Electrical and thermal analysis of polymer insulator under contaminated surface conditions

Electrical and thermal analysis of a 15 kV silicone rubber distribution insulator was made under contaminated surface conditions. The electric field on the insulator surface and in the surrounding area was determined by using the finite element method technique, while the temperature distribution along the insulator surface was calculated by solving the heat transfer differential equation numerically. A special mathematical treatment was used to reduce the heat transfer equation into a 1-dimensional problem. The effects of initial surface contamination upon the features of electric field was studied. The dependence of the change in insulator surface temperature as a result of leakage current flowing over the contaminated surface on the physical parameters involved in the heat conduction process was studied and is presented in detail.