非对称半桥交错并联输出式LLC谐振DC-DC变换器设计

LLC谐振变换器由于谐振特性,能够较容易实现软开关和增大变换器功率密度,在中大功率场合得到广泛应用。为了增大功率密度提高输出容量,设计了一种非对称半桥交错并联输出式LLC谐振DC-DC变换器,对变换器的工作过程进行了分析。分析了不同k值对变换器的影响,对谐振网络进行了等效分析。不同谐振频率下变换器分布在不同的工作区域,不同的工作区域中开关MOS管实现软开关过程的难易程度不等。通过仿真和样机测试验证了设计的变换器开关管能够实现零电压开关(ZVS),能够有效减小变换器的开关损耗。

Design of Asymmetric Half Bridge Interleaved Parallel Output LLC Resonant DC-DC Converter

LLC resonant converter is widely used in medium- and high-power applications. Because of its resonant characteristics, soft switching and the increase of power density can be realized easily. To increase power density and improve output capacity, an asymmetric half bridge interleaved parallel output LLC resonant DC-DC converter is designed. The working process of the converter is analyzed. The influence of different k values on converter is analyzed, and equivalent analysis of resonant network is carried out. Under different resonant frequencies, converters are distributed in different working areas, and the accomplishment level of soft switching process of switching MOS transistor is different. Simulation and prototype test show that the converter can realize zero voltage switch (ZVS). The switching loss of converter is effectively reduced.