Reduced Saliency PMSM V/f Sensorless Control with Initial Rotor Position Estimation

An initial rotor position estimation method without any position sensor for reduced saliency PMSM is presented. The algorithm is used in combination with a stabilized scalar control. An oscillating high-frequency voltage signal is injected at standstill to estimate the magnet pole position and after that voltage pulses are injected in the corresponding direction in order to detect the rotor polarity. Experimental results have shown the validity of the algorithm for a commercial reduced saliency motor.