Study of the oversized capacity and the increased energy loss of hybrid energy storage systems and design of an improved controller based on the low-pass filter

A hybrid energy storage system (HESS) consisting of batteries and supercapacitors (SCs) is an effective approach to stability problems brought by renewable sources (RESs) in microgrids. This paper investigates the exchange between two devices (ESDs) caused low-pass filter (LPF), which leads oversized capacity HESSs. In addition, ESDs more loss Based on analysis power flows, this proposes improved controller based LPF controller. direction control strategy eliminates non-beneficial flow reduce HESSs improve round-trip efficiency. a SOC regime balances desired state charge (SOC) instead depending LPF. paper, case study shows that reduces HESS minimized improves Furthermore, it has no adverse effect battery aging achieves lifetime extension with smaller capacity. scaled-down experimental setup validates effectiveness simulation results. Finally, proposed compared various existing controllers verify performance.