Grid code certification by simulation

Abstract

To achieve a sustainable energy future, increasing amounts of renewable energy sources (RESs) are being integrated into power systems, replacing traditional high-inertia synchronous generators. Most RES units are inverter-interfaced, lacking natural inertia, which alters power system dynamics, making them more sensitive and dependent on the inverter control schemes. To mitigate stability risks, such as unnecessary disconnections of distributed energy resources during disturbances or faults, grid code requirements and interconnection standards, such as EN50549-1 and EN50549-2 define different operation requirements. These requirements include fault-ride-through (FRT) capability in terms of voltage, frequency, and rate-of-change of frequency, reactive, and negative sequence fault current injection principles during unbalanced faults. Current grid code certification and on-site commissioning tests are costly, time consuming, and limited in scope. This paper proposes simulation-based testing using MAT-LAB Simulink and hardware-in-the-loop (HIL) platform to efficiently demonstrate grid code compliance. By simulating FRT scenarios, such as under-voltage and over-voltage ride-through, the method provides a cost-effective alternative, reducing time-to-market for manufacturers while maintaining reliability. The simulation results confirm compliance with EN50549 standards, and the HIL testing validates the effectiveness of the approach. This work advances testing procedures, bridge design, and commissioning phases to establish standardized, efficient, and reliable grid code compliance methods.