ABSTRACT: This paper presents a current-fed full-bridge boost dc/ac/dc converter with transformer isolation operating without switching power dissipation. The output voltage is regulated by dc/ac converter control frequency changes with a constant turn-off time of transistors. The proposed converter is devoid of parasitic oscillations, as all of the parasitic capacitances and inductances are included in a resonant tank circuit. The main advantage of such systems is that they include a capacitive output filter, which is preferred in higher voltage applications. Moreover, it achieves ZCS for all active switches and zero-voltage switching (ZVS) operation for all diodes on high voltage side, which is an additional benefit. In this paper, the system operation is first explained, and the simulation results for optimal mode of operation and sub-optimal mode of operation are presented.

Keyword: Bridge, current-fed, dc/ac/dc converter, resonant.