CN115593180A - Air-conditioning control method and automobile in low-battery scene - Google Patents

Abstract

The invention discloses an air-conditioning control method in a low-battery scene, comprising: judging whether to enter a low-battery state mode according to collected vehicle data; The remaining power is used to drive and control the work of the air conditioner compressor. The advantages of the present invention are: it does not involve the improvement of the hardware cost, it only needs the improvement of the software, the cost is low, and the implementation is convenient; when the power is low, the user's demand is comprehensively considered to control the operation of the air conditioner, which ensures the user's demand and improves the user experience. ; Low battery mode will give reminders through pop-up windows or voice, ensuring the user's right to know, and the system is more intelligent and reasonable.

Description

Air-conditioning control method and automobile in low-battery scene

technical field

The invention relates to the field of automobile control, in particular to an air-conditioning control method and an automobile in a low-battery scene.

Background technique

With the rapid development of new energy vehicle industry technology and changing user needs, electric vehicles are characterized by intelligence, networking, and scenarios. As one of the most important parts of the car, the car air conditioner plays an important role in controlling the environment inside the car. However, the long-term use of the air conditioner will not only greatly reduce the battery life of the electric car, but also cause poor battery discharge capacity in low-battery scenarios. If the battery temperature is too high or too low, the discharge capacity of the battery will be further weakened. At this time, the user will face the potential safety risk of insufficient vehicle power when driving with the air conditioner on, which will seriously affect the user experience. How to reasonably control the opening control in the low-battery scene is very important for the battery life of electric vehicles and user experience. The existing technology is generally only for the air conditioning control of internal combustion engine vehicles, and cannot be directly replaced by the air conditioning control of pure electric vehicles.

Contents of the invention

The purpose of the present invention is to overcome the deficiencies of the prior art, and provide an air-conditioning control method and a car in a low-battery scenario, by distributing and controlling power in a low-battery situation, to improve user experience and ensure driving safety of the vehicle.

In order to achieve the above purpose, the technical solution adopted by the present invention is: an air conditioner control method in a low battery scene, comprising:

According to the collected vehicle data, it is judged whether to enter the low-battery state mode. In the low-battery state mode, the remaining power after the battery discharge power satisfies the low-voltage load power and the throttle request power is used to drive and control the work of the air conditioner compressor.

Judging whether to enter the low battery state mode based on the collected vehicle data includes: collecting the SOC data of the vehicle and the mode information of the air conditioner. When the threshold A is set and the vehicle speed is lower than the set speed threshold, the vehicle enters the low battery state mode.

After entering the low-battery state mode, a reminder signal to enter the low-battery state mode is sent to the user through the vehicle-machine interaction.

The battery discharge power includes: the corresponding rated discharge power P obtained by the VCU according to the SOC and the maximum allowable discharge power corresponding to the SOC obtained by the BMS based on the battery temperature.

The VCU calibrates the corresponding discharge power P according to the terminal SOC, obtains the VCU calibrated discharge power corresponding to multiple SOC point values through pre-calibration, and obtains the corresponding adjacent SOC by linear interpolation of the power between two adjacent SOC point values The corresponding discharge power between the point values finally forms the SOC-P calibration discharge power comparison table.

BMS calibrates multiple SOC-Pb maximum allowable discharge power comparison tables based on temperature; the SOC-Pb maximum allowable discharge power comparison table corresponding to each temperature is firstly calibrated according to the battery SOC at the current temperature. The maximum allowable discharge power corresponding to different SOCs is obtained The point values corresponding to multiple SOCs and the maximum allowable discharge power, and then the power between two adjacent SOCs is linearly interpolated to obtain the corresponding discharge power between the corresponding adjacent SOC point values, and finally the SOC at this temperature is formed - Pb maximum allowable discharge power comparison table.

The VCU calculates the required throttle power P_pedal according to the size of the throttle request, and compares the required throttle power P_pedal with the available battery power Pb. When P_pedal<Pb, the maximum allowable power of the compressor P_com=Pb-P_pedal-P_load; otherwise, the maximum allowable power of the compressor Power P_com=0.

The VCU sends the maximum allowable power of the compressor to the air-conditioning controller, and the air-conditioning controller CLM compares it according to the information of the current compressor working power. Execution, if it is lower than the allowable power of the compressor, execute according to the current power, if the allowable working power of the compressor is 0kw or lower than the minimum working power capacity of the compressor, the compressor will stop running.

