變電所遭受雷擊突波暫態之研究

Study on Lightning Surge Transients of Substations

陳俊偉(Jyun-Wei Chen)

指導教授 ： 李清吟

國立臺北科技大學/機電學院/電機工程系所/碩士(2006年)

摘要

在台灣地區，雷害是電力系統中最常發生的天然災害，約佔全年機電系統事故的一半以上。當落雷擊中輸電線路時，其會注入之巨大的能量，將產生很高電壓與電流突波，此突波經由輸電線路傳播後，進而入侵變電所的各種變電設備。雷擊突波入侵方式可分為逆閃絡雷擊、直接雷擊和感應雷擊等三種途徑，其中又以發生在變電所引出入口處鐵塔的近距離逆閃絡雷擊現象最具嚴重性。因突波可能會破壞設備之絕緣損壞，而影響電力系統的供電可靠。台電公司變電所的耐雷設計，主要是為了要保護變壓器，所以儘可能的將避雷器裝在主變壓器附近。避雷器之有效保護範圍是有限的，故靠近引出入口周邊設備可能位於避雷器保護範圍之外，而遭受雷擊破壞。變電所中之眾多變電設備，必須能夠承受由輸電線路導入的雷擊突波衝擊，為此有必要對變電所之雷擊過電壓進行研究，採取更適當的對策，來減低設備損壞，進而保護人員生命安全，並提升運轉可靠度。
本文針對台電系統南湖與松山一次變電所(屋外式)，藉由電磁暫態分析程式ATP/EMTP模擬，探討在雷擊事故發生時的暫態過電壓現象。模擬條件分別為：變電所匯流排連接方式、斷路器配置、並聯電容器組使用情況及主變壓器之使用情形等，做不同雷擊電流的大小與不同鐵塔位置遭受雷擊情況模擬。分析結果顯示，若只在變電所主變壓器側裝置避雷器，則無法完全保護到匯流排上的設備，使其免受雷擊傷害，故可考慮在重度雷擊區域的變電所，在輸電線路入口處加裝避雷器來保護變電所之設備。

關鍵字

變電所 ； 雷擊 ； 暫態過電壓 ； 避雷器 ； 絕緣協調

並列摘要

In Taiwan, lightning stroke is the natural calamity that happen the most in power systems. It occupied more than 50% in power system accidents every year. There are three ways of lightning surge invade methods – Indirect Lightning Stroke, Direct Lightning Stroke, and Back Flash Lightning Stroke. And the Back Flash Lightning Stroke near the transmission tower of substation is most gravity. The surge might destroy the insulation of device and influence the service reliability of power system. In order to protect the transformer, the Tai-Power Company's substation installs the arrester neat the main transformer as close as possible. The protecting range for the arrester is finite; therefore, the electrical equipments near the current entrance may exceed in the protecting range of arrester and be destroyed by the lightning stroke.
This article is aimed at Tai-power Company’s Nan-Hu and Song-Shan primary substation (outdoor substation), to probe into the transient overvoltage phenomenon whiles the lightning stroke happening by the simulation of ATP/EMTP–the electromagnet transient analysis program. To simulate the situation of different lightning strokes and different lightning stroke points and analyze the protection of arrester in substation. The result of the analysis shows that if we locate the arrester next to the main transformer in substation only, it can not protect all the equipments in substation at all. Therefore, we can consider assembling arrester at the transmission entrance in order to protect the equipments in the substation which located in the area that suffer the lightning strokes the most.

並列關鍵字

Substation ； Lightning stroke ； Transient overvoltage ； Arrester ； Coordination of insulation

參考文獻

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