- 學位論文
161kV氣封絕緣開關設備比壓器鐵磁共振分析及抑制方法
Analysis of Potential Transformer Ferroresonance and Suppression Methods in the 161kV Gas Insulated Switchgear
摘要
雖然第一篇有關鐵磁共振（Ferroresonance，簡稱FR）的文獻早在1920年即被發表，但是此一特殊的現象至今仍然未被完全了解，本論文將討論電力系統中之氣封絕緣開關設備（Gas Insulated Switchgear，簡稱GIS），由於斷路器的極間電容和電感型比壓器（Potential Transformer，簡稱PT）的非線性電感所構成的單相鐵磁共振；理論上，鐵磁共振是由電容和非線性電感所構成的非線性串聯共振，造成電壓和電流波形明顯的畸變。鐵磁共振的振盪模式可分為基波模式、次諧波模式、類週期模式、及混沌模式，鐵磁共振產生之過電壓與過電流可能導致高壓設備和PT因絕緣與過熱等問題而損壞；雖然電感型比壓器在某些GIS架構中有發生鐵磁共振的風險，但是因為電感型比壓器在長期使用下，不論可靠性、精確度與電壓轉換比等特性都優於電容分壓型比壓器，因此電感型比壓器比電容分壓型比壓器更廣泛被使用在GIS設備上，為此，本論文結合相關文獻之理論基礎及GIS、PT專業廠家的經驗與技術，對GIS各種可能的架構進行完整之檢視，討論各個參數對鐵磁共振行為的影響，並介紹相關的分析流程與方法，提出避免鐵磁共振發生之方法和有效之抑制措施，本論文並對一個161kV GIS發生鐵磁共振之實際案例進行探討，先建立詳細的系統參數模型，再透過電磁暫態解析程式（ElectroMagnetic Transients Program）EMTP/ATPDraw模擬，最後將電腦程式模擬的結果與現場試驗的量測結果進行比較分析，以確認分析流程與方法的正確性與實用性，提供電力工程師們在規劃和設計時之參考。
並列摘要
Although the first thesis on Ferroresonance（FR） was published in 1920, FR is still not a fully understood phenomenon. This thesis focuses on single phase FR in Gas Insulated Switchgear（GIS）with inductive potential transformers（PT）, fed by the circuit breaker grading capacitance. In principle, FR is a forced oscillation in a non-linear series resonance circuit including a capacitance and non-linear inductance, which shows significantly distorted voltage and current waveforms. The complex non-linear behaviour of the saturable inductance can cause fundamental FR, subharmonic FR, quasi-periodic and even chaotic oscillations. FR can result in high overvoltage and high overcurrent, which can finally damage the high voltage equipments or PTs due to dielectric and thermal problems. Even if there is the risk of ferroresonance for specific GIS configurations, inductive PTs are used rather than capacitive ones because of their reliability, higher accuracy and stable transformation ratio during the entire lifetime. However, combine the theory, GIS and PT maker,s experiences, this thesis provides an overview of network configurations, parameters influencing the FR behaviour and a number of methods to avoid or suppress FR are discussed. This thesis also presents a ferroresonant experience involving inductive PT in a 161kV substation. A very comprehensive analysis is performed by detailed modelling using time domain simulation with a digital computer transient analysis program such as the EMTP/ATPDraw and compares them with field test and measurements.