Optimization of Operational Costs in Multi-Microgrid Systems with Renewable Energy and Energy Storage Systems

Abstract

Microgrids (MGs) play a vital role in the era of deregulated power systems. The number of MGs connected to the power grid increases the complexity of energy management among the main grid and MGs. A multi-microgrid (MMG) system utilizes all available energy sources (renewable and non-renewable) and energy storage systems to manage power exchange efficiently within the MGs and the main grid, enhancing system reliability, stability, and efficiency. With the integration of renewable and non-renewable energy sources, the system can adapt to different energy availability scenarios.  This paper presents an optimized energy management scheme for MMG, implemented using multiple integer nonlinear programming in GAMS software. The objective is to minimize the overall operational cost of MMG and reduce emission costs. The dynamic nature of renewable energy sources, the fluctuating demand patterns, and the operational constraints of both the MGs and the main grid. The proposed approach is applied to an MMG system interconnected with the main grid, incorporating both renewable and non-renewable energy sources. The simulation results demonstrate the effectiveness of the presented energy management strategy in lowering system costs for two operating case-I and case-II. The impact of integrating energy storage systems has also been evaluated on the overall cost of the system, revealing their potential to enhance the overall efficiency and cost-effectiveness of the energy management system (EMS). The results show that overall operational cost has been reduced from $1163 in case-I to $1096 in case-II and MMG becomes more independent in case-II as power demand from the main grid is reduced from 10259 kW(case-I) to 9171kW (case-II).