Investigation of possibilities to increasing efficiency of full bridge converter designed for low output voltage and high output current applications

Abstract

The paper deals with research of the ways of efficiency increase of proposed hard switching full bridge converter which is suited for electroplating. The main circuit is designed as standard full bridge converter with IGBT transistors, whose switching frequency is 17 kHz. Main attention of optimization of power stage is focused on configuration of output, secondary side rectifier, which is designed in double center tapped configuration providing therefore current doubling of output current. Various types have been investigated, including diode Schottky rectifier, synchronous MOSFET rectifier together with additional auxiliary and snubber circuits and its combinations. Each solution has been experimentally verified for various and most probable operating conditions of proposed converter, whereby results have been consequently compared. Several results show, that efficiency is able to be increased when proper optimization steps are being utilized.