Experimental Evaluation and Coordinated Deployment of Ramp-Rate Limitation Against Rapid Voltage Changes in Distribution Systems

Climate change has expedited the integration of converter-interfaced renewable energy sources (CIRESs) in distribution systems. Nevertheless, the active power volatility of CIRESs and the resulting high ramp rates are known to downgrade the voltage quality of distribution systems, causing rapid voltage changes (RVCs). In this context, the operation of CIRESs under ramp-rate limitation (RRL) schemes, employing an energy storage system, could serve as a preventive action against RVCs, thereby restoring voltage quality. To this end, this paper provides insights into the deployment of RRL control against RVCs in two stages. Firstly, the aptness of RRL as a preventive action is experimentally evaluated in a scaled-down laboratory testbed of the CIGRE European benchmark medium-voltage feeder, hosting CIRES prototypes. The RVCs are defined as per the IEEE 1547:2018 and IEC 61000-4-30:2015 Standards. The experimental results demonstrate that the operation of CIRESs under RRL control can enhance voltage quality by suppressing RVCs. Subsequently, a novel, system-level strategy for the coordinated mitigation of RVCs is developed. For a given distribution system, the proposed strategy allocates the RRL functionalities among CIRES units, to achieve the elimination of RVCs under minimal CIRES engagement and energy storage requirements. The effectiveness of the strategy is tested via dynamic rms simulations on the IEEE European Low Voltage test feeder.