Study on Abnormal Heat of Polymeric Insulators on Coastal Power Transmission Line

Abstract Heating at the high-voltage end has become one of most frequent defects on polymeric insulators in service, particularly humid and hot regions. Recent case surveys show that some highly overheated sample survive almost all standardized lab tests, which could not be fully explained by common related heating factors, including fracture defects, superficial wet pollution, water absorption moisture housing, uneven sunlight, etc. In this paper, we try to find an alternative perspective explain temperature rise order 10°C studying relationship between heat degree corrosion a cast aluminum grading ring.