大眾捷運系統牽引動力變電站接地故障 之地電位分佈及其影響研究

Ground potential Distribution and Its affections When A Ground Fault occurred on the Traction Power Substation of Metropolitan Rapid Transit System

涂立榮(Li-Long Tu)

指導教授 ： 周至如

中原大學/工學院/電機工程研究所/碩士(2002年)

https://doi.org/10.6840/cycu200200016

摘要

摘 要
大眾捷運系統穿梭於都會地區人口密集之處，首重安全，而安全應考慮的因素很多，其中供電系統的牽引動力變電站發生高壓接地故障的影響非常嚴重，因不但會造成停電而且造成接地系統地電位昇，此地電位昇可經由各種互連導體轉移至各地，形成一種轉移電壓之傷害，尤其軌道、車站、行控中心及維修廠都可能遭受此種轉移電壓傷害人員及設備的安全，目前國內的捷運系統尚處於萌芽階段累積經驗不足，對於接地故障的問題雖然在設計時已針對個別變電站考慮其接地電阻，但接地系統地電位昇引起的轉移電壓傷害，牽涉到整體系統地電位分佈的問題，有必要進一步分析並評估其影響，以作為防護的參考。
本研究探討大眾捷運系統牽引動力變電站接地故障之地電位分佈及其影響，首先建立其電路模型，此模型是一種「交錯連結的階梯電路模型」，此模型將考慮所有牽引動力變電站的接地系統及各種互連導體，然後依據此模型分析牽引動力變電站接地故障造成重要地點的地電位湧昇及其衍生的轉移電壓，最後根據分析結果進一步評估對人員及設備的影響。

關鍵字

轉移電壓 ； 地電位昇 ； 交錯連結的電路模型 ； 大眾捷運系統

並列摘要

ABSTRACT
The metropolitan rapid transit system（MRTS）passes through urban area with thick people distribution. The first consideration to MRTS is safety, i.e., the MRTS must be safe for people and equipments. Many factors affect the safety of MRTS, in which the high voltage ground fault occurred on the traction power substation is very critical to people and system. This is because of that the ground fault will not only cause the traction power system to tript out of service but also cause the grounding system to produce ground potential rise（GPR）which will be transferred to other places by some interconnected conductors to form transferred voltages to damage personnel and equipments, especially, the damage of transferred voltage may occurred on rail way, passenger stations, control center, maintenance/repair depot, etc. At present, the domestic MRTS are still in the initial stage with lack of experience in ground faults. In the problem of ground fault, although the grounding resistance had been considered in the design of each substation grounding system, the damage of transferred voltage can not be full characterized by grounding resistance without analysis of grounding potential distribution of the whole MRTS. The proposal is aimed to study the ground potential distribution when a ground fault occurred on the traction power substation of an operated MRTS.
In this paper, the ground potential distribution due to the ground fault on the traction power substation of metropolitan rapid transit systems (MRTS) and its affections are studied. The circuit model is called "the cross-bonding ladder circuit model". The circuit model represents the interconnected ground system of MRTS is first constructed, in which all the grounding systems of traction power substation and various interconnects conductors are considered. The ground potential rise (GPR) and the associated transfer voltages at the critical positions are analyzed by using the circuit model. Finally, the affections of GPR and the transfer voltages on the personnel and equipments are assessed.

並列關鍵字

metropolitan rapid transit system（MRTS） ； the cross-bonding ladder circuit model ； ground potential rise (GPR) ； transferred voltages

參考文獻

〔1〕 F. Dawalibi and George B. Niles, “Measurements and Computations of Fault Current Distribution on Overhead Transmission Lines”, IEEE Trans. on Power Apparatus and Systems, Vol. PAS-103, No. 3, March 1984, pp. 553-560.

〔3〕 J. Fortin and H. G. Sarmiento, “Field Measurement of Ground Fault Current Distribution and Substation Ground Impedance at LG-2 QUEBEC”, IEEE Trans. on Power Delivery, Vol. PWRD-1, No. 3, July 1986, pp. 48-60.

〔4〕 W. George, “Power System Ground Fault Current Distribution Using the Double-side Elimination Method”, IEEE Trans. on Power Delivery, Vol. PWRD-1, No. 1, 1986, pp. 17-25.

〔5〕 L. Levey, “Calculation of Ground Fault Current Using an Equivalent Circuit and a Simplified Ladder Network”, IEEE Trans. on Power Apparatus and Systems, Vol. PAS-101, No. 8, Aug 1982, pp. 2491-2497.

〔6〕 A. P. Meliopoulos,R. P. Webb, E. B. Joy and S. Patel, “Computation of Maximum Earth Current in Substation Switchyards”, IEEE Trans. on Power Apparatus and Systems, Vol. PAS-102, No. 9, Sep 1983, pp. 3131-3139.