Study Of Shift-phase Full-bridge ZVS Converters

This thesis focuses on the research of phase-shift full bridgezero-voltage-switching converter and its parallel current-sharing technology.The detailed analysis of the soft-switching, single-loop voltage control, parallelcurrent-sharing technique, and the related problems of the PS-FB-ZVS converterare proposed in the this paper, the result of simulations and experiments are alsoprovided.The PS-FB-ZVS converter is widely used in the case of medium or highpower levels, and it’s a hotspot of power electronic. The two arms of theconverter all work at zero-voltage switching (ZVS) condition, thus manyadvantages are brought, for example, little loss of power, simple structure, etc.But there also exists some problems, such as inherent duty cycle loss，theparasitic oscillation and voltage spike on the output rectifier diodes. In this paper,the reasons of these problems are analyzed, and the solutions are presented.There is also a brief introduction of the topology of ZVZCS.In this paper, a ZVS converter topology is proposed which adopts clampingdiodes in the former side of transformer, thus the parasitic oscillation iseliminated. The operation principle of the converter is described and the methodof component parameter design is presented.The experimental results from a prototype converter include two5.5kWmodule indicate that: main circuit’s parameter is right and ZVS is achievedcorrectly; the parasitic oscillation on the output rectifier diodes is almosteliminated; the control system works properly; current-sharing work well on twomodule. Thus the correctness and availability of the whole design is validated.