Electrical aging experiment of epoxy resin insulation equipment and research on the influence of electrical field uniformity

The insulation characteristics of solid materials in high voltage switches directly affect the service life of these switches, which is of great significance to the reliability of power system. The electrical aging lifetime of epoxy resin materials in solid insulation switches is studied in this paper. The electrical aging lifetime test is carried on the epoxy resin materials at room temperature with various testing power-frequency voltages from 20 kV to 42 kV, while the electrodes gap distance in the materials is 2 mm for unequal-diameter electrodes and sphere-plan electrodes. The aging lifetime curves of the materials with unequal diameter electrode and sphere-plan electrodes are obtained with the fitting the empirical formula method of inverse power laws in MATLAB, and the electrical aging lifetime of the materials under set condition can be calculated with the curves. And the electric field simulation models are built to compare the electrical aging lifetime differences of two electrode structures. With the experiment and theoretical calculation results, the unequal diameter electrode epoxy resin samples which are closer to the practical switch structures have an electrical aging lifetime of 836190h under power-frequency voltage at 2.4kV while that of the plate electrode epoxy resin samples is 329440h. The unequal diameter electrode epoxy resin samples shows better insulation characteristics than the sphere-plan electrode samples which have comparatively worse uniformity of electric field. And the electrical field uniformity is the mainly influence factors on the electrical aging lifetime of epoxy resin insulation equipment.