避雷器阀片绝缘层破损的放电特性分析OA

Externally gapped line arresters(EGLA)are critical devices for lightning protection of transmission lines.Explosion incidents involving these arresters can lead to line tripping and even conductor breakage.Conven-tional understanding attributes such explosions primarily to aging and moisture ingress,while insufficient attention has been paid to mechanisms associated with damage to the insulating layer of arrester blocks.In this study,a 220 kV EGLA explosion caused by a lightning shielding failure is investigated.Detailed post-failure dissection of the damaged unit indicates that damage of the insulating layer directly triggered surface flashover,ultimately resulting in the explosion.A single-pulse current test platform capable of generating high voltage and high current was devel-oped to conduct comparative impulse tests on intact blocks and blocks with varying degrees of insulation damage.The results show that insulation damage significantly increases the probability of discharge,and that greater damage severity leads to more intense discharges.Once surface flashover occurs,a high-temperature arc channel forms,causing severe erosion of the electrodes and insulating layer and accelerating the progression toward explosive fail-ure.These findings contribute to a more comprehensive understanding of arrester explosion mechanisms and provide guidance for analyzing similar incidents in the future.