Compensation of position estimation error for precise position-sensorless control of IPMSM based on high-frequency pulsating voltage injection

This paper proposes a compensation method for precise position-sensorless control using high-frequency pulsating voltage injection and the criterion for applicability of the proposed compensation method is discussed. Theoretical background of the proposed 3-dimensional compensation table as well as the implementation method is described and it is disclosed that the real rotor position and the convergent position should have one-to-one relationship for precise estimation of the rotor position. Also, in the proposed method, additional compensation for inductance harmonics or voltage distortion is not needed, since they are all reflected in the pre-commissioned table. Experimental results including speed and position control validate the proposed compensation method maintaining the position error within ±2°E at all load conditions and rotor positions.