Position Sensorless Control of a Ferrite Magnet assisted Synchronous Reluctance Machine in the Whole Speed Range

Abstract

In this paper the position sensorless control of a ferrite magnet assisted synchronous reluctance machine is discussed and its performance is analyzed. Depending on the speed, different methods are used for this purpose. In the low-speed range including standstill the INFORM method is recommended. It is based on the magnetic anisotropy of the rotor, which makes it ideal for use on reluctance machines. At higher speeds two different EMF based position sensorless methods are recommended. The first method is the integrating Back-EMF model, which determines the flux linkage by integrating the induced voltage in order to estimate the rotor position. The second method, the so called short-circuit method, directly uses the current slopes to determine the rotor position and therefore provides higher control dynamics compared to the integrating Back-EMF method.