Evaluation of power losses and their impact on battery life in AC, DC, and hybrid microgrids

Abstract

Microgrids (MGs) are being deployed more extensively worldwide, as they represent the most viable solution for expanding energy access in energy-poor countries. Power loss is a fundamental factor to consider, as it directly impacts the overall efficiency and cost-effectiveness of the system. Power loss occurs in various microgrid components, including lines, converters, and power electronic devices. In the first stage, transmission line voltage droop and power losses were determined for different microgrid topologies. The second stage involved analyzing power losses across all converters (specifically switching and conduction losses) to determine the operational efficiency of each unit. The total power loss summation allowed for an evaluation of global microgrid efficiency, facilitating the identification of the optimal configuration. Furthermore, battery State of Charge (SOC) and Depth of Discharge (DOD) were analyzed across the different topologies, accounting for both ideal and loss-affected scenarios. The findings indicate that DC microgrids maintain a higher SOC, whereas AC configurations lead to a lower SOC; these variations in DOD directly impact the projected battery cycle life. In addition to MATLAB/Simulink simulations, HOMER Pro software was employed to perform design optimization and evaluate energy management strategies. This provided a comparative analysis of the economic feasibility across the proposed microgrid topologies.