An automobile, including the air-conditioning control method in a low-battery scene.

The advantages of the present invention are: it does not involve the improvement of the hardware cost, only the software improvement is required, the cost is low, and the implementation is convenient; when the low battery is running, the user's demand is comprehensively considered to control the operation of the air conditioner, which ensures the user's demand and improves the user experience. ; Low battery mode will give reminders through pop-up windows or voice, ensuring the user's right to know, and the system is more intelligent and reasonable.

This solution develops an air-conditioning control method in a low-battery scenario for pure electric vehicles to improve user experience. Inventions or improvements proposed by this technical solution:

1. The system determines the available remaining power of the battery according to the maximum allowable discharge power when the battery is low in power, the calibrated discharge power under different SOCs of the vehicle, and the throttle request power;

2. Based on the available remaining power of the battery, control the air conditioner to reduce power or turn off the air conditioner to ensure that the vehicle can run normally. At the same time, it takes into account the defogging scene during the user's driving to ensure driving safety;

3. Designed a power verification strategy to efficiently manage the discharge power at the end of the battery, making battery utilization more efficient and the vehicle safer;

4. When the status of the air conditioner changes, the system will actively pop up a window to remind the user to avoid causing panic to the user.

Description of drawings

The content expressed in each accompanying drawing of the description of the present invention and the marks in the figure are briefly described below:

Fig. 1 is the schematic diagram of the in-vehicle hardware involved in the control method of the present invention;

Fig. 2 is the power calculation flowchart of the control method of the present invention;

Fig. 3 is a flow chart of power control in the control method of the present invention.

detailed description

The specific implementation manner of the present invention will be described in further detail below by describing the best embodiment with reference to the accompanying drawings.

As shown in Figure 1, it is a schematic diagram of the automobile control system involved in the air-conditioning control method in the low battery state of the present application, mainly involving BMS, VCU, and CLM, and its working principles include:

The BMS (Battery Management System) feeds back the charging status information of the vehicle to the VCU (Vehicle Controller). If the vehicle is not connected to the charging gun and the vehicle is in the READY state, the VCU determines that the vehicle is running or can be driven. If the vehicle is connected to the charging gun, the VCU Determine that the vehicle is in a non-driving state;

The BMS sends the current SOC information to the VCU. If the current SOC is lower than a certain threshold A, the VCU determines that the vehicle is in a low battery state. If the SOC is higher than the threshold A, the VCU determines that the vehicle is in a high battery state;

CLM (air conditioner controller) feeds back the air conditioner working status information and working speed information to VCU;

As shown in Figure 3, the VCU sends the maximum allowable compressor power to the CLM, and the CLM compares it based on the current compressor power information. If it is higher than the The allowed power of the compressor is executed according to the current power. If the allowed working power of the compressor is 0kw or lower than the minimum working power capacity of the compressor, the compressor will stop running;

The IHU (big-screen controller) receives compressor working status information and battery power information. If the battery power is lower than a certain threshold A and the compressor is in the state of stopping or reducing power, a pop-up window on the large screen will prompt the user of the working state of the air conditioner. Prevent users from panicking.

The concrete control method of this application is as follows:

According to the collected vehicle data, it is judged whether to enter the low-battery state mode. In the low-battery state mode, the remaining power after the battery discharge power satisfies the low-voltage load power and the throttle request power is used to drive and control the work of the air conditioner compressor. After entering the low-battery state mode, a reminder signal of entering the low-battery state mode is sent to the user through the vehicle-machine interaction, so that the user can know the vehicle condition and avoid the user's complaint or panic caused by restricting the air conditioner in the low-battery mode without knowing it.

Progress low battery state mode includes: collecting vehicle SOC data and air conditioner mode information, when the vehicle battery SOC is lower than the set threshold A and the air conditioner working mode is non-defogging mode or the vehicle battery SOC is lower than the set threshold A and the vehicle When the vehicle speed is lower than the set speed threshold, the vehicle enters the low battery state mode at this time.

The battery discharge power includes: the corresponding rated discharge power P obtained by the VCU according to the SOC and the maximum allowable discharge power corresponding to the SOC obtained by the BMS based on the battery temperature.

