Soft Switched Current Fed Dual Active Bridge Isolated Bidirectional Series Resonant DC-DC Converter for Energy Storage Applications

Abstract

This paper proposes a high-frequency isolated current-fed dual active bridge bidirectional DC–DC series resonant converter with an inductive filter for energy storage applications, and a steady-state analysis of the converter is carried out. The performance of the proposed converter has been compared with a voltage-fed converter with a capacitive output filter. The proposed converter topology is operated in continuous conduction mode with zero circulation current (ZCC), less current stress and high efficiency. The conditions required for soft switching are determined, and it is found that the converter operates with soft switching of all switches for a wide variation in load and input voltage without loss of duty cycle. Current-fed converters are suitable for low-voltage renewable energy applications because of their inherent boosting capability. An inductive output filter is chosen to make the output current ideal for fast charging and high-power-density battery storage applications. Simple single-phase shift control is used to control the switches. The performance of the converter is studied using PSIM simulation software. These results are confirmed by an experiment on a 135 W converter on an OPAL-RT real-time simulator. The maximum efficiency obtained in simulation is 96.31%. Simulation and theoretical results are given in the comparison table for both forward and reverse modes of operation. A breakdown of the losses of this converter is also presented.