Dynamic Control of Li-Ion Battery-Supercapacitor Hybrid Energy Stora ge System Power Sharing Through Low Pass Filter's time constant

Abstract

Energy storage has a number of benefits, including the ability to balance generation and demand. In microgrid (MG) operation, this means enhancing power quality, smoothing out the intermittent nature of renewable energy sources, and providing ancillary services like frequency and voltage regulation. Hybrid Energy Storage Systems (HESS) has emerged as a solution for achieving desired output by combining the best qualities of various storage technologies. As a result, the literature has documented a variety of HESS designs that take into account storage type, interface, control technique, and service provided. This study investigates how a 5-kW grid-connected photovoltaic array with HESS that consists of a battery and a supercapacitor can dispatch solar electricity at one-hour intervals for a complete day. A Low Pass Filter (LPF) was used to decompose the total difference between generated and load power into high frequency and low frequency components. The high frequency component is substituted by the supercapacitor, while the low frequency one is substituted by the battery. A control system was built that would dynamically modulate the power-sharing between battery and supercapacitor by changing the time constant of LPF.