The VCU calibrates the corresponding discharge power P according to the terminal SOC, obtains the VCU calibrated discharge power corresponding to multiple SOC point values through pre-calibration, and obtains the corresponding adjacent SOC by linear interpolation of the power between two adjacent SOC point values The corresponding discharge power between the point values finally forms the SOC-P calibration discharge power comparison table, as shown in Table 1.

BMS calibrates multiple SOC-Pb maximum allowable discharge power comparison tables based on temperature; the SOC-Pb maximum allowable discharge power comparison table corresponding to each temperature is firstly calibrated according to the battery SOC at the current temperature. The maximum allowable discharge power corresponding to different SOCs is obtained The point values corresponding to multiple SOCs and the maximum allowable discharge power, and then the power between two adjacent SOCs is linearly interpolated to obtain the corresponding discharge power between the corresponding adjacent SOC point values, and finally the SOC at this temperature is formed - Pb maximum allowable discharge power comparison table, such as Table 2 is a corresponding SOC-Pb maximum allowable discharge power comparison table at a certain temperature.

As shown in Figure 2, the VCU calculates the throttle demand power P_pedal according to the throttle request, and compares the throttle demand power P_pedal with the available battery power Pb. When P_pedal<Pb, the maximum allowable power of the compressor P_com=Pb-P_pedal-P_load ; Otherwise, the maximum allowable power of the compressor P_com=0. The VCU sends the maximum allowable power of the compressor to the air-conditioning controller, and the air-conditioning controller CLM compares it according to the information of the current compressor working power. Execution, if it is lower than the allowable power of the compressor, execute according to the current power, if the allowable working power of the compressor is 0kw or lower than the minimum working power capacity of the compressor, the compressor will stop running.

When controlling the operation of the compressor, the compressor speed corresponding to the compressor power is calibrated by calibration, and the speed corresponding to the compressor power between two adjacent compressor power points is calculated by linear interpolation, and finally forms a compression The comparison table of engine power and speed, the air conditioner controller controls the work of the compressor based on the speed through the comparison table.

The VCU calibrates different discharge powers according to different SOCs at the end, in order to better manage the battery discharge power, prevent fluctuations in the battery discharge power, and affect drivability. Linear interpolation is used to calculate the power between different SOCs, as shown in Table 1;

Table 1

Power/% SOC₁ SOC₂ SOC₃ SOC₄ SOC₅ SOC₆ VCU calibrated discharge power/kw P₁ P₂ P₃ P₄ P₅ P₆

The BMS sets the maximum allowable discharge power of the battery under different SOCs according to the battery characteristics (temperature, SOC and other factors), and uses linear interpolation to calculate the power between different SOCs, as shown in Table 2

Table 2

Power/% SOC₁ SOC₂ SOC₃ SOC₄ SOC₅ SOC₆ The maximum allowable discharge power of the battery/kw Pb₁ Pb₂ Pb₃ Pb₄ Pb₅ Pb₆

The air conditioning control system (CLU) sets different compressor speeds according to different compressor powers, and uses linear interpolation between different compressor powers to calculate the compressor speeds, see Table 3

Compressor power/kw P_{ac_min} P_{ac_1} P_{ac_2} P_{ac_3} P_{ac_4} P_{ac_max} Compressor speed/rpm N_min N₁ N₂ N₃ N₄ N_max

The vehicle is in READY state, BMS, VCU, CLM, MCU communication is normal, BMS sends current SOC, available discharge power Pb to VCU, air conditioner sends current compressor working speed and working state to VCU, if SOC is less than a certain threshold value A, air conditioner is working state, the depth of the accelerator pedal is not 0%, activate the air conditioning control function under low battery status, and enter the air conditioning control strategy under low battery status;

In the low battery state, the VCU calculates the throttle demand power P_pedal according to the user's throttle request, and compares it with the available battery power Pb and the VCU calibrated power P. The low-voltage load power consumption is recorded as the constant value P_load;

If P_pedal<P and P_pedal<Pb, then the maximum allowable power of the compressor P_com=Pb-P_pedal-P_load;

If P_pedal=P and P_pedal<Pb, then the maximum allowable power of the compressor P_com=Pb-P_pedal-P_load;

If P_pedal>P and P_pedal<Pb, then the maximum allowable compressor power P_com=Pb-P_pedal-P_load;

