Fault Analysis in a Microgrid Context: DEMOCRAT Project

The development of energy storage systems and the transition to greener generation profiles, driven by global environmental concerns, have contributed to the transformation from traditional thermal generator-based microgrids to renewable energy-based systems. The main challenge of these solutions is to ensure flexibility, reliability and energy quality while providing ancillary services. This work presents the dynamic analysis of the behaviour of a microgrid (MG) integrating storage under different operational contexts and exposed to different fault scenarios. The proposed methodology allows to evaluate the contribution from Converter-Based Distributed Generation (CBDG) to fault currents in MGs, and the ability the system's protections have to suppress them. Moreover, it focuses on the dynamic response of the Battery Energy Storage System (BESS) to different Short-Circuit (SC) faults. A MATLAB/Simulink simulation is developed, in order to model the connection of the MG envisioned in the DEMOCRAT project to the Low Voltage (LV) and Medium Voltage (MV) grids and its operation in isolated mode.