小电流接地系统选线方法的灵敏度分析  

Sensitivity Analysis of Fault Line Detection Method in Small Current Grounded System

作　　者：廖俊宏 帅红[1] 梁伟[1] 

机构地区：[1]重庆市电力公司电力调度控制中心,重庆400014

出　　处：《电力系统及其自动化学报》2014年第6期65-69,80,共6页Proceedings of the CSU-EPSA

摘　　要：分析了现有的多种单相接地故障选线方法,研究基于暂态量的选线方法的灵敏度在CT采样过程中的影响。小电流接地系统的故障暂态信号很有可能被噪声信号覆盖或相互混淆,影响选线的正确性,本文提出在电压形成回路之前加入带通滤波器,利用滤波器除去对选线结果没有影响的工频信号,通过合理选取电流变送器的变比将故障暂态量放大,在保证暂态量的完整性和正确性的同时,提高了选线的可靠性。仿真计算结果表明,该方法可行且适用于实际应用。By analyzing the existing single-phase ground fault line selection methods,this paper studies influence on CT sampling process caused by the sensitivity of line detection methods which are based on transient components.The transient signal after fault in small current neutral grounding system is probably to be inundated with noise signal,thereby affecting the correctness of fault line detection.This article proposes the introduction of band-pass filter to eliminate the 50 Hz signal which begets no impact on line detection,then amplifies the transient component by regulating the transformation ratio of current transmitter,hence this method can ensure the completeness and correctness of transient signals,and enhance the reliability of fault line detection.Simulated results denote that the proposed method is viable in engineering practicality.

关 键 词：配电网 单相接地故障 故障选线 选线灵敏度 

分 类 号：TM711[电气工程—电力系统及自动化]