Initial Rotor Position Detection Based on Peak Dc-Link Current Comparison for SPMSM

Initial rotor position detection is important for the control of PMSM (Permanent Magnet Synchronous Motor) in rail transit. One method is proposed to detect initial rotor position at standstill based on peak dc-link current comparison in this paper. Initial rotor position detection with resolution of 30° is achieved by injecting four pulse voltages into the motor windings. This method is suitable for the application that rotor keeps at standstill during the starting process. One SPMSM is used to validate the proposed method.