【摘要】 分析了反激变换器共模(common mode, CM)噪声的特点，并基于屏蔽法与平衡法原理，提出了屏蔽-对消法，在变压器中加入屏蔽-对消绕组层，与原边CM噪声互相抵消的同时，也屏蔽了变压器副边至原边的噪声耦合路径，抑制了变压器内部CM噪声的传导。建立了反激变换器CM噪声传导路径模型，通过实验对比了无屏蔽层、采用全屏蔽铜箔与使用了屏蔽-对消绕组三种变压器结构样机的CM噪声，实验结果验证了屏蔽-对消绕组在反激变换器中抑制CM噪声的有效性。更多还原

【Abstract】 In this paper, the common mode(CM)noise characteristics of a flyback converter is analyzed, based on shielding method and equilibrium method, this paper proposes a shielding cancellation scheme which adds a layer of shielding cancellation winding in the transformer.This winding can not only cancel the common mode noise on the primary side, but also cut off the coupling path of transformer to suppress the conduction of common mode noise in transformer.A CM noise conduction path model of the flyback converter is bulit and the CM noise of three different transformer including without shielding, with fully shielded copper foil and shielding cancellation winding are compared.The experimental results reveal the effectiveness of shielding cancellation winding in suppressing CM noise in the flyback converter.更多还原