Abstract
Salient-pole permanent magnet synchronous motors have been widely used in industrial applications for their high efficiency. To control these motors, knowledge of rotor position and velocity are necessary and expensive sensors have been used to detect these signals. Although many sensorless control algorithms have been developed for cylindrical permanent magnet motors, they cannot be applied for salient-pole machines without any approximation because of the complicated mathematical model, and this may lead to unstable problems. To solve this problem, new extended electromotive force models for synchronous motors have been proposed in this paper. The proposed models have a simple structure integrating position information both in the magnet and in the inductance into one extended electromotive force term. Using these models, no approximation is necessary. Experimental results show that the proposed model and method are valid.
