超高壓變電所內外接地故障之電磁特性研究

A study on the Electromagnetic Characteristics of Ground Fault inside and outside of Extra High Voltage Substation

陳哲樟(Che-Chang Chen)

指導教授 ： 周至如 ； 何金滿

中原大學/工學院/電機工程研究所/碩士(2007年)

https://doi.org/10.6840/cycu200700249

摘要

摘要
超高壓變電所連接超高壓輸電系統以及特高壓輸電系統，是輸電系統的樞紐，影響整個電力系統的運轉。又因其短路容量很大，一旦發生接地故障時，有大量故障電流注入其接地系統，對變電所的人員及各種系統與設備將有很不利的影響。本研究以一個典型的超高壓變電所為對象，分別探討所內、外發生接地故障時，接地系統的各項特性，包括地電位昇(GPR)、步間電壓、接觸電壓及電磁場的分佈情形，並藉此，評估對於人員、設備及其它系統之影響。文中首先應用電磁暫態分析程式(EMTP/ATP)分析接地故障電流，其中考慮不同接地故障位置及故障電阻，經由分析結果可獲得注入接地網的電流，包括故障點、主變壓器中性點及架空地線皆地點等處之電流，然後應用接地系統電磁分析軟體分析不同故障條件下之各項電磁特性，包括穩態及暫態特性。最後根據這些分析結果以評估其影響，包括對人員及設備的影響，評估結果以目前變電所之設計對人員安全較尚無安全上之顧慮，但對敏感的設備及系統應加以防護，本研究相關分析所得之數據可作為進一步探討防護措施之參考。

關鍵字

地電位昇 ； 步間電壓 ； 縱向感應電壓 ； 接觸電壓 ； 接地故障

並列摘要

Abstract
The extra-high voltage substations (E/S) interconnect with extra-high voltage (EHV) and very-high voltage (VHV) transmission systems, thus they are vital points of power system with very important affections on the operation of power system. Due to their very large short circuit capacity, very large ground fault current will inject into their grounding systems when ground fault which why produce detrimental effects on personnel and various system and equipments in the substation. In this thesis, the ground fault characteristics of a typical E/S are studied considering internal external ground faults, in which the distributions of ground potential rise (GPR), step voltage, touch voltage and electromagnetic field, on the ground system of E/S are analyzed and their affections on personnel, equipments and other systems are evaluated. The ground fault currents with respect to different fault location and various ground fault resistances are first analyzed by the electromagnetic transient program/alternative transient program (EMTP/ATP). Form which, the fault currents injected into grounding system at fault points, neutral points of main transformers and the grounding points of overhead ground wires are obtained. Based on these injected currents, a software package of grounding electromagnetic characteristics is used to analyze the distributions of GPR, step voltage, touch voltage and electromagnetic fields on the grounding system of E/S both in steady state and transient state. Finally, based on these analysis results, the affections on personnel, equipments and systems are evaluated. The evaluation results had shown that the personnel safety can be assured but more affections should be given to sensitive equipments and systems. The associated data from this study is useful for further survey on the protection measures.

並列關鍵字

GPR ； Touch Voltage ； Grounding Fault ； Step Voltage

參考文獻

[26] 胡開泰，”多地網大型接地系統接地故障之電磁特性研究”，中原大學電機研究所碩士論文，民國九十年六月。

[27] 吳孟昌，”大型高科技工廠接地系統雷擊與開關突波特性分析”，中原大學電機研究所碩士論文，民國九十一年六月

[38] 曾世翰，”特高壓地下環路供電系統之接地系統接地故障特性研究”，中原大學電機研究所碩士學位論文，June.2004。

[50] 林南瑞，”大型科技廠接地系統之接地故障特性研究”，中原大學電機研究所碩士論文，92年6月。

[51] 鄭富雄，”25kV高壓電纜接頭之施工與事故分析及防範對策”，中原大學電機研究所碩士技術報告，92年6月。