Modelling and examination of the influence of a short-circuited rotor winding for saliency tracking of a machine with a three-phase single-tooth winding
Christoph Hittinger, Dominik Thyroff, Ingo Hahn · 2017
A resistance-or inductance-based saliency is needed as a prerequisite for signal-injection based encoder less position estimation methods. The differential quantities can be influenced by applying a short-circuited electrical winding on the rotor of an electrical machine. To optimize the position of this winding with little computational effort, a simplified model of the machine with a three-phase single-tooth winding based on the machine's voltage equations is presented. Afterwards, the most adequate simulated designs will be verified by an experimental setup. They show good agreement between simulation and measurement. Furthermore, the influence of the wire diameter and the number of turns on the accuracy of the sensorless position estimation for no-load conditions will be investigated. Finally, the influence of the test signal frequency on the feasibility of the encoder less position estimation for the different rotor coils will be examined. The results point out, that the wire diameter provides an additional degree of freedom for the performance of the sensorless position estimation based on magnetic saliency with a short-circuited electrical winding on the rotor.