基于暂稳态电流幅值比较的谐振接地系统故障选线方法  

Fault Line Selection Method for Resonance Grounding System Based on Comparison Between Transient and Steady-state Current Amplitudes

作　　者：李高明 黎皓彬 卢颖 梁永亮[2] LI Gaoming;LI Haobin;LU Ying;LIANG Yongliang(Foshan Power Supply Bureau,Guangdong Power Grid Company,Foshan 528000,China;College of Electrical Engineering,Shandong University,Jinan 250061,China)

机构地区：[1]广东电网有限责任公司佛山供电局,佛山528000 [2]山东大学电气工程学院,济南250061

出　　处：《电力系统及其自动化学报》2022年第10期97-103,共7页Proceedings of the CSU-EPSA

基　　金：南方电网公司科技项目(030600KK52190184 GDKJXM20198132)。

摘　　要：针对传统单相接地故障选线方法因互感器极性反接而误动或拒动的问题,提出一种基于零序电流幅值比较的选线方法。根据谐振接地系统单相接地故障等值电路,计算各线路出口处零序电流工频分量与暂态分量的幅值之比,分析各线路出口处零序电流的幅值特征,得出所有健全线路零序电流暂态分量与稳态分量的幅值之比相等,且明显小于故障线路零序电流暂态分量与稳态分量的幅值之比。该方法仅利用了零序电流幅值信息,实现简单,不受零序互感器极性的影响。通过MATLAB仿真和现场数据验证了方法的正确性。The traditional single-phase grounding fault line selection methods will malfunction or refuse to operate due to the incorrect polarity connection of transformers.To solve this problem,a line selection method based on the comparison between zero-sequence current amplitudes is proposed.According to the equivalent circuit of the resonant ground⁃ing system under single-phase grounding fault,the ratios of power-frequency component of zero-sequence current to the transient component at the outlet of each line are calculated,and the amplitude characteristics of zero-sequence current at the outlet of each line are analyzed.Results show that the ratios between the amplitudes of transient and steady-state components of zero-sequence current in all the healthy lines are equal,and they are obviously smaller than those in the fault line.This method only uses the information about the zero-sequence current amplitude,which is simple to implement and not affected by the polarity of the zero-sequence transformer.Simulations based on MATLAB and field data verified the correctness of the proposed method.

关 键 词：谐振接地系统 小电流接地故障 故障选线 互感器极性 幅值之比 

分 类 号：TM713[电气工程—电力系统及自动化]