A GENERAL DESCRIPTION OF HIGH-FREQUENCY POSITION ESTIMATORS FOR INTERIOR PERMANENT-MAGNET SYNCHRONOUS MOTORS

This paper discusses fundamental equations used in high-frequency signal based interior permanent-magnet synchronous motor (IPMSM) position estimators. For this purpose, an IPMSM model is presented that takes into account the nonlinear magnetic condition, the magnetic interaction between the two orthogonal magnetic axes and the multiple saliencies. Using the novel equations, some recently proposed motion-state estimators are described. Simulation results reveal the position estimation error caused by estimators that neglect the presence of multiple saliencies or that consider the magnetizing current in the d-axis only.