Cascaded multilevel conversion technology facilitates the realization of high efficiency,high power density and high modularity in low voltage AC/DC converters,but the traditional cascaded multilevel power factor correction rectifier has serious common-mode noise interference problems and high-frequency circulation problems.In view of this,a new type of single-phase cascaded half-bridge three-level PFC rectifier and cascaded full-bridge five-level PFC rectifier without increasing the circuit cost is proposed in this paper.First,by analyzing the causes of common-mode noise interference in the traditional cascaded topologies,the improved topologies that can suppress common-mode noise interference are deduced.Secondly,the circuit superposition theorem is used to analyze the common mode and circulation of the proposed PFC rectifiers in detail.Finally,experimental prototypes of a new type of cascaded half-bridge and cascaded full-bridge rectifiers was built in the laboratory,and the experimental results verified the effectiveness of the proposed topologies on common-mode noise suppression,circulation suppression,and efficiency improvement without the increase of circuit costs.
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