Multi-Port Converter Integrating Automatic Current Balancing Interleaved PWM Converter and Dual Active Bridge Converter with Improved Transformer Utilization

Abstract

Multi-port converters (MPCs) that integrate multiple converters into a single unit have been proposed to reduce the converter count in renewable energy systems where multiple power sources are employed. The conventional MPCs consisting of a dual active bridge (DAB) converter and interleaved PWM converter, however, require feedback control loops and current sensors to balance inductor currents. Furthermore, the transformer utilization in the DAB converter tends to decrease as the duty cycle of the interleaved PWM converter moves away from 0.5. This paper proposes a novel MPC integrating a DAB converter and interleaved PWM converter with an automatic current balancing capability and a high transformer utilization. Major features and fundamental operation principle are discussed. The experimental verification test using a 300-W prototype demonstrated that the proposed MPC could improve the transformer utilization and achieve an automatic current balancing.