CAJ | 학술논문

直流系统的可靠性和安全性对于发电站、变电所的各种负载装置的正常运行有重要的影响，与电网的安全生产息息相关。低频信号注入法作为常用的直流系统接地故障检测方法之一，容易受到对地电容的影响而影响检测的准确性，针对这一问题，深入分析低频信号注入法的原理及存在问题，提出在低频信号注入法的基础上，用小波变换原理，选取适当的小波函数，对提取的信号进行分析和处理。仿真结果表明，该方法可以有效消除对地电容对直流检测的影响，为实现接地故障点的准确定位奠定基础。
직류계통적가고성화안전성대우발전참、변전소적각충부재장치적정상운행유중요적영향，여전망적안전생산식식상관。저빈신호주입법작위상용적직류계통접지고장검측방법지일，용역수도대지전용적영향이영향검측적준학성，침대저일문제，심입분석저빈신호주입법적원리급존재문제，제출재저빈신호주입법적기출상，용소파변환원리，선취괄당적소파함수，대제취적신호진행분석화처리。방진결과표명，해방법가이유효소제대지전용대직류검측적영향，위실현접지고장점적준학정위전정기출。
The reliability and security of DC system have a significant impact on normal operation of various load de -vices in power stations and substations , which is closely bound up with the grid production safety .As one of the most common detection methods in DC system grounding fault , the low frequency signal injection will be influenced easily by the capacitance to ground so as to influence the detecting accuracy .Aiming at such problems , the method and the principle of low frequency signal injection have been analyzed deeply .Furthermore , according to the low frequency signal injection method , a new wavelet transform based method has been put forward to analyze and deal with the ex-tracted signal by selecting the proper wavelet function .The simulation results show that the proposed method can alle-viate the influence of the capacitance to ground so as to realize the accurate location for the ground fault .