Advanced computational tool for analysing the impact of distributed generation on distribution systems planning

This paper aims to describe the main results of a research and development project for allowing the analysis of impacts due to the connection of distributed generation (DG) units to a distribution network and synergies with the expansion planning. The computational implementation has included innovative modules for optimum allocation of DG units, evaluation of system average RMS frequency index (SARFI) for a specific voltage sag magnitude with or without DG units in the network as well as analysis of the impact of a large number of small photovoltaic ( PVs) panels. The impact of PV microgrids is taken into account using the foreseen seasonal and daily variations of sunlight for calculating the generated energy. Since the model allows an integrated representation of low, medium and high voltage networks, the impacts of the DG units can be analysed in any part of the system under study with a single processing. The software has a full graphics interface with integrated maps for helping the planning activities.