Advanced planning methods maintaining reliability and power quality in networks with increased distributed generation

Distributed generation (DG) is finding its way into the worldwide distribution networks very rapidly. As the existing networks were not created for this new structure of electricity production, the preservation of a reliable network operation and a high level of power quality is a big challenge for all network operators. In a study conducted by the University of Erlangen and the Erlanger Stadtwerke AG (public utility company of Erlangen), this problem was investigated using an existing distribution network. In this paper the study and its results are presented. Different future scenarios of network configurations with increased DG will be shown. On the basis of calculations for each scenario regarding load and voltage profile, short-circuit currents and (n-1)-aspects the effect of DG on the distribution network will be pointed out. Using these results methods will be presented that guarantee a secure operation in those scenarios. In addition, necessary investment costs are registered in this paper.