Switched capacitor converter fed SRM drive with power factor correction

Abstract

In this paper, a switched capacitor (SC) buck boost converter is proposed as a front end converter for power factor correction at AC mains in switched reluctance motor (SRM) drive. Aiming at low power household applications, SRM is demonstrated as one of the fine selection because of its simple construction and winding free rotor. On the selection part, a buck boost converter serves the best results when controlled output voltage is required over wide speed range of SRM drive. The speed of SRM is controlled by varying the DC-bus voltage appearing across the midpoint converter which is used to drive 4-phase SRM. The proposed converter working in discontinuous inductor current mode is used to regulate the DC output voltage and improves the power quality at the AC mains. Total harmonic distortion (THD) of input current at AC mains when SRM is fed by a diode bridge rectifier is observed of the order of 70% to 80% which violates standards for power quality, which is brought down below 5% to meet an IEEE-519 standard.