Shape optimization of GIS insulators using Taguchi method

Gas insulated switchgear barrier with conical insulators from a cast epoxy resin was optimized in its shape to withstand AC and DC stresses. The field distribution across insulators with the deposition of charge on the insulator surface was calculated on a parametric geometry model by finite element technique and the profile of electron (cold cathode) emission related to over-critical value of electric field at the busbar surface. A fast improvement in shapes of insulator and surrounding electrodes was achieved using Taguchi method with orthogonal arrays. The former optimization and test results verified this approach in shape modeling of high voltage insulators in SF6 gas.