Optimization of the electric field distribution along the insulator surface can effectively improve the flashover voltage of insulators

but the characteristics of the electric field distribution which determine the flashover voltage of insulators are still unclear. In order to further study the characteristics of the electric field distribution along the flashover voltage of insulators

48 kinds of epoxy pillar insulators with different electric field distributions along the surface were obtained by adjusting the geometrical parameters of the insulator’s surface shape

embedded electrode and external shielding electrode. The static electric field distribution of the samples was calculated by finite element method. The maximum

average

gradient

square integral and potential distribution of the electric field along the surface and its tangential

normal components were obtained by post-processing. The flashover voltages of the samples immersed in 0.2 MPa SF6 were measured experimentally under a standard lightning voltage. By studying the correlation between flashover voltage and electric field distribution

it is found that the flashover voltage of insulators is not only related to the distribution of electric field along the surface

but also significantly related to the distribution of tangent and normal components of electric field. After screening

the characteristic parameters which are related to the flashover voltage and are independent of each other are obtained as follows: the maximum value of the electric field along the surface and its normal component

the field inhomogeneity and maximum gradient of the tangential component of the electric field along the surface

the integral of the area where the tangential component of the electric field along the surface is greater than 90% of its maximum value. Moreover

the influence mechanism of these characteristic parameters on the flashover initiation and development process is also qualitatively analyzed.