摘要
针对在线路始端和末端将电流分配系数当作实数处理时存在较大误差的问题,提出一种基于高频谐波分量的距离保护阻抗测量改进方案。利用频率越高,电流分配系数越接近于实数的特点,首先,通过保护安装处的序电流与故障点电流的关系,推导出由保护安装处测量信息构成的故障距离百分比表达式。然后,通过提取故障波形中的高频谐波分量,求取保护安装处距离保护的真实故障阻抗。基于新英格兰10机39节点系统的仿真结果表明,不论过渡电阻大小和故障位置远近,方案的计算误差均优于与传统方案;同时,提取高频谐波所需采样窗长短,有助于提升距离保护的动作时间,具备良好的工程实用价值。
Aiming at the increased errors when the current distribution coefficient is treated as a real number at the beginning and end of transmission line,an improved scheme of impedance measurement for distance protection based on high-frequency harmonics is proposed in this paper.Firstly,in application of the feature that the current distribution coefficient is closer to real number in higher frequencies,with the relationship between the sequence current of relaying point and fault point current,the expression of the fault distance percentage composed of the measurement information of the relaying point is derived.Then,by extracting the high-frequency harmonics in fault waveform,the true fault impedance of the distance protection at the relaying point is obtained.Simulation results based on New England 10-machine 39-bus test system show that the calculation error of the proposed scheme is lower than traditional schemes,regardless of transition resistance and fault location.In addition,the required length of sampling window to extract the high-frequency harmonics is helpful in improving the action time of distance protection,providing a great potential practical value.
作者
马伟
黄晓波
吴旻昊
罗少杰
尤敏
丁冬
陈聪
王明昶
MA Wei;HUANG Xiaobo;WU Minhao;LUO Shaojie;YOU Min;DING Dong;CHEN Cong;WANG Mingchang(State Grid Hangzhou Power Supply Company,Hangzhou 310009,Zhejiang Province,China;State Grid Xiamen Power Supply Company,Xiamen 361000,Fujian Province,China)
出处
《电网技术》
EI
CSCD
北大核心
2020年第3期1134-1139,共6页
Power System Technology
基金
国家电网公司总部科技项目资助(521104170012,521101180004).
关键词
距离保护
阻抗测量
电流分配系数
过渡电阻
故障位置
distance protection
impedance measurement
current distribution coefficient
transition resistance
fault location
作者简介
通信作者:马伟(1989),男,硕士,工程师,主要研究方向为电力系统继电保护,E-mail:jnyz-mawei@163.com;黄晓波(1973),男,硕士,高级工程师,主要研究方向为电力系统运检管理;吴旻昊(1989),男,硕士,工程师,主要研究方向为电力系统调度与运行。
