ENHANCING DISTRIBUTED POWER MANAGEMENT IN INTERCONNECTED AC/DC MICROGRIDS, PARTICULARLY UNDER UNBALANCED CONDITIONS

Abstract

This paper introduces a hybrid AC/DC microgrid aimed at streamlining the
conversion processes within individual AC or DC grids, thereby minimizing the need for
multiple DC–AC–DC or AC–DC–AC conversions. The hybrid grid integrates both AC and DC
networks through multi-bidirectional converters, with AC sources and loads linked to the AC
network and DC sources and loads connected to the DC network. Energy storage systems can be
integrated into either the DC or AC links. The proposed hybrid grid offers flexibility to operate
in either grid-tied or autonomous modes. Coordination control algorithms are devised to
facilitate seamless power transfer between AC and DC links and to ensure stable system
operation across diverse generation and load scenarios. The control strategies account for
uncertainties and intermittencies associated with variables such as wind speed, solar irradiation
level, ambient temperature, and load fluctuations. A small-scale hybrid grid model is developed
and simulated using Simulink in MATLAB. Simulation results demonstrate the system's ability
to maintain stable operation under the proposed coordination control strategies during transitions
between different operating conditions.