中文摘要：

针对传统星接链式STATCOM较难实现不平衡补偿的问题．提出了一种星接链式STATCOM实现不平衡补偿功能的新拓扑结构。即增加一台接地变压器，将STATCOM和接地变压器的中点相连．实现负序补偿所需的零序电流通路。通过功率分析．分析了这种新拓扑结构下参考电流和零序电流生成方法．并推导了该结构下相间直流电压平衡的控制方法。仿真波形和整机实验数据表明．采用所提结构和控制方法后．负荷中的负序电流得到了较好的补偿．相间直流电压平衡的效果较好。工程分析表明．所提方法与增加△／Y连接变压器实现不平衡补偿的方式相比．在成本和占地上都有较大优势。

英文摘要：

A new topology is proposed for the unbalance load compensation of cascaded STATCOM with star configuration,which connects the neutral point of an additional grounding transformer with STATCOM to form the pass of zero-sequence current needed by negative-sequence compensation. The way to generate the reference current and the zero-sequence current is explained by the power analysis and the method to control the DC voltage balance among phases is deduced. Simulative and experimental results show that, with the proposed topology and control method,the negative-sequence current of load is preferably compensated and the DC voltage balance among phases preferably satisfied. Engineering analysis shows that,compared with the Δ/Y configuration,the proposed configuration is more cost-effective and space- effective.