三電平光伏并網逆變器共模電壓SVPWM抑制策略研究

摘要：本文提出了一種優化空間矢量脈寬調制方法來抑制光伏并網逆變器中產生的共模電壓。在分析共模電壓產生機理的基礎上，對通常SVPWM調制技術進行改進, 調整了有效矢量的選擇范圍, 并對開關次序進行優化。該空間矢量合成算法克服了SPWM調制存在的母線電壓利用率低，線性調制區小的問題。仿真結果表明，該算法可以將共模電壓幅值抑制到普通SVPWM算法的1/2，具有良好的有效性和實用性。 敘詞：三電平逆變器 二極管中點箝位式 共模電壓 SVPWM Abstract：In this paper, an optimization SVPWM method is used to restrain the common-mode voltage generated in grid-connected PV inverters. Based on the analysis of the generated mechanism of the common-mode voltage, the normal SVPWM modulation technology is improved by adjusting the range of choose effective vector and optimizing the switching order. The simulation results show this algorithm can suppress common-mode voltage amplitude low to 1/2 of the general SVPWM algorithm. Keyword：Three-level inverter, NPC, Common mode voltage, SVPWM