High voltage flashover along a solid-liquid interface

摘要

It is common experience to observe a reduction in the insulating strength of an insulating liquid, when the space between the electrodes contains a solid insulating support extending between the electrodes. This has been found to be true regardless of the insulating medium and of the insulating support. Major difficulties are encountered in obtaining flashover data for the solid-liquid insulating system. Each flashover drastically changes the insulating properties of the system: the moisture, gas, and carbon content of hydrocarbon liquids are changed, electrode surfaces are modified by the conditioning process and in cases where flashover occurs at the interface, destruction of the surface of a solid organic support usually occurs by tracking, making it unsuitable for further tests. After surface flashover occurs, therefore, the solid support, the insulating liquid, and the electrode surfaces must be replaced or treated.