Sensorless operation capability of surface-mounted permanent-magnet machine based on high-frequency signal injection methods

This paper analyzes the sensorless operation capability of a surface-mounted permanent-magnet (PM) (SPM) machine based on high-frequency (HF) voltage injection techniques. To investigate the machine saliency, the magnetic saturation-induced rotor saliency by PM is experimentally measured and analyzed under various load conditions. Moreover, the influence of crosssaturation and the magnetic polarity identification are also examined. Furthermore, the investigation has considered the resistance-based saliency due to HF eddy-current loss. In order to highlight the effectiveness of the sensorless operation capability, the tests are carried out under different operating conditions.