A centralized control architecture of a hybrid photovoltaic, wind turbine, and battery autonomous microgrid with a support diesel generator

A high interest in autonomous microgrids refers to the increasing penetration of renewable energy resources and their availability. The Energy Storage System (ESS) is integrated into an islanded microgrid to ensure a balance between generation and consumption and regulate the unpredictable behavior of renewable energy resources. This paper proposed a centralized management system based on a coordination strategy to provide tasks such as SoC equalization, active power curtailment, load shedding, and mismatching compensation. The coordination strategy should be consider the limitation of ESSs to avoid their degradation. Also, it is ensure the balance between generation and conception in different cases, the proposed active power curtailment for avoiding battery overcharge when battery SoC reach to 100% during charging process, and load shedding algorithm disconnect the non-critical load when SoC reach to minimum value 60% to avoid battery deep-discharge. Also, the paper proposed strategy involve SoC algorithm for equalizing SoCs of batteries to ensure uniform charge/discharge process between different batteries irrespective to their capacities. If all of these resources are not cover the load requirement.Then, the proposed strategy connect diesel generator to ensure power balance in small power system. These tasks aim to ensure microgrid stability and reliability, optimal power flow between generation units and loads, and increase the lifespan of energy storage systems. The validation of the proposed EMS and control architecture was tested using MATLAB/Simulink. The results show the effectiveness of the proposed EMS during the charging and discharging process under different operation conditions. From the results the equalization time between two different battery capacities elapse time 10% more than batteries with similar capacities.