架空輸電線路之防雷策略及其接地系統之雷擊特性研究

Lightning Protection Strategies and Lightning Characteristics of Grounding System of Overhead Transmission Lines

洪得峻(Te-Chun Hung)

指導教授 ： 周至如

中原大學/工學院/電機工程研究所/碩士(2004年)

https://doi.org/10.6840/cycu200400171

摘要

雷擊是架空輸電線路的重大天然災害之一，雷擊所造成的線路及設備的損壞及其衍生的損失相當慘重，故架空輸電線路的防雷措施非常重要，雖然目前的架空輸電線路都有其防雷措施，但雷害事故仍時有所聞，對輸電系統的供電品質及可靠度都有極為不利的影響，為達到高品質及高可靠度的供電，傳統的防雷策略須有檢討改進的必要。為此，本文先根據IEEE-Std.1243標準整理防雷對策，然後檢討台電輸電系統現行的防雷對策，並提出可再加強的部分，其中特別針對其輸電鐵塔的接地系統深入的檢討，因為雷害事故都與鐵塔的接地系統有密切的關係。檢討發現目前輸電鐵塔的接地系統都以接地棒為主，而且主要考慮其接地電阻，由於接地電阻僅能描述低頻的特性，無法完全描述雷擊特性，故本文由接地系統的雷擊特性分析著手，探討不同接地系統架構在不同雷突波的作用下之特性，包括地電位昇、電磁場、接觸電壓與步間電壓之特性，最後以這些特性分析結果為基礎加以比較，檢討目前台電輸電鐵塔的接地與防雷性能之關係，並提出改善策略。研究結果顯示69kV輸電鐵塔接地系統的雷擊特性最差，宜配合增設線上避雷器、架空地線、線下遮蔽線等方式來改善其防雷能力。

關鍵字

雷擊防護 ； 接地系統 ； 架空輸電線

並列摘要

The lightning is one of the most serious natural disasters on the overhead transmission lines. Many damages on transmission lines and apparatus and their related losses due to lightning are very severe. So, it is very important to protect the overhead transmission lines from lightning damages. At present, although the overhead transmission lines always have lightning protection measures, the lightning damages are still happened frequently, and thus greatly decrease the power quality and reliability of transmission system. Hence, the conventional lightning protection strategies should be reviewed and improved for the requirements of high quality and reliability of transmission system. For this, the thesis firstly integrates the lightning protection strategies based on the standard ” IEEE-Std.1243 ”. Then the existent lightning protection strategies on Taipower transmission system are reviewed and their reinforcements are proposed, in which the grounding system of transmission tower will be deeply investigated because the lightning faults are very close relation with the grounding system of tower. From the investigations, it is found that most of grounding systems of tower are mainly constructed with vertical ground rods and focused on their grounding resistances of grounding system. The grounding resistance can not completely describe the lightning characteristics of grounding system. So, the investigations of grounding system of tower will be based on the lightning characteristics analysis by considering various different schemes of grounding system and different lightning surge currents. The lightning characteristics of grounding system to be analyzed include the grounding potential rise (GPR), the electromagnetic field and the touch and step voltages, from which the defects of grounding system will be found out. Finally, the improvement strategies for increasing the performance of lightning protection of transmission lines are proposed based on the investigations of grounding system. The study shows that the performance of lightning protection of grounding system of 69kV transmission system is weakest of all transmission systems. Other improvement methods such as to install line arresters, and to increase overhead ground wires or shielding wires under lines may be needed for improving the performance of lightning protection.

並列關鍵字

Grounding Systems ； Overhead Transmission Lines ； Lightning Protection

參考文獻

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