A simplified variable speed switched reluctance motor drive without using encoder

The switched reluctance motor (SRM) and drive system is a candidate in various applications including the home appliance. The simple and low cost system with an adequate performance is also one topic to be developed. A speed sensor directly increases the cost and it directly influences the reliability of the system. This paper proposes a simplified variable speed control system for the SRM without using an encoder. The method is not based on the exact rotor position estimation, only the turn off angle is determined from the simple relation between measured terminal voltage and current. The effectiveness of the proposed method is verified by the experimental result on the 3 kW 3-phase 6-stator-pole and 4-rotor-pole SRM.