An Adaptive droop Curve for the Superimposed Frequency Method in DC Microgrids

This paper proposes a new adaptive droop curve to ensure the stability of the superimposed frequency method (SFM) for the control of DC Microgrids. SFM has a remarkable accuracy in load-sharing and voltage regulations among different control strategies of DC microgrids. However, this method suffers from some levels of instability in terms of the load variations. This is due to (i) location of the system dominant poles; which is really sensitive to the variations of the system loading, and (ii) limitations in the transferred reactive power; which is used to regulate source DC voltages. Therefore, a new strategy based on an adaptive droop curve is presented in this paper to keep the system dominant poles in an acceptable area and its performance is verified using different simulation studies in MATLAB/SIMULINK environment.