25-08-2017, 09:32 PM
This paper outlines design, manufacturing, testing and service maintanence of high voltage bushing used in Power Transformers. Particular importance is given to Oil Impregnated paper condenser bushing which is generally used. International as well as national standards define bushing as a structure carrying one or several conductors through a partition such as a wall or tank and insulating it or them there from, incorporating the means of attachment (flange or other fixing device) to the partition. The conductor may form an integral part of the bushing or be drawn through. Bushing in its simplest form would be around conducting electrode covered with insulating materials like porcelains, synthetic resin bonded paper, Cast Epoxy Resin, Polythene, stard rubber etc. In all cases the radial thickness of the bushing is determined by the electric strength of the insulting material and axial clearance governed by the electric strength of the medium surrounding the main insulation eg: air, oil SF-6 gas etc