Sensorless operation of SRM drives: R & D status

Sensorless operation is very crucial to the successful commercial entrance of a majority of SRM drives. A large number of sensorless (both current and rotor position) control schemes have been under development over a period of 16 years. It is timely to classify and summarize the industrially important schemes among them for future research, development and applications. Such an attempt is made in this paper.