级联式谐振变换器的电路特性及其非连续导通模式的分析

Analysis of circuit characteristics of cascade resonant converter and its discontinuous conduction mode

本文介绍了一种多元件级联式谐振变换器,该变换器结合了串联谐振变换器和并联谐振变换器的特点,并且在运行性能上有所提高。文章利用经典交流分析法,推导了电压传输增益,同时分析了非连续导通模式下的各种开关状态,得出相应的等效电路,并且运用数值解法求得谐振电压电流的波形和临界负载电流。

A multielement cascade resonant converter is presented in this paper, which improves the performance by combining the characteristics of series resonant converter and parallel resonant converter. The voltage transfer gain is derived by making use of classical AC analysis. It implies that the proposed converter has wider bandwidth and larger voltage gain than conventional resonant converters, especially at light load. Furthermore, various switching subintervals and the corresponding equivalent circuits under discontinuous conduction mode are also investigated. The critical load current between continuous conduction mode and discontinuous conduction mode is given as well. Finally, the simulative and the experimental results confirmed the validity of the theoretical analysis. 