Research of position sensorless control of PMSM based on high frequency signal injection

The paper introduces a sensorless control method which is called high frequency (HF) injection for salient-pole permanent magnet synchronous motor (PMSM). High frequency signal injection means to inject three phase symmetric constant amplitude voltage into the stator of PMSM. If the rotor has saliency, the current magnetic field of HF voltage signal must be influenced by the modulating function of the salient pole rotor, and then a HF carrier wave relating to the position of the rotor will appear. From these carrier wave signals, the position information of the rotor can be further extracted, and the special position of the rotor can be accordingly decided. The self-detecting process of PMSM rotor position is simulated which proves the effectiveness of this method.