Modeling and analysis of new zero current transition SEPIC converter

In this paper, modeling and analysis of new Zero current Transition (ZCT) SEPIC Topology is proposed. It gives reduction in the auxiliary elements current ratings, which leads to lower conduction losses and improved converter efficiency. In addition, a reduction in size of auxiliary magnetic elements can be accomplished. The converter with the proposed ZCT softswitching can operate with soft-switching for wide line and load ranges at considerably high frequencies. The operation principles, a detailed analysis and a soft switching resonant circuit design procedure of proposed zero current transition converter are presented. A 100 W, 50 kHz ZCT-SEPIC prototype circuit is built and tested. The proposed design methodology is verified both in simulation and experiments for different loading conditions. Measurement observations are in close agreement with the simulation and analytical predictions.