Adaptive Droop and Voltage Recovery Control of DC Microgrids Based on Output Current Feedback

In order to solve the problem that when the line impedance is inconsistent, the traditional droop control with fixed coefficients is difficult to take into account multi-source accurate power sharing and reducing voltage deviation at the same time. An adaptive droop and voltage recovery control of DC microgrids based on output current feedback is proposed in this paper. Firstly, the power allocation loop is added to the traditional droop control, and the load allocation coefficient is dynamically adjusted according to the output current characteristics of the distributed power supply. Then, an adaptive coefficient adjustment loop is introduced to dynamically adjust the droop coefficient by using the output current feedback information to solve the problem of power allocation error caused by the fixed coefficient of traditional droop control. Meanwhile, for the problem of excessive bus voltage deviation, a voltage recovery loop based on PI controller is introduced to make the steady voltage recover to the rated value. Finally, the effectiveness of the proposed method is verified by PSCAD/EMTDC based simulation.