A Pulse-Injection-Based Sensorless Position Estimation Method for a Switched Reluctance Machine Over a Wide Speed Range

In this paper, a pulse-injection-based method for determining the rotor position of a switched reluctance motor (SRM) over its entire speed range is presented. In this method, a single high-frequency pulse is injected in an idle phase to determine the rotor position at high speeds. The proposed method estimates the rotor position through analysis of the resultant current after voltage pulse injection. A low-speed sensorless method previously developed based on pulse injection has also been extended to improve robustness against varying operating conditions. The developed pulse injection with varying duty ratios provided uniform sensing thresholds over varying dc bus voltages. The low- and high-speed methods are integrated together to provide a robust wide-speed-range rotor position estimator for SRM.