【正文】 L5表示的是線端子。 使用連續(xù)小波變換在配電系統(tǒng)中故障定位 小波 變換為基礎(chǔ)的算法是構(gòu)思要再加上一個(gè)分布式測(cè)量系統(tǒng)。 此外，它提供 1S為周期 精度 177。 統(tǒng)計(jì)相關(guān)的不確定性 隨機(jī)變量 參數(shù)所產(chǎn)生的 數(shù)據(jù) 以及 通過(guò)使用 大量的模擬測(cè)量算法執(zhí)行 ， 估計(jì)獲得 數(shù)目的計(jì)量 和有關(guān) PDF。 geometry 配電網(wǎng)絡(luò)是由一個(gè) 10Km 長(zhǎng)的主要饋線（ L1 ， L2和 L3 ） 和由兩個(gè) 2Km 長(zhǎng) 的輔助電纜 （ L4 ）和 1Km長(zhǎng) 的 （ L5 ） 及150、 20kVd的 變電站 組成 。 Z254。 b222。 N : n188。a222。 Appendix), the simulated transients relevant to balanced and unbalanced lines do not di?er signi?cantly. d2Iph dx2 188。c2189。 7 frequency value (traveling wave at light speed) (kHz) frequency value (kHz) For the case of nonsymmetrical faults, the di?erent propagation velocities of the various modes of the traveling waves must be taken into account [15]. Considering the line con?guration shown in the Appendix, as a ?rst approxima L1 + L5 2 Im h i 240。Z0189。x222。 [5]): i 188。 2. Fault location information provided by continuous wavelet transform The CWT of a signal s(t) is the integral of the product between s(t) and the socalled daughterwavelets, which are time translated and scale expanded/pressed ver sions of a function having ?nite energy w(t), called motherwavelet. This process, equivalent to a scalar prod uct, produces wavelet coe?cients C(a, b), which can be seen as ‘‘similarity indexes’’ between the signal and the socalled daughterwavelet located at position b (time shifting factor) and positive scale a: Z11 Unlike DWT, CWT can operate at any scale, speci?cally from that of the original signal up to some maximum scale. CWT is also continuous in terms of shifting: during putation, the analyzing wavelet is shifted smoothly over the full domain of the analyzed function. The CWTanalysis is performed in time domain on the voltage transients recorded after the fault in a bus of the distribution work. The analyzed part of the transient recorded signal s(t), which can correspond to a voltage or current fault transient, has a limited duration (few milliseconds) corre sponding to the product between the sampling time Ts and the number of samples N. The numerical implementa tion of the CWT to signal s(t) is a matrix C(a,b) de?ned as p wtb 240。 Continuouswavelet transform。 此外 作者認(rèn)為， 該論文 所 得 到 的結(jié)果 構(gòu)成了故障定位系統(tǒng) （ 分布式體系結(jié)構(gòu) ） 發(fā)展的基礎(chǔ) 。 然而，在我們的 已知 其他許多實(shí)際 情況下，不確定度評(píng)定所提供的手段 是不適用 分析這樣的不確定步驟。其輸出信號(hào) 反饋檢測(cè)模塊 ，其中已實(shí)施的手段模擬 電路中描述的 [ 16 ] 。中立被認(rèn)為是毫無(wú)根據(jù)。在這種情況下只有兩條路 對(duì) L1+L2 有影響。 圖 .1也說(shuō)明了六 個(gè) 涵蓋的 行進(jìn)小波 路徑所 產(chǎn)生的 一個(gè) 故障， 總線 1 。 如下： 平方 和的 值 為 所有 相應(yīng)的以同樣的 頻率的 系數(shù) ，這是 為以 后所 有 連續(xù) 小波 變換信號(hào) Ecwt（ a） ，確定了 每個(gè)頻率元件規(guī)定的重量 的“ 尺度 ” ： 通過(guò)檢查相對(duì) 應(yīng) 最高的 峰值就可以 得到的 Ecwt（ a） 的大小 ，該信號(hào)的檢測(cè) 由 最 明顯 的高頻成分 確定 。 小波 變換 所 提供 故障定位 的資料 一個(gè) S（ t）的該 CWT信號(hào) 是 S（ t） 和所 產(chǎn)生的 諧波 之間積分產(chǎn)品 ， 是 轉(zhuǎn)換 的時(shí)間和 擴(kuò)大 規(guī)模 /壓縮版本一個(gè)函數(shù)具有 有限 能量 的 ）（ t? 函數(shù) 的 基波 。連續(xù) 小波 變換 。電磁暫態(tài) 。這個(gè)過(guò)程中，相當(dāng)于一個(gè)標(biāo)產(chǎn)品， 生產(chǎn) 小波 系數(shù) C（ a,b） ，其中可以看出 作為 “ 相似性指標(biāo) ”的信號(hào)和所謂的 諧波 位于立場(chǎng) 之間 ， b（ 時(shí)間 平移 因數(shù)）是 積 分模型并且正數(shù) a: 其中 *表示復(fù)共軛。