Penetration of mixed distributed generators in a medium voltage network

This paper examines the results of the penetration of mixed distributed generators in a medium-voltage power distribution network. Specifically, the connected distributed generation resources are mainly photovoltaic units, a wind farm and a hydroelectric plant and they operate with different power factors. Their influence on the network branch currents, losses and voltage profile as well as on the short-circuit level at the medium-voltage busbars of the infeeding substation are examined, for differed load conditions, according to international and national standards. The arising problems are explored by parametric investigations concerning the operating characteristics of the connected units. Finally, general conclusions regarding the handling of relevant practical problems are set out.