Power Factor Correction in Isolated SEPIC Converter Fed SRM Drive

The design and implementation of high power factor based isolated SEPIC (Single Ended Primary Inductance Converter) fed switched reluctance motor (SRM) drive is presented here. The input current shaping is achieved by operating SEPIC converter in discontinuous conduction mode (DCM). The selected DCM has resulted in the reduction of size and cost of magnetic structure considerably. The, high frequency transformer provides input-output isolation in the system. The variable speed operation of the proposed drive is based upon DC link voltage control, which is obtained by modulating pulse width of the SEPIC converter. The converter is featured with almost unity power factor operation over a wide output voltage range. Experimental results of a prototype of isolated SEPIC converter fed SRM drive is demonstrated in the paper. The input mains current THD is reduced below 5% to comply with the given regulation for harmonics, such as IEC 61000-3-2.