单相三电平PFC拓扑构成方案及调制方法

Topology and Modulation Scheme Based on Single-phase Three-level PFC

传统单相三电平整流器的开关器件较多;两电平整流器开关器件相对少,但其交流侧输入滤波电感体积大,开关频率相对较高导致功率器件损耗增大,工作效率有所降低。针对上述问题,文中提出级联、电平等效、镜像、去冗余等三电平电路拓扑方案,并以两电平伪图腾柱式功率因数校正电路(pseudo totem-pole power factor correction,PTP-PFC)为例进行上述拓扑方案的推导过程分析,提出一类三电平PTP-PFC电路。首先,对所提新型单相三电平PTP-PFC变换器进行工作原理分析,并提出一种适合此类拓扑的调制方法;其次,对所提拓扑进行功率器件数量、电压应力、损耗等方面分析和对比,总结出各电路特性;最后,设计输出电压400V、功率1kW的3种三电平PTP-PFC实验样机,实验结果证明级联、电平等效、镜像、去冗余等三电平电路拓扑方案的有效性,同时验证所提三电平PTP-PFC电路理论分析的正确性和工程应用的可行性。

Traditional two-level converters have high switching frequencies,low efficiency,and large power device losses.The AC-side filter inductor also has a large volume,making it difficult to increase power density.To address these issues,starting from the Pseudo Totem-pole power factor correction(PTP-PFC)circuit,diode-clamped bridges are implemented through cascading,level equivalence,mirroring,and redundancy removal.The arm structure is derived,and a family of three-level PTP-PFC circuits is proposed.First,the operating principles of the proposed family of new single-phase three-level PTP-PFC converters are analyzed,and a modulation method suitable for this topology is proposed.Second,the number of power devices,voltage and current stress,loss and other factors of the proposed topology are analyzed and compared,and the advantages of each circuit are summarized.Finally,three experimental prototypes AC input 220V/50Hz,output 400V,power 1kW representative three-level PTP-PFC are designed.The experimental results verify the theoretical analysis and topological derivation of the proposed three-level PTP-PFC circuit.