A New Multiport Non-Isolated Bidirectional dc/dc Converter with Zero Voltage Switching and Free Ripple Input Currents

In this paper, a multi-port non-isolated bidirectional dc-dc converter is proposed. Some privileges of the proposed converter are included the capability of zero voltage switching for main switches, capability of zero current switching for the auxiliary switches, cancelling input currents ripple and bidirectional power flow between the ports. By using an inverse coupled inductor and a capacitor the input currents ripple at low voltage side are reduced. In order to achieve zero voltage switching of the main switches in each stages, an auxiliary circuit which is consists of an auxiliary inductor, two switches and two diodes is utilized. In this paper, theoretical analysis for all operating modes of the converter, voltage conversion ratio, required conditions for attaining ZVS operation of switches, voltage and current stresses of all switches, also, the required condition for cancelling input currents ripple in both boost and buck operations are presented. Finally, to testify the validity of theoretical results and demonstrate the performance of the converter, simulation results of the proposed converter in EMTDC/PSCAD software are presented.