An interleaved PFC converter based welding power supply with improved power quality

Abstract

A power factor corrected switched mode power supply (SMPS) using interleaved boost converter is presented for arc welding applications. Reductions in input current ripple, electromagnetic interference, conduction losses, diode current stress and input inductor volume are among the many advantages offered by interleaved operation of boost converter. Nearly unity input power factor with low total harmonic distortion in supply current is attained by using an interleaved boost converter at the front end of SMPS. The second stage comprising of three full bridge converters connected in parallel perform dc-dc conversion with high-frequency isolation. The modularity of entire structure allows flexibility in current, voltage and power levels, using the same range of components and ease of maintenance. Independent control loops are used to optimize the operation of the power supply. Double-loop control scheme is used to attain a regulated DC output voltage and overcurrent protection. Theoretical analysis of both the converters is presented and performance of proposed arc welding power supply (AWPS) is verified through experimental results obtained on laboratory prototype. Test results confirm the effectiveness of proposed AWPS in maintaining excellent power quality at utility interface point over a wide load range while over-current handling capability leads to improved welding performance and weld bead quality.