A Novel LLC Converter with a Wide Output Range in High efficiency And Lower switching Loss

This paper presents a novel LLC converter that achieves a wide output range of the voltage gain with PWM control of the auxiliary switches connected in series with configurable capacitors on the secondary side. Compared with conventional LLC converters and other LLC converters with wide output range, the proposed converter achieves to expands the voltage gain range to theoretically zero while ensuring zero-voltage switching (ZVS) for all switches and zero-current switching (ZCS) for all secondary-side diodes. The analysis of the topology, operation principle, voltage gain, and soft-switching characteristics have been discussed. Finally, a prototype with a 50V input and 0-100V output is simulated and the results demonstrate that the converter achieves an ultrahigh efficiency of over 96.6% under a 300W load, along with excellent dynamic response during voltage transitions. And the converter also shows lower switching loss than other LLC converters.