A Distributed Control Scheme for Cyber-Physical DC Microgrid Systems

Abstract

An innovative distributed secondary control technique for balanced current sharing and voltage regulation for an off-grid DC microgrid setup is presented in this research. The droop control scheme is conventionally used for current sharing amongst distributed sources (DSs) in a microgrid. However, this method has two major drawbacks. Firstly, due to the line resistance of each DS, the output voltage is different for each DS, and the output current-sharing property deteriorates. Secondly, the droop action increases the DC bus voltage variation. To address these drawbacks, a fuzzy-based distributed secondary controller is proposed. The proposed controller in each DS simultaneously ensures balanced current sharing and sustains DC bus voltage at the reference value by using a communication network to interact with one another. The required circumstance to guarantee the proposed controller’s stability is provided. The stability analysis is beneficial to inform the choice of control parameters. The real-time simulation outputs demonstrate the proposed control scheme’s robustness in achieving the control objectives under varying operating conditions.