Electric Field Simulation and Defect Analysis of Transformer Oil-Paper Capacitive Bushing

In order to study the insulation performance of oil-paper capacitive bushing, the finite element model of 40.5 kV transformer oil-paper capacitive scaled bushing with field strength similar to that of actual 1000 kV bushing is established based on COMSOL software. Based on this model, the 2D electric field analysis is carried out. The field strength distribution and potential distribution of the bushing under different defects are calculated, and the degree of electric field distortion at the defects is obtained. The calculation results show that the design of the capacitor core of the casing can effectively uniform the electric field distribution in the casing under normal working conditions. When the fault occurs, the internal electric field distorts in different degrees at the defect. Therefore, it is very important to avoid bushing the dirty and wrinkled capacitive screen, keep the bushing environment dry and avoid the humidity of the capacitor core.