- 學位論文
345kV氣封絕緣開關設備接地故障及開關突波特性分析及其影響評估
Analysis of Ground Fault and Switching Surge Characteristics of 345kV GIS and Their Affection Assessments
摘要
345kV氣封絕緣開關設備(Gas Insulated Switchgear, GIS)已廣泛應用於345kV發電廠及變電所中，一旦發生事故對系統衝擊很大，在各種事故中以接地故障及突波傷害最為常見，往往引發大停電造成極大的損失，由於GIS是電路的匯集點，故障電流本來就相當大，加上結構上匯流排內導體與外殼距離很近，兩者互感很大，若是發生接地故障，則故障電流瞬間可達數萬安培，此時感應到GIS金屬包封容器之感應環流也有可能達上萬安培，感應環流對盤體本身、盤面及盤內的設備，甚至盤外相關的一些系統及設備都有不利的影響。此外匯流排內導體與外殼間的電容很大，與主變壓器之電感在開關操作時將可能引起嚴重的開關突波電壓、電流以及後續殘餘電壓，這些都會使GIS內部設備(如PT)造成不利的影響，為此，本文將進行開關突波之分析。本文首先採用電磁暫態分析軟體(EMTP/ATP)建立電路模型，然後分析發生接地故障時，GIS之內導體電流及外殼電流的大小，以及開關投入或切離時產生的突波電壓及電流。其中接地故障之分析包括345kV GIS本體及主變壓器一次側單相接地故障；而開關突波之分析包括一般操作及特殊操作，亦考慮三相同步及三相非同步等條件，最後根據分析結果，評估接地故障及開關突波對GIS之影響，以供後續擬定改善策略之參考。
並列摘要
345kV gas-insulated switchgear (Gas Insulated Switchgear, GIS) has been widely used in power plants and substations of 345kV, in the event of accidents greatly impact on the system, in a variety of ground -fault accident and the surge in the most common injury, often caused blackout caused a great deal of loss, as the GIS is the focal point for the circuit, fault current was quite large, with the structure of the bus conductor and the shth in close proximity, mutual inductance between the two great, if the occurrence of ground fault, the fault instantaneous current of up to tens of thousands of amperes, when the sensors to the encapsulation of metal containers of GIS circulation may also be induction of the 10,000 amperes, circulating current on the panel itself, with the panel and panel devices, and even set the number of foreign-related systems and equipment have an adverse impact. The bus with the conductor and capacitance between the large shth, with the Auto transformer of the inductor, when the switching operation of the switch may cause a serious surge of voltage, current and follow-up residual voltage, which will enable the GIS equipment (such as the PT) adverse effects, this paper will also be carried out the analysis of switching surges. In this paper, the use of Electromagnetic Transients Program/Alternative Transients Program (EMTP / ATP) software to establish circuit model, and then an analysis of ground failure, GIS within the conductor current and the size of the current shth, and switch inputs or cut off when the surge voltage and current . Ground fault of one 345kV GIS analysis includes the main body and a side of the transformer single-phase ground fault; and switching surge analysis, including general operations and special operations, is also considering three-phase synchronous and asynchronous three-phase conditions, the last light of the outcome, assessment of ground fault and switching surges on the impact of GIS for improving the strategy to develop the follow-up reference.