Power factor corrected bridgeless modular zeta converter based SMPS

Abstract

This paper proposes a three-phase single stage power factor corrected (PFC) bridgeless modular zeta converter based switched mode power supply (SMPS) suited for welding applications demanding high current and low voltage at the output. Typically, for high-power welding applications, modular arrangement of converters is suggested to reduce the device rating and provide ease of power expandability as well as maintenance. To minimise the conduction losses, a diode bridge rectifier and power factor (PF) correction circuit are merged to form a bridgeless AC-DC converter. The proposed converter is operating in discontinuous inductor current mode (DICM) for innate PF correction at the utility interface. The converter offers an excellent input PF, low input current total harmonic distortion (THD), regulated DC voltage and also restricts the output current during extreme overload conditions. The operation of the proposed converter is elucidated in detail and its steady state as well as dynamic behaviour are examined over a wide range of load to validate the efficacy of the proposed SMPS for arc welding applications.