Distributed Energy Resource Behavior During Faults: Navigating Voltage Ride-Through Compliance Within the Realm of EN 50549

This paper presents a comprehensive investigation into the effects of increasing inverter-based renewable energy resources (RERs) on fault-level propagation in medium voltage (MV) distribution networks (DNs). The study aims to ensure compliance with European grid codes EN 50549-1 and EN 50549-2, particularly regarding low-voltage ride-through (LVRT) requirements for distributed energy resources (DERs). A two step ahead finite control set model predictive (FCS-MPC) current control strategy for two-level inverters, along with an LVRT control algorithm and a secondary power controller to align with the grid code, is implemented. To demonstrate real-world implications, a detailed MATLAB/Simulink model of the Sundom Smart Grid in Vaasa, Finland, is developed, employing available data to replicate the actual network configuration with high fidelity. Subsequently, various penetration levels of power-electronics converter (PEC)-based generation are integrated to assess fault propagation under both weak and strong grid conditions. Results explain how higher shares of DERs can alter network fault dynamics and voltage profiles, emphasizing the importance of grid-code-compliant control schemes in managing operational and safety margins. The proposed approach provides a robust framework for utilities and operators to optimize DER integration, ensuring grid stability and reliability.