基於同步相量之多端複合線徑輸電線路故障定位演算法設計

Design of Synchrophasor-Based Fault Location Algorithm for Multi-Terminal Nonhomogeneous Transmission Lines

李育儒(YU-JU LEE)

指導教授 ： 劉志文

國立臺灣大學/電機資訊學院/電機工程學研究所/博士(2018年)

https://doi.org/10.6342/NTU201804308

摘要

本論文針對多端複合線徑之輸電線路以及三端複合線徑之輸電線路架構其中一端之匯流排斷路器開路之情況，分別提出兩套以同步相量量測為基礎之故障定位演算法。其中，同步相量量測資料來自安裝於各匯流排上之相量量測單元(Phasor Measurement Unit, PMU)或智慧型電子裝置(Intelligent Electronic Device, IED)。此兩種故障定位演算法概述如下。
首先，多端複合線徑之輸電線路故障定位演算法係以本研究室過去所提出之雙端輸電線路故障定位演算法為基礎，藉由判斷出故障所在之分歧線(Branch)，進而計算出故障位置。本演算法利用圖學理論(Graph Theory)的概念以兩個拓墣(topology)矩陣來表示各匯流排(buses)與各引接點(Junction points)間之連結關係。依據此連結關係依序求出各引接點之代表電壓/電流相量，判斷出故障所在之分歧線。為了有效提升故障定位技術之精準度，本論文亦提出一最佳化故障定位指標計算視窗可有效降低因直流衰減(DC decay)以及電弧現象(Arcing phenomenon)造成之定位誤差。
其次，本論文針對三端複合輸電線路其中一端之匯流排斷路器開路之情況進行討論。此故障定位方法係利用雙端輸電線路故障定位演算法來判斷故障所在之分歧線。當故障發生在未停用之輸電線上時，由雙端輸電線路故障定位演算法求得之故障定位指標將可用來計算故障發生位置。然而，當故障發生於停用之輸電線上時，該故障定位指標會判斷故障發生於線路引接點(Junction point) 上。此時，本研究利用線路引接點上之視在電抗(Apparent reactance)以及相序網路提出一進階故障定位指標(Advanced fault location index)以計算發生在停用之輸電線路上之故障點位置。
本論文提出之故障定位演算法以及最佳化故障定位指標計算視窗經MATLAB/Simulink進行模擬後證實本研究提出之方法均能有效求出故障點之精確位置。此外，本研究亦利用台電輸電線路事故資料進行故障定位指標計算視窗之效能驗證。結果證實，利用本論文提出之故障定位指標計算視窗求得之故障點位置，其計算誤差遠低於目前建置於台灣輸電線路上數位保護電驛所提供之故障點資訊。

關鍵字

故障定位 ； 相量量測單元 ； 智慧電子裝置 ； 網路拓樸

並列摘要

In this dissertation, there are two synchrophasor-based fault location techniques for multi-terminal nonhomogeneous transmission lines and three-terminal nonhomogeneous transmission lines with one off-service line branch proposed. The synchronized voltage and current data sets are provided by intelligent electronic devices (IEDs) or phasor measurement units (PMUs) which are deployed on buses. These two fault location methods are explained briefly as below.
For multi-terminal nonhomogeneous transmission lines, the method uses two-terminal fault location technique as the basis to locate the exact fault point by distinguishing the faulty line branch in multi-terminal nonhomogeneous transmission lines. The graph theory is adopted to represent the connection relationship among buses and junction points. Based on the connection relationship, the represented voltage and current phasors of junction points can be obtained orderly so as to identify the faulty line branch. For enhancing accuracy, an appropriate calculation data window is also proposed to mitigate the undesirable influence caused by DC decay and arcing phenomenon.
This three-terminal nonhomogeneous transmission lines with one off-service line branch is also taken into account in this dissertation. This algorithm also uses two-terminal fault location technique to identify the faulty line branch and locate the fault point when a fault exist on one of in-service line branches. Contrarily, the two-terminal fault location technique only can point out that a fault exists at the junction point even if the real fault point is on the off-service line branch. Therefore, an advanced fault location index is proposed by using the apparent reactance of the junction point P and sequence network to locate the exact fault point which occurs on the off-service line branch.
Two proposed fault location techniques and the appropriate calculation data window are demonstrated by MATLAB/Simulink, the results show that proposed methods can calculate the exact fault point within minor calculation error regardless of the different fault types and fault resistance. The result of the proposed calculation data window is also verified by realistic cases of TPC (Taiwan Power Company), the calculation error derived by using the proposed calculation data window is lower than the results which provided by installed digital relays apparently.

並列關鍵字

Fault location ； phasor measurement units (PMUs) ； intelligent electronic devices (IEDs) ； network topology

參考文獻

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