Control of power inverter in islanded microgrids based on online line impedance estimation

In this paper, proposed an adaptive droop control method using estimated the line impedance in real time and compensate for the mismatch in voltage drops across line impedance, to enhance reactive power sharing accuracy in island microgrids. The block of line parameter estimation using the current and voltage parameters in the microgrid and estimation algorithm recursive least squares method (LSM). The Second-order generalized integrator-phase-locked loop (SOGI-PLL) is used to monitor such amplitude voltage phases and frequency at the point of common coupling (PCC) of the inverters. The line parameters are a mixture of resistance and reactance and has been estimated in real time. Therefore, the adaptive droop control method is more real, providing good performance under all conditions of load and line. The feasibility and effectiveness of the proposed method are demonstrated by using simulation on Matlab/Simulink.