A precise method to estimate the initial rotor position of IPMSM

A precise method to estimate the initial rotor position of Interior Permanent Magnet Synchronous Motor (IPMSM) is proposed in this paper. In order to improve the accuracy of estimation, a modified model of IPMSM considering saturation is established. A high frequency rotating voltage is imposed on the stator of the motor; the current responses of the motor are analysed in the DSP controller and the accuracy of the rotor position information is obtained with simple polarity detection. Simulations and experiments are done to verify the correctness of the proposed IPMSM model. And also experimental results for a 40-kw IPMSM system demonstrate the feasibility of the proposed method.