Development of current-controllable batteries charging system based on multi-stage mechanism

Increasing demand for back-up electric power supply has enforced the development of efficient battery chargers in industry. However, the study of an effective charging management mechanism still needs a further improvement to overcome some limitations of traditional methods. For this reason, this paper proposes a current-controllable batteries charging system using multi-stage charge mechanism for achieving more effective performance. First, a high frequency two-transistor forward converter is designed to provide necessary DC power supply for both charger and control unit. For the charger, it is designed based on an ideal multi-state strategy and it can provide a desired/changeable constant charging current. Also, each battery is ensured at a balanced level by the proposed battery equilibrium circuit before the charging process. The experimental results confirm that the proposed charging system is superior in terms of flexibility, high efficiency and self-management capability.