An Improved High Power Factor-Soft Switched AC-DC Converter

In this study, an improved high power factor AC-DC converter with soft switching is proposed. In this high power factor-soft switched (HPF-SS) converter, main switch is turned on with zero voltage transition (ZVT) and turned off with zero voltage switching (ZVS). The auxiliary switch is turned on with zero current switching (ZCS) and turned off with ZVS. The main diode and all of auxiliary diodes are operating with SS. Also, in this converter, most of SS energy stored in the snubber inductance is transferred effectively to the output by a transformer, and so the current stress of the auxiliary switch is reduced significantly. In this converter, no semiconductor device has any additional voltage stress and SS operating conditions are maintained at very wide line and load ranges. The performance of proposed HPF-SS AC-DC converter is verified experimentally by a 1 kW and 100 kHz prototype, operating with universal line range. Copyright (c) 2012 Praise Worthy Prize S.r.l. - All rights reserved