- 學位論文
電纜連接站避雷器之電場分佈研究
Electrical Field Analysis of Arrester in Cable Connection Stations
摘要
電纜連接站避雷器在配置上因受到場地限制，部份避雷器均壓環未裝設，致使避雷器頂端電場分佈情形受影響，發生的多起避雷器事故疑與此有關。避雷器主要由基本元素閥元件所組成，故閥元件上的電場、電壓變化成為本文探討的重點。本文以有限元素法，搭配有限元素分析法軟體，針對避雷器閥元件在各種配置下的電場、電壓變化進行深入分析，了解可能的真正事故原因。 本文先參考各類文獻提出避雷器損壞的原因，指出避雷器老化與電場分佈不均勻的關係，結果顯示電場分佈越不均勻，避雷器電場最強處之閥元件越易加速老化。再利用有限元素分析法軟體，建立電纜連接站與避雷器模擬模型，分析電纜連接站與避雷器的電場分佈情形，對避雷器電場分佈進行計算並紀錄，歸納影響避雷器裡閥元件的電壓偏移率的種種因素，對場地配置、元件距離與均壓環裝設與否，進行模擬作業。 本文也對避雷器配置與電場分佈的影響進行模擬分析，利用各種場地立面圖與配置圖，研究各種配置下電場分佈情形與絕緣距離之影響。其中對引接線接入避雷器的模擬分析的結果顯示，高壓引線越是垂直引接入避雷器，對避雷器的影響越小。而避雷器的均壓環是受過設計的均壓設備，經模擬結果所示，288kV避雷器不宜拆換均壓環，對避雷器內外部的電場改變影響很大，可能會造成避雷器老化加速；而144kV避雷器因電壓等級較小，在有條件的裝設情形下，是可不裝設均壓環。
並列摘要
In recent years, many station type zinc oxide arresters have found fault in system special on cable connection stations where space is limited. Here, we study the electric field distribution difference between the arresters which equipped with and without corona ring. This factor seems to be the main reason to influence arresters performance and cause to damage. The topics to be discussed are not only fault investigation but also discuss other topics as following items. 1. The electric field influence by corona ring of arrester on the cable connection station and its degradation impact. 2. The electric field deviation analysis of the arresters with different arrangement geometry on cable connection stations. We use the finite element method (FEM) to analyze the electric field distribution along the length axis and the field stress of each metal oxide element. We have built the simulation models and analyzed the electric field distribution inside and outside of arrester , and whole cable connection station according to Taipower’s parameter. The conclusion of these simulations shown that 288kV arresters shall install with corona rings and the 144kV arresters are not necessarily to install corona rings. In conclusion, through the simulations and results, the researcher can figure out the possible reason for the damages and set up some preventive measures.