Enhanced Inertia Estimation in Microgrids using a Modified RoCoF Method

The increasing integration of inverter-based resources alters the system’s dynamic response, including inertia distribution. Accurate inertia estimation and its monitoring are crucial for ensuring stable operation in power grids with high renewable energy penetration. In this connection, this paper introduces an enhanced rate of change of frequency (RoCoF) based method for estimating inertia in a microgrid. The key attribute of the proposed method is its capability in estimating the inertia even without knowing the magnitude of disturbance, which is the main limitation of the conventional method. The effectiveness of the proposed approach is first validated on a system composed solely synchronous generators, followed by an evaluation in a hybrid energy system. The results are then compared with those obtained using conventional inertia estimation techniques. The findings demonstrate that the proposed method accurately estimates the system inertia, which is contributed by rotating/dynamic elements, however with a diverse generation mix without needing the disturbance magnitude.