Measurement and Simulation of the Voltage Distribution on an Insulator String

In this paper, the voltage distribution o n a porcelain insulator string, which is used for the suspension of 150 kV overhead transmission lines, is investigated. In order to calculate the voltage distribution, a model of the insulator string was set up using OPERA, an electromagnetic analysis program based on the Finite Elements method. Simulation results have been compared with experiments which were carried out in the High Voltage Laboratory of the National Technical University of Athens. The paper highlights the significance of the three-dimensional part of the geometry by comparing OPERA-2d/ST and OPERA-3d/ST results. More significantly, the paper discusses the limitations of an electrostatic solution for this class of problem and presents results from alternative formulations that account for the conducting and dielectric properties of the materials.