Experimental Verification of Position Sensorless Control of SynRMs based on Magnetic Saturation depending on Current Phase Angles

This paper presents a new rotor position sensorless control method based on information of magnetic saturation for synchronous machines such as PMSMs and SynRMs. In general, magnetic saturation causes performance deterioration and an unstableness of sensorless control in the worst case, because magnetic saturation leads to the disappearance of magnetic saliency and a reversal between the estimated d- and q- axes. Furthermore, heavy magnetic saturation largely rotates saliency position in the direction of the current vector and thus destabilizes the sensorless control. The proposed method achieves stable sensorless control in extensive heavy load states by using information of magnetic saturation. In consequence, the proposed method doubles the torque range for sensorless control of the test SynRM, and achieves stable position sensorless control in all torque ranges.