Charge distribution characteristics of bottle type insulator with shield ring in vacuum

The objective of this paper is to research the charge distribution characteristics on the inner surface of a bottle type insulator depending on the shape of shield ring, which is used to mitigate the high electric field near the triple junction. The bottle type insulator was sandwiched between upper and lower parallel electrodes. These electrodes were equipped with the shield ring inside the bottle type insulator. The charge distributions were measured over the whole area of the inner cylindrical insulator by an electrostatic probe after a ramped dc voltage application. We investigated the charge distribution on the inner surface by varying the shape of the shield rings. As a result, we have obtained the relation between the shape of shield ring and charge distribution on insulator.