全桥隔离型单相单级功率因数校正变换器研究

Research on Full-bridge Isolated Single-phase Single-stage Power Factor Correction Converter

隔离型单相单级全桥功率因数校正(SS-FB-PFC)变换器具有高功率密度、高功率因数、电气隔离等特点,适用于中大功率应用场合。介绍了该变换器的工作原理,建立了其动态模型,进行补偿器设计,提升了系统的稳态调节和动态响应能力。在此基础上分析SS-FB-PFC电路固有的隔离变压器偏磁产生机理,基于数字控制技术提出一种简单的SS-FB-PFC变换器解决方案,该方案易于实现,且能避免原有控制方式带来的变压器偏磁现象,与传统偏磁抑制方案相比不增加电路成本和复杂度。最后,通过实验验证了电路拓扑及控制方案的有效性。

Single-phase single-stage full-bridge power factor correction （SS-FB-PFC） converter has the characteristics of high power density, high power factor, galvanic isolation, etc., and fits for medium or high power application.The oper- ational principles of this converter are introduced, while its dynamic model is established and the relevant compen- sator designed increasing the ability of steady state regulation and dynamic response of the converter.On this basis, the inherent flux bias mechanism of the transformer in SS-FB-PFC converter is analyzed, a simple solution scheme of SS-FB-PFC converter based on digital control is proposed, which is easy to realize and can avoid the flux bias of the original control scheme.In addition,the novel scheme doesn＇t increase the cost and complexity of the converter.At last, the validity of the topology and control scheme is verified by the experiment.