DSP based sensorless control scheme for SRM drive

This paper describes a novel method of detecting rotor position in SRM(switched reluctance motor). The measurement scheme detects a varying phase inductance using the phase currents. A pulse voltage is applied to an unenergized phase and uses the current information to estimate inductances. The rotor position information can be obtained from the detected varying inductance. The suggested method is able to achieve position information under running in addition to starting and stand still condition. The proposed scheme is very useful for sensorless drive of SRM including starting and standstill. This scheme can be used in stable speed control scheme with a wide range of speed and load torque without a conventional encoder. Test results show the validity of the proposed scheme.