Evaluation of a Battery-Supercapacitor Energy Storage System effectiveness based on Fuzzy Logic for Energy Management in DC Microgrids

This research shows a comprehensive intelligent energy management strategy of a Direct Current Microgrid (DCMG) incorporating hybrid energy storage system (HESS). The HESS is a proposed scheme to fulfil the performance improvements of SIEMENS gas turbine dc battery charger conventional unit. The HESS consists of a Lead Acid Battery (LAB), Lithium-ion Battery (LIB), and Supercapacitor (SC) under variable load demand. An energy management system (EMS) based on Fuzzy Logic Controller (FLC) and a classical proportional–integral (PI) controller. The HESS with energy management strategy based FLC admits improved time response for sudden and slowly varying load demands, resulting in reduced battery stresses with an improved battery lifetime. An intelligent energy management strategy, using frequency decoupling and fuzzy logic control, provides a reference sharing current needed from LAB and regulates the batteries’ state-of-charge (SOC) within the desired limits. A classical proportional–integral (PI) controller keeps the DC bus voltage (DCBV)to the desired limits. Results of the research, compares with conventional scheme Battery storage system (BSS), explain that by controlling the power flow and maintaining the SOC within the desired limits, the hybrid energy storage system can meet effectively the DC auxiliaries of gas turbine in Emergency situations with lowest DCBV disturbance (2.2%), and performance improvements. Furthermore, the batteries’ lifetime increases.