수배전계통의 여러 가지 고장조건에서 피뢰기에 흐르는 누설전류 = Leakage Currents Flowing through Lightning Surge Arresters under Various Fault Conditions in Receiving and Distribution Power Systems

다국어 초록 (Multilingual Abstract)

Unsymmetrical faults are classified into single line-to-ground faults, line-to-line faults, or double line-to-ground faults in receiving and distribution power systems. Many of overhead distribution-line faults are single line-to-ground faults, and lightning surge arresters are stressed by system frequency overvoltages due to unsymmetrical faults. In this work, the unsymmetrical faults in receiving and distribution systems were experimentally simulated, and the characteristics of total leakage current flowing through lightning surge arresters due to various unsymmetrical faults were investigated. As a result, a little variations of the leakage current flowing through Zinc oxide (ZnO) surge arresters in the range of $\pm$10[%] voltage regulations were observed. It could be concluded that the unsymmetrical faults have no effect on the long-term life performance of ZnO surge arresters in effective grounding systems. On the other hand, the magnitude of the leakage current flowing through ZnO surge arrester elements under single line-to-ground faults was more than 140 times as compared with that under normal operating voltages in ineffective grounding systems. But abnormal voltages caused by line-to-line faults and double line-to-ground faults have a little effect on total leakage current of ZnO surge arrester elements.

국문 초록 (Abstract)

수배전계통의 고장에는 1선 지락, 선간 단락, 2선 지락 등의 고장이 있다. 가공 배전 계통에서 일어나는 대부분의 고장은 1선 지락이며, 피뢰기는 이러한 고장에 의한 빈번한 과전압에 의해 스트레스를 받는다. 본 논문에서는 수배전계통에서 일어날 수 있는 고장을 모의하여 여러 가지 고장에 의해 피뢰기에 흐르는 누설전류의 특성에 대하여 조사하였다. 결과적으로, $\pm$10[%] 범위의 전압변동률에 의해서 피뢰기에 흐르는 누설전류는 거의 변화가 없었다. 성능이 우수한 접지 시스템 하에서는 전압변동률은 피뢰기의 긴 시간동안의 동작에 별 영향을 줄 수가 없었다. 하지만, 1선 지락 고장에서 피뢰기에 흐르는 누설전류의 최대값은 비효과적인 접지 시스템의 운전 전압에서의 누설전류와 비교하였을 때 140배 이상이 되었다. 그러나 선간 단락과 2선 지락 고장의 경우에는 피뢰기의 누설전류에 거의 영향을 미치지 못했다.

참고문헌 (Reference)

1 "Protection of Information and Communication Facilities against Lightning" Inha university 11-40, 2004.2.

2 "New method for measurement of resistive leakage currents of metal-oxide surge arrester in service" 5 (5): 1990-, pp.1811-1822

3 "Effective Installations Technique of Grounding Conductors for Metal Oxide Surge Arresters" 51c (51c): 253 -259, 2002.

4 "Degradation of ZnO based surge arresters under field conditions" 143 (143): 291-297, 1996.

5 "A procedure for estimating the life time of gapless metal oxide surge arresters for AC application" no. 2 : 1986-, pp.67-74

6 "A Monitoring Device of Leakage Currents Flowing through ZnO Surge Arresters" 42 (42): 1568-1574, 2003.

7 "A Detection Method of Resistive Leakage Current Flowing through ZnO Arrester Blocks" 15 (15): 67 -73, 2001.

8 "?Hd?H?H?Hn?H?H?HZ?Hp?Hv?HZ ??Hp" ?H?H?H?H?Ho?H?H ?H`? 134-152, 2000.1.

9 "?Hd?H?H?HB?H?H?HH?H{" ?H?H?H?H?H?H?H?H?H?H 138-140, 2001.2.