Abstract：In this paper, a two-stage DC-DC topology, which consists of primary series transformer LLC and output interleaved Buck, is presented. The proposed topology can be applied in DC power converters of high/wide input voltage, low output-voltage/high output-current and high power density. This cascaded topology makes full use of the high efficiency of the open-loop operating LLC converter with constant switching frequency. Moreover, the electrical isolation and voltage step-down are also realized by the LLC. The output voltage regulation as well as the automatic current sharing is achieved by the second stage interleaved Buck. The operation mode of the cascaded converter and the parameter of the LLC are designed, and the steady-state output current sharing is analyzed even with mismatched parameter. Finally, the theoretical analysis is validated by simulation and experiments.
石健将, 章江铭, 龙江涛, 刘天骥. 高频变压器一次侧串联LLC+输出端并联Buck级联直流变换器[J]. 电工技术学报, 2015, 30(24): 93-102.
Shi Jianjiang, Zhang Jiangming, Long Jiangtao, Liu Tianji. A Cascaded DC Converter with Primary Series Transformer LLC and Output Interleaved Buck. Transactions of China Electrotechnical Society, 2015, 30(24): 93-102.
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2015, Vol. 30 
