谐振变换器开关死区引起的直流变压器的功率损失

随着直流微电网和直流配电网的兴起，作为直流电压隔离变换的直流变压器备受关注。具有恒变压比的直流变压器通常采用高频谐振变换器和50%占空比控制，具有高效简洁的特点。本文分析了考虑开关死区情况下直流变压器的典型工作模态，推导建立了传输功率与开关死区时间的数学表达式，得到了死区将会降低直流变压器的传输功率的结论。建立了一种CLLC型谐振变换器拓扑的直流变压器的仿真模型和实验平台，结果验证了上述结论的正确性。

Power loss of DC transformer caused by switching dead zone of resonant converter

With the rise of DC microgrid and DC distribution network, DC transformer as DC voltage isolation conversion has attracted much attention. High frequency resonant converter and 50% duty cycle control strategy are usually used for DC transformer with constant voltage ratio, which has the characteristics of high efficiency and simplicity. In this paper, the typical working modes of DC transformer considering the dead time of switch are analyzed. The mathematical expressions of transmission power with switching dead time are derived. It is concluded that the dead time will reduce the transmission power and efficiency of the transformer. An experimental platform of DC transformer with CLLC resonant converter topology is established, and the experimental results verify the correctness of the above conclusions.