用于配电网单相接地故障选线的注入信号检测技术  

Signal Injection Detection Technology for Fault Line Selection of Single Phase to Ground Fault in Distribution Power System

作　　者：王希[1] 

机构地区：[1]华北电力大学,河北保定071003

出　　处：《山东电力技术》2015年第8期13-17,共5页Shandong Electric Power

摘　　要：注入信号法已广泛应用于配电系统单相接地故障选线。注入信号的幅值与工频信号相比十分微弱,能否可靠、准确检测出注入信号就成为选出接地线路的关键。在分析注入信号幅值和频率对检测影响的基础上,设计一种模拟滤波与数字滤波相结合的注入信号检测方案。模拟滤波采用双T滤波器,主要完成工频陷波和对注入信号的选频放大;数字滤波采用差分滤波器和带通滤波器,对直流分量、基波和各次谐波进一步衰减,并准确提取注入信号。采用PSPICE和MATLAB分别对模拟滤波电路和数字滤波器性能进行仿真分析,结果表明所设计的滤波系统能够准确、可靠地对注入信号进行检测。Signal injection method has been widely applied in distribution power system to select single phase to ground fault line for many years. The amplitude of injected signal is much weaker than 50 Hz. How to detect the injected signal with high reliability and accuracy is very important for reliable fault line selection. The effect of the amplitude and frequency of injected signal on detection is analyzed, an signal injection detection scheme is designed. This scheme consists of analog filters and digital filters. Analog filters apply double-T filters, which can attenuate 50 Hz signal and amplify injected signal. Digital filters contain differential filters and band-pass filters, which can eliminate direct current signal, 50 Hz signal and harmonic further while picking up the injected signal accurately. Performances of analog and digital filters are analyzed by PSPICE and MATLAB,and results show that this filter system can test the injected signal reliably and accurately.

关 键 词：配电网 单相接地 注入信号检测 模拟滤波 数字滤波 

分 类 号：TM773[电气工程—电力系统及自动化] TM727