A novel double-quadrant SoC consistent adaptive droop control in DC microgrids

Abstract

This brief uses a double-quadrant state-of-charge (SoC) consistent adaptive droop control method for extending the service life of distributed energy storage units (DESUs). During charging, the power absorbed by DESU is inversely proportional to its SoC. On the other hand, during discharging, the power emitted by DESU is proportional to its SoC. The SoC of DESUs and the power absorbed or emitted by the DESUs tend to be consistent under charging and discharging conditions. To compensate for the direct-current (DC) bus voltage change caused by droop control during charging and discharging of DESUs, this brief proposes a novel double-quadrant SoC consistent adaptive droop control method which is based on multi-agent approach and considers the real-time capacities of DESUs. The reliability of the proposed novel control design method is confirmed by simulations.