Barrier effect on the dielectric strength of oil gaps under DC voltage

This paper deals with the influence of insulating barriers on the dielectric strength of two elect-rode arrangements point-to-plane and point-to-point - under dc voltage. It is shown that the dielectric strength of such insulating structures is the improved when the barrier is inserted near the sharp electrode. The effectiveness of the barrier depends on the geometry and the physical nature of the barrier. The presence of an air-pocket in the insulating structure or a hole within the barrier significantly reduce the dielectric strength of the system.