This paper