Atmosférické přepětí na venkovním vedení

Abstract

This thesis deals with the means of protection against lightning strikes and modeling of lightning strikes to high voltage overhead lines using the EMTP-ATP. The aim is to acquaint the reader with problems related to lightning strike into the line, followed by underlining the importance of protection against lightning strikes. In the first part of this work is explained principle of the electrical discharge between cloud and ground and is characterized a lightning and its basic parameters. The second part deals with line protection against lightning and ways how ligntning can strike to the line. Furthermore, this part analyzes the most common means of protection against lightning strikes that are placed on overhead line and their characteristics. In the third part are modeled two cases the consequences of a strike to the line. Strike to the ground wire followed by the backflash over and strike to the ground wire with subsequent analysis of voltages and currents that characterize this surge protection.