An improved active-clamp ZVS forward converter with a lossless snubber

Abstract

In this paper, an improved active-clamp forward converter with a lossless snubber composed of a tapped inductor, a snubber capacitor and two diodes is proposed. By adding the lossless snubber at the secondary side of the active clamp forward converter, better ZVS operation, higher efficiency and lower ripple noise of the output voltage are achieved. The operational principles and the equivalent mode analysis of the proposed topology are described. A 300W (50V 6A) prototype is designed, tested, and compared to the conventional active clamp forward converter.