级联STATCOM阀组直流侧电压不平衡现象及原因分析

在级联H桥静止同步补偿器（STATCOM）研究实验过程中,发现各相阀组间存在直流侧电压不平衡,且阀组间直流侧电压不平衡度随着补偿电流的增大有增大的趋势。阀组间的直流侧电压平衡,对于级联H桥STATCOM的安全运行以及性能均具有重要意义,但尚未有阀组间直流侧电压不平衡的原因分析。文中通过对系统电压的正负序分解,分析了级联...

Analysis of Voltage Unbalance Phenomenon and Causes in Cluster DC Link of Cascaded H-bridge STATCOM

Voltage unbalance in clusters DC link exists during experiments,and the unbalance degree increases with increase of the compensation current.DC link voltage balance among clusters is important for the safe operation and performance of cascaded H-bridge multilevel STATCOM.However,there is lack of reason analysis about voltage unbalance in clusters DC link nowadays.Through decomposing the positive and negative sequence of system voltage,interaction between the positive sequence voltage and the negative sequence current in cascaded H-bridge topologic structure,which has influence on active power,is analyzed.It also explained the physical reasons for voltage unbalance in clusters DC link,and a quantitative analysis on the cluster unbalance is given.Simulation and experimental results proved the validity of this method,and provided the reasonable basis for solution of voltage unbalance in clusters DC link. This work is supported by International Science and Technique Cooperation Plan(No.2010RR0002) and Key Project of Science and Technology Department of Heilongjiang Province(No.01314025).