Surface flashover characteristics of polymeric rods with temperature gradient

Surface flashover characteristics of polymeric rods were investigated experimentally by artificially creating a temperature gradient along the rod. Two types of temperature gradient were studied. In one case, the temperature gradient was obtained by cooling a portion of the rod with liquid nitrogen, because such temperature gradients are known to occur along electrical insulating materials of superconducting power apparatus. In the other case, part of the rod was warmed with a heater since such temperature gradients along an insulating material may occur at a contact point with a conductor of power apparatus operating at ambient temperature. In both cases, the flashover voltages were reduced in the case of higher temperature gradients.