- 學位論文
具有汲流自耦變壓器之軌道系統車道磁場分析
Magnetic Field Analysis for Railway System With Drain Auto Transformer
摘要
本論文針對具有汲流自耦變壓器之軌道系統分析沿車道之磁場分佈，首先考慮軌道供電系統正常運轉下進行負載電流分析，以得到電車線系統上各列車供電線路之負載電流，包含接觸線，回流線及鋼軌之電流，由於這些電流產生之磁場將會感應並行的線路使之產生感應電流，對整體磁場分佈會有影響，故文中將在考慮並行之架空地線及保護線之影響，分析感應電流，這些感應電流與前述接觸線，回流線及鋼軌之電流共同決定軌道沿線之磁場分佈。由於這些電流為低頻，故其產生之磁場為低頻磁場，故本文將應用適合低頻磁場分析之畢歐-沙瓦定律(Biot-Savart’s Law)推導出沿車道空間之磁場分佈公式，並藉此發展一套分析軟體以分析磁場沿車道分佈的全貌，包括整體磁場三維(3D)分佈圖及各特定地點之磁場變化情形。最後針對典型之軌道系統區段之實例進行分析，其中將考慮各變壓器區間皆有滿載列車運行下，進行全區段之磁場模擬分析，以三維立體圖展示分析結果，並描述各項分析結果之意義及其可能之影響。本論文所開發之軟體可廣泛應用於同型系統之各項磁場分析，包括參數變化對磁場之影響分析，除可供現有軌道系統磁場分佈之模擬分析外，亦可作為新建軌道系統之規劃與設計應用工具，以及供磁場防護設計之用。
並列摘要
This thesis aims at railway system with drain auto transformers, analyzing the magnetic field distribution along the railway. First, this thesis conducts the load current analysis of the power system of railway under normal operation, obtaining the load current of power lines above the electric train system; these lines include contact wires, return conductors and steel rails. Since the current of these lines will generate magnetic fields, inducing current in other parallel lines, and these induced currents will also affect the total magnetic field distribution. Thus, this thesis incorporates the influence of parallel ground wires and protection wires, analyzing their induced currents. These induced current and the above currents of contact wires, return conductors and steel rails, will altogether compose the total magnetic field distribution along the railway. Since the currents considered belong to low frequency, the resulting magnetic fields belong to low frequency as well; therefore, this thesis adopts Biot-Savart’s Law, which is most suitable for low frequency magnetic field analysis. Subsequently, this thesis derives the formulae for calculating the magnetic fields along the railway, and then develop an analysis program based on these formulae to procede research and demostrate the panorama of magnetic field distribution along the railway. These inculde the 3D figure of total magnetic field and the behavior at specific spots. The program developed by this thesis can be widely applied to the magnetic field analysis for the same type of rail systems; besides, this program can provide not only magnetic field simulation and analysis of existing rail system, but also the planning and design tool for new rail systems and guide for the design of magnetic field protection.