高速鐵路系統之大地洩漏電流特性分析

The Earth Leakage Current Characteristics of High Speed Railway Systems

劉彥宏(Yan-Hong Liu)

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/cycu200200224

摘要

目前台灣高速鐵路系統正在進行規劃建造，其主變電站將由台電161kV輸電系統供電，再由主變壓器以史考特(Scott)接法，將三相161kV轉換成兩相55kV，每相55kV繞組之兩端分別接引至軌道饋電線及回流線，配合自耦變壓器供電至軌道的列車以減少電壓降及大地洩漏電流。

高速鐵路系統由於負載電流直接以接地網路及軌道當回流路徑，故大地洩漏電流嚴重，因此在系統運轉時無可避免的有些電流會流入地中，此電流在各地流竄將污染大地，甚至造成一些公害，為改善此問題，需對大地洩漏電流的特性有充分的瞭解，包括其成因、大小的分佈、產生的地電位昇分佈以及一些重要的影響參數。本研究首先探討其大地洩漏電流的成因，然後描述高速鐵路系統的組成架構，據此建立分析的電路模型並計算高速鐵路之相關參數。文中提出「擴充修正解耦法」以建立高速鐵路系統的階梯模型，及應用「高斯喬登消去法」發展運算法則來分析電路模型以計算高速鐵路系統正常運轉及接地故障下隨各種參數變化之大地洩漏電流，這些參數包含接地電阻、負載電流、間距長度、自耦變壓器匝數比及故障發生之位置，這些分析的結果可提供高速鐵路之大地洩漏電流分佈的資訊，供後續研究改善降低大地洩漏電流的參考。

關鍵字

擴充修正解耦法 ； 高速鐵路系統 ； 地電位昇 ； 大地洩漏電流

並列摘要

At present, the Taiwan High Speed Railway (HSR) systems are in the process of designing and construction. The main power substation will be fed by the taipower 161kV transmission systems, its main transformers with Scott-connection windings transform the three phases of 161kV to the two phases of 55kV. Each phase of 55kV winding connect to the power feeder and return feeder of railway. The trains are fed by the power feeder with auto-transformers to decrease the voltage drop and earth leakage current (ELC).

The high speed railway systems have heavy ELC due to the load current returned from grounding network and the rail directly. Therefore, when the systems are energized, some ELC will inevitably flow into the earth. The ELC flowing everywhere to pollute the earth and even produce some public-detriments. For solving the problems related to ELC, it is necessary to full understand the ELC characteristics, which include the causes and distributions of ELC, distributions of ground potential rise (GPR) due to ELC, and some critical affection parameters to ELC. In this thesis, the causes of ELC are first investigated. Then, based on the causes of ELC, the circuit models for analyzing ELC distributions are constructed by taking into considerations of various parameters of HSR systems. An "extended-modified-decoupled method" is proposed for constructing the ladder circuit model of HSR systems. The solution algorithm base on "Gauss Jordan elimination method" is developed to analyze the circuit model for calculating the ELC of HSR systems on normal operation with respect to parameters variations versus the grounding resistance, load current, span and turn ratio of auto-transformers and the fault position are analyzed. All of these analysis results had provided the useful information of HSR systems for continuing study of improving strategy to reduce ELC.

並列關鍵字

Ground Potential Rise ； Earth Leakage Current ； Extended-Modified-Decoupled Method ； High Speed Railway Systems

參考文獻

[1]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, pp. 48-60, July 1986.

[2]F. Dawalibi and R. R. Southey, "Analysis of Electrical Interference From Power Lines to Gas Pipelines, Part I: Computation Methods," IEEE Trans. on Power Delivery, Vol. PWRD-4, No. 3, pp. 1840-1846, July 1989.

[3]ANSI/IEEE Std. 80, "IEEE Guide for Safety in AC Substation Grounding," IEEE Society, New York, 2000.

[4]M. A. EI-Kady and M. Y. Vainberg, "Risk Assessment of Grounding Hazards Due to Step and Touch Potentials Near Transmission Line Structures," IEEE Trans. On Power Apparatus and System, Vol. PAS-102, No. 93, pp. 3080-3087, Sept. 1983.

[6]R. B. West, "Equipment Grounding for Reliable Ground Fault Protection in Electrical System Below 600V," IEEE Trans. on Industry Applications, Vol. IA-10, No. 2, March/Apr. 1974.