Research On Themal Management Strategy For Powertrain Of Electric Vehicle

The automobile industry is an important pillar industry in China,and the main challenges are from the dual problems of energy and environment.Therefore,vigorously developing pure electric vehicles has become an important strategy for the development of China's automobile industry.The thermal management system of the pure electric vehicle is to keep the temperature of the powertrain system within the allowable range,which can not only prevent the service life of the power battery,the driving motor and the electric motor controller from being shortened due to the high temperature,but also make the driving motor run in the high-efficiency range to improve the driving range of the vehicle.In this paper,pure electric vehicles power always becomes the research object,through the design of split type cooling system,on the premise of meet the demand of thermal management systems and control,to powertrain thermal management system of the lowest energy consumption as the goal,the cooling system of the control method of model predictive controller was designed,and with it the switch type control,PID control,control method of thermal management system,under the same conditions were analyzed,for the pure electric vehicle thermal management system of engineering design to provide certain guiding significance.The main contents of this paper are as follows:(1)The heat generation and heat dissipation models of pure electric vehicle power battery,driving motor and motor controller are established respectively,and the influence of driving motor operating condition and temperature on the heat generation of motor and motor controller and the influence of discharge current and temperature on the heat generation of battery are analyzed.(2)The cooling system of powertrain of pure electric vehicle is designed and an experimental bench is built.This paper analyzes the motor and motor controller,the cooling system mode and scheme design of power battery,and completes the selection and parameter matching of each part of the cooling system.(3)The experimental scheme of powertrain cooling system was developed to measure the heat generation power of driving motor and motor controller under different working conditions,and to record the parameters of power battery cooling system when discharging.(4)Based on the built test bench,the driving motor model base,hydraulic component model base,thermodynamic model base and electrical component model base in AMEsim software were used to build the cooling system model of pure electric vehicle powertrain.The parameters of each model in the cooling system were matched and the model was verified.(5)Based on simulink software has set up a state space model for the cooling system,cooling system to the overall power consumption at least as the goal,to study the control method of the cooling system,designs the multiple input multiple output model predictive controller,the cooling system of thermal power production as the disturbance quantity,electronic pump flow,electronic fan air volume for operation,and has carried on the joint simulation AMEsim software,and the simulation results compared with PID control,switch control analysis.