Flux weakening control of IPMSM used for xEV traction

This paper analyzes the practical operation limits of an IPMSM and proposes a speed control strategy which is suitable for real engineering implementation. Given a specific IPMSM which is used for low-speed EV traction, operation limits are pre-calculated according to motor parameters. Subsequently, a speed control strategy is implemented. Both speed and torque are used to find out d/q-axis current reference. Maximum torque per ampere (MTPA) control is used below base speed, and flux-weakening control is used for the operation above base speed. Test results are shown and analyzed to prove the effectiveness of the proposed control method.