Enhanced voltage regulation and current sharing of radial DC microgrids

Abstract

DC microgrids are gaining more attention as their control is simpler, their efficiency is higher and they are more reliable. DC microgrid control aims to regulate load voltage at the nominal value and share load among distributed generation units with a certain ratio. This paper presents a control strategy for radial DC microgrids that achieves these two goals accurately and simultaneously. It doesn't require communication among distributed generators. Only global sensing is required and only one signal is transmitted among DGUs. Tianji Horse Racing Optimization algorithm was used to tune controller parameters. A stability analysis was conducted to evaluate the effect of load change on system stability. This control method has much faster dynamic response compared to previously reported methods. MATLAB Simulink was used to build a model for the microgrid to test the proposed control strategy. Its stability was tested by applying sudden load changes. Also, plug-in and plug-out capability was verified. Constant power load was also used to test the proposed control strategy performance. Communication delay effect was also tested.