Economic operating characteristics of permanent magnet synchronous motor in electric vehicle

Permanent magnet synchronous motor (PMSM) is of high efficiency and high torque density. The field oriented control (FOC) is usually used in the motor and the maximum efficiency control can be achieved. In electric vehicle (EV) application, the PMSM efficiency model, combining with the EV and road load system, is used to study the optimal energy-saving control strategy, which is significant for the economic operation of EV. With the help of GPS,IMU and other information technology, the road conditions can be measured. For simple road conditions, the economic operating points of PMSM can be obtained through the efficiency model of PMSM and the vehicle dynamic model of EV. For complex road conditions, considering the dynamic characteristics, the economic operating trajectory of PMSM can be obtained through dynamic programming (DP) algorithm. Simulation and experiment results show that the optimum mileage and global energy optimization can be achieved when the PMSM operates in the economic operation area.