Design And Implementation Of A 70kW PMSM Control Platform For Electric Vehicle

Electric vehicle is becoming more and more popular for its low pollution, low noise and good acceleration performance, and all these benefits are brought by the electric propulsion system. The permanent magnet synchronous motor(PMSM) is widely used in the electric propulsion system for its high efficiency, high power density and high starting torque.This dissertation intends to study the methods to enhance the performance of the electric propulsion system based on PMSM by theory and practice.1. The mathematical model of PMSM is introduced in this paper. Based on the model, the effects of the PI controller parameters are analyzed and demonstrated with simulation.2. Two kinds of speed regulators: IP controller and PI controller are compared in the paper and the experimental results prove that the IP controller can suppress the speed overshoot. The resonant controller is introduced to suppress the speed ripple and verified effective by simulation.3. The field-weakening control principal is discussed and the speed region is classified into three parts, and the control strategy varies in these parts. The experimental results show that the torque and speed region of PMSM can be greatly increased by field-weakening control.4. The initial rotor position estimation theory based on high frequency signal injection is introduced. Based on the theory, a modified initial rotor position detection method is proposed, the experiment is carried out and the proposed method performs well on the platform.5. The hardware and software of the experimental platform is introduced in detail.