Analysis and implementation of multi-port bidirectional converter for hybrid energy systems

Abstract

In this work, a novel multi-port bidirectional converter is proposed for energy storage in electric vehicles (EV). The proposed converter has the ability to work in both bidirectional step-up (boost) and step-down (buck) modes. There are three ports in the proposed structure that the energy can flow between them. The main features of the proposed converter are the low components count, the low peak voltage of the main switches and low losses. Moreover, only two power switches are utilized in the proposed converter, which makes it easy to transfer the power between the sources. The suggested converter can be worked in energy storage system (ESS) due to the ability of step-up and step-down operation principles. Thus, it can charge and discharge the ESS with high voltage conversion ratio. Besides, the low number of components is utilized in the suggested converter to provide a bi-directional feature that leads to a reduction in the overall cost of the system. In order to investigate the effectiveness of the proposed converter, a technical survey, mathematical calculation, and a comparison study with other existing structures have been introduced in this paper. Finally, to validate the performance of the proposed converter, a laboratory prototype is implemented with a 150 W output power rate at 50 kHz switching frequency 20 V and 12 V input voltages, efficiency about 94.11% in step-up mode and 94.46% in step-down mode.