摘要
配电网中发生最多的是接地故障，因此如何快速准确地检测接地故障成为配电自动化的一个较为重要的研究课题。国内外配电网中性点均采用非直接接地方式，在发生接地故障时，故障电压和电流的暂态过程持续时间短但含有丰富的特征量，而稳态时数值很小，因此在接地故障检测中选用一种适合分析其暂态分量的新理论，将有利于提高接地故障检测保护的性能。小波分析克服了傅里叶变换不能对信号同时进行时频局部化分析的缺点，具有很强的信号特征提取能力，尤其对暂态突变信号或微弱变化信号的处理表现出明显的优势。文中把快速衰减振荡的小波函数运用于配电网接地故障检测中，通过对ＥＭＴＰ仿真数据的分析，证明该方法可以有效提高接地保护的动作性能。
How to detect earth-fault quickly and accurately is an important subject in distribution automation system.Because the neutral point in distribution automation system is not grounded directly,the transient status of fault-voltage and current last only for a short time but comprise abundant characteristic values when earth-fault happens.On the other hand,the static value is very small,so choosing a new theory to analyze the transient value will enhance the ability of earth-fault relaying.Wavelet analysis over comes the shortcoming of Fourier transform in the term of time-frequency analysis.It has strong ability to abstract the character of signal,especially in analyzing the transient signal or faint signal.The paper uses the declining and oscillating wavelet function into the earth-fault detection of distribution automation system.The analysis of the data from EMTP proves that the proposed method can enhance the ability of relaying greatly.
出处
《电力系统自动化》
EI
CSCD
北大核心
1999年第13期33-36,共4页
Automation of Electric Power Systems
