A Decentralized Power and Bus Voltage Regulation Approach for DC Microgrids

In this paper a decentralized power regulation approach is presented for converters operating in DC microgrids. The method enables classical droop control to perform power regulation tasks by employing auto-adaptive virtual resistances for the controlled devices. Moreover, the auto-adaptive nature of the droop characteristic is employed to constraint, through a decentralized approach, the microgrid DC bus voltage within an admissible range of values, despite unpredictable changes in the operating conditions of the microgrid (i.e., sudden variations in load and/or in renewable production). The proposed approach is formalized as a multi-objective optimization problem whose solution is entrusted to a method based on dynamic system theory and Lyapunov theory. Simulations are carried out on test DC microgrids, in order to prove the approach effectiveness.