Investigating Pole Assignment of Full-Order Observer Based on Extended Electromotive Force for Position Sensorless Control of IPMSMs

Several position sensorless control methods of interior permanent magnet synchronous motors (IPMSMs) using observers have been proposed. In the case of full-order observers, these designs are difficult because the order of the error equations of observers becomes an order of four. In this paper, to realize the position sensorless control of IPMSMs, a design method for full-order observers based on the extended electromotive force (EEMF) is proposed, and the pole assignment of the proposed observer is studied. Experimental results of the position sensorless control of an IPMSM show the usefulness of this proposed design method for the full-order observer compared to the case where poles are merely assigned on the left half plane.