Bridgeless Single-Ended Primary Inductance Converter with Improved Power Quality for Welding Power Supplies

This paper presents a new single-phase, single-stage bridgeless SEPIC (Single-Ended Primary Inductance Converter) based arc welding power supply operating at unity PF (Power Factor). The proposed converter provides an approach of implementing a simple AWPS (Arc Welding Power Supply) with an additional feature of long term short circuit capability. By eliminating input DBR (Diode Bridge Rectifier), the number of conducting components is reduced thereby lowering the conduction losses and increasing the overall efficiency. Simple structure, electrical isolation and simple control circuitry are the other advantages of the proposed AWPS. Bridgeless SEPIC based AWPS designed in DCM (Discontinuous Conduction Mode), provides inherent power factor correction. Dynamic and steady state performances are presented for a 3 kW, 25 V AWPS.