Application of statistical methods in insulation coordination of overhead power lines

The process of insulation coordination of power systems is conditioned by a number of factors, among which the improvement of methods of surge analyses occupy a special position. The use of statistical procedures in coordination of insulation of overhead power lines requires knowing statistical distributions of surges and reliability of their parameters. Establishing the type of distribution and the evaluation of values of its parameters may be obtained with the mathematical modeling, computer simulations and respective statistical analyses. The simulations of statistical distributions of switching overvoltages for 400 kV power line are presented in this paper.