제주지역 낙뢰특성 및 풍력발전단지 접지사례 분석

Abstract

This dissertation analyzes characteristics of seasonal and hourly lightning occurred over Jeju Island by using cloud-to-ground lightning polarity data measured by Korea Meteorological Administration for last 5 years (2010 ~ 2014). Because lightning protection considering accumulated lightning distribution around Jeju Island must be ensured, this thesis proposes plan of lightning protection. Frequency on lightning is a lot of different every year. And average frequency on lightning is 1200 times a year. On the contrary to average frequency, frequency on lightning in 2011 is more than 4500 times. Lightning strength on straight and reverse polarity is similar. However, a lot of reverse polarity is in low lightning strength. A large number of lightning phenomenon occur on eastern region than western. Eastern region, especially side of coast, is also higher than western about all of characteristics including frequency, strength and so on. Because an amount of on-shore large scale wind farm is built in side of coast and mountain recently, One of the most important thing is lightning protection. According to KS C IEC 62305 (Korean standard on lightning protection system), only vertical lightning rod, horizontal lightning conductor, mesh grounding system and rolling sphere method are allowed. Consequently, this dissertation presents not only analyzing domestic and international standard on lightning protection but also proposing plan of lightning protection considering domestic standard about technique on electricity facilities. Because of feature of high earth resistance in Jeju Island, lightning protection on pylon is an alternative method by using equipotential grounding and early streamer emission lightning protection. In order to perfectly design inner and outer lightning protection system, lightning rod, surge protective device and equipotential common grounding is essential.