Impact of distributed generation connection with distribution grids - two case-studies

Distributed generation (DG) can have an important impact over distribution grids, especially concerning voltage levels, reliability, line losses and planning methodologies. This paper presents two case-studies assessing the impact of the connection of significant amounts of DG with distribution networks. The first case-study shows a medium voltage (MV) 30 kV distribution grid connected with a substation located in a mainly industrial area of the North of Portugal, having several cogenerations plants in some industrial units (dispatchable DG). The second case-study is related with the high voltage (HV) 60 kV distribution grid that feeds two HV-MV substations located in the centre of Portugal, which has associated some wind farms (non-dispatchable DG). In both cases significant benefits can be observed