Implementation of a novel digitally-controlled lead-acid battery management system

A digitally-controlled lead-acid battery management system is proposed in this paper. Each battery is maintained independently by corresponding battery management module (BMM). A digitally-controlled symmetrical half-bridge transformer-isolated buck converter with synchronous rectifier (SR) in secondary side forms the body of the BMM and a digital PID algorithm is employed to accomplish the feedback loop control. The power is pre-regulated by a boost active power factor correction (APFC) circuit before inputting to the BMM. Each BMM charges the corresponding battery according to state of charge (SoC), charging current and terminal voltage of the battery. The performance of the system is validated by experiments.