COMSOL modeling of the lightning-generated electric field distribution in a chain of insulators of a 115 kV power transmission line

Abstract

The transmission lines installed in our city, to the outskirts of it and in the rest of the national territory produce a level of emissions of electric field, these levels vary depending on the physical disposition of the drivers, the distance between spans, the voltage level of the line, among others. These values must respect the exposure limits for individuals, as stipulated in Article 14 of RETIE. In this work will be developed a study of distribution of the electric field along a chain of insulators standard of tempered glass of a transmission line of 115 kV with the aid of the software COMSOL Multiphysics, to the impact of an atmospheric discharge on the storage cable with the help of ATPDraw software, taking into account variations in the value of the earthing resistance of the structure. With the electric field distribution values obtained by means of simulations carried out in the COMSOL Multiphysics software, comparisons are made of the magnitude of the obtained field, taking as a reference the stable state of the system without condition of pollutants. Initially a simulation of a transmission line of 115 kV is performed in the ATPDraw software, analyzing the lightning impulse generated on the guard cable, at different values of grounding resistance, to determine the waveform and reached value of overvoltage in the insulator chain. Then the overvoltage signal obtained with the help of ATPDraw software is recreated in the COMSOL Multiphysics software, to be able to visualize the distribution and behavior of the electric field along the chain, taking into account the different factors involved in the process, pollutants such as salinity, themes such as travelling waves etc. and thus determine possible line isolation failures by comparing the values achieved by simulating in COMSOL Multiphysics with respect to the CFO of the insulator chain.