Lithium-ion Battery/Supercapacitors Combination in Backup Systems

Combining hybrid Electrical Storage Systems (ESS) is solving many electrical devices problems while using them separately. Batteries present limited charge/ discharge cycles which affect their lifetime and increase their cost. In fact, the lithium ion (li-ion) batteries are more and more studied and evolving in term of cycles. They provide high energy density while the supercapacitors (SCs) ensure long lifetime cycles and operate at large range temperatures. This paper presents a control strategy of battery/ SCs in Uninterruptible Power Supply (UPS) application in order to improve the efficiency, lifetime and reduce the cost. A comparison of using the hybridization with and without control system was established to highlight the power split between the two storage systems. A comparison of lead acid and li-ion battery was established. Finally, different ESS’ financial study was set.