一种双管双变压器结构的正-反激组合变换器的分析

提出了一种双管双变压器结构的正反激组合变换器。该变换器电路结构简单,控制方便。该双变压器结构减少了单个变压器的原边匝数,从而降低了原边的铜耗,同时也使得低造型设计成为可能。文中着重对两变压器匝比相等和不等两种情况进行了分析比较。在匝比不等情况下,正反激变压器功率分配可灵活设计。最后试验结果验证了理论分析。

ANALYSIS OF FORWARD-FLYBACK CONVERTER EMPLOYING TWO SWITCHES AND TWO TRANSFORMERS

A novel forward-flyback converter employing two switches and two transformers is presented. Two diodes of the primary side enable the voltage stress of two switches to be clamped at the input voltage,which is lower than that of a conventional forward-flyback converter. Two transformers offer the following advantages.Firstly,the turns of primary transformer winding are reduced to half of that of a conventional forward-flyback converter with a single transformer; Secondly, the use of two transformers enables the smaller low-profile cores to be utilized, thus facilitating a low-profile design. The unequal condition of turn ratios is compared with the equal condition of turn ratios. When two turn ratios are unequal,the power distribution between the two transfor-mers can be easily designed. Finally, experimental results verify the above analyses.