Comparison of active clamping circuits for isolated forward converter

Abstract

The single-ended forward converter is a buck derived Isolated DC-DC Converter. Forward converter is most suitable for low voltage and high current applications microprocessors, battery chargers, EHV etc. The active clamp transformer reset technique offers many advantages over conventional single-ended reset techniques, including lower voltage stress on the main switch, the ability to switch at zero voltage and duty cycle operation above 50 percent. Several journals have compared the functional merits of the active clamp over the more extensively used RCD clamp, third winding and resonant reset techniques. This paper presents how to effectively to apply various active clamp circuits like positive clamp, negative clamp or combination of both positive and negative clamp for most favorable circuit performance. This paper summarizes a comparative analysis on various active clamping circuits for forward converter.