地下電纜之傳輸容量與感應電壓分析

Ampacity and Induced Voltage Analysis for Underground Cable System

廖仁呈(Jen-Cheng Liao)

指導教授 ： 張文恭

國立中正大學/工學院/電機工程學系/碩士(2014年)

摘要

地下電纜之導體會受到集膚效應與近接效應所產生之交流電阻影響，當截面積達到2000 以上，交流效應更加顯著，導體損失對於送電容量影響甚大，而高壓電纜金屬遮蔽層之感應電壓過高或感應暫態電壓時，電纜被覆層有擊穿之風險，所以電纜金屬遮蔽層必須安裝被覆電壓限制器來抑制過電壓，因此提高導體送電容量探討與遮蔽層感應電壓的掌控而維持線路安全的議題便相當重要。
本論文的主要目的在於研究提升地下電纜之送電容量，並在實際的345kV系統下探討故障時的感應電壓，在本研究中，首先利用理論探討交流效應並以現有規範計算交流電阻與送電容量，並實際測量電纜溫度與送電容量之關係。接著模擬最嚴重之單相接地故障探討其感應電壓對保護元件的影響，經由模擬結果，可對地下電纜導體與系統設計提供建議。

關鍵字

突波電壓限制器 ； 感應電壓 ； 近接效應 ； 集膚效應 ； 送電容量 ； 增容導體

並列摘要

The Ampaicty of underground cable is reduced dramatically by the effects of alternating current effects called d skin and proximity effects. Alternating current effect is quite remarkable when the cross-sectional area reaches more than 2000 . The losses of conductor that affect ampacity has become of interests. Both of induced voltage and intrusion surge voltage on sheath of high voltage underground transmission system is high, it maybe damage the sheath insulation. Therefore, the study of increasing ampacity and controlling induced voltage becomes important.
In the thesis, a brief review of electromagnetic theories and the factors of alternating current resistance have study. For AC resistance calculation, the increase of ampacity of conductor and alternating current effects has been demonstrated and meets the design value. Single-line ground faults on 345kV underground cable system have been study and simulation. The results are benefit for impact study of induced voltage on sheath of underground cable system. The results are observed and suggestions are benefit sheath voltage limiter design. It clarify the concept of induced transient overvoltage and fault current induced voltage on underground transmission system.

並列關鍵字

Sheath voltage limiter ； Induced voltage ； Proximity effect ； Skin effect ； Ampacity ； Enamelled stranded conductor

參考文獻

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