Initial rotor position detection is vital to ensure the starting process of static frequency converter (SFC), which is used for the control of synchronous motor in pumped storage power station. This paper has proposed a novel method based on rotating high frequency signal injecting into estimated synchronous reference frame (SynRF). With the improved demodulation method, it is easy to extract rotor position and is immune from delays caused by digital control, resistance, filters and other nonlinear factors. Furthermore, the magnetic polarity is proposed based on magnetic saturation effect, without extra signal injection and is of high signal-to-noise ratio (SNR). Finally, the experimental results have proved the validity and practicability of the proposed method.

Synchronous motor, initial rotor position, control system, high frequency signal injection