Isolated Zero-Voltage-Switching Sepic Converter

An isolated zero-voltage-switching (ZVS) single-ended primary inductor converter (SEPIC) is presented in this paper. An active clamp circuit is added to the conventional isolated SEPIC converter to provide ZVS operation. A coupled inductor and an auxiliary capacitor are utilized to obtain the ripple-free input current. Moreover, the reverse-recovery problem of the output diode is alleviated due to the leakage inductance of the transformer. The major advantages of this converter besides step up/down capability and an electrical isolation are the ripple-free input current and soft-switching commutations of the power semiconductor devices. The operation principle and steady-state analysis of the proposed converter are provided in detail. A prototype of the proposed converter is developed, and its experimental results are presented for validation. Copyright (C) 2011 Praise Worthy Prize S.r.l. - All rights reserved.