A Power Distributed Control Method for Proportional Load Power Sharing and Bus Voltage Restoration in a DC Microgrid

This paper proposes a new power distributed control method for a dc microgrid. This method was developed to share the load power proportionally to the distributed power source ratings and restore the dc bus voltage when the load changes. To achieve this effectively, a shifted voltage technique was developed based on the power rating and the instantaneous power of distributed generators. By adding the shifted voltage, the voltage drop caused by the droop controller is effectively compensated such that the dc bus voltage is constantly regulated regardless of the load change. To realize the method, all the required information to determine the reference voltage is transmitted through low-bandwidth communication. The controller design process is presented in detail along with a system stability analysis. The effectiveness of the method was verified by simulation and experiments, which were carried out using a 2.8-kW prototype of a dc microgrid.