Koordinace izolace v sítích vysokého napětí

Abstract

This bachelor thesis deals with problems with unwanted phenomena in medium voltage networks. It consist of three main parts, which are insulation coordination in medium voltage networks, switching overvoltage and back flashover. In the first part we can find an analysis of changes of the new version of the standartd ČSN EN IEC 60071-2 ed 2, which defines problematics of insulation coordination in medium voltage networks. The second part of the thesis focuses on the phenomenon switching overvoltage. There we can come to know about general information about this type of overvoltage, suge as effects of parameters, ways and methods for reduction, as well as information about transient switching overvoltage, which is closely related with part. The last part deals with the phenomenon back flashover. Again, there are described general information about creation, influences of parameters, methods of restriction, protection etc.