摘要
针对三电平中点钳位逆变器在不同的负载条件下,传统的最近三矢量合成方法中点电压存在不能平衡的区域,利用基于虚拟空间矢量的调制方法,当输出三相电流之和为零时,能实现对中点电压的完全控制。为了在扇区切换时输出矢量平稳过渡,提出了在每个大区内全部采用相同首发正小矢量或负小矢量的方法。构建了三电平中点钳位型逆变器实验平台,对基于虚拟空间矢量的三电平NPC逆变器中点电压平衡控制方法的有效性进行了验证。
This paper explores the limitations of neutral-point potential balancing problem for different loading conditions of three-level neutral-point-clamped inverters. It introduced a novel modulation approach for the complete control of the neutral-point potential. The new modulation approach, which based on the virtual space vector concept, guaranteed the balancing of the neutral-point potential for any load over the full range of converter output voltage and for all load power factors, and the only requirement being that the addition of the output three-phase currents equals zero. In order to avoid the abrupt change of output voltage vectors during the process of desired vector changing from one section to another, a novel space vector modulation algorithm is proposed where the same positive or negative small vectors are adopted as first active vector. Some experimental results are given to validate the method.
出处
《电工技术学报》
EI
CSCD
北大核心
2009年第5期100-107,共8页
Transactions of China Electrotechnical Society
基金
安徽省“十一五”科技攻关资助项目(06012143H)
