A Three-Phase Battery Charger with Constant Current and Pulse-Ripple-Current Charging Capability

The aim of this paper is to propose a three-phase ac-dc converter with constant current (CC) and pulse-ripple-current (PRC) charging capability for battery applications. The input port of the converter is connected to the three-phase ac mains whereas the output port will be connected to the battery module. In order to simply the energy transfer between the ac-side and the dc-side, the direct quadrature (d-q) transformation concept is adopted for the three-phase ac-dc converter. Under normal condition, the three-phase ac-dc converter charges the battery with CC charging. However, if the battery temperature is higher than the predefined threshold value, the PRC charging or the Trickle charging method will be adopted to prevent the battery damage as well as to extend the stability of the battery. Finally, simulation results from a 5-kW circuit demonstrate the capability of the proposed three-phase ac-dc battery charger.