Research On Phase Shift Full Bridge Converter With Two Transformers

With the rapid development of science and technology today, a growing number of DC/DC converter is used in all walks of life. And along with increasingly tense energy crisis, the demands on DC/DC converter’s efficiency, volume and cost are higher and higher. For this reason, choosing a more suitable topology to meet the requirements is more necessary. Based on the practical engineering background, a novel full bridge topology with two transformers is proposed in this paper. The application of phase shift control technology in such topology is researched.First, the common DC/DC topologies and the DC/DC topologies with two transformers are introduced in this paper, then the research subjects is presented. Second, this novel full bridge converter is analyzed in detail. The soft switching conditions of leading and lagging legs under different load are analyzed in this paper. Based on research of the rectifier diode process of the inversion and the duty ratio loss, the results of the theoretical analysis through simulation verification by PSIM are verified. Then, the designing parameters of high frequency transformer and the control circuits is analyzed in this paper.At last, based on the former theoretical analysis and designing, two experimental prototypes with different rectifier methods have been designed based on analog controller of UCC3895, and the debugging has been completed. The experimental results proves that the performance of two experimental prototypes with different rectifier methods has reached the designing requirement. The soft switching operation of leading and lagging legs can be achieved.