A Concept of Accelerating the Demagnetization of Switched Reluctance Motor

Abstract

The demagnetization of switched reluctance motor (SRM) is usually a nonnegligible problem as the speed increases due to large back electromotive force (EMF). A slow demagnetization causes long tail current and negative torque, which reduces the efficiency and the output capability of SRM. In the conventional SRM design method, the inductance slope is normally designed to be high. However, it causes the problems of slow demagnetization in the negative torque region and low utilization efficiency of the torque-generative region. This article proposed a totally contrary way of SRM design, a small value of the inductance slope is chosen. Therefore, the effect of the back EMF can be diminished and the demagnetization is improved. The utilization of the torque-generative region is also improved due to the delayed turn-off angle. Simulation results are provided to verify the advantages of the proposed idea compared with the conventional one.