Research On Control Strategy Of Electric Vehicle Air Conditioning Considering Vehicle Working Conditions

In today’s society,pure electric vehicles,as new energy vehicles,have the characteristics of low noise,no exhaust emissions,high energy utilization,and low energy consumption,and are widely favored by people.However,the energy of a pure electric vehicle is completely derived from the on-board power battery.Its energy is limited and the current charging time is long.Therefore,it is required that the electric vehicle can have a greater driving range with limited power.As the auxiliary equipment with the largest energy consumption in the car,the power consumption of the air-conditioning system will directly affect the driving mileage of the vehicle,and under certain operating conditions,it may even affect the vehicle’s dynamic performance.The vehicle power battery will emit heat during the work process,and the high battery temperature will directly affect the battery’s working efficiency.According to the existing conditions,we can regard the heat dissipation of the battery as the heat load of the air conditioning system,and use the air conditioning system to dissipate the power battery.Therefore,we need to model the air-conditioning system and power battery system of electric vehicles,and it is of great practical significance to develop a comprehensive air-conditioning system control strategy.In this paper,a new air-conditioning system structure is designed on the basis of considering the heat dissipation requirements of the lithium battery pack.The air-conditioning structure is calculated for the cab thermal load and the lithium battery pack thermal load.,And then perform parameter matching on the electric compressor of the air conditioner.A fuzzy controller for the air-conditioning compressor is proposed,and the power of the air-conditioning system is limited,and the related control strategies are compiled on the premise of considering the vehicle’s dynamics.In this paper,an air-conditioning system control module,an air-conditioning system module,a lithium battery pack module,and a vehicle module are established in Matlab / Simulink and Amesim respectively.Each module is connected through an interface,and joint simulation is performed in two softwares.And the accuracy of each model is verified,and satisfactory results are obtained.From the data obtained,we can see that the control strategy designed in this paper has a good control effect,which can control the cabin temperature and lithium battery temperature in a relatively stable temperature range,and work under heavy load of the entire vehicle and the battery SOC.When it is lower,it can automatically limit the operating power of the air conditioning system,thereby ensuring the power of the entire vehicle.