中文摘要：

针对已有的单相多电平电压型逆变器（VSI）结构，结合对偶原理得到几种基本的单相多电平电流型逆变器（CSI）拓扑类型。通过研究单相CSI基本拓扑类型，将多电平变换器拓扑结构自由度的概念引入到多电平CSI拓扑构造中，得到多种新型的单相多电平CSI组合拓扑，从而扩展了多电平CSI的拓扑类型。在研究组合拓扑的基础上，结合两种常用的多载波SPWM调制策略，给出应用于组合拓扑的调制策略，为组合拓扑结构的实际应用奠定了基础。最后针对一种七电平组合拓扑进行了仿真分析和实验验证。

英文摘要：

In this paper, several single-phase multilevel current-source inverter （CSI） topologies are obtained by applying duality principle to single-phase multilevel voltage-source inverter （VSI） topologies. Based on the analysis of the typical CSI structures, several new combined CSI topologies are produced by introducing the control freedom degree of converters structures. Thus single-phase multilevel CSI topology types are extended. At the same time, modulation strategies of the combined topologies are investigated based on the multi-carrier SPWM. The validity of a seven-level combined topologies and the corresponding modulation strategies are verified by the simulation and experimental results.