Error Analysis for Disconnectors of Type ASEA NUB 420/2000 and ASEA NUB B 245/4000

Abstract: An important part in developing the power gridis maintaining the older parts of the system. This reportexamines the reliability of disconnectors ASEA NUB/NUB-Bin the electrical power grid in order for maintenance to beoptimised. Different mathematical models were used to analyseerror statistics of the disconnectors. This is used to obtain animage of the disconnectors life cycle. The report concludes thatASEA NUB 420/2000 have a life expectancy of 20 years and NUBB245/4000 are expected to last for 30 years. It also concludes thatthe amount of data used in this project is insufficient and does notgive a correct representation of the lifespan of the disconnectors.