Finite element analysis of electric field around an ice-covered semi-conducting glazed insulator using a form of Kelvin transformation

This paper describes electric field distributions around a semi-conducting glazed standard post insulator for power frequency, lightning impulse(1.2/50 μs) and switching impulse(250/2500 μs) voltages under icing conditions, which were computed numerically using finite element method. Thin glaze coating on the insulator requires a very large number of elements for finite element analysis because of an open boundary around an ice-covered insulator. To reduce number of elements and hence computation time, the region between domain of interest and infinity was modeled by a form of Kelvin transformation. Simulation results are compared with laboratory experiments and are found to be in agreement.