An Adaptive Droop scheme for improving transient and steady-state power sharing among Distributed Generators in Islanded Microgrids

In this study, a control strategy to proportionally share the power among the distribution generation (DG) units in transient as well as steady-state conditions is proposed. The control strategy is based on the droop control method, which can ensure the parallel operation of inverter based DGs using their local measurements (without any communication). However, the droop control technique have slow transient response and cannot ensure proportional power sharing in steady-state as well. In this paper, an appreciable improvement is achieved in the power sharing by using adaptive droop coefficients instead of fixed coefficients values. The droop coefficients are adaptively changed based on the output currents of the DG. The proposed method does not involve any communication for its operation. The proposed method can be applied to conventional as well as inverse droop control techniques. The effectiveness of the proposed scheme has been validated by performing detailed simulation studies for both the conventional as well as inverse droop cases.