Hybrid Energy Storage Systems: A Brief Overview

In this paper, a brief overview on the Hybrid Energy Storage Systems (HESSs) is provided. In literature, different architectures are chosen to realize the HESSs, and they are based on the principal aim of the HESSs employment. In this paper, the most used HESS topologies are presented, with particular attention to the active, passive and semiactive topologies, highlighting their characteristics. To have a complete schematic idea of the HESSs application, a focus on the principal sizing methodologies is provided, distinguishing the conventional approaches and the advanced ones, exploiting their main applications. Together with a proper sizing, a correct power-sharing strategy is one of the HESSs key points. For this reason, several control strategies are described, focusing on the energy management control and on the underlying control.