Whole vehicle control method for heating of new energy vehicle

Abstract

The invention relates to the technical field of new energy automobile whole vehicle control, in particular to a new energy automobile heating whole vehicle control method which comprises the following specific steps that S1, whether a driver has a heating request or not is judged; s2, the CLM further judges the size of an air volume switch; s3, the CLM sends a heating request to the TBOX, and then forwards the heating request and the opening degree of the cold and warm air door to the VCU; and S4, after the VCU receives the heating request and the opening degree of the cold and warm air door, an engine starting instruction is set immediately, the VCU sends the engine starting instruction to an APU control unit GCU through a bus, the GCU controls the engine to be started to conduct heating control immediately, and the problem that when the fixed small APU power generation power is set for heating, heat generated by the engine is little, and the heating efficiency is high is solved. The problems that when a large fixed APU power generation power is set for heating, too much heat is generated when the APU is not too cold, so that the economical efficiency and the heating effect cannot be achieved at the same time, and the car using income and the heating experience of a user are affected are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of new energy vehicle overall vehicle control, and more specifically, to a new energy vehicle heating overall vehicle control method. Background Art

[0002] A series hybrid electric vehicle is equipped with an engine. In winter, the heat generated by the engine during operation after startup can be used to heat the passenger compartment. By transferring the coolant heat to the passenger compartment and the battery electric drive system, the purpose of using the waste heat of the engine to heat the passenger compartment and the battery electric drive is achieved.

[0003] A series hybrid electric vehicle has multiple driving modes and is equipped with a large-capacity battery. Power consumption is prioritized. When the temperature is low in winter, after the user requests heating, the VCU will control the engine to start and run to provide a heating heat source for the whole vehicle. The VCU controls the operation of the engine by sending a power generation power demand to the range extender APU. When the requested power is large, more heat is generated. However, for the scenario where the battery is fully charged, a higher APU power generation power means more fuel consumption, and the vehicle economy of the user is bound to decline. When a fixed and very small APU power generation power is set to operate for heating, the heat generated by the engine is less. When a relatively large fixed APU power generation power is set to operate for heating, too much heat is generated when it is not so cold, resulting in the inability to have both economy and heating effect, affecting the user's vehicle use benefit and heating experience. Summary of the Invention

[0004] The present invention provides a new energy vehicle heating overall vehicle control method, which solves the problem that at present, when a fixed and very small APU power generation power is set to operate for heating, the heat generated by the engine is less, and when a relatively large fixed APU power generation power is set to operate for heating, too much heat is generated when it is not so cold, resulting in the inability to have both economy and heating effect, affecting the user's vehicle use benefit and heating experience.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is: a new energy vehicle heating overall vehicle control method, and the specific steps are as follows: Step S1, the vehicle is powered on and initialized, and it is judged whether the driver has a heating request. If so, step S2 is executed; Step S2, the CLM further judges the size of the air volume switch, and judges whether the opening degree of the cold and warm air damper and the air blowing volume are greater than the threshold value. If greater than the threshold value, step S3 is executed; Step S3, the CLM sends a heating request to the TBOX. The TBOX receives the heating request and the opening degree of the cold and warm air damper, and then forwards the heating request and the opening degree of the cold and warm air damper to the VCU; Step S4: After the VCU receives the heating request and the opening degree of the heating and cooling air door, it immediately sets the engine start command. The VCU sends the engine start command to the APU control unit GCU via the bus, and the GCU then controls the engine to start for heating control.

[0006] Further specified, when the driving mode is the EV mode and there is a heating request in the EV mode, the APU operates solely to provide the heating heat source and is controlled according to the opening degree of the heating and cooling air door sent by the CLM. Considering the economy of the vehicle operation, the APU power generation power range corresponding to the opening degree of the heating and cooling air door is 2kW - 6.5kW. The VCU obtains the required APU power generation operating power by looking up the table in real time according to the opening degree of the heating and cooling air door. The APU power generation operating power is obtained through comprehensive calculation and trade-off by mapping the heating fuel consumption to the comprehensive vehicle use cost calculated based on the actual measured heating effect and the fuel-electric conversion rate.

[0007] Further specified, when the battery SOC is higher than the threshold, the VCU will control the APU to start according to the heating request, and at the same time send the power obtained by looking up the table of the opening degree of the heating and cooling air door to the APU for execution, and control the APU to operate at a constant power request to provide the heating heat source for the passenger compartment. When the VCU controls the APU power generation power to exit the heating mode and enter the power following mode, the VCU will calculate the total required APU power generation power based on the driving demand, the battery power preservation demand power, and the high-voltage accessory power consumption.

