Background to certification of power generating units and systems
As a result of certain grid bottlenecks, concerns about grid stability in Germany led the Government to order statutory technical requirements for system services provided by wind turbines with fixed deadlines. The consequences of these requirements are well-known and the effects could hardly be followed more appropriately than in the FGW Expert Committee for Electrical Characteristics.
The “Guideline for generating plants’ connection to and parallel operation with the medium-voltage network”, published by the German Association of Energy and Water Industries BDEW, restated the technical requirements for feeding-in power from wind, photovoltaics, combustion engines and other energy sources at the voltage level decisive for wind turbines and a certificate obligation was introduced for units and systems. Framework regulations were created in connection with the statutory requirements from previous amendments to the German Renewable Energy Sources Act (Erneuerbare-Energien Gesetz – EEG) and the System Services Ordinance (Systemdienstleistungsverordnung – SDLWindV), which introduced joint testing and certification regulations for planners, manufacturers, operators as well as grid operators, measuring institutes and the certification offices. At the same time the above-mentioned BDEW guideline requested the certification obligation for connection to the grid and an accreditation in accordance with ISO/IEC 17065:2012 (Conformity assessment, DIN EN 45011 replaced in 01/2013) for the implementation of these testing responsibilities by a third party.
Since then the FGW Expert Committee for Electrical Characteristics has adopted generally recognised testing and certification guidelines for power generating units and systems at all voltage levels in a broad consensus with far-reaching involvement of all stakeholders and published these for all grid connection regulations applied in Germany. This concerns requirements from the above-mentioned BDEW guideline with its four supplements, SDLWindV, the application regulations already published by the Network technology/Network operation forum (FNN), requirements of the EU Regulation establishing a network code on requirements for grid connection of generators (RfG) as well as the Transmission Code 2007 and the VDN guidance “EEG-Erzeugungsanlagen am Hoch- und Höchstspannungsnetz” (EEG power generating systems on the high and extra-high voltage grid).
The FGW testing requirements ensure both uniform assessments in line with the state of the art and considerably reduce planning efforts and the need to communication. The procedures were gradually expanded, initially for wind turbines, then for PV inverters, combustion engines (directly-coupled synchronous generators) and storage systems.