基于反射系数和模型匹配的柔性直流电网单端量线路保护  

Single-end Line Protection Based on Reflection Coefficient and Model Matching in Flexible DC Power Grid

作　　者：戴志辉[1] 秦昊宇 李杭泽 邱宏逸 邱晓璇 DAI Zhihui;QIN Haoyu;LI Hangze;QIU Hongyi;QIU Xiaoxuan(School of Electric and Electronic Engineering,North China Electric Power University,Baoding 071003,China)

机构地区：[1]华北电力大学电气与电子工程学院,河北省保定市071003

出　　处：《电力系统自动化》2023年第11期101-109,共9页Automation of Electric Power Systems

基　　金：国家自然科学基金资助项目(51877084)。

摘　　要：针对柔性直流电网线路保护区内远端高阻故障拒动、雷击干扰误动的问题,提出一种基于反射系数和模型匹配的单端量线路保护。首先,根据电压行波反射系数构成方向判据,避免反方向故障或雷击下保护误动;其次,利用电压行波传递函数解析区内短路故障,以及正方向区外故障或正方向雷击下保护处故障电压首行波满足的函数模型,根据故障首行波与基准函数模型之间匹配程度的不同,设计了一种基于模型匹配的识别判据;然后,结合启动判据和选极判据形成完整的单端量线路保护方案;最后,PSCAD仿真结果验证了所提保护方案可靠性高,能耐受500Ω过渡电阻和20 dB噪声。A single-end line protection based on reflection coefficient and model matching is proposed to address the issues of internal remote high-resistance fault rejection and lightning interference misoperation of line protection in flexible DC power grid.First,based on the reflection coefficient of voltage traveling waves,a directional criterion is constructed to avoid protection misoperation under backward faults or lightning stroke.Secondly,using the voltage traveling wave transfer function to analyze internal short-circuit faults,as well as the function model satisfied by the initial traveling wave of fault voltage at the protection point under forward external faults or forward lightning strikes,a recognition criterion based on model matching is designed according to the different matching degrees between the first traveling wave of fault and the reference function model.Then,a complete single-end line protection scheme is constructed by combining the starting criterion and pole-selection criterion.Finally,the PSCAD simulation results verify that the proposed protection scheme has high reliability and can withstand 500Ωtransition resistance and 20 dB noise.

关 键 词：柔性直流电网 单端量线路保护 行波 反射系数 模型匹配 

分 类 号：TM721.1[电气工程—电力系统及自动化] TM773