小波包分析和小波包能量介紹

基于五次諧波和小波重構(gòu)能量的配電網(wǎng)單相接地故障的選線方法研究*

孫其東，張開如，伊利峰，宋祥民，李婭蕓

(山東科技大學(xué) 電氣與自動化工程學(xué)院 山東 青島 266590)

摘要: 對配電網(wǎng)經(jīng)常發(fā)生的單相接地短路故障，因為故障點電流非常小，很難通過五次諧波幅值比較來準確地判斷故障線路。提出了五次諧波和小波包能量相結(jié)合的方法。利用小波包對各線路的零序電流的五次諧波進行三層小波包分解，對第三層重構(gòu)系數(shù)進行能量計算求出總的能量值。通過比較各線路零序電流五次諧波的能量值判斷出故障線路。搭建了10kV中性點經(jīng)消弧線圈接地的小電流單相短路接地系統(tǒng)的仿真模型，結(jié)果表明五次諧波與小波包能量結(jié)合的分析方法能夠準確地進行故障選線。

關(guān)鍵詞: 配電網(wǎng)；五次諧波；小波包；能量計算；仿真

中圖分類號：TM773 文獻標識碼：A 文章編號：1001-1390(2016)00-0000-00 Research of single-phase?fault earth fault line selection method for the distribution network based on fifth harmonics and wavelet reconstruction

Sun Qidong, Zhang Kairu, Yi Lifeng, Song Xiangmin, Li Yayun

(College of Electrical Engineering and Automation, Shandong University of Science and Technology, Qingdao 266590, Shandong, China)

Abstract: In view of frequent single-phase grounding fault in distribution network system, because the fault point current is very small, so judging fault line accurately becomes very difficult through fifth harmonics amplitude comparison. The method of fifth harmonics and the combination of wavelet packet energy are presented. The wavelet packet is used to do the third layer wavelet packet decomposition on fifth harmonics of zero sequence current of each line, and then, the total energy on the third floor reconstruction coefficient is calculated. By comparing the fifth harmonic energy of the zero sequence currents, the fault line can be judged. By setting up 10 kV neutral points via arc suppression coil grounding current of single phase short circuit grounding system simulation model, the results show that the method of fifth harmonics and combination of wavelet packet energy can accurately select the fault line.

Keywords: distribution network, fifth harmonics, wavelet packet, energy calculation, simulation

0 引 言

配電系統(tǒng)所出現(xiàn)的故障里，很大部分是單相接地故障。當小電流接地系統(tǒng)出現(xiàn)單相接地故障的時候，因為故障點此時的電流特別小，并且三相彼此間的線電壓是對稱的，對負荷供電一般沒有影響，所以一般情況下允許系統(tǒng)運行一到二小時，沒有必要立刻跳閘[1-4]。但是單相故障發(fā)生后，另外兩相對地電壓要比最初的電壓高锝多，考慮到避免其發(fā)展成兩點或者三點接地故障，這時就應(yīng)該發(fā)出及時信號，以便相關(guān)工作人員采取相應(yīng)的措施消除故障危險。

本文通過對各配電線路零序電流五次諧波提取，然后運用小

總結(jié)

以上是生活随笔為你收集整理的小波包能量matlab,小波包分析和小波包能量介绍.doc的全部內(nèi)容，希望文章能夠幫你解決所遇到的問題。

如果覺得生活随笔網(wǎng)站內(nèi)容還不錯，歡迎將生活随笔推薦給好友。