Plug and play nonlinear droop construction scheme to optimize microgrid operations

The operating cost of islanded microgrids can be minimized by performing an optimal power sharing among the distributed generators (DGs) therein. In this study, a plug and play optimization scheme (PPOS) for developing nonlinear droop relations is proposed to achieve an optimal power sharing among the sources in islanded microgrids. The PPOS constructs nonlinear frequency droop relations that minimize the microgrid operating cost by adjusting the DGs output power. The construction of nonlinear droop relations is performed individually for each DG by optimizing each one against some user-defined reference DGs, which ensures an operating cost minimization irrespective of microgrid topology. An islanded microgrid model has been developed in MATLAB/Simulink environment to verify the effectiveness of the proposed method and the performance of the nonlinear droop control. An experimental study has been conducted on a microgrid test bench (MGTB) to prove the feasibility and performance of the proposed nonlinear droop control.