Reconstructed Droop Control for Peer Current Sharing of Battery Storage in DC Microgrids

Droop control has been widely applied in DC microgrids for regulating the power sharing of battery storage. However, conventional droop control needs to select appreciate droop coefficients and large droop coefficients could have the potential to change the system quiescent operating point, thus causing instability. To solve such concern, this paper proposes a novel droop control realization with a natural droop coefficient. A reconstructed control block is used to achieve this purpose. The reconstructed control block also generates a controllable variable for integrating with hierarchical control scheme. Besides, this variable enhances the stability performance of converter due to variable load-adjusted bandwidth of controller. Numerical analysis is provided to visually inspect to the relationship between the bandwidth of controller and load power. A Matlab/simulink model is used to validate this novel reconstructed droop control.