Mehdi Ashouri - Department of Electrical & computer Engineering,Babol University of Technology, Babol, Iran
Mohammad Mirzaie - Department of Electrical & computer Engineering,Babol University of Technology, Babol, Iran
Ahmad Gholami - Department of Electrical Engineering, Iran University of Scienceand Technology, Tehran, Iran

At present, porcelain and composite insulators are widely used in high voltage transmission line owing to their outstanding features. The electric field (E-field) strength along these insulators is great concern. Calculation of the electric field and potential distribution is extensively performed in the design and development of insulators for high voltage transmission applications. In conventional calculations of the E-field and potential distribution along the insulators, it is assumed that, there is no wind and foggy air condition. In this paper, three- dimensional (3-D) Finite Element Method (FEM) software–Maxwell is employed to calculate the effects of windy, dry and foggy air condition on the E-field and potential distribution over suspension porcelain string and composite insulator in 63kV transmission line. The calculation results show that the factors investigated have different levels of effects on the distribution of each insulator. The results can be served as a basic reference in the proper use of line insulators in practical condition.

Insulators, 3-D Simulation, E-field and Potential Distribution, Wind, Fog