高频谐振型直流变压器模块设计与研究

Design and Research of High-frequency Resonant DC-transformer Module

此处针对电力电子变压器(PET)中核心直流变换环节,提出了使用LLC串联谐振变换器作为高压大功率的高频谐振型直流变压器的基本模块,并详细分析了各项设计原则,以实现高功率密度条件下高效稳定地直流功率变换。分析了该高频谐振型直流变压器工作原理及稳态增益的频谱特性。通过简化等效电路推导出了该直流变压器谐振轨迹特性,以指导谐振电容的设计。详细分析和推导了高频变压器的磁芯损耗和绕组损耗及变换器开关损耗的计算方法,并研究了影响直流变压器模块效率的各项因素。最后,研制了一台实验型高频谐振型直流变压器,通过实验结果验证了大功率高频谐振型直流变压器模块设计理论的可行性与正确性。

This paper introduces the LLC resonant converter module for power electronic transformer （PET） applicati- ons and analyzes its design principles ,which can supply high-frequency electric isolation and power conversion efficiently. With the high-frequency operation, the module has the high power density by reducing the volume of core and winding.The operating modes are analyzed, which can explain the operating principle and features of LLC DC- transformer, and the gains of the resonant DC-transformer are described based on frequencies and load characteristics. Then the resonant trajectory of the resonant DC-transformer is discribed based on the simplified equivalent circuit.The calculation method of the winding loss and core loss of high-frequency transformer and the effect of physical factors are given.Finally, an experimental resonant DC-transformer is constructed, the physical features of this DC-transformer based on the tested results under different load conditions is described and analyzed.As the conclusion ,the method of designing a high power and frequency resonant DC-transformer is verified by the experiment.