Research on the Effective Range of Auxiliary Resonant Networks Employed in ZVS-Full Bridge Converter with Phase-Shift Control

It is usually considered that if the ZVS performance of phase-shift (PS) ZVS full-bridge (FB) converter can be achieved with the help of auxiliary circuits at light load, then the ZVS performance can be achieved naturally at heavy load. However under certain circumstance, the drain to source capacitor will be recharged during the commutating period. Therefore, the ZVS performance of lagging leg may not be achieved. The principle of this abnormal phenomenon is analyzed in this paper and some important restriction equations as well as an optimal design process are presented. Experimental results are given to verify the theoretical analysis