Two-stage fast charging method using dual-switch flyback converter

Abstract

To improve the charging speed, a new two-stage charging method with dual-switch fly-back converter for Li-ion battery is proposed in this paper. The proposed charging method adopts a two-stage charging of constant current and adaptive pulse current (CC-APC) charging to reduce the charging time for batteries. A dual-switch fly-back converter has the features of simple topology, low cost, galvanic isolation, low voltage stress, no need of additional RCD clamp, and the leakage inductance energy is recovered to the input voltage when the switch is off. Based on the above advantages, a dual-switch fly-back converter is used and designed for the charging system. With the proposed charging method, the charging time is reduced by about 34% compared with the traditional constant current-constant voltage charging method, and the charging time is reduced by about 6% compared with the constant current-fixed duty cycle pulse charging method. The simulation results are provided to verify the system performance.