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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.

Combining Fuel Cell (FC) system with high power density Supercapacitors (SCs) leads to a system with a high efficiency, high performance and long lifetime. This paper compares two configurations for FC/SCs combination in Uninterruptible Power Supply (UPS). The objective is to present the power split between Fuel Cell and Supercapacitors hybrid system by MATLAB/Simulink software. The main criteria studied are system performance, lifetime and UPS cost.

In this paper, the authors propose firstly a method based on genetic algorithm to identify the parameters of a novel electric equivalent schema of electrolytic capacitors. Genetic algorithms allow to find the parameters of the model starting from measurements of magnitude and phase according to the frequency and different temperatures, which are obtained using a HP Impedance-Analyzer. Then, they show that the main advantage of this model is that all its parameters are frequency independent and it also redraws with high accuracy the capacitor behaviour for several temperatures and for a large frequency range. Finally, the identified model is introduced into a Boost Power Factor Correction circuit. The power loss variation versus switching frequency is computed using PSIM Software for different temperatures. By the end of this work, we propose the new power loss calculation approach which is more accurate than those already used by taking into account the increase of ESR at high frequencies due to the Skin Effect.