柴謙益+鄭文斌+潘捷凱+陸紹彬+溫積群
摘 要: 針對(duì)智能配電網(wǎng)傳統(tǒng)保護(hù)方法整定復(fù)雜、容錯(cuò)和適應(yīng)性差等問題,基于大數(shù)據(jù)分析,提出并設(shè)計(jì)一套智能配電網(wǎng)狀態(tài)監(jiān)測(cè)及故障處理方法。該方法先后經(jīng)過數(shù)據(jù)預(yù)處理、數(shù)據(jù)融合、數(shù)據(jù)分析與可視化以及狀態(tài)辨識(shí)與處理共4個(gè)環(huán)節(jié),將多電氣特征量融合轉(zhuǎn)變成為單個(gè)綜合特征量,監(jiān)測(cè)配電網(wǎng)運(yùn)行狀態(tài),并能根據(jù)各個(gè)節(jié)點(diǎn)關(guān)聯(lián)情況和局部異常因子大小實(shí)現(xiàn)對(duì)智能配電網(wǎng)故障區(qū)域的判定和定位。經(jīng)RTDS半實(shí)物閉環(huán)測(cè)試,故障判定和定位準(zhǔn)確性及可靠性較高,具有一定的參考價(jià)值。
關(guān)鍵詞: 智能配電網(wǎng); 保護(hù)方法; 大數(shù)據(jù)分析; 狀態(tài)監(jiān)測(cè); 故障定位; 故障處理
中圖分類號(hào): TN915?34; TP393 文獻(xiàn)標(biāo)識(shí)碼: A 文章編號(hào): 1004?373X(2018)04?0105?04
Abstract: In allusion to the problems of complex setting, poor fault tolerance and poor adaptability of the traditional smart distribution network protection methods, a condition monitoring and fault processing method of smart distribution network is proposed and designed based on big data analysis. In this method, four procedures of data preprocessing, data fusion, data analysis and visualization, and condition identification and processing are performed to make multi?electrical characteristic quantities fused and transformed into single comprehensive characteristic quantity. The operation state of distribution network is monitored, and the judgment and location of fault area in smart distribution network are realized according to the correlation condition of nodes and the values of local outlier factors. The RTDS semi?object closed?loop test was carried out. The results show that the method has high accuracy and reliability of fault judgment and location, which also has a certain reference value.
Keywords: smart distribution network; protection method; big data analysis; condition monitoring; fault location; fault processing
智能配電網(wǎng)中引入新能源類DG容易在局部區(qū)域產(chǎn)生雙向不定潮流,不僅使網(wǎng)絡(luò)結(jié)構(gòu)復(fù)雜化,改變配電網(wǎng)的眾多故障特性,還給保護(hù)控制設(shè)計(jì)提出了一定的挑戰(zhàn)[1?2]。而大多數(shù)保護(hù)方法的故障判據(jù)均使用小樣本的單一電氣特征量,整定所需計(jì)算較為復(fù)雜,且在運(yùn)行環(huán)境變化時(shí)需要重新進(jìn)行整定,保護(hù)可靠性方面也存在著一定的風(fēng)險(xiǎn)。在通信或傳感器異常時(shí),也容易產(chǎn)生誤動(dòng)或拒動(dòng)保護(hù)[3?6]。
在智能配電網(wǎng)中加入大量傳感設(shè)備,采集、上傳并分析運(yùn)行數(shù)據(jù),形成智能配電網(wǎng)的大數(shù)據(jù)。目前已被用于用電行為分析、負(fù)荷預(yù)測(cè)等應(yīng)用中,潛力較大且也為配電網(wǎng)保護(hù)方法提供了一個(gè)新的思路[7?10]。因此,本文基于大數(shù)據(jù)分析設(shè)計(jì)了一種智能配電網(wǎng)狀態(tài)監(jiān)測(cè)及故障處理方法。該方法將多電氣特征量融合轉(zhuǎn)變成為單個(gè)綜合特征量,監(jiān)測(cè)配電網(wǎng)運(yùn)行狀態(tài)。并能根據(jù)各個(gè)節(jié)點(diǎn)關(guān)聯(lián)情況和局部異常因子大小對(duì)故障區(qū)域進(jìn)行判定及定位,其準(zhǔn)確性與可靠性較高,能為類似基于大數(shù)據(jù)的智能配電網(wǎng)狀態(tài)監(jiān)測(cè)及相應(yīng)的故障處理提供技術(shù)支持。
