SHEV mode normally can the mode management issue the APU start instruction normally. The VCU APU start instruction needs to be allowed to be issued when it is not in the ON position, so that the engine can be started normally for heating when the remote air conditioning and heating are started; Step S3, since the electricity cost is relatively lower, when the charging gun is plugged in and there is a heating request, the APU is allowed to play the role of "diesel heater", that is, the APU only needs to meet the heating demand, and the VCU will take into account the power generation efficiency and request the APU to generate low-power power, without the APU needing to generate high-power power to supplement the whole vehicle. This not only meets the heating demand of the passenger compartment, but also does not consume too much fuel to increase the user's vehicle cost. In order to achieve this demand, a separate map should be set for the APU power generation control to ensure that in the scenario of plugging in the gun for charging and there is a heating request for the passenger compartment, the APU power generation value calculated by the VCU will not be affected by the vehicle energy management control, thereby affecting the user's vehicle economy; Step S4, after the APU is started by plugging in the gun for charging and heating, if the driver changes his mind and cancels the heating request due to reasons such as leaving the cab, then the VCU will control the APU to stop running. Since the GCU has a large capacitor, the VCU will actively discharge the GCU as in the conventional high-voltage discharge process to avoid the risk of electric shock caused by the driver touching the high-voltage components when the GCU has a large amount of electricity. If the driver keeps requesting heating in the passenger cabin, the BMS will control the charging to stop after the gun is charged. The VCU side's control of the APU operation is based on the driver's The driver has a heating request and the logic judgment is performed in the plug-in charging state. When the BMS exits the plug-in charging state, it will control the gradual disconnection of the high-voltage main positive and main negative relays. At this time, if the APU still requests low-power operation, then since the high-voltage connection has been disconnected, the rectified voltage of the GCU will directly act on the power device and the voltage stabilizing capacitor. At the same time, according to the law of energy conservation, the GCU will begin to heat up. When the power gradually accumulates, the capacitor will break down, the high-voltage components will be damaged, and the GCU may also burn out. In order to take into account the heating needs of the passenger compartment during the conversion gap from charging to high voltage, Request, while avoiding damage to GCU components. After the gun is fully charged, the GCU should be controlled to run with 0 power. When the APU is running at 0 power, the engine only outputs the torque to maintain idle operation, executes the idle control of the speed closed loop, and does not output additional torque for power generation. The generator simply follows the rotation. Since the power generation power of the APU increases monotonically with the engine speed, the engine speed itself is also the lowest when 0 power is requested, and the back electromotive force generated by the GCU side is also small under the same conditions. For remote air conditioning and heating control, the VCU will synchronously monitor the APU operation time. When the APU operation time exceeds the threshold, the APU will be controlled to shut down. The purpose is to avoid the driver from arriving at the car late or forgetting to turn off the remote air conditioning due to temporary matters, causing the APU to consume too much fuel due to long-term operation and seriously affecting the economy of the vehicle. For the APU low-power power generation operation, in order to prevent the battery from overcharging, the VCU will monitor the actual power generation power of the GCU in real time, calculate the compensation current of the battery charging, and send the calculation result to the battery management unit BMS to calculate the requested charging current of the charging pile to protect the battery from overcharging; Step S5: The BMS calculates the charging current of the charging pile according to the compensation current provided by the VCU.

[0019] The APU start timing must be met after the high-voltage relay is closed to prevent the high-voltage relay from being closed after the APU start command is issued in advance. The APU startup consumes power and generates a high current, which will cause arcing and sparking when the main positive relay is closed under load, and in severe cases, the main positive relay will be burned.

[0020] 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 method for controlling heating of a passenger compartment of a new energy vehicle, characterized in that: The specific steps include: Step S1, the vehicle is in a plug-in charging state, and it is determined whether the driver has a heating demand, if so, step S2 is executed; Step S2, VCU wakes up the generator controller GCU and the engine controller EMS, synchronously enables the fault diagnosis monitoring of EMS and GCU, and determines whether EMS and GCU report a high-level fault. If so, VCU will not send an APU start instruction to APU. If not, execute step S3; Step S3, the VCU sends an APU start instruction to the APU, and at the same time sends a constant low-power power generation request to the APU; Step S4, VCU will synchronously monitor the APU operation time. When the APU operation time exceeds the threshold, it will control the APU to shut down. At the same time, it will monitor the actual power generation of GCU in real time, calculate the compensation current of battery charging, and send the calculation result to the battery management unit BMS to calculate the requested charging current of the charging pile to protect the battery from overcharging; Step S5: The BMS calculates the charging current of the charging pile according to the compensation current provided by the VCU.

2. A method for controlling heating of a passenger compartment of a new energy vehicle according to claim 1, characterized in that: In step S3, the method used to send a constant low-power power generation request to the APU is as follows: a separate map should be set for the APU power generation control to ensure that in the scenario of plug-in charging and passenger compartment heating request, the APU power generation value calculated by the VCU will not be affected by the vehicle energy management control, thereby affecting the user's vehicle economy.

3. A method for controlling heating of a passenger compartment of a new energy vehicle according to claim 1, characterized in that: For mode management and control of VCU, the whole vehicle should be allowed to enter SHEV mode when plugging in for charging, so that the whole vehicle can actually enter SHEV mode. When VCU determines that the plug is charging and there is a heating request, it controls the drive mode to enter SHEV mode. Only when the mode management can enter the SHEV mode normally can the mode management issue the start APU instruction normally.

4. A method for controlling heating of a passenger compartment of a new energy vehicle according to claim 1, characterized in that: After the APU is started by plug-in charging and heating, if the driver cancels the heating request, the VCU will control the APU to stop running. If the heating request is maintained, the BMS will control the charging to stop after the plug-in charging is completed. The VCU side's operation control of the APU is based on the logical judgment that the driver has a heating request and is in the plug-in charging state. After the plug-in charging is completed, the GCU should be controlled to run at 0 power. When the APU is running at 0 power, the engine only outputs the torque to maintain idle operation and executes idle speed control with a closed speed loop. It will not output additional torque for power generation, and the generator simply runs.

5. A new energy vehicle passenger compartment heating control method according to claim 1, characterized in that: For plug-in charging and heating request conditions, the vehicle is prohibited from being ready after the APU starts the engine.

6. A method for controlling heating of a passenger compartment of a new energy vehicle according to claim 1, characterized in that: When the VCU recognizes that the vehicle is in the plug-in charging condition, the VCU will prohibit the power system from being enabled and the range extender cannot start and run. When the air-conditioning control panel forwards the passenger compartment heating request to the VCU through the central gateway, the VCU will enable the APU and then further judge the vehicle status to decide whether to start the APU.

7. A method for controlling heating of a passenger compartment of a new energy vehicle according to claim 1, characterized in that: The VCU APU start command needs to be issued when the gear is not ON, so that the engine can be started normally for heating when the remote air conditioning and heating are started.

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