從現(xiàn)在起，這些高頻 成分 被稱為 暫態(tài)的“ CWT的 確定頻率 ” 。該行波反映在線路終端 并在故障定位。 與 之相對(duì) 應(yīng) 故障 位置 在主饋線發(fā)送端和 L1 + 15有影響 ， 其 反射系數(shù)的同時(shí) 顯示 在線端子。 雖然有些結(jié)果表明，一些限制的通過(guò)的 Morlet 小波 ，即那些有關(guān)故障 在圖 .1 的 該網(wǎng)絡(luò) (例如， 在 總線 2 均衡故障 )， 其 整體理論計(jì)算值 確定已經(jīng)達(dá)到 CWT 頻率。其輸出是的 TTL雙邏輯信號(hào)，在符合要求的基于 GPS 設(shè)備。 因此， 數(shù)控技術(shù)的基礎(chǔ)上 評(píng)價(jià)方式進(jìn)行 模擬統(tǒng)計(jì) 一些 有意義的 測(cè)量 數(shù)目 ，以便估計(jì)有關(guān)概率密度函數(shù)（ PDF 格式）。 鳴謝 使用連續(xù)小波變換在配電系統(tǒng)中故障定位 這項(xiàng)工作 得到了 CESI研究計(jì)劃的支持 。 Electromagic transients。1222。 0。 240。Y0189。8222。 3 50 tion, the Clark transformation is applied to the voltage transients at the observation point (bus 4) of the distribu tion work of Fig. 1, for di?erent types of unbalanced faults at various locations, also with nonzero fault velocity equal to the speed of light with those identi?ed from the peaks in Fig. 3. If the CWTanalysis is applied to the voltage transients recorded in a di?erent observation point, in other words we are considering a measurement system with distributed architecture (see Section 5), it is possible to increase the information relevant to the fault location. Fig. 4 and Table 2 show the results of the CWTanalysis at bus 2 for the previous case of a zeroimpedance threephase fault at bus 1. For this observation point three paths are of interest: L3 + L4, with opposite sign re?ections at the fault location and at the bus 2, L1 + L2 + L4, with re?ection at the line terminations having the same sign, and L2 + L4 + L5 with re?ection at the line terminations having the same sign. As it can be seen, by joining the information provided by this observation point with those of bus 4, two fault locations can be obtained and an increase of the reliability of the procedure therefore achieved. Fig. 5 and Table 3 show the results for the case of a bal anced fault at bus 5. In this case only two paths are of interest: L1 + L2, with opposite sign re?ections at the fault location and at the main feeder sending end and L1 + L5, with re?ection coe?cient of the same sign at the line terminations. Fig. 6 and Table 4 show the results for the case of a bal anced fault at bus 2, which is the termination of a lateral. In this case three paths are of interest: (a) L1 + L2 + L4, with opposite sign re?ections at the fault location (bus 2) and at the main feeder sending end (bus 4), (b) L1 + L2 + L3 and (c) L1 + L5, with re?ections at the line terminations. The CWTanalysis, performed by using the Morlet motherwavelet, is able to detect only the frequencies asso ciated with two paths, namely the ?rst and the third ones, while the frequency peak associated with the second path appears to be hidden by the ?rst peak due to the large ?lter amplitude related to the adopted motherwavelet. The in?uence of the presence of distributed generation has been also investigated. The analysis is repeated for bal anced faults at bus 1 and bus 5 in presence of a generator connected at bus 2 through a transformer. The CWTiden ti?ed frequency values are very similar to those of Tables 1–3, showing that the presence of the generator does not impedances. Fig. 7 illustrates the results of the CWTanalysis of the voltage