웨이브렛 계수를 이용한 고저항 지락고장 감시데이터 산출방법 연구

다국어 초록 (Multilingual Abstract)

As the increasing HIF(High Impedance Fault) with the arc cannot be easily detected for the low fault current magnitude compared to actual load in distribution line. However, the arcing current shows that the magnitude varies with time and the signal is asymmetric. In addition, discontinuous changes occur at starting point of arc. Considering these characteristics, wavelet transformation of actual current data shows difference between before and after the fault. Althogh raw data(detail coefficient) of wavelet transform may not be directly applied to HIF detection logic in a device, there are several developing methods of HIF monitoring data using the original wavelet coefficients.
In this paper, a simple and effective developing methods of HIF monitoring data were analized by using the signal data through an actual HIF experiment to apply them to economic devices. The methods using the sumation of the wavelet coefficient squares in one cycle of the fundamental frequency as the energies of the wavelet coefficeits and the sumation of the absolute values were compared. Besides, the improved method which less occupies H/W resouces and can be applied to field detection devices was proposed. and also Verification of this HIF detection method through field test on distribution system in KEPCO power testing center was performed.

목차 (Table of Contents)

• Abstract
• 1. 서론
• 2. 절연전선의 HIF 특성
• 3. HIF 감시데이터 전개 방법
• 4. 주기단위 HIF 감시데이터 수행결과
• 5. 결론
• References

참고문헌 (Reference)

1 "http://wavelets.pybytes.com/wavelet/db4"

2 Ground Alert, "Reliable detection of High-Impedance Fault caused by Downed Conductor" 2004

3 Carl L. Benner, "Practical High-Impedance Fault Detection on Distribution Feeders" 33 : 1997

4 Seung-Hun Lee, "Introduction to the Wavelet Transform" Jinhanbook 31-, 2003

5 Hyun Kim, "High Impedance Fault Detection using Wavelet transform" KIEE 48A : 1496-, 1999

6 John Tengdin, "High Impedance Fault Detection Technology" IEEE PES PSRC Working Group

7 "High Impedance Fault Detection"

8 B. Don Russell, "Behavior of Low Frequency Spectra during Arcing Fault and Switching Events" 3 : 1487-, 1998

9 KEPCO, "A Study for the Improvement of the Protection Relay Scheme on Multi-grounded Distribution System, RI Final Report" KEPCO 41-,