Modeling and Design of an Oscillatory Current-Sharing Control Strategy in DC Microgrids

Abstract

This paper presents an effective control scheme in dc microgrids to precisely share the load current oscillatory and dc components among distributed generation (DG) units. The proposed control strategy includes current and voltage control blocks. The current control block consists of oscillatory and dc current-sharing units. The main idea of the proposed method is to share the load current oscillatory and dc components among the DG units based on their rated power, by assigning appropriate output impedance values and droop coefficients to each DG unit. The voltage control block is a multiloop voltage control unit employed to control the microgrid voltage. The detailed model of the proposed control architecture is established, and the system dynamics is analyzed. Since the synthesis of a local controller uses only information of the corresponding DG unit, the design procedure is totally decentralized. The performance and dynamic response of the proposed control scheme are verified through extensive simulation studies and experimental results.