An Improved Nonlinear Droop Control Method Applied to DC Microgrid.

Droop control can achieve load sharing among paralleled sources in DC microgrid. But pursuing high allocation accuracy will cause a voltage variation on the bus. To face the trade-off between better current sharing accuracy and slighter voltage variation in traditional linear droop control method, an improved nonlinear droop control method was proposed in this paper. Aiming at the limitation of existing nonlinear droop method, which is low current sharing accuracy in light load, the proposed fitting curve combined linear and nonlinear droop curves. With both linear and nonlinear properties, it can improve the performance of nonlinear control method especially in light load. The simulation was carried out in Matlab/Simulink, and the superiority of this method was verified.