Economic Model Predictive Control for Frequency Regulation and SoC Optimization in VSG-Based Microgrids

In modern power systems, the increasing penetration of renewable energy resources that depend on power electronic converters has led to a decrease in both the inertia constant and the damping coefficient. Virtual synchronous generators (VSGs) have been increasingly integrated into microgrids (MGs) due to their ability to simulate inertia, offering some damping to dynamic changes in system frequency. The performance of the VSG is greatly influenced by the state of charge (SoC) of the energy storage system (ESS) that supplies it with power. Based on the considerations, this paper implements control and optimization of the MG using an economic model predictive control (EMPC) strategy. By controlling the output of VSG based on the SoC of ESS, the system frequency regulation and battery optimization are achieved. Theoretical analysis has demonstrated that the long-term average performance of the EMPC is at least as good as the optimal steady-state performance of the system. Case studies have validated the efficacy of the proposed control strategy.