摘 要：為抑制三電平逆變器共模電壓，以二極管鉗位式拓撲為例，分析其共模電壓產(chǎn)生機理并提出一種抑制共模電壓的簡化三電平5段式空間矢量脈寬調(diào)制算法。該算法通過選取輸出共模電壓幅值小的基本電壓矢量參與調(diào)制來抑制共模電壓。仿真和實驗結果表明，所提算法將共模電壓最大幅值抑制到Vdc/6，比傳統(tǒng)一般算法、抑制共模電壓的7段式、7段式算法分別減少2/3，1/2，0，且可以克服上述3種算法輸出共模電壓幅值隨其調(diào)制度變化而變化的缺點。
關鍵詞：二極管鉗位式三電平逆變器；空間矢量脈寬調(diào)制；共模電壓；5段式算法
文獻標志碼：A 文章編號：1674-5124（2015）12-0106-05
Common-mode voltage analysis and reduction for three-level inverter
GAO Fang， GAO Rui
（College of Engineering and Technology，Changchun Vocational Institute of Technology，Jilin 130033，China）
Abstract: In order to reduce common-mode voltage of three-level inverter， this paper takes diode-clamped topology for instance， analyzes its common-mode voltage generation mechanism and proposes a simplified common-mode voltage reduction three-level five-segment space vector pulse width modulation algorithm（SVPWM）. To reduce common-mode voltage， this algorithm selects proper basic voltage vectors to modulate. Simulative and experimental results show that， the proposed algorithm can suppress the maximum value of common-mode voltage to one sixth of DC voltage source value， and decrease respectively about two thirds， one second， zero comparing with traditional space vector modulation， seven-segment， five-segment algorithm. Meanwhile， it can overcome the disadvantage of common-mode voltage value varies with the modulation index of above three algorithms.
Keywords: diode-clamped three-level inverter； SVPWM； common-mode voltage； five-segment algorithm
