- 學位論文
345kV輸電鐵塔雷擊遮蔽分析
Shielding of 345kV Transmission-Line Tower from Lightning Stroke
摘要
本研究探討345kV 輸電鐵塔的雷擊遮蔽方法，比較遮蔽角法和 滾球法之差異，並針對滾球法提出一套可節省工時之模擬程序。台電 345kV 超高壓輸電線第一路的天輪-龍崎區段為高雷害區段，因此本 研究以該區段為對象進行模擬分析。 所謂節省工時，係指執行滾球法的模擬程序，在傳統上須要針對 每一座鐵塔的東、南、西、北，各個方向估計其坡度變化，以現場量 測勘查方式或根據等高線估計，兩者皆相當耗費工時。為改善以上缺 點，本論文提出一套鐵塔雷擊遮蔽的檢測流程，在流程中係以兩項指 標衡量鐵塔的雷擊遮蔽能力，第一項指標衡量鐵塔橫擔鐵構的足以遮 蔽導線能力，第二項指標進一步衡量坡度的影響。整個檢測流程包含 四個步驟：（1）假設各個鐵塔位於平地，亦即忽略其坡度，檢出鐵塔 架構最不能遮蔽的導線相位以及該導體相對於遮蔽邊界之距離（此距 離為所稱之第一項指標）；（2）逐步增大坡度直至三相導線皆無法予 以遮蔽，而以該坡度為臨界坡度（稱為第二項指標）；（3）依兩項指 標衡量鐵塔的遮蔽能力，據之對於鐵塔排序；（4）依此排序，再針對 遮蔽能力最為不足的鐵塔，以等高線地形圖計算其實際坡度。 本文針對天輪-龍崎區段＃109~＃121 號鐵塔進行模擬分析，依檢 測流程排序，對於遮蔽能力最為不足的鐵塔，再與實際的雷擊紀錄相 比較。研究結果顯示：（1）在諸多影響雷擊遮蔽能力的因素當中，最 主要的仍為鐵塔型式及坡度；（2）在檢測的鐵塔型式當中，以A、B、 F 型，遮蔽能力最為不足；（3）本研究所提出的檢測流程與93-96 年 雷擊紀錄相比較，雖存有誤差，但在考量節省工時的效益情況下，仍 具有相當價值。
並列摘要
The thesis discusses the shielding of 345kV transmission-line tower from lightning stroke. In the thesis, differences between the protection angle method and the rolling sphere method were evaluated, and a procedure to implement the rolling sphere method, which can save man-hours, was proposed. The Tien-Lune to Lun-Chi section of the first 345kV transmission route might be the highest lightning stroke frequency within Taipower’s 345kV transmission system. As such, this section was selected in this study to fest the proposed simulation procedure. The so-calld labor saving refers to the saving of high man-hours conventionally required to estimate the slope in the east, west, north and south directions of each tower by actually measuring at the field or based on the contour map. To solve this problem, a new procedure is proposed and presented in this thesis, which uses two indices to measure the lightning shielding capability. The first one measures the capability of the overhead ground wire and the arm structure of tower to shield the line conductors. The second one further measures the effect of slope. The procedure comprises of four steps: on the shielding of conductors, (1) assuming that all towers were located on the horizontal plans by ignoring the slopes temporarily then identify the phase conductor which is outside the shielding range, having the farthest distance from the boundary of shielding (referred to as aforementionedthe first index above); (2) increase the slope gradually until all the three-phase wires are out of the shielding range, which is called the critical slope; (3) rank the towers into order two indices; (4) select the ones having the least shielding capability according to (3) and evaluate the slope by the contour map for the selected towers. This thesis focuses on the simulation of tower no. 109 through no. 121 within the Tien-Lune to Lun-Chi section. The resulted shielding capability order compared with the record of lightning stroke of year 2005 through 2007 at these towers are also presented. The results show that: (1) the most influential factors that affect the lightning shielding capability are the type of towers and the slope, (2) type A, B, and F are of the lower of mountains at the location of towers shielding capability than the other types of tower. The benefit on the saving man-hour worth. Though the simulated order does not exactly match with the recorded, in view of the proposed procedure is still of high value in the future application.