Bidirectional converter based on boost/buck DC-DC converter for microgrids energy storage systems interface

In this paper, a new bidirectional nonisolated DC-DC (direct current-direct current) converter to interface microgrid energy storage systems is proposed. This converter is based on the classical bidirectional boost/buck converter, the most used converter in microgrids and can operate both in step-down and step-up modes. Besides that, this converter presents low number of components, low voltage and current stress on components, simplicity of operation, low current ripple from low-side power supply, and two different modes of operation: synchronous and asynchronous. In addition, in this paper, the modeling, control, and power losses estimate of the proposed converter are carried out and the performance of the converter in different aspects of the microgrid application is evaluated, such as step load, abrupt power flux change, and transient analysis. A prototype of 1 kW, 144 to 400 V, is developed in the laboratory to validate the theoretical evaluations of the proposed converter. Besides that, the proposed converter is also evaluated under different dynamic condition which illustrates the effectiveness of the converter. Finally, the maximum efficiency obtained is 97.1% for 500 W working in step-down operation.

Automated summary

This paper proposes a new bidirectional nonisolated DC-DC converter for interfacing microgrid energy storage systems. The converter has the advantages of low cost, low energy consumption, and simplicity of operation, and its performance is validated through experiments.