Energy Management Strategy for Microgrid of Multi-energy Storage Based on Dual Droop Control

The energy storage system is of great significance in stabilizing the bus voltage and the safe operation in DC microgrid. The difference of line impedance between energy storage units leads to the deviation of DC bus voltage and thus the power can not be distributed accurately between energy storage units. This paper proposes dual droop control, which adopts two-stage droop control. The improved first-stage droop control compensates the power deviation caused by line impedance and realizes the voltage stability. The second-stage droop control realizes the power distribution accurately. After the fluctuation amplitude of bus voltage is taken into account, this paper analyses the power voltage curve of converter with droop characteristics, and studies the selection range of droop coefficient. The system model is developed to investigate the effects of coupling relationship in the system parameters. Finally, the simulation results in the MATLAB/ Simulink verify the effectiveness and robustness of the proposed method. © 2023 Science Press. All rights reserved.