Research On Speed Control Of Electric Vehicle Heat Pump Air Conditioning Compressor Based On Improved Fuzzy PID Algorithm

Compared with fuel vehicles,electric vehicles consume less energy and have no exhaust emissions.These two advantages make electric vehicles more and more popular.How to increase the mileage of the car by saving the electric energy of each system of the electric car is a hot research topic.The air-conditioning system is a device with high energy consumption in electric vehicles.Therefore,research on control algorithms that can reduce the energy consumption of electric vehicle air-conditioning systems is of great significance to the promotion of electric vehicles.Electric vehicles equipped with heat pump air conditioners are more energy-efficient than the Positive Temperature Coefficient(PTC)electric heating method used in most mass-produced electric vehicles.The temperature control of the automobile air conditioner can be controlled by changing the compressor speed,the air volume of the blower,the opening of the electronic expansion valve,etc.By changing the speed of the compressor,the heating/cooling capacity of the system can be changed,so as to achieve the effect of heating/cooling the cabin.In summary,this paper takes the speed of the electric vehicle heat pump air-conditioning compressor as the controlled object,and studies a control strategy to save air-conditioning energy consumption.First,a simulation model of the heat pump air conditioning system of an electric vehicle was established.By comparing the data obtained by running the test system with the data obtained by running the simulation system,it is obtained that the error between the simulation system model and the test system is within the allowable range,then by switching the flow direction of the refrigerant in the simulation model,the heating and cooling functions of the cabin are realized.Then,common controller simulation models for compressor control were established,including switch controllers,Proportion Integration Differentiation(PID)controllers,and fuzzy PID controller models.Then compare the temperature control effects of the electric vehicle heat pump air conditioner under the three controllers.The simulation results show that under fuzzy PID control,the minimum stable difference between the cabin temperature and the set temperature is 0.4℃;under PID control,the stable temperature difference between the cabin temperature is 0.5℃;and the cabin temperature fluctuates up and down under the switch control.Under fuzzy PID control,the compressor power consumption is the smallest,which is reduced by 69% and 11% respectively compared with PID control and switch control.After the cabin temperature stabilizes,the system Coefficient of Performance(COP)can reach 3.4 under fuzzy PID control,and 3.2 under PID control.Based on the simulation results,the fuzzy PID algorithm is selected to control the speed of the electric vehicle heat pump air-conditioning compressor.Finally,this paper uses the linearly decreasing inertia weight particle swarm algorithm to optimize the fuzzy PID.The simulation results show that the optimized fuzzy PID is reduced by about 0.2℃,the adjustment time is reduced by about 40 s,and the temperature overshoot is reduced by about 0.2℃ compared with the unoptimized fuzzy PID control.