Effect of renewable energy sources on power quality - recent research activities

Renewable energies are gaining increasing importance for the electrical supply system. The integration of distributed electricity generation (DG) by many small generation units into the existing supply structure calls for new technological solutions. New developed devices, improved energy management procedures and advanced communication technologies are demanded to support a reliable, economic and safe operation of all power plants. The Institut für Solare Energieversorgungstechnik e.V. (ISET) is engaged with the development of methods to support the integration of DG - like Renewables, small CHP units and fuel cells - into the public mains. The main focus is put on new approaches in system technology regarding the decentralisation, grid stability and quality, reliability, grid planning, safety aspects and application of communication and forecast methods. In this paper we shortly present research activities regarding power quality improvement by means of inverter based generators, safety aspects of distributed generation and field studies regarding the impact of Photovoltaic systems on the low voltage grid.