一种不对称半桥反激变换器的设计方法

Design of Asymmetrical Half-bridge Flyback Converter

研究了不对称半桥反激变换器的参数设计方法。首先,简单介绍了变换器的工作原理和波形。其次,针对谐振类变换器谐振参数设计不准确的问题,提出了一种修正的变换器电流的数学计算方法,引入正弦基波等效的方法,对次级输出电流进行等效,用于谐振参数设计,据此设计变换器的各项参数,包括:变压器匝比、励磁电感及隔直电容。最后,通过搭建一台64 W的不对称半桥变换器样机,以验证参数设计的合理性和有效性。

The parameter design method of asymmetric half-bridge flyback converter is studied.An improved and practical mathematical model is established.Based on this model,resonant parameters are designed optimally.Firstly,the principle and waveform of the converters are introduced.Secondly,the traditional mathematical model of the converter is modified.Through the sinusoidal-like equivalent method,output current is transformed to improve the precision of the model.Then,resonant parameters are designed including the ratio of transformer,the magnetizing inductance and blocking capacitor.Finally,a 64 W prototype is built to verify the feasibility of the parameter design.