An Empirical Study on the Deterioration of Lightning Arrester for Extra-High Voltage Customer

In this paper, we compared and analyzed three methods to determine whether a 22.9kV MOF arrester was deteriorated. First, based on the ‘Caution’ deterioration results from the three-phase comparison method among the infrared thermal imaging diagnosis, which is a non-power diagnosis of power facilities, second, the leakage current measurement was within the normal range, although it is based on the KEPCO distribution facility leakage current judgment standard. Third, the insulation resistance measurement results of the replacement lightning arrester with a ‘Caution’ deterioration rating along with discoloration and a new product showed a difference in insulation performance of approximately 150 times. As a result, it was confirmed that the three-phase comparison method, which measures the temperature of an object in a non-contact, uninterrupted state without a power outage and uses the relative temperature difference between each phase to diagnose the presence or absence of a lightning arrester abnormality, is easy to diagnose and is practically valid in industrial settings.