Robust position sensorless control of switched reluctance motor drives over the entire speed range

Position sensorless technology in switched reluctance motor (SRM) drives is of prime interest in many applications. Needs for enhanced reliability as well as reduction in cost and hardware are among factors justifying this renewed attention. Development of sensorless techniques with adequate resolution over the entire speed range, however, is challenged by excessive changes in the motor dynamics. This, in turn, calls for a resilient sensorless technique that identifies the proper dynamics and adapts itself accordingly. The present paper introduces this outstanding problem in much detail and offers a solution. By incorporating a detection technique, the operating region of the drive is identified. Once a change in operating region occurs, the most appropriate version of our sensorless methods will be invoked. This removes the shortcoming of low resolution, poor performance, and limited range in sensorless SRM technology. Theoretical and experimental results are presented to support our claims.