Fully soft switched and high power factor AC-DC converter

In this study, a fully soft switched and high power factor AC-DC converter is proposed. In this fully soft switched and high power factor AC-DC converter, main switch turns on with zero voltage transition (ZVT) and turns off with zero voltage switching (ZVS). The auxiliary switch turnes on and off with current switching (ZCS) and ZVS, respectively. The main diode and all of auxiliary diodes operate with SS. Furthermore most of SS energy stored in the snubber inductance is transferred effectively to the output by a transformer and so the current stress on the auxiliary switch is reduced significantly. In this converter, no semiconductor device has any additional voltage stresses and SS operating conditions are maintained at very wide line and load ranges. The performance of the proposed fully soft switched and high power factor AC-DC converter is verified experimentally with a 1 kW and 100 kHz prototype.