Research On PMSM Control System For Electric Vehicle

With the Deterioration of the world energy crisis and environmental pollution,electric vehicles have attracted wide attention.because of it's characteristics of zero exhaust emission,low energy consumption and high energy efficiency.In the driving process of electric vehicles,the battery energy of electric vehicles is limited,the driving conditions are complex and full of uncertainties,so the requirement of driving motor's performance is very high.because of its high power density and high efficiency,PMSM has become the main drive motor of electric vehicle.But the motor driving system is a complex,highly coupling,nonlinear,and time-varying system,which brings a lot of difficulties for the precise control of electric motor,so the research of advanced motor driving method is the key to improve the control performance of electric vehicle.Firstly,in this paper,the model of EV drive system is established,which includes the dynamic model of electric vehicle and the mathematical model of PMSM,which lays the groundwork for the design of the controller behind.Secondly,considering the complex and changeable situation in the actual driving process of electric vehicle,adopting the traditional double-closed loop PID control drive motor will lead to the low speed tracking accuracy,weak anti-jamming ability and so on.An adaptive backstepping sliding mode control strategy based on load observer is proposed in this paper.The new strategy combining backstepping control with non-singular terminal sliding mode control has increased the accuracy,rapidity and robustness of the system.Furthermore,the speed and torque requirement of electric vehicle are satisfied,and the driving performance is improved.In this paper,a sliding mode load observer is designed for the frequent changes of road load in the driving process of an electric vehicle.The torque of the load is accurately observed,and be dynamically compensated to the controller,which enhanced the electric vehicles' ability to adapt to changes in road conditions.For the other unknown disturbances of the system,the adaptive method is used to estimate it's upper bound and the stability of the system is proved.Finally,the new controller model is built with MATLAB/Simulink,and be added to the vehicle dynamics model,then the electric vehicle mode is tested by the standard cycle condition to testify the validity of the controller designed in this paper.