计及主动故障限流策略的柔性直流电网纵联保护  

Pilot protection of flexible DC grid considering active fault current limiting strategy

作　　者：宋国兵[1] 侯俊杰 郭冰 王婷[1] 常仲学 沈冰 SONG Guobing;HOU Junjie;GUO Bing;WANG Ting;CHANG Zhongxue;SHEN Bing(School of Electrical Engineering,Xi’an Jiaotong University,Xi’an 710049,China;State Grid Shanghai Electric Power Research Institute,Shanghai 200437,China)

机构地区：[1]西安交通大学电气工程学院,陕西西安710049 [2]国网上海市电力科学研究院,上海200437

出　　处：《电力自动化设备》2021年第4期123-131,138,共10页Electric Power Automation Equipment

基　　金：国家自然科学基金联合基金重点支持项目(U1766209);国家电网公司总部科技项目(52170218000M,52094020006U)。

摘　　要：针对传统直流保护原理应用于柔性直流电网中存在可靠性降低、灵敏度下降的问题,提出计及换流器主动故障限流策略的柔性直流电网纵联保护原理。分析了故障电流在换流器电容放电阶段和换流器主动故障限流阶段的极性特征,进一步构造了改进型故障电流极性特征序列,引入基于斯皮尔曼相关性系数的电流波形特征判别方法,实现柔性直流电网故障区域判别。仿真结果表明,所提保护原理在换流器的电容放电阶段和换流器主动故障限流阶段均能识别出柔性直流电网故障区域,具备较高的可靠性和灵敏度。In view of the problems of low reliability and sensitivity when the traditional DC protection principle is applied to flexible DC grid,the pilot protection of flexible DC grid considering active fault current limiting strategy of converter is proposed.The polarity characteristics of fault current in the capacitor discharge stage and active fault current limiting stage of converter are analyzed.Then the improved polarity sequence of fault current is constructed,and the current waveform identification method based on Spearman correlation coefficient is introduced to realize the fault area identification of flexible DC grid.The simulative results show that the proposed protection principle can identify the fault area of flexible DC grid in the capacitor discharge stage and active fault current limiting stage of converter,and has high reliability and sensitivity.

关 键 词：柔性直流电网 主动故障限流策略 相关性判别 直流保护 继电保护 

分 类 号：TM77[电气工程—电力系统及自动化]