The dual-active-bridge (DAB) converter is widely used in many applications. When the port voltages are not matched, the switches of the converter are hard to realize zero-voltage switching (ZVS). By introducing different dc voltage offsets across the blocking capacitors, this article proposes a hybrid modulation technique, which makes the converter switch between different working modes to enlarge the ZVS region according to specific operating conditions. In this article, the soft switching regions of different working modes are derived mathematically, and the switching boundary of the hybrid modulation is determined graphically. Finally, the experimental results verify the validity of the proposed strategy.

中文翻译：

---

使用阻塞电容器的DAB转换器的ZVS范围增强策略

双有源桥（DAB）转换器广泛用于许多应用中。当端口电压不匹配时，转换器的开关很难实现零电压开关（ZVS）。通过在跨接电容器两端引入不同的直流电压偏移，本文提出了一种混合调制技术，该技术可使转换器在不同的工作模式之间切换，以根据特定的工作条件扩大ZVS区域。本文通过数学推导了不同工作模式下的软开关区域，并以图形方式确定了混合调制的开关边界。最后，实验结果验证了所提策略的有效性。