Power quality improvement in bridgeless zeta converter fed switch reluctance motor drive

This paper deals with the power factor correction (PFC) based bridgeless zeta converter-fed switch reluctance motor (SRM) drive as a cost effective solution for low power applications. The presence of one diode and one semiconductor switch in current path during each switching cycle reduces the conduction losses as compared to conventional zeta converter. The speed of SRM is controlled by varying the DC-bus voltage appearing across the midpoint converter used for a 4-phase SRM. The bridgeless zeta converter working in discontinuous inductor current mode is used to control the DC output voltage and to improve the power quality at the AC mains. Total harmonic distortion (THD) at AC mains current when SRM is fed by a diode bridge rectifier is observed 70% to 80% which is brought down to <5% as per the IEEE-519 standard of power quality.