a comparative study of lithium-ion battery and pb-acid battery-supercapacitor hybrid energy storage system for frequency control and energy management of islanded microgrids

Among various storage technologies used for the energy storage systems, the supercapacitors, the pb-acid-batteries (pabs) and the lithium-batteries (lbs) are widely used for microgrid applications. the supercapacitors with high-power density are suitable for fast power regulations; conversely, the pabs have high-energy density, which makes them suitable for long-term energy management. since the pabs and the supercapacitor can complement each other deficiencies, their combination as a hybrid energy storage system is used. however, the lb has both high-energy and high-power densities. therefore, an lb energy storage system (lbess) can similarly function like a pb-acid battery-supercapacitor-hybrid-ess (pshess). this paper tends to determine which one is technically and economically more suitable for applications in islanded microgrids. for this purpose, a frequency control and energy management scheme is proposed. it maintains the balance between demand and supply, and also keeps the microgrid frequency within safe operational limits using the least needed sizes for the energy storage systems. simulation results reveal the costs of libess and pshess would be $140325.93 and $209408.37, respectively, which shows that the cost of the pshess is $69082.44 or almost 49.2 % more than the cost of the libess. this indicates that the lbess is more cost-effective than the pshess.