Flexible interconnection of DC microgrid cluster based on isolated bidirectional DC–DC converter

Abstract

To make full use of the power of the microgrid and improve the reliability of the power supply system, a flexible interconnection control strategy for the DC microgrid cluster based on isolated bidirectional DC–DC converters is proposed in this paper. First, an isolated bidirectional DC–DC converter is used to flexibly interconnect the two DC microgrids based on electrical isolation to ensure that both DC microgrids can operate independently, and then the extended phase shift control is adopted for the isolated bidirectional DC–DC converter, which increases the control dimension and controls flexibility. At the same time, the extended phase shift control circuit is improved, which solves the traditional constant power transmission problem and ensures the real-time bidirectional transfer of energy between microgrids. The microgrid cluster simulation platform is built in MATLAB/Simulink, and the electrical isolation effect of the isolated bidirectional DC–DC converter is verified through simulation. At the same time, it is verified that the shift ratio of the regulating converter can realize the energy between the microgrids in the microgrid cluster, which improves the stability of the system.