Partial discharge performance improvement of covered conductor (CC)/high voltage insulator based electrical distribution systems

Abstract In this paper, performance improvement of covered conductor (CC) based distribution systems is achieved through reducing partial discharge (PD) at CC/high voltage insulator (HVI) interface. The reduction of PD is achieved through electric field reduction at CC/HVI interface. The reduction in electric field at CC/HVI interface is done using room temperature vulcanized (RTV) silicone rubber as a coating to high voltage porcelain insulator. The use of RTV coating to improve the performance of CC/HVI systems is evaluated. The evaluation is carried out through electric field calculation considering CC fitted with porcelain insulator as well as the same CC with RTV coating applied to the same porcelain insulator. Electric field calculations at dry and wet polluted conditions are carried out using finite element software (FEM) considering coated and uncoated insulators. Also, experimental validation is carried out through PD current measurement considering dry and wet polluted conditions. Wet pollution condition is carried out at equivalent salt deposit densities of 0.2, 0.4 and 0.6 mg/cm2. The obtained PD current measurements are validated by measuring temperature distribution of the two studied cases using an infra-red (IR) camera. The obtained temperature distribution results from the IR camera validate the obtained results from PD tests.