Experimental investigation of the influence of different wetting conditions on DC strength of a flat insulating surface

This paper reports some results of experiments conducted using a flat plate geometry, in order to understand the unevenly wetted DC wall bushing flashover problem. Two basic configurations are considered, i.e. a bushing-type configuration in which both longitudinal and normal electric field components exist and an insulator-type configuration in which the longitudinal component of E-field is dominant. The electric field distributions of these configurations under different surface conditions are mapped, and the influence of uneven wetting conditions on the E-field distribution and DC flashover are investigated