A sensorless speed estimation method for wound rotor induction machine

In this paper, the authors investigate the possibility of achieving sensorless speed detection in a wound rotor induction machine. The proposed method is based on tracking the frequency of identified slip-dependent stator current spectral components in a well defined spectral bandwidth. No knowledge of machine slotting is necessary for estimating the current spectral frequencies that carry information on rotational speed. The proposed method feasibility is tested by post-processing the simulated and measured transient stator current data for a range of different operating conditions.