Research on Improved Droop Control Strategy of Microgrid in Island Mode

When the traditional droop control is applied in the islanded microgrid system, the uneven distribution of reactive power in the system is caused by the different line characteristics of transmission lines. Based on the analysis of the traditional droop control theory and the reactive power distribution principle, an improved droop control strategy to realize the reactive power distribution is proposed. The line characteristic curves of different transmission lines are adjusted to make them intersect at one point, with a fixed droop characteristic curve. Firstly, a small voltage perturbation is injected into the system to obtain the observed line impedance, and then the reference voltage is compensated. Finally a simulation model is built with the MATLAB/Simulink software. The accuracy of the line impedance observer and the distribution effect of the reactive power in the islanded microgrid are verified with the simulation experiment.