Fast Demagnetization and Vibration Reduction in Switched Reluctance Motor Drive System

In this paper, a Switched Reluctance Motor (SRM) drive system is proposed to make a trade-off between torque profile and vibration amplitude. In the proposed drive system, the power factor correction and fast demagnetization are achieved using a single-phase Vienna rectifier as a front-end converter for SRMs with a nominal voltage equal to half DC-link voltage. The three-level Vienna rectifier provides doubled negative voltage in demagnetization, resulting in a shorter current tail and faster demagnetization. But, applying higher voltage in demagnetization has a negative impact on the vibration amplitude at the point of demagnetization. Therefore, a control algorithm is designed to apply a negative modulated voltage to the motor phase, with a minimum change rate at the beginning of demagnetization and a linear average during the demagnetization interval. Accordingly, the mitigation of the vibration occurring at the commutation point and prevention of negative torque are simultaneously achieved over a wide speed range. The simulation and experimental results demonstrate the proposed drive system's positive effect on the vibration amplitude, grid side current quality, and SRM performance in a wide range of speed variations.