Energy-Aware Finite-Horizon MPC Coordination of Adaptive VSG Inertia and BESS Control for Transient-Stability Enhancement in Renewable-Dominated Low-Inertia Hybrid Microgrids

Abstract

The increasing integration of renewable energy sources (RESs) into modern power grids has reduced the rotational inertia traditionally provided by synchronous generators. This reduction poses significant challenges for transient stability, frequency regulation, and the dynamic resilience of power systems. The problem is more pronounced in renewable-dominated hybrid microgrids, where inverter-based resources are progressively replacing conventional generation units. In this context, sudden disturbances can produce large frequency deviations, high RoCoF values, oscillatory behavior, and even loss of stability. This paper proposes an energy-aware adaptive virtual synchronous generator (VSG) control strategy coordinated with a model predictive control (MPC)-based energy-management layer for a battery energy-storage system (BESS), in order to enhance the transient stability of a hybrid microgrid with high renewable penetration. Unlike conventional fixed-parameter VSGs, the proposed MPC–VSG–BESS framework dynamically updates active-power references and adjusts the virtual inertia J and damping D parameters in real time. In this way, the framework seeks to reduce RoCoF, improve the frequency nadir, and preserve the BESS operating constraints, including its energy availability. The methodology is evaluated using detailed EMT simulations in MATLAB–Simulink® R2023b under severe contingencies, including three-phase faults and sudden loss of conventional generation, with renewable-penetration levels ranging from 70% to 100%. Under the most severe 100% RES condition, the proposed MPC–VSG–BESS framework limits the frequency nadir to 59.26 Hz compared with 56.78 Hz for the conventional control case, corresponding to a 77.0% reduction in the magnitude of the frequency nadir deviation. The proposed controller also extends the critical clearing time from 0 ms to 185 ms under the considered severe fault condition, while maintaining a maximum observed RoCoF of approximately 0.32 Hz/s. During the transient response, the virtual inertia and damping reach maximum observed values of 48.5 kg·m2 and 38.2 N·m·s/rad, respectively. Under a low initial SoC of 22%, the energy-aware constraint limits the admissible virtual inertia to 12.4 kg·m2. The MPC implementation requires an average computation time of approximately 2.8 ms and a maximum of 6.5 ms for a 10 ms control interval, demonstrating computational feasibility within the adopted simulation framework.