Shape Optimization of GIS Insulator Barriers Using Orthogonal Arrays

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 long creepage path and field distortion due to the deposition of charge on the insulator surface was calculated on a parametric geometry model by finite element technique. A fast improvement in shapes of insulator and surrounding electrodes was achieved using a method with orthogonal arrays. The former optimization and test results verified this approach in modeling of high voltage insulators in SF6 gas.