特高压直流滤波器电容器组不平衡电流保护整定计算分析  

Calculation Analysis of Unbalanced Current Protection Setting for Capacitor Bank of UHVDC Filter

作　　者：李威 符劲松 张欢 邓维 文习山[2] 陈小月[2] LI Wei;FU Jingsong;ZHANG Huan;DENG Wei;WEN Xishan;CHEN Xiaoyue(State Grid Hunan Maintenance Company,Changsha 410009,China;School of Electrical Engineering,Wuhan University,Wuhan 430072,China)

机构地区：[1]国网湖南省电力有限公司检修公司,长沙410009 [2]武汉大学电气工程学院,武汉430072

出　　处：《电力电容器与无功补偿》2018年第6期1-6,共6页Power Capacitor & Reactive Power Compensation

摘　　要：直流滤波器在特高压直流输电工程中发挥着消谐的重要作用,高压电容器组是直流滤波器运行中容易损坏的设备,有必要根据换流站内的具体配置方案,对电容器组不平衡电流保护动作的整定值进行计算研究。本文基于特高压换流站直流滤波电容器的结构特性,推导了桥差保护下电容器组的不平衡电流百分比计算方法,然后计算了韶山特高压换流站直流滤波器电容器组在不同程度故障条件下的不平衡电流百分比,与相同故障条件下的不平衡电流仿真结果相符合。考虑到环境和杂散电容等因素,保留一定裕度后得到了三段不平衡保护动作时的整定值,与韶山站所用光电流互感器的测量精度相比较,证明了不平衡保护动作的准确性和可靠性。本文研究内容对特高压换流站直流滤波电容器不平衡保护的配置具有一定的参考意义。DC filter in the UHVDC project plays such important role as harmonic elimination and high-volt-age capacitor bank is easily damaged during the operation of DC filter.It is therefore necessary to calculate and study the setting of the unbalanced current protection action of the capacitor bank in accordance with the specific configuration proposal in the UHV converter station.In this paper,the percentage calculation method of unbalanced current of capacitor at bridge differential protection is deduced on the base of the structural characteristics of DC filter capacitor in UHV converter station.Then,the unbalanced current per-centage of the DC filter capacitor banks under different fault conditions at Shaoshan UHV converter station is calculated and which is in agreement with the simulation result of unbalanced current under the same fault condition.With such factors as environment and stray capacitance,the setting of the three unbalanced protection actions are obtained under holding a fixed margin,and it is compared with the measurement ac-curacy of optical current transformer for Shaoshan station and both accuracy and reliability of the unbal-anced action is proved.The study contents in this paper have definite reference significance for the unbal-anced protection configuration of DC filter capacitor in the UHV converter station.

关 键 词：特高压直流滤波器 高压电容器组 不平衡电流保护 整定计算 

分 类 号：TM53[电气工程—电器]