A simple position-sensorless algorithm for rotor-side field-oriented control of wound-rotor induction machine

A simple position-sensorless method for the rotor-side field-oriented control of a wound-rotor induction machine is described in this paper. The algorithm is based on axis transformations. Compared to the previously proposed methods, it is more direct and the dependence on machine parameters is also largely reduced. The algorithm can be started on the fly without the knowledge of the initial rotor position. Operation at synchronous speed, corresponding to zero rotor frequency, is stable, thus making it suitable for variable speed constant frequency operations. Simulation and experimental results show excellent performance of the scheme.