Projektering av lokalnät med fördjupning i selektivitet

Sammanfattning: In power system, when a local network with over head lines is replaced by a network laid underground, itchanges the characteristics of the material used and gives an opportunity for an updated sizing. The goal withthe project was to present a proposal of a reconstruction of a old local network to a modern local network andpresent a selective coordination plan for all the branches in the new network. The methods that are used isthe Velanders method for interleaver of the maximum power, sizing according to “SvenskStandard”(Swedish Standards) and curve fit of trip curves to present digital produced selective coordinationplan. The new underground local network delivers a better electrical quality, that fulfills the triggerconditions and obtains a good selective coordination.