E-REDES requirements for simulation in meeting RFG compliance on Portuguese distribution grid connections

Integrating renewable energy into power grids requires rigorous validation to ensure compliance with European Network Codes for generator connection (RfG), which transfers to the grid operators the responsibility of verifying its assessment of their area of operation. This conformity can be achieved by several means, such as certificate analysis, numerical simulation or on-field testing. The RfG conformity criteria is left to the grid operator. Since the grid code entered into force, E-REDES Portugal, the Portuguese Distribution System Operator (DSO), established a connection process compliant with the RfG and put a focus on evidence gathering. E-REDES conformity assessment is based on numerical simulation and set requirements for the generator owner's simulations. To ensure adequate testing parameterization and alignment with other DSO requirements, E-REDES and EDP LABELEC teamed up to review requirements. The approach involved a comprehensive benchmarking study of the simulation methods used by various DSOs. This comparison aims to identify the methods, software, and simulations needed to guide generator facility owners in ensuring grid code compliance, starting with evaluating generator behaviour during grid faults. The authors ran several simulations and analysed the results in accordance with grid code requir ements and E-REDES requirements to conclude the merit of requiring such simulations.