If P_pedal>P and P_pedal>Pb, the maximum allowable power of the compressor is P_com=0kw;

If P_pedal=P=Pb, then the maximum allowable power of the compressor is P_com=0kw;

Of course, since this application is mainly to ensure that the vehicle can run and improve user experience, since the air conditioner is an additional comfort component, the stable and reliable operation of the vehicle at low battery level can be achieved through the above control while improving user experience, but since the air conditioner is in the defogging mode It is also an automobile safety performance parameter, so if the vehicle speed is higher than a certain value, and the air conditioner is in the defogging mode, the compressor will work normally, and it is not allowed to reduce power or stop running to avoid traffic accidents.

Apparently, the specific implementation of the present invention is not limited by the above methods, as long as various insubstantial improvements are made by adopting the method concept and technical solutions of the present invention, they all fall within the protection scope of the present invention.

Claims (9)

1. An air-conditioning control method in a low battery scene, characterized in that: comprising, According to the collected vehicle data, it is judged whether to enter the low-battery state mode. In the low-battery state mode, the remaining power after the battery discharge power satisfies the low-voltage load power and the throttle request power is used to drive and control the work of the air conditioner compressor. 2. The air-conditioning control method in a low-battery scene according to claim 1, wherein: judging whether to enter the low-battery state mode according to the collected vehicle data comprises: collecting the SOC data of the vehicle and the mode information of the air conditioner, When the vehicle battery SOC is lower than the set threshold A and the air conditioner working mode is non-defogging mode or the vehicle battery SOC is lower than the set threshold A and the vehicle speed is lower than the set speed threshold, the vehicle enters the low battery state mode. 3. The air-conditioning control method in a low-battery scenario according to claim 1 or 2, characterized in that: after entering the low-battery state mode, a reminder signal to enter the low-battery state mode is sent to the user through vehicle-machine interaction. 4. The air-conditioning control method in a low-battery scene according to claim 1 or 2, wherein the battery discharge power includes: the corresponding calibrated discharge power P obtained by the VCU according to the SOC and the SOC obtained by the BMS based on the battery temperature The corresponding maximum allowable discharge power. 5. The air-conditioning control method in a low-battery scene as claimed in claim 4, wherein the VCU calibrates the corresponding discharge power P according to the terminal SOC, and obtains the VCU calibrated discharge corresponding to a plurality of SOC point values through pre-calibration. Power, and the power between two adjacent SOC point values is linearly interpolated to obtain the corresponding discharge power between the corresponding adjacent SOC point values, and finally form the SOC-P calibration discharge power comparison table. 6. The air-conditioning control method in a low battery scene as claimed in claim 4, wherein: the BMS calibrates a plurality of SOC-Pb maximum allowable discharge power comparison tables based on temperature; the maximum allowable SOC-Pb discharge power corresponding to each temperature The discharge power comparison table first calibrates the maximum allowable discharge power corresponding to different SOCs at the current temperature according to the battery SOC to obtain the point values corresponding to multiple SOCs and the maximum allowable discharge power, and then the power between two adjacent SOCs is passed through the linear The corresponding discharge power between the corresponding adjacent SOC point values is obtained by interpolation, and finally the SOC-Pb maximum allowable discharge power comparison table at this temperature is formed. 7. An air-conditioning control method in a low-battery scenario according to any one of claims 1-6, wherein the VCU calculates the throttle demand power P_pedal according to the throttle request, and compares the throttle demand power P_pedal with the available battery power Pb For comparison, when P_pedal<Pb, the maximum allowable power of the compressor P_com=Pb-P_pedal-P_load; otherwise, the maximum allowable power of the compressor P_com=0. 8. The air-conditioning control method in a low-battery scene as claimed in claim 7, wherein the VCU sends the maximum allowable power of the compressor to the air-conditioning controller, and the air-conditioning controller CLM according to the current compressor working power information For comparison, if the current working power of the compressor is higher than the allowable working power of the compressor, execute according to the maximum allowable power of the compressor; if it is lower than the allowable power of the compressor, execute according to the current power; if the allowable working power of the compressor is 0kw or lower The compressor has the lowest working power capability, and the compressor stops running. 9. A car, characterized in that the car comprises the air-conditioning control method in a low-battery scene according to any one of claims 1-8.

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