1 狀態(tài)監(jiān)測(cè)及相應(yīng)故障處理方案設(shè)計(jì)
本文方法的處理流程如圖1所示,其分為數(shù)據(jù)預(yù)處理、數(shù)據(jù)融合、數(shù)據(jù)分析與可視化、狀態(tài)辨識(shí)與處理4個(gè)環(huán)節(jié)。
2 狀態(tài)監(jiān)測(cè)及相應(yīng)故障處理算法設(shè)計(jì)
2.1 數(shù)據(jù)預(yù)處理
數(shù)據(jù)預(yù)處理用于對(duì)各傳感設(shè)備所上傳的原始數(shù)據(jù)進(jìn)行初步篩選和預(yù)處理,減少無關(guān)數(shù)據(jù)量并產(chǎn)生所需的初始特征量矩陣。該環(huán)節(jié)主要包括選取特征量、構(gòu)建關(guān)聯(lián)矩陣、處理區(qū)域差分。選取特征量過程中,本文選取的電氣特征量為電流與功率。其中,涵蓋了三相電流、負(fù)序電流、及零序電流和相應(yīng)的有(無)功功率。
構(gòu)建關(guān)聯(lián)矩陣,其過程為:首先對(duì)配電網(wǎng)中的各終端節(jié)點(diǎn)Ej進(jìn)行編號(hào),節(jié)點(diǎn)間的區(qū)域Zi同樣也進(jìn)行編號(hào),最終根據(jù)表1所示的規(guī)則構(gòu)建矩陣。
4) 最后獲得降維后的二維空間表示[M=x1x2]。
離群點(diǎn)檢測(cè)過程采用的是局部異常因子的相關(guān)檢測(cè)方法(基于密度),檢測(cè)對(duì)象的LOF數(shù)值與離群點(diǎn)的離群程度成正相關(guān),若數(shù)值約為1則離群點(diǎn)不存在。
2.4 故障判定與處理
由于配電網(wǎng)運(yùn)行也會(huì)發(fā)生由傳感器故障而導(dǎo)致的保護(hù)誤判甚至是誤動(dòng)。因此,本文設(shè)定單一類型觸發(fā)故障條件(傳感器、電力)并進(jìn)行處理,所需的判據(jù)如下:滿足故障啟動(dòng)判據(jù),然而廣義節(jié)點(diǎn)處的LOF并未滿足整定閾值。此時(shí)判定為傳感器故障,故障節(jié)點(diǎn)即為最大的LOF值所在的節(jié)點(diǎn),數(shù)據(jù)處理中心向各測(cè)控終端發(fā)送告警信息,確保終端的可靠不動(dòng)作;若是滿足判據(jù)且LOF值也達(dá)到甚至超過了整定閾值,此時(shí)判定出現(xiàn)電力系統(tǒng)故障,物理節(jié)點(diǎn)所處的公共區(qū)域被定位,數(shù)據(jù)處理中心則對(duì)故障發(fā)生節(jié)點(diǎn)發(fā)送動(dòng)作命令,并進(jìn)一步執(zhí)行隔離操作。endprint
3 實(shí)例分析
為了驗(yàn)證本文所設(shè)計(jì)提出方法的可行性,文中以某含雙DG的10 kV智能配電網(wǎng)為研究對(duì)象,如圖2所示,在RTDS中結(jié)合實(shí)際參數(shù)搭建相關(guān)模型,如圖3所示。
圖4所示為配電網(wǎng)運(yùn)行正常狀態(tài)下,多維尺度降維和相應(yīng)的LOF值的可視化分析圖??梢娬_\(yùn)行狀態(tài)下,并未出現(xiàn)離群點(diǎn),且各節(jié)點(diǎn)(1~17,17為廣義節(jié)點(diǎn))由于較為近似,圖4中降維結(jié)果表現(xiàn)為一處于坐標(biāo)原點(diǎn)的點(diǎn)狀區(qū)域,LOF值均在1附近。根據(jù)判定規(guī)則,此時(shí)配電網(wǎng)并無故障發(fā)生。
圖5所示為Z11饋線區(qū)段存在單相接地故障,所對(duì)應(yīng)的多維尺度降維和相應(yīng)的LOF值的可視化分析圖。其中,13和14物理節(jié)點(diǎn)、廣義節(jié)點(diǎn)(17)均成為離群點(diǎn),對(duì)應(yīng)的LOF值達(dá)到約96。
此時(shí),判定發(fā)生了電力系統(tǒng)的相關(guān)故障,定位故障為節(jié)點(diǎn)13,14所處的Z11區(qū)域。數(shù)據(jù)處理中心及時(shí)向故障節(jié)點(diǎn)終端發(fā)送跳閘指令,將Z11區(qū)域隔離。此外,本文也做了節(jié)點(diǎn)4傳感器出現(xiàn)故障而失效、母線節(jié)點(diǎn)Z2區(qū)域出現(xiàn)故障(兩相接地)場(chǎng)景下的測(cè)試,監(jiān)測(cè)和定位效果良好,能將故障及時(shí)有效地反饋和定位出來。
4 結(jié) 語
以大數(shù)據(jù)在智能電網(wǎng)出現(xiàn)運(yùn)用為背景,本文基于大數(shù)據(jù)技術(shù)設(shè)計(jì)并提出了一套智能配電網(wǎng)狀態(tài)監(jiān)測(cè)及故障處理方法。狀態(tài)監(jiān)測(cè)中將多電氣特征量融合成為單個(gè)綜合特征量,保證辨識(shí)準(zhǔn)確性。再以LOF值替代電氣特征量的判定,避免了繁瑣的整定計(jì)算。
經(jīng)實(shí)驗(yàn)測(cè)試,該方法能對(duì)單一故障條件下發(fā)生的電力系統(tǒng)或傳感器故障進(jìn)行有效的識(shí)別和定位,并具有一定的容錯(cuò)能力,為類似檢測(cè)與故障處理方法的研究提供了參考。
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