Sensorless Control in Low-speed Region for Switched Reluctance Motor

Inductance-based sensorless control method for a switched reluctance motor at low speeds is presented. In this method, to determine the commutation timing, the interval from the value of the excited phase flux linkage at the commutation point to zero and the variation of the unexcited phase inductance are used. The instantaneous voltage pulse application gives the prior-excited phase inductance. Furthermore, the interval for determining commutation is extended because the commutation could fail due to position errors at low speeds. Experimental results are shown to verify the validity of proposed method.