Design and Implementation of a High-Efficiency Multiple Output Charger Based on the Time-Division Multiple Control Technique

Multiple output converters (MOCs) are widely applied to applications requiring various levels of output voltages due to their advantages in terms of cost, volume, and efficiency. However, most of the conventional MOCs cannot regulate multiple outputs tightly and they can barely avoid the cross-regulation problem. In this paper, the recently developed time-division multiple control (TDMC) method, which can regulate all of the outputs with a high accuracy, is used for a multiple output battery charger based on the phase-shift full-bridge topology to simultaneously charge three batteries. The proposed charger is able to charge three different kinds of batteries or three of the same kind of battery in different state of charges (SOCs) independently and accurately with the constant current/constant voltage (CC/CV) charge method. As a result, the strict ripple specification of a battery can be satisfied for multiple battery charges without difficulty. In addition, the proposed charger exhibits a high efficiency since the soft switching of all of the switches during the entire charge process can be guaranteed. The operating principle of the converter and the design of the controller, including the state-space average modeling, will be detailed, and the validity of the proposed method is verified through experiments.