新型三电平Buck型功率因数校正器

Three-level Buck-type power factor corrector

针对Buck电路输入电流不连续而限制了Buck型功率因数校正技术的应用和发展问题,并考虑多电平拓扑结构的优势,提出了一种新型的三电平Buck型功率因数校正器拓扑结构。该拓扑结构基于输入、输出共地的Buck三电平变换器,在此变换器基础上并联增加了由功率开关、补偿电感和电容构成的补偿环节。新拓扑结构有效地解决了Buck电路输入电流不连续问题,实现了单位功率因数,且开关器件承受电压应力降低一半。控制策略基于单周控制技术,控制电路简单可靠,响应速度快,精确度高。对所提出的新型拓扑结构及其工作模态和控制实现进行了详细的分析,并给出了仿真和实验结果,结果表明校正后功率因数在0.99～1.0之间,验证了所提出的拓扑结构的正确性和有效性。

The application and development of Buck-type PFC（Power Factor Corrector） is restrained by its discontinuous input current.Three-level Buck-type PFC topology is presented to take the advantage of multi-level topology,which,based on the three-level converters with the common ground for both input and output,is added with a parallel compensation circuit composed of power switch,inductor and capacitor.It effectively solves the problem of discontinuous input current,achieves unity power factor and reduces half the voltage stress of power switches.The control strategy is based on the one-cycle control and the control circuit is simple and reliable,with fast response and high precision.The proposed topology,operating mode and control implementation are analyzed in detail.Simulative and experimental results show the corrected power factor is between 0.99 and 1,verifying its correctness and validity.