Simulation of voltage distribution calculation methods over a string of suspension insulators

Insulators for overhead lines are considered to be of basic importance to the transmission system, through their ability to insulate the power lines as well as their function in carrying the weight of the line conductor. For higher voltages, a string of suspension insulators is used. The number of insulator units used depends on the voltages of the lines. The voltage is not equally shared between the units in a suspension insulator string. The capacitances between each cap/pin junction and the tower and between the cap and pin of each unit determine the voltage distribution. Calculation of the voltage distribution can be made by different methods. In this study, these calculation methods and a formulation for each method are studied theoretically through computer programs in case of clean-dry condition. String efficiency comparison for each method is presented, and studying the equalizing voltage drops across insulators is also covered.