Control of DC Microgrid for Improved Current Sharing and Voltage Regulation

This paper presents a distributed secondary controller in DC microgrid to improve the distribution of converters' output current and minimize load voltage regulation. The main theory adopted in the proposed controller is the variable droop resistance, which changes with change in line resistances, inequality in the converters' output currents, and output voltages. The voltage error obtained through the secondary controller participates in determining variable droop resistance and modifies the reference for DC output voltage after compensating voltage drop across droop resistance The converters used in this system are isolated full-bridge DC-DC converter, which allows the proposed controller's adaptability in both isolated and non-isolated converters.