Dynamic torque response analysis of IPMSM in flux weakening region for HEV applications

An over-modulation based vector control strategy for interior permanent magnet synchronous machine (IPMSM) is proposed and investigated. The strategy increases the reference flux weakening voltage to improve efficiency in flux weakening region of IPMSM with the same dynamic torque response performance in standard SVM technique. The relationship between dynamic torque performance and the reference flux weakening voltage is also discussed. In order to achieve fast and smooth shift process, the torque response must be less than 20 ms in the parallel hybrid electric vehicle (HEV), according to this, modeling and experimental studies were carried out. The results show that the proposed strategy can achieve the same dynamic and steady state torque performance with higher reference flux weakening voltage, which means higher efficiency.