An Adaptive Fast Charging Strategy for LiFePO4 Battery Applied to Heavy-Haul Train ECP Brake System

A dedicated LiFePO4 battery management system (BMS) used in the electrically controlled pneumatic brake system of a heavy-haul train needs a reliable, efficient and safe charging system to guarantee an uninterrupted power supply. To achieve that, this paper proposes an adaptive fast and safe charging strategy for Li-ion batteries based on the Lyapunov stability theory. In the strategy, a sliding-mode state of charge (SOC) observer is designed, and based on this, the dynamical reference charging current profile is derived. With the estimated SOC and dynamical setting current, the adaptive current control law is proposed by using a Lyapunov function. Finally, experiments are conducted to verify the feasibility and superiority of the proposed method.