Electric field calculation and material optimization of 765kV bushing using FEA

Transformer bushings are one of the important components in the construction of high voltage power transmission. The structure and materials used in electrical bushings play a vital role in the durability and lifespan of the bushing. Although the cost of transformer bushing is very minimal in the transmission system extensive damages are caused in case of failure. The main reason of failure in the insulation materials are caused due to moisture ingress and formation of voids, cavities. When the appropriate material is used along with an optimized structure, the electric field is distributed evenly which reduces the stress and increases the longevity of the bushing. In this paper, Finite Element Analysis(FEA) is used to calculate The ELECTRIC FIELD DISTRIBUTION and THERMAL(Temperature) Analysis is done for 765kV transformer bushing by using different insulating materials such as Epoxy Resin, Porcelain, Oil Impregnated Paper, Resin Impregnated Paper and Polymer. Henceforth, by using the above insulating materials the total stress level of the bushings corresponding to the net electric field distribution is in turn calculated using ANSYS 13.0 Software. The results are compared and analysis is done for the different insulating materials. Based on the electric field distribution over bushing material, it is used to identify optimization of bushing design.