Real-time sensorless speed estimation in wound rotor induction machines using a dichotomous search algorithm

This paper investigates the development and realtime implementation of a dichotomous search algorithm based sensorless speed estimation technique in wound rotor induction machines. To this end the authors present the description of the structure and implementation of the technique proposed to extract the desired slip dependent frequency and hence the rotor speed information from the machine stator current spectrum. The performance of the presented algorithm in delivering estimation rate and accuracy improvements is then assessed and validated in real-time speed estimation tests undertaken on a 7.5 kW induction generator operating in the nominal and extended slip range.