Zero-voltage-switching (ZVS) has been widely applied in widebandgap devices based on high-switching-frequency converters, for instance, dual-active-bridge isolated dc–dc converter, which consists of two H-bridges. To secure ZVS for all eight switches, previous literature mostly focuses on half-bridge to analyze switching transitions, which, however, is rather incomplete due to ignoring the impact of modulation strategies and cannot fulfill all circumstances. In this letter, the whole H-bridge is used as a unit to analyze the ZVS transient process, addressing the ZVS setting in different modulation strategies. The minimal initial inductor energy to complete the ZVS process is also quantified, which in return can reduce the transformer current, thereby enhancing the efficiency. Furthermore, the accurate ZVS transition time is derived incorporating with the nonlinearity of switch output capacitance, which can be further used to set the dead-band time. An H-bridge prototype with SiC devices is built up to verify the theory proposed in this letter.

中文翻译：

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双有源桥中的完整 ZVS 分析

零电压开关 (ZVS) 已广泛应用于基于高开关频率转换器的宽带隙器件，例如由两个 H 桥组成的双有源桥隔离 dc-dc 转换器。为了确保所有八个开关的 ZVS，以前的文献主要侧重于半桥来分析开关转换，然而，由于忽略了调制策略的影响，并且不能满足所有情况，因此这是相当不完整的。在这封信中，以整个 H 桥为一个单元来分析 ZVS 瞬态过程，解决不同调制策略中的 ZVS 设置。完成 ZVS 过程的最小初始电感能量也被量化，这反过来可以降低变压器电流，从而提高效率。此外，结合开关输出电容的非线性，推导出准确的 ZVS 转换时间，可进一步用于设置死区时间。构建了带有 SiC 器件的 H 桥原型，以验证这封信中提出的理论。