Optimal Model Predictive Control for Virtual Inertia Control of Autonomous Microgrids

For the time being, renewable energy source (RES) penetration has significantly increased in power networks, particularly in microgrids. The overall system inertia is dramatically decreased by replacing traditional synchronous machines with RES. This negatively affects the microgrid dynamics under uncertainties, lowering the microgrid frequency stability, specifically in the islanded mode of operation. Therefore, this work aims to enhance the islanded microgrid frequency resilience using the virtual inertia frequency control concept. Additionally, optimal model predictive control (MPC) is employed in the virtual inertial control model. The optimum design of the MPC is attained using an optimization algorithm, the African Vultures Optimization Algorithm (AVOA). To certify the efficacy of the proposed controller, the AVOA-based MPC is compared with a conventional proportional-integral (PI) controller that is optimally designed using various optimization techniques. The actual data of RES is utilized, and a random load power pattern is applied to achieve practical simulation outcomes. Additionally, the microgrid paradigm contains battery energy storage (BES) units for enhancing the islanded microgrid transient stability. The simulation findings show the effectiveness of AVOA-based MPC in improving the microgrid frequency resilience. Furthermore, the results secure the role of BES in improving transient responses in the time domain simulations. The simulation outcomes are obtained using MATLAB software.

Automated summary

Renewable energy sources (RES) have been increasingly integrated into power networks, especially in microgrids, leading to a significant decrease in system inertia. This reduction in inertia negatively impacts microgrid frequency stability, particularly in islanded operations. To address this issue, this study proposes a virtual inertia frequency control concept combined with optimal model predictive control (MPC) using the African Vultures Optimization Algorithm (AVOA). Simulation results demonstrate the effectiveness of the proposed AVOA-based MPC in improving microgrid frequency resilience and the role of battery energy storage (BES) units in enhancing transient responses.