Introduction of Grid Forming Converters in the European Grid Codes

The increased penetration of Converter-Interfaced Distributed Renewable Energy Sources (CI-DRES) and the simultaneous decommitment of fuel-driven Synchronous Generators (SGs) has revealed problems related to the robustness and stability of the electric grid, which in turn lead to displacement of SG support functions -e.g., inertia, fault-current contribution- and Ancillary Services (AS), e.g., reactive power and primary frequency regulation. The advanced controllability of Voltage Source Converters (VSCs) and the use of Energy Storage Systems can be exploited to boost the functionalities of CI-DRES beyond their current operation, i.e., uncontrolled power provision. Within the H2020 project EASY-RES such VSC has been developed. In this paper, suggestions for the modification of European grid codes are presented, so that such units are integrated in distribution networks (DNs) to provide existing and new AS and achieve 100% RES penetration. In this way, DNs can be transformed into active DNs with dynamic capabilities like dynamic Virtual Power Plants. Finally, suggestions are presented for: the introduction of new grid codes with respect to AS measurement and quantification; specifications on ICT systems within DNs; the development of a CI-DRES registry with all their steady-state and dynamic properties.