Optimized Battery Energy Storage System Operation for Enhanced Voltage Stability

Abstract

Renewable energy source-based microgrids (RES-MGs) offer improved energy efficiency and reduced dependence on utility grid imports. However, high renewable penetration and load variations can introduce voltage instability, leading to reduced system performance and increased operational costs. To address this issue, this study proposes an Energy Management System (EMS) integrating a Volt-VAR Response (VVR) control strategy through Battery Energy Storage System (BESS) inverters, together with a maximum demand mitigation function. A commercial-scale RES-MG model consisting of solar photovoltaic (PV), BESS, variable loads, and utility grid connection was developed in MATLAB/Simulink. Simulations were conducted under sunny and cloudy weather conditions across three load-to-PV scenarios: Load > PV, Load ≈ PV, and Load < PV. The proposed EMS was evaluated for voltage stability and economic performance. Results showed that the VVR strategy effectively maintained voltage within acceptable limits and significantly mitigated severe voltage instability. Meanwhile, the maximum demand mitigation strategy successfully reduced electricity costs in most operating scenarios, achieving savings of up to RM1000. Overall, the proposed EMS demonstrated effective improvements in voltage stability and reduced operational costs in RES-MGs.