For applications with hold-up time requirements, the LCLC converter can achieve a wider voltage gain range than the LLC converter without degrading the normal operation efficiency due to its variable-magnetizing-inductor (VML) structure, which is formed by an inductor and an additional capacitor. However, the wide gain range achieved by the VML is at the expense of a high resonant voltage stress of the VML’s capacitor, which affects the converter volume/cost. Hence, to solve the contradiction between wide gain range and low capacitor voltage stress when the VML technique is adopted for hold-up operation, this paper proposes a novel C-LLC-LL converter. Specifically, the VML is arranged into a novel C-dual-LL structure. By relying on the unique output voltages relation between C-dual-LL’s two branches, the reduced voltage stress of the VML’s capacitor and the expanded voltage gain range can be simultaneously realized. To evaluate the feasibility of the proposed solution, a comprehensive analysis is conducted, and experimental results obtained from a 500-W C-LLC-LL prototype are also provided.

对于有保持时间要求的应用，LCLC 转换器可以实现比 LLC 转换器更宽的电压增益范围，而不会降低正常工作效率，因为它的可变磁化电感 (VML) 结构由一个电感器和一个附加电容器。然而，VML 实现的宽增益范围是以 VML 电容器的高谐振电压应力为代价的，这会影响转换器的体积/成本。因此，为了解决采用 VML 技术进行保持操作时宽增益范围和低电容器电压应力之间的矛盾，本文提出了一种新型 C-LLC-LL 转换器。具体来说，VML 被安排成一种新颖的 C-dual-LL 结构。依靠C-dual-LL的两个支路之间独特的输出电压关系，可以同时实现降低VML电容的电压应力和扩大电压增益范围。为了评估所提出的解决方案的可行性，进行了综合分析，并提供了从 500-W C-LLC-LL 原型获得的实验结果。