摘要
针对采用IGBT的软开关三电平变换器中IGBT关断过程存在的电流拖尾现象,以及基本三电平拓扑变压器次级存在的电压过冲和电压振荡现象,提出了改进型ZVZCS三电平结构。该结构在基于拓扑的三电平桥臂侧和两电平桥臂侧分别加入了一个无源辅助网络,三电平桥臂侧的辅助变压器在续流阶段为主变压器初级电流回零提供了条件,两电平桥臂的谐振电感和箍位二极管有效地抑制了主变压器次级电压的过冲现象。详细分析了改进拓扑的工作原理、工作模态,以及辅助网络的工作特点,并研制了实验样机,验证了理论分析的正确性以及改进拓扑的可行性。
An improved ZVS and ZCS three-level（ZVZCS TL） converter with dual-sides passive auxiliary net is proposed in this paper to solve the problems of current trailing when the IGBT in the soft switch three-level converter switches off,and the voltage overshoot as well as voltage oscillation existing in the basic three-level topology transformer’s secondary side.A passive auxiliary networks are added in each side of three-level leg and two-level leg respectively.The auxiliary transformer beside the three-level leg provides the conditions for primary current reseting of main transformer in the free-wheeling stage.The resonant inductance and the clamping diodes beside the two-level leg can effectively restrain the voltage overshoot in the main transformer’s secondary side.Moreover,the operation mode and principle of the improved topology circuit as well as the characteristics of the auxiliary net are analyzed in detail in this paper.An elementary experimental prototype was made to verify the correctness of theoretical analysis and the feasibility of the improved topology.
出处
《现代电子技术》
2012年第16期122-125,共4页
Modern Electronics Technique
