Improvement in the electric field distribution of silicone rubber composite insulators by non-linear fillers

It is well known that the electrical stress concentration contributes to the premature degradation on dielectric behavior and hydrophobicity of silicone rubber composite insulators. In order to homogenize the electric field distributions along surface of silicone rubber insulators, the non-linear silicone rubber composites filled with nano-silicon carbide (SiC) are prepared. The non-linear conductivity properties of 65wt%, 70wt% nano-SiC filled silicone rubber composites are investigated. The relationship between conductivity and electric field strength is obtained. The electric field and potential distribution along the surface of SiC/silicone rubber composite insulators is simulated by finite element method. The results showed that the non-linear characteristics of SiC/silicone rubber composites can effectively homogenize the electric field distributions along the insulators surface, and have a small effect on potential distribution. It is proved by the electric field simulation that the more of non-linear conductivity level increases, the more uniform of the electric field distributions along surface of silicone rubber composite insulators is.