Evaluación del aislamiento de una línea de transmisión de 500 kV ante descargas atmosféricas utilizando un método estadístico

Abstract

The lightning performance evaluation of a 500 kV transmission line insulation using a statistical method; which is based on the calculation of the risk of insulation failure. In order to calculate the mentioned risk a systematic simulation of the impact of ten thousand downward negative lightning was developed. At first, overvoltage density curves were statistical estimated from these simulations. The ATP transmission line model has considered all electrical elements involved in this phenomenon, the random nature of lightning and four different stroke locations. It must be pointed out that lightning current parameters were represented by aleatory numerical data generated according to the originated density functions from direct stroke current measurements performed in several countries. Moreover, the stroke location was determinated by applying the electro geometric model. Second, insulation was represented taking account its dielectric strength statistical behavior. Then, the risk of failure of line insulation is calculate. Finally, the insulation evaluation is performed by verifying if the risk of failure of line insulation meets the reliability criteria that applies in our country.