Averaged Modeling Of A New Bi-directional DC-DC Converter

A novel isolated bi-directional dc- dc converter is proposed in this paper which implements zero current switching (ZCS) for current-fed inverter of the low voltage (LV) side of the converter and zero voltage switching(ZVS) for voltage-fed inverter of the high voltage (HV) side of the converter. Applying the ZCS technique, circulating current of the transformer is limited by the current of input currentsources, so the circulating current and thus the circulating loss of the converter is minimized. Involving the input inductors in the zero voltage switching resonant periods, ZVS is realized for all HV switches approximately in the whole load range. The converter is verified by simulation results of ORCAD Software. A reduced order switching cell averaged model of the converter is developed and then state space averaged model of the converter is derived from the switching cell averaged model. The MATLAB/Simulink simulated waveforms of the mathematical model are compared with the detailed circuit simulation to verify the accuracy of the modeling.

Keywords:

Bidirectional dc-dc converter , zero voltage switching(ZVS) , zero current switching(ZCS) , Average modeling