摘 要
本文旨在探討典型161kV以六氟化硫氣體作為絕緣開關裝置之比壓器暫態響應問題，提出分析及改善。在數公里外遠端變電所內的斷路器啟斷時，地下電纜線路電容緩慢的放電電流會流入近端變電所的匯流排比壓器而產生巨大電磁力並造成一次側線圈移位及損壞。本文根據實際現場參數作模擬及分析，放電電流的模擬與實際到大電力試驗場測試的結果非常接近。匯流排比壓器高壓線圈位置的重新配置會引起截然不同的效應。文中提出機械應力的計算以決定匯流排比壓器能否承受前述三相峯值電流之電磁場產生的機械應力而不損壞。藉著可承受較高線路電容的新型匯流排比壓器及驗證測試結果，本文建議於匯流排比壓器規範書內詳註可承受的最大線路電容值。
另者，於161kV變電所操作隔離開關或斷路器時，電源經由斷路器之電極間均壓電容器至儀錶用比壓器及絕緣開關裝置之並聯的對地電容，形成典型電感–電容電路。由於儀錶用比壓器二次側安裝的氣隙型鐵心電感阻尼器設計不當會引起鐵磁共振，導致儀錶用比壓器過電壓及嚴重的過電流，高壓側繞組會因此發生過熱、閃絡及絕緣材料損毀。文中亦提出三種有效的抑制策略，作為161kV氣體絕緣開關儀錶用比壓器鐵磁共振效應的改善，建立鐵磁共振模型之等效電路並以實際量測值作模擬。
模擬及實測結果顯示，本文所提出的抑制器可快速抑制鐵磁共振，使儀錶用比壓器免於損壞，並安全、可靠地使用於開關切換場合。

Abstract
This dissertation is concerned with the analysis and improvement of transient response on potential transformers applied to 161kV gas insulated switchgear (GIS) systems with SF6 insulation. The slow discharging overcurrent through the inherent line capacitance of underground inter-substation power cables may result in large magnetic force shifting and damaging bus potential transformer (BPT) primary windings of local substation when opening circuit breaker of remote substation located several kilometers away. The simulation models are built according to field parameters and the discharging current simulation results agree closely with those of field tests in electric power laboratory. BPT primary winding relocation may cause strongly different effects. Calculations are given to determine whether BPT can survive over the mechanical force resulted from the magnetic field generated by the aforementioned three-phase peak transient currents or not. Based on the newly improved BPT and its line-capacitance withstanding test, recommendations of BPT specification with respect to the maximum allowable line capacitance are also given.
In addition, while operating disconnecting switch or circuit breaker in distributed substation, an inductance-capacitance loop is formed from grading capacitor of circuit breaker to metering out-fit potential transformers (MPT) paralleled with the capacitance of GIS. Improper design of gap-core inductance damper equipped on secondary winding of MPT may cause ferro-resonance effect, resulting in over-voltage and serious over-current on windings of MPT to overheat and damage insulation material. Three kinds of efficient strategies are proposed in this dissertation to improve ferro-resonance effect on MPT applied to 161kV GIS, the corresponding equivalent circuit models are established and simulations of ferro-resonance based on the field parameters are given.
Simulation and experimental results show that the presented suppressors can quickly inhibit ferro-resonance in field test from damaging MPT, and assure safe and reliable switching operations.

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