A Novel Method of Initial Rotor Position Estimation for Surface Mounted Permanent Magnet Synchronous Motor

The initial rotor position estimation for a surface mounted permanent magnet synchronous motor(SPMSM) is an essential part of the SPMSM sensorless control system. Its accuracy directly determines whether the motor could be stated-up successfully. In this regard, a novel method is proposed. Using fluctuating high frequency injection, the estimated angle can be gotten through closed-loop regulation. Based on the characteristics of time constant belonging to the direct-axis equivalent circuit, polarity determination can be achieved. The simulation investigation and experimental results show that the method is correct.