高運量捷運系統軌道電位及雜散電流分析

The Heavy Carriage Rapid Transit System Rail Voltage and Stray Current Analysis

陳孟堯(Meng-Yao Chen)

指導教授 ： 周至如

國立臺北科技大學/電資學院/電機工程系 優質電力產業研發專班/碩士(2008年)

https://doi.org/10.6841/NTUT.2008.00318

摘要

典型高運量捷運系統電車牽引動力採直流供電並以行車軌做為路徑，牽引動力之電流係由牽引動力變電站經第三軌送至電聯車上。這些牽引電流再經鋼軌回流至牽引動力變電站的負端，在此部分牽引電流會經行車鋼軌洩漏至大地，稱為雜散電流，而行車鋼軌相對於大地之間的電位稱為軌道電位。雜散電流是直流對鐵質結構物及管路等都會加速其腐蝕(稱為電蝕現象)，對於一些敏感的系統亦可能造成干擾，因此，雜散電流可是一種公害，有必要加以評估。至於軌道電位的上升，則會影響軌道相關設備及維護人員的安全。為此，本研究針對兩種可能的電車供電方式，即單邊供電及雙邊供電兩種方式探討其雜散電流及軌道電位，首先推導其軌道電流及雜散電流分佈公式，並定義了累積雜散電流、雜散電流長度及雜散電荷長度等做為評估雜散電流影響的指標，這些指標的分析方式亦將加以推導。文中將以典型大台北都會區兩條大運量捷運系統進行詳細之模擬與分析，其中考慮電車之負載量及位置變化，最後將根據分析結果評估其可能之影響。

關鍵字

雜散電流 ； 軌道對地電位 ； 雜散電流分佈 ； 累積雜散電流 ； 雜散電流長度 ； 電荷長度指標

並列摘要

Typical heavy carriage rapid transit system adopts DC as traction power and takes rails as current return path. Traction current is delivered for traction substation through the third rail to the vehicle, and then returns to the negative end of traction power substation through steel rail. A portion of traction current will leak from the steel rialto the ground; which is called “stray current”, and the voltage between steel rail and ground is called rail-to-ground potential. The stray current is dc-current which will produce severe electrical corrosive effects on iron （or steel）structures, pipes, etc. Further more, some sensitive system may suffer from interference from stray current. Therefore, stray current can be regarded as a public detriment. And besides, the rise of rail-to-ground potential may bring threat to the safety of personnel and railway related equipments. This thesis focuses on two appropriate types of power supply source to train namely“single-side source” and “double-side source” respectively. Firstly, the equations of rail current and stray current distributions along the railway with respect to each type of power source are derived, theoretically, and then the accumulative stray current, stray current-length and stray charge-length are defined as the indexes for assessing the affections of stray current. These index equations will also be derived. This thesis will conduct detailed analysis and simulation on the two typical lines of heavy carriage rapid transit system in Taipei urban area, with the variation of carriage load and positions taken into consideration. Finally, potential threats and influence will be evaluated based on the analysis result.

並列關鍵字

Stray Current ； Rail-to-Ground Potential ； Stray Current Distribution ； Accumulative Stray Current ； Stray Current-Length ； Index of Charge-Length

參考文獻

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