161 kV電磁感應型比壓器鐵磁共振分析、量測及抑制方法

本論文提出一個在台灣各類型發電廠之開關場採用阻尼電抗器成功抑制 161 kV氣封絕緣開關設備(Gas Insulated Switchgear，簡稱GIS)電磁感應型比壓器(Potential Transformer，簡稱PT)鐵磁共振(Ferroresonance，簡稱FR)的經驗。由於量測與計費之需要，比壓器必須具備低容量與高精確度，因此，低鐵芯損耗是必要的，但也同時降低其阻尼能力，並增加了鐵磁共振發生的可能性。在本論文研究案例，同一個開關場曾在九個月內發生兩次肇因於鐵磁共振的比壓器事故。為了深入了解鐵磁共振的行為與抑制方法，在民國96年至100年間，共執行了四次現場試驗，其中前二次在台灣西部的燃氣火力發電廠，第三次在台灣中部的水力發電廠，第四次在台灣東北部興建中的核能發電廠，經由在電力系統中的實地測試，取得了比壓器鐵磁共振的完整波形，第一次實地測試經由11次隨機操作，重現了鐵磁共振的現象，最長的共振持續了22.9秒，第二次至第四次實地測試，經由29次隨機操作，證實了採用阻尼電抗器可抑制並縮短鐵磁共振的時間在4.36秒以內，此外，從西部的燃氣火力發電廠 SCADA系統之操作紀錄統計，自民國97年11月至99年9月間共23個月82次可能發生鐵磁共振的操作，證實得到長期良好的運轉實績。本論文證明採用電磁暫態解析程式(ElectroMagnetic Transients Program)EMTP/ATPDraw 的模擬可以有效預測鐵磁共振發生與否與鐵磁共振之型態，並證明規格適當的阻尼電抗器可以成功抑制鐵磁共振。本論文為台灣電力系統中首次為了了解電磁感應型比壓器鐵磁共振的行為，投入五年的時間進行深入廣泛的研究與實地測試，對於未來更高電壓等級非線性行為的研究，極具價值。雖然第一篇有關鐵磁共振的文獻早在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，本論文討論了電力系統中之氣封絕緣開關設備，由於斷路器的極間電容和電磁感應型比壓器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；雖然電磁感應型比壓器在某些GIS架構中有發生鐵磁共振的風險，但是因為電磁感應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，因此電磁感應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，本論文就一個161 kV 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，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。

關鍵字

阻尼電抗器；氣封絕緣開關設備；電磁感應型比壓器；鐵磁共振； SCADA ；電磁暫態解析程式EMTP/ATPDraw

並列摘要

This dissertation presents a successful mitigation experience of ferroresonance (FR) with a Damping Reactor(DR) involving electromagnetic type Potential Transformers(PTs) of a 161 kV Gas Insulated Switchgear(GIS) in Taiwan. PTs have a typically low thermal capacity and high accuracy due to their measuring functions. Low core losses are necessary to obtain high accuracy, but they also reduce its damping ability and therefore increase the possibility of FR. FR happened twice and destroyed PTs for just nine months in the study case. Complete FR waveforms of 161 kV PT were obtained via field tests never conducted before in Taiwan. The first field test had a reappearing FR which sustained up to 22.9 seconds in 11 random operations and the second to fourth field tests confirmed the validity of DR which shortened FR less than 4.36 seconds in 29 random operations which are carried out in thermal power plant, hydro power plant and nuclear power plant. A reliable prediction by EMTP/ATPDraw simulation and a useful mitigation method with a proper DR were proved by both field tests and the following 23 months satisfactory operations for 82 times which extracted from SCADA system in a thermal power plant since Nov., 2008. The five years study would prove valuable for further research in higher voltage level GIS. Although the first paper on FR was published in 1920, FR is still not a fully understood phenomenon. This dissertation focuses on single phase FR in GIS with PT, fed by the circuit breaker grading capacitance. In principle, FR is a forced oscillation in a nonlinear series resonance circuit including a capacitance and nonlinear inductance, which shows significantly distorted voltage and current waveforms. The complex nonlinear behavior 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 equipment or PTs due to dielectric and thermal problems. Even if there is the risk of ferroresonance for specific GIS configurations, electromagnetic 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 dissertation provides an overview of network configurations, parameters influencing the FR behavior and a number of methods to avoid or suppress FR are discussed. A very comprehensive analysis is performed by detailed modeling using time domain simulation with a digital computer transient analysis program such as the EMTP/ATPDraw and compares them with field tests and measurements. It would be valuable on planning and designing for electrical engineers.

並列關鍵字

Ferroresonance ； Damping Reactor ； Electromagnetic Potential Transformer ； Gas Insulated Switchgear ； EMTP/ATPDraw ； SCADA

參考文獻

[4] B.A. Mork, D.L. Stuehm, "Application of nonlinear dynamics and chaos to ferroresonance in distribution systems," IEEE Trans. on Power Delivery, vol. 9, no. 2, 1994, pp. 1009-1017.

[6] J.W. Butler , C. Concordia, "Analysis of series capacitor application problems," AIEE Trans., vol. 56, 1937, pp. 975-988.

[7] R.G. Andrei, B.R. Halley, "Voltage transformer ferroresonance from an energy transfer standpoint," IEEE Trans. on Power Delivery, vol. 4, no. 3, 1989, pp. 1773-1778.

[9] David A.N. Jacobson, Peter W. Lehn, Robert W. Menzies, "Stability domain calculations of period-1 ferroresonance in a nonlinear resonant circuit," IEEE Trans. on Power Delivery, vol. 17, no. 3, 2002, pp. 865-871.

[10] Yunge Li, Wei Shi, Rui Qin, and Jilin Yang, "A systematical method for suppressing ferroresonance at neutral-grounded substations," IEEE Trans. on Power Delivery, vol. 18, no. 3, 2003, pp.1009-1014.

國際替代計量

161 kV電磁感應型比壓器鐵磁共振分析、量測及抑制方法

全文下載

主題瀏覽