Simulation of the Effect of Bubble Defect on the distribution of Electric Field in Epoxy Resin Pouring Type Insulated Tubular Bus-bar

Insulated tubular bus-bar, functioning as the current-carrier, is widely used in electric generator. Once the bus-bar malfunctions, the generator could not be working properly which would lead to serious economic loss. Therefore, a three dimensional simulation model of 35kV/4000A epoxy resin pouring type insulated tubular bus-bar was established based on the principle of finite element simulation to study the variation law of the electric field with bubble defect in insulation in this paper. The electric field distribution of insulated tubular bus with or without bubble defect in insulation was simulated, and influence of the bubble size and position on the electric field in the insulation structure was analyzed systematically. The simulation results showed that the existence of bubble defect could easily lead to the partial discharge, or even worse, the breakthrough of the insulation finally since the electric filed of the bubble surrounding was serious distortion. The result has important implications for promoting the operation reliability of the generator.