Dielectric loss prediction of silicone rubber after moisture absorption under AC corona

摘要

Silicone rubber (SR) is widely used in HVDC/HVAC external insulation equipment because of its excellent electrical insulation performance and good hydrophobicity. In this paper, the variation of dielectric loss of SR after moisture absorption under AC coronas of 8.1 kV cm(-1), 10.8 kV cm(-1), 13.5 kV cm(-1), 16.2 kV cm(-1), 18.8 kV cm(-1) and 21.6 kV cm(-1) was investigated, respectively. Then, an equivalence equation of time and electric field intensity of corona, which was inspired by a time-temperature equivalence principle, was put forward. The test results verified the validity of the equivalence equation of time and electric field intensity of AC corona in describing the trend of dielectric loss of SR after moisture absorption under AC corona. At last, the aging time, reaching different dielectric losses of SR after moisture absorption under AC coronas of 10.0 kV cm(-1), 15.0 kV cm(-1) and 20.0 kV cm(-1), was predicted. This study would help to guide the operation and maintenance of the silicone rubber on external insulation equipment.