應用阻抗演算法偵測靜態電容器組故障之研究

The Fault Detecting Study for Static Condenser Banks by Using Impedance Algorithm

蘇文志(Wen-Chih Su)

指導教授 ： 何金滿

中原大學/工學院/電機工程研究所/碩士(2001年)

https://doi.org/10.6840/cycu200100362

摘要

靜態電容器組(Static Condenser Bank, SC Bank)的不平衡保護方式通常須於不接地Ｙ接電容器組中性點安裝比壓器(Voltage Transformer, VT)以偵測中性點電壓，或於不接地雙Ｙ接電容器組中性點連接處安裝比流器(Current Transformer, CT)以偵測不平衡電流，而本文所介紹的是一個新的以”阻抗”來偵測電容器組故障的方法，不需要於中性點安裝比壓器就能偵測靜態電容器組的故障現象，特別是不接地Ｙ接電容器組。但對不接地雙Ｙ接電容器組而言，作者仍建議安裝比流器來偵測不平衡現象，因為這樣較所介紹的方法更為靈敏。本文一開始先分析各種電容器組的穩態故障行為，所得結果可提供電容器組不平衡保護電驛設定參考。其次，列舉與分析各種電容器組的保護方式。然後進一步提出”阻抗演算法”來偵測電容器組的故障。此種演算法係由電容器組的三相電壓與電流中，推導求得三相阻抗與中性點電壓方程式，推導的過程以MAPLE軟體輔助，推導所得之結果可進一步決定是否跳脫電容器組的斷路器或只產生警報。再以MATLAB Simulink建構阻抗電驛模組，並分別以模擬與實測信號輸入此模組，以驗證其功效。此演算法之驗證使用兩種型式的測試資料，一是由EMTP或MATLAB模擬產生；另一是實際從電容器組移除一些電容器單元後所得的量測資料。所得之結果證明此演算法確實可以用在電容器組作為故障偵測之用。

關鍵字

靜態電容器 ； 阻抗演算法 ； MATLAB Simulink ； 電磁暫態程式 ； MAPLE

並列摘要

The unbalance protective method for static condenser (SC) bank normally requires the installation of a voltage transformer (VT) at neutral of ungrounded Y to sense neutral voltage, or that of a current transformer (CT) at neutral tie of ungrounded double Y to sense its unbalance current. This study presents a novel method to detect faults in SC bank by using impedance algorithm without VT, especially for ungrounded Y. But for ungrounded double Y, the author still suggests to install CT to sense unbalance current, because it is more sensitive than the proposed method. The first stage of this study is to analyze steady-state faults of each type of SC bank configurations. The results can be refereed to unbalance relay parameter setting. The second stage is to present and to compare the protective methods for different types of SC banks. Then, the author further provides “impedance algorithm” to detect faults in SC bank. This algorithm is to derive impedance and neutral voltage equations from three-phase voltages and currents of SC banks by use of MAPLE program. Its results are used to decide whether to trip circuit breaker or to make alarm only. Then, to model this algorithm as an impedance relay module by using MATLAB Simulink, and finally, put the simulating and real testing data into this model to verify its effectiveness. The simulating data is generated by EMTP or MATLAB simulation and the testing data is derived from onsite real measurement after removing some SC units from an existing SC bank. The results prove that the proposed “impedance algorithm” can be applied to fault detecting of SC banks.

並列關鍵字

Impedance Algorithm ； MAPLE ； MATLAB Simulink ； Static Condenser ； EMTP

參考文獻

[15] Working Group 3.4.17 of the IEEE Surge Protective Devices Committee, "Impact of Shunt Capacitor Banks on Substation Surge Environment and Surge Arrester Applications," IEEE Transaction on Power Delivery, Vol. 11, No. 4, pp.1798-1809, Oct. 1996.

[16] Jean Mahseredjian and Fernando Alvarado, "Creating an Electromagnetic Transients Program in MATLAB: MatEMTP," IEEE Transaction on Power Delivery, Vol. 12, No. 1, pp.380-388, July 1997.

[18] M.B.Djuric, Z.M.Radojevic and V.V. Terzija, "Time Domain Solution of Fault Distance Estimation and Arcing Faults Detection on Overhead Lines," IEEE Transaction on Power Delivery, Vol. 14, No. 1, January 1999.

[19] Zhang Qingchao, Zhang Yao, Song Wennan, Yu Yixin and Wang Zhigang, "Fault Location of Two-parallel Transmission Line for Non-earth Fault Using One-terminal Data," IEEE Transactions on Power Delivery, Vol. 14, No. 3, July 1999

[20] M.M.Saha, J.Izykowski, E.Rosolowski and B.Kasztenny, "A New Accurate Fault Locating Algorithm for Series Compensated Lines," IEEE Transaction on Power Delivery, Vol. 14, No. 3, pp.789-797, July 1999.