Initial Rotor Position Estimation of IPMSM Based on Improved Rotating High Frequency Signal Injection

Aiming at the low accuracy and the complex design procedure in the detection of the initial rotor position of permanent magnet synchronous motor with the high frequency signal injection method, an improved method is proposed. The estimated initial rotor position and the estimated error brought by the nonlinear factors such as the inverter delay, the deadtime and the sampling delay are obtained by using of the Synchronous Frame Filter (SFF) through the analysis of the current response in the alpha-beta coordinate system, and the rotor's N/S pole is determined according to the nonlinear magnetization characteristics of the stator core. Then, the influence of nonlinear factors on the initial rotor position estimation is eliminated and the estimation precision is improved. The experiment results show that the proposed method can improve the estimation accuracy of the initial rotor position.