星接串联H桥多电平静止无功发生器不平衡补偿分析  

Analysis on the Unbalanced Compensation of Star Connection Cascaded H-bridge Multilevel Static Var Generator

作　　者：罗锐 何英杰[1] 刘云峰[1] 

机构地区：[1]电力设备电气绝缘国家重点实验室(西安交通大学)

出　　处：《中国电机工程学报》2018年第3期861-869,共9页Proceedings of the CSEE

基　　金：国家自然科学基金项目(51777158);基本科研业务费综合交叉类项目(1191329727);大型电气传动系统与装备技术国家重点实验室开放基金(SKLLDJ022016004)~~

摘　　要：在电网电压不平衡和补偿电流不平衡的情况下,需要采取合适的控制策略以保证星接串联H桥多电平静止无功发生器（static var generator,SVG）的各相H桥模块直流侧电压恒定。常用的方法是在星接串联H桥多电平SVG中叠加零序电压。该文综合考虑并网电压不平衡和补偿电流不平衡的情况,研究了星接串联H桥多电平SVG正常运行的条件。详细分析了并网电压不平衡度、补偿电流不平衡度与装置额定电压之间的定量关系,推导出在电网电压一定的情况下,装置的负序电流补偿能力;同时,讨论了在补偿电流一定的情况下,电网电压变化对装置输出的影响。通过仿真和实验验证了相关理论分析的正确性。这些量化分析对星接串联H桥多电平SVG的应用和选型具有指导意义。The appropriate control strategy, which takes the unbalanced grid connected voltage and unbalanced compensation current into account, is needed to keep the DC side voltage of each phase H bridge constant in star connection cascaded H-bridge multilevel static var generator（SVG）. The common method is to add the zero sequence voltage to the SVG. Considering the unbalanced grid voltage or unbalanced compensation current, the requirements for the normal operation of the SVG were analyzed based on the zero sequence voltage component superposition method. The relationship of the grid voltage unbalance degree, compensating current unbalance degree and the rated voltage was analyzed. The compensation characteristic of the negative sequence current was deduced with the certain grid voltage. The influence of grid voltage variation on the output voltage was also considered with the certain compensating current. Finally, the correctness of the relevant theoretical analysis was verified by simulation and experiment. These quantitative analyses have directive significance for the application and selection of the star connection cascaded H-bridge multilevel SVG.

关 键 词：星形连接 串联H桥SVG 零序电压 不平衡度 

分 类 号：TM761[电气工程—电力系统及自动化]