单相无变压器型光伏并网逆变器的拓扑结构及共模电流分析

摘要

In view of the problem of common-mode current existed in topology of single-phase transformerless type photovoltaic grid-connected inverter, several topologies were introduced which can restrain common-mode current effectively, namely single-phase full-bridge topology with double-polarity modulation, full-bridge topology with AC bypass, H5 topology and NPC topology. Principle of restraining common-mode current of these topologies were analyzed in details, and these topologies were compared in terms of switching loss and system efficiency. Finally, it was pointed out that H5 topology has best performance.%针对单相无变压器型光伏并网逆变器拓扑结构存在共模电流的问题,介绍了几种能有效抑制共模电流的拓扑结构,即双极性调制的单相全桥式拓扑结构、带交流旁路的全桥式拓扑结构、H<,5>拓扑结构及NPC拓扑结构;详细分析了这几种拓扑结构抑制共模电流的原理,并从开关损耗及系统效率两个方面对这几种拓扑结构进行了比较,指出H<,5>拓扑结构性能最优.