An Improved TL Buck Converter for Fast-Charging Energy Storage System Using UCs

Abstract

Due to the disadvantages of existing ultracapacitor (UC) charging topologies, e.g., slow transient response, an improved three-level (TL) buck charging topology is proposed. Voltage is divied by the energy transformation of the flying-capacitance. The model of the circuit is shifted adaptively on the basis of the dynamic parameters of the reference current, improving the speed of the output current adjustment. Finally, simulation results validate the feasibility of the proposed TL buck topology for the UC energy storage system.