Modellering av Forsmarks 10 kV nät system 637 i PowerFactory : Undersökning med avseende på belastning och selektivitet

Sammanfattning: This master thesis is done within the Energy Systems Engineering program at Uppsala University and performed for Forsmarks Kraftgrupp, Vattenfall. The distribution grid for the outer area of the nuclear power plant at Forsmark is an old grid from the time during construction of the plant which later became permanent. Many changes have been made to the grid thus far and Forsmark’s need for an updated model to easily simulate upcoming changes to the system has increased. In this thesis, the distribution grid for the outer area of Forsmark is modeled and evaluated from the aspect of load and selectivity. The simulation software PowerFactory has been used to model and perform the necessary network calculations. The results from these calculations will serve as source material for a future system health report for the distribution grid. The results show that some components in the system are overloaded in some modes of operation. A few buses have a fault clearing time that is too long and the system is not selective. The problem with fault clearing time can be solved with new settings on a protection relay and swapping changing out a few fuses. The selectivity in the system would also be greatly improved by the new relay settings.