Mixed distributed generation technologies in a medium voltage network

This paper examines the results of the penetration of mixed distributed generation technologies in a medium-voltage power distribution network. Specifically, the connected distributed generation resources are mainly photovoltaic units, a wind farm, and a hydroelectric plant; these all operate with different power factors. Their influence on the network currents, losses, voltage profile, and 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 problems that arise are explored through parametric investigations concerning the operating characteristics of the connected units. Furthermore, the optimum allocation of the same or different types of distributed generation resources to the examined network is determined in order to obtain the maximum penetration without technical problems. Finally, general conclusions regarding the handling of the relevant practical problems are given.

► Impacts of mixed distributed generation penetration in real rural medium voltage power distribution networks.
► Technical constraints.
► Currents, losses, voltage profile and short-circuit level of the examined networks.
► Optimum distributed generation penetration.
► Arbitrary distributed generation penetration leads to network sterilisation and to violation of the technical constraints.