Loss variation calculations in distribution grids

Initially the intention was to investigate what loss levels to expect in different grid areas and to compare the levels to those obtained by the Grid Settlement Group at E.ON Elnät. The data from the grid settlement vary a lot between different grid areas and within a certain network during the year. There has been doubt about the accuracy in determining these variations. Network calculations and simulations of a grid area at voltage levels of 10 kV and below were performed, using computer programmes. The available software turned out to be useful only to obtain yearly energy losses and only for one of the studied networks. Lack of quality data and limitations in software made accurate monthly energy loss calculations impossible. Consequently key factors, crucial for further studies, have been identified. The major conclusion from this thesis is that E.ON Elnät does not have proper tools for precise determination of monthly energy loss levels in distribution networks. Improvement of available software, or on site measurements is recommended in order to improve the accuracy in loss determination