Research On Control Method And Implementation Of Permanent Magnet Synchronous Motor For Electric Vehicle

Electric vehicles can help to solve energy shortages and environmental pollution problems,therefore motor control technology,as the one of the core technologies of electric vehicles,has become the hot research topic.In addition,because of the permanent magnet synchronous motor’s high efficiency,wide speed range,it is widely used in the field of electric vehicles.However,the control algorithm of permanent magnet synchronous motor has a large amount of calculation and requires high level processing,especially the processing speed for the micro controller.Comparing with the DSP,the FPGA can be found that the operation speed of the FPGA is faster and the real-time performance is stronger.In this thesis,the electric vehicle is taken as engineering background,and the permanent magnet synchronous motor is used as concrete object.A control system of permanent magnet synchronous motor for electric vehicle based on FPGA is designed and developed.What’s more,we make a deep research on the control method of permanent magnet synchronous motor MTPA-FW based on anti-windup PI control and the realization of software and hardware of the control system.The main research work and conclusions are as follows:Firstly,in order to meet the requirements of low speed start,climbing high torque of and high speed driving of electric vehicles,and solve the problems including the low utilization rate of reluctance torque in traditional id=0 control and the high speed overshoot and the poor anti-intetference ability in PI control,a MTPA-FW control method of permanent magnet synchronous motor based on PI speed regulator with anti-windup is proposed.It worth mention that the designed anti-windup PI Speed Regulator can effectively solve the problem of slow speed response and large overshoot under the traditional PI control.The design of maximum torque per ampere control based on iq current feedback solves the problem that the traditional high-order equation of torque-current is difficult to solve,and meets the requirements of high torque for low speed start and high torque of climbing for electric vehicles.The negative id compensation method for flux weakening control effectively enlarges the speed range of electric vehicles.The simulation results of MATLAB show that this motor can realize MTPA control at low speed and flux weakening control at high speed.And the speed can smoothly transit from constant torque region to constant power region.At the same time,the speed overshoot is small and the anti-interference ability is strong.Secondly,for the proposed MTPA-FW control method of permanent magnet synchronous motor based on PI speed regulator with anti-windup,an FPGA-based permanent magnet synchronous motor control system for electric vehicles is designed.The modular design is used to design the coordinate transformation module,SVPWM module,PI module,MTPA module and encoder module.The designed module is simulated by the Modelsim software.The simulation results show that the designed module is correct and feasible.Finally,the main circuit and peripheral circuit of permanent magnet synchronous motor control are designed and verified by experiments.After MATLAB and FPGA simulation and experimental verification,the FPGA-based permanent magnet synchronous motor control system for electric vehicles has good anti-disturbance capability and dynamic performance,wide speed range,fast response,and small overshoot.It is basically meets the driving requirements of electric vehicles on the road.