[0008] Further specified, when the driving mode is AUTO, the VCU will start the APU in a timely manner according to the driving power demand. If it is in the N - gear parking, or driving - to - coasting or driving - to - braking working conditions, then the APU required power calculated by the VCU may return to zero at high SOC. However, at this time, there is a heating demand in the passenger compartment, so it is necessary to determine whether the APU power demand at this time is less than the APU demand power corresponding to the opening degree of the heating and cooling air door. If so, then the VCU will control the APU power generation according to the APU demand power corresponding to the opening degree of the heating and cooling air door, otherwise, the APU power generation will be controlled according to the APU demand power calculated by its own control in the Auto mode.

[0009] Further specified, when the battery power is low in the Auto mode, since the required APU demand power will be greater than 2kW, there is no need to automatically exit the heating mode like in the EV mode after determining that the SOC is lower than the threshold to prevent the actual demand from being higher than the heating demand power and affecting the vehicle energy management.

[0010] Further limitation: To balance battery protection under extreme working conditions, if the battery is directly loaded with continuous climbing after being fully charged, theoretically, the battery may have an overheating trend. If the Max temperature of the battery cell is higher than the threshold, the VCU will first control the APU to start and enter the SHEV mode. At the same time, the power generation power of the APU is obtained by two-dimensional look-up based on the battery temperature and SOC, and the task of discharging the battery alone is assigned to two parts to achieve "power splitting" for the purpose of cooling the battery.

[0011] Further limitation: When the user presses the heating button and the VCU successfully controls the APU to start running, the VCU will send a heating economy prompt message to the TBOX. After receiving it, the TBOX forwards it to the instrument, and the instrument will perform a 20s pop-up prompt after parsing.

[0012] The beneficial effects of adopting the above technical solutions are: By correlating the heating power generation of the APU controlled by the VCU with the opening degree of the heating and cooling air damper of the air conditioning controller CLM to dynamically control the heating power generation of the APU, the opening degree of the heating and cooling air damper can truly reflect the driver's heating intention. If the heating capacity is large, the opening degree of the heating and cooling air damper can be reduced to reduce the heat generated by the APU power generation. If the heating capacity is small, the opening degree of the heating and cooling air damper can be increased to increase the heat generated by the APU power generation, solving the problem that the fixed APU power generation for heating cannot achieve both economy and heating effect in the passenger compartment, ensuring the user's vehicle use benefits, and improving the heating experience when the user uses the vehicle. Description of the Drawings

[0013] Figure 1 It is the overall control strategy flowchart of the present invention Figure 2 It is the APU heating power generation control flowchart of the present invention Figure 3 It is the instrument pop-up prompt control flowchart of the present invention Detailed Description of the Invention

[0014] The following is a more detailed description of the specific implementation of the present invention by describing the embodiments with reference to the drawings, aiming to help those skilled in the art have a more complete, accurate and in-depth understanding of the concept and technical solution of the present invention and contribute to its implementation.

[0015] The present invention is a method for controlling the heating of a new energy vehicle as a whole. By correlating the heating and power generation power of the APU controlled by the VCU with the opening degree of the heating and cooling air damper of the air conditioner controller CLM, the heating and power generation power of the APU is dynamically controlled. The opening degree of the heating and cooling air damper can truly reflect the driver's heating intention. If the heating capacity is too much, the opening degree of the heating and cooling air damper can be reduced to reduce the heat generated by the APU power generation. If the heating capacity is too little, the opening degree of the heating and cooling air damper can be increased to increase the heat generated by the APU power generation. This solves the problem that the fixed heating power of the APU power generation cannot achieve both economy and the heating effect of the passenger compartment, ensures the user's vehicle use benefits, and improves the heating experience when the user uses the vehicle.

[0016] As Figures 1 - 3 shown, the specific steps are as follows: Step S1: After the vehicle is powered on and initialized, it is judged whether the driver has a heating request. The CLM sends the opening degree of the heating and cooling air damper to the central gateway TBOX through the bus in real time. The opening degree range is 0 - 100%, which reflects the actual opening degree of the heating and cooling air damper knob. When the knob rotates to the heating area, the larger the rotation angle, the larger the corresponding heating demand opening degree. When the rotation angle reaches the maximum physical position, the heating demand reaches the maximum. If there is a heating request, execute Step S2; Step S2: The CLM further judges the size of the air volume switch, and judges whether the opening degree of the heating and cooling air damper and the blowing air volume are greater than the threshold value. If it is greater than the threshold value, a heating request is sent to the TBOX. The TBOX receives the heating request and the opening degree of the heating and cooling air damper, and then forwards the heating request and the opening degree of the heating and cooling air damper to the VCU; Step S3: After receiving the heating request and the opening degree of the heating and cooling air damper, the VCU immediately sets the engine start command. The VCU sends the engine start command to the APU control unit GCU through the bus, and the GCU then controls the engine to start for heating control.

[0017] Judge whether the driving mode is the EV mode or the AUTO mode. If it is the EV mode, the heating request in the EV mode can be understood as the heating control of a pure electric vehicle model. The APU runs only to provide a heating heat source. Therefore, the APU power generation power control can be simply controlled according to the opening degree of the heating and cooling air damper sent by the CLM. Considering the economy of the vehicle operation, the APU power generation power interval corresponding to the opening degree of the heating and cooling air damper is 2kW - 6.5kW. The VCU obtains the required APU power generation operating power by looking up the table according to the opening degree of the heating and cooling air damper in real time. The APU power generation operating power is comprehensively calculated and weighed according to the heating fuel consumption mapped by the actual test heating effect and the fuel-electric conversion rate and the comprehensive vehicle use cost. The one-dimensional table of the APU operating power corresponding to the opening degree of the heating and cooling air damper is as follows: Cooling and heating air damper opening APU operating power 10% 2KW 20% 2.5KW 30% 3KW 40% 3.5KW 50% 4KW 60% 4.5KW 70% 5KW 80% 5.5KW 90% 6KW 100% 6.5KW The VCU will judge the state of charge of the battery in real time to prevent the vehicle from breaking down due to out-of-control vehicle energy management caused by APU power generation control based on the heating demand of the passenger compartment when the battery power is too low. When the SOC is lower than the threshold, the VCU will control the APU power generation control to exit the heating mode and enter power following. When the battery SOC is higher than the threshold, the VCU will control the APU to start according to the heating request, and at the same time send the power obtained by looking up the table of the opening degree of the heating and cooling air damper to the APU for execution, and control the APU to operate with a constant power request to provide heating heat source for the passenger compartment. After the VCU controls the APU power generation control to exit the heating mode and enter power following, the VCU will calculate the total APU demand power generation according to the driving demand, the battery power retention demand power and the high-voltage accessory power consumption.

[0018] The economy and thermal efficiency of using the waste heat of the APU engine for heating are higher than those of the diesel heater. However, commercial vehicle users are very concerned about vehicle economy. Therefore, users should be reminded to adjust the heating and cooling air damper in time according to their body temperature perception to avoid unnecessary excess heating capacity causing fuel waste and reducing vehicle economy. After the user presses the heating button and the VCU successfully controls the APU to start and run, the VCU will send a heating economy prompt message to the TBOX. After receiving it, the TBOX will forward it to the instrument, and the instrument will perform a 20s pop-up prompt after parsing: "Heating is obtained by using the waste heat of the engine. Please pay attention to adjusting the heating and cooling air damper in time during heating to avoid unnecessary fuel waste."

[0019] When the driving mode is AUTO mode, the VCU will start the APU in a timely manner according to the driving power demand. When there is heating intervention, the engine will run constantly, but the power generation is calculated according to the total power consumption. If it is in the N-gear parking, or drive-to-coast or drive-to-brake conditions, then the APU demand power calculated by the VCU may return to zero at high SOC. However, if there is a heating demand in the passenger compartment at this time, it is necessary to judge whether the APU power demand at this time is less than the APU demand power corresponding to the opening degree of the heating and cooling air damper. If so, then the VCU will control the APU power generation according to the APU demand power corresponding to the opening degree of the heating and cooling air damper, otherwise, the APU power generation will be controlled according to the APU demand power calculated by the AUTO mode itself, so as to balance the vehicle power demand and the heating demand.

[0020] In Auto mode, when the battery power is low, the required APU demand power will be much greater than 2kW. There is no need to automatically exit the heating mode after judging that the SOC is lower than the threshold like in EV mode to prevent the actual demand from exceeding the heating demand power and affecting the overall vehicle energy management. At the same time, in order to take into account the battery protection under extreme conditions, if the battery is fully charged and then directly climbs continuously under heavy load, theoretically, the battery may show a trend of overheating. If the Max temperature of the battery cell is higher than the threshold, the VCU will first control the APU to start and enter the SHEV mode. At the same time, the power generation power of the APU is obtained by two-dimensional look-up based on the battery temperature and SOC, and the task of discharging the battery alone is assigned to two parts to achieve "power splitting" for the purpose of cooling the battery.

[0021] The present invention has been described exemplarily in combination with the accompanying drawings. Obviously, the specific implementation of the present invention is not limited by the above-mentioned manner. As long as various non-substantive improvements are made by adopting the method concept and technical solution of the present invention; or without improvement, the above-mentioned concept and technical solution of the present invention are directly applied to other occasions, they are all within the protection scope of the present invention.

Claims

1. A new energy vehicle heating control method, characterized in that: The specific steps are as follows: Step S1, the vehicle is powered on and initialized, and it is determined whether the driver has a heating request, and if so, step S2 is executed; Step S2, CLM further determines the size of the air volume switch, determines whether the opening of the cooling and heating air doors and the blowing volume are greater than the threshold, and if they are greater than the threshold, executes step S3; Step S3, CLM sends a heating request to TBOX, TBOX receives the heating request and the opening of the cooling and heating doors, and then forwards the heating request and the opening of the cooling and heating doors to the VCU; Step S4, after receiving the heating request and the opening of the heating and cooling air doors, the VCU immediately sets the engine start instruction, and sends the engine start instruction to the APU control unit GCU through the bus, and the GCU immediately controls the engine to start for heating control.

2. A new energy vehicle heating whole vehicle control method according to claim 1, characterized in that: When the driving mode is EV mode, for heating request in EV mode, the APU operation simply provides heating heat source, and is controlled according to the opening of the heating and cooling air doors issued by CLM. Considering the economy of the vehicle operation, the APU power generation range corresponding to the heating and cooling air door opening is 2kW-6.5kW. The VCU obtains the required APU power generation operating power according to the table of the heating and cooling air door opening in real time. The APU power generation operating power is obtained by comprehensive calculation and weighing of the comprehensive cost of the vehicle based on the actual tested heating effect and the heating fuel consumption calculated by the oil-to-electricity conversion rate.

3. A new energy vehicle heating whole vehicle control method according to claim 2, characterized in that: When the battery SOC is higher than the threshold, the VCU will control the APU to start according to the heating request, and at the same time send the power obtained by looking up the table of the cold and warm air door openings to the APU for execution, and control the APU operation with a constant power request to provide a heating heat source for the passenger compartment. When the VCU controls the APU power generation control to exit the heating mode and enter the power following mode, the VCU will calculate the total APU required power generation power based on the driving demand, the battery power preservation demand power, and the high-voltage accessory power consumption.

4. A new energy vehicle heating whole vehicle control method according to claim 2, characterized in that: When the driving mode is AUTO, the VCU will start the APU in time according to the driving power demand. If the vehicle is parked in N gear, or the drive switches to coasting or the drive switches to braking, the APU demand power calculated by the VCU may return to zero at high SOC. However, there is a demand for heating the passenger compartment at this time, so it is necessary to determine whether the APU power demand at this time is less than the APU demand power corresponding to the opening of the heating and cooling air doors. If so, the VCU will control the APU power generation according to the APU demand power corresponding to the opening of the heating and cooling air doors. Otherwise, the APU power generation control will be performed based on the APU demand power calculated by the Auto mode's own control.

5. A new energy vehicle heating whole vehicle control method according to claim 4, characterized in that: When the battery power is low in Auto mode, the required APU power will be greater than 2kW, so there is no need to automatically exit the heating mode after determining that the SOC is lower than the threshold like in EV mode, so as to prevent the actual demand from exceeding the heating demand power and affecting the energy management of the entire vehicle.

6. A new energy vehicle controller drive protection control method according to claim 2, characterized in that: In order to take into account the battery protection in extreme working conditions, if the battery is directly loaded and continuously climbed after being charged, the battery may theoretically tend to overheat. If the Max temperature of the battery cell is higher than the threshold, the VCU will first control the APU to start and enter the SHEV mode. At the same time, according to the battery temperature and SOC two-dimensional table lookup, the APU power generation power is obtained, and the task of discharging the battery alone is allocated to two parts, realizing "power diversion" to achieve the purpose of cooling the battery.

7. A new energy vehicle controller drive protection control method according to claim 1, characterized in that: When the user presses the heating button and the VCU successfully controls the APU to start running, the VCU will send a heating economy prompt message to the TBOX. After receiving the message, the TBOX will forward it to the meter. After the meter parses the message, a pop-up window will be displayed for 20 seconds.

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