基于电压行波极性特征的新能源送出线路保护方案  

Renewable energy line protection based on voltage traveling wave polarity

作　　者：叶远波 章昊 王同文 宋祥艳 苏毅[2] 郑涛[3] YE Yuanbo;ZHANG Hao;WANG Tongwen;SONG Xiangyan;SU Yi;ZHENG Tao(State Grid Anhui Electric Power Co.,Ltd.,Hefei 230022,China;Beijing Sifang Aotumation Co.,Ltd.,Beijing 100085,China;North China Electric Power University(State Key Laboratory of Renewable Energy Power System),Beijing 102206,China)

机构地区：[1]国网安徽省电力有限公司,安徽合肥230022 [2]北京四方继保自动化股份有限公司,北京100085 [3]华北电力大学(新能源电力系统国家重点实验室),北京102206

出　　处：《电力工程技术》2024年第1期127-135,共9页Electric Power Engineering Technology

基　　金：国家重点研发计划资助项目(2021YFB2401003)。

摘　　要：新能源经交流线路送出时,由于其弱馈性和受控特性,传统的工频量保护难以适用,而行波保护能够在新能源控制系统介入导致故障特性发生较大变化之前完成故障识别,是目前解决新能源送出线路工频量保护问题的有效途径之一。然而现有的单端行波保护方案无法准确识别区内近端故障和区内末端故障,因此文中分析了区内和区外故障情况下行波的折反射过程,并利用电压行波零模分量与线模分量到达保护安装处的时间差对故障位置进行初判;针对基于时间差难以准确识别的区内近端故障和区内末端故障,进一步挖掘电压行波的极性特征,利用首个反极性的电压行波和故障初始电压行波到达保护安装处的时间差与故障位置的关系来识别区内近端故障,利用前2个电压行波的极性关系来识别区内末端故障。仿真结果表明,该方案能够快速识别区内外故障,并且具有较好的耐过渡电阻能力。Renewable energy has weak feedforward and controlled characteristics,so the traditional industrial frequency protection does not work when renewable energy is sent out through AC transmission line.On the contrary,the traveling wave protection methods can judge the fault before the control system responds,which are one of the effective ways to solve the problem encountered in renewable power system.However,the existing traveling wave protection schemes are limited by the sampling rate,which makes it difficult to accurately identify the internal near-end fault and the internal remote-end fault.To solve this problem,the grid diagram of traveling wave in case of internal and external faults is analyzed at first.Then,the time difference between zero-mode and line-mode is used to judge the fault location.For the near-end fault and remote-end fault which are difficult to be accurately identified based on the time difference,the first reverse polarity traveling wave is used to identify the near-end fault and the polarity of the first two line-mode traveling waves is used to identify the remote-end fault.Simulation results show that the proposed scheme can quickly identify internal and external faults.At the same time,the proposed scheme has good ability to withstand transient resistance.

关 键 词：新能源线路 行波保护 电压行波 小波变换 极性比较 单端量保护 

分 类 号：TM771[电气工程—电力系统及自动化]