移相H桥变换器的一种新型软开关拓扑

摘要

针对目前软开关变换器拓扑结构复杂、损耗较大的问题，提出移相H桥变换器的一种新型软开关拓扑，基于原有的逆变变压器和整流、滤波元件，增设一种无源辅助箝位电路，拓扑结构简单易行，无需有源器件和附加控制，通过其换流重叠及续流、箝位作用，实现超前桥臂的零电压通断和滞后桥臂的零电流通断，有效地降低变换器损耗和提高系统效率。对新型软开关拓扑进行原理定性阐述，结合各时段波形进行理论分析，得出有关软开关条件。实验结果证实了本拓扑方案及理论分析方法的有效性。%In view of the current problems in soft-switching converter with complicated topology and greater consumption, a no-vel soft-switching topology of phase-shift H-bridge converter was presented. Based on the original transformer, rectifier and fil-tering elements, a passive auxiliary clamp circuit is added. The circuit topology is simple and easy to implement, and requires no active components and additional control. Both ZVS leading-leg and ZCS lagging-leg are realized adaptively. The converter reduces the consumption and improves the system efficiency effectively. The principle of the new soft-switching topology is elab-orated qualitatively. Waveforms on every time interval are analyzed theoretically. The soft-switching conditions are derived. The robustness and feasibility of the new topology and the associated theory analyzing method are verified using experimental results.