Temperature Rise Prediction on Silicone Rubber Housing of Composite Insulator in High Humidity Environment

Abstract

With the popularity of infrared detection on transmission lines, abnormal temperature rise of composite insulator has drawn great attention from industry and academia. The silicone rubber housing is one of the heating source and corona discharge is regarded as the primary factor that lead to the degradation of the material. In this paper, corona discharge aging was carried out on high temperature vulcanized (HTV) silicone rubber. The moisture absorption and dielectric loss angle of the silicone rubber sample were measured. The surface micromorphology is observed by SEM and the composition is obtained by TGA. The moisture absorption and dielectric loss angle showed an increasing trend with aging time. SEM and TGA results illustrated that the decomposition of PDMS and ATH led to the formation of the holes on the surface of silicone rubber, which enhanced the hygroscopicity. A predict model of temperature rise of composite insulator was put forward based on the time-temperature equivalence model of silicone rubber under AC corona discharge. The temperature rise can be predicted with known aging time and the intensity of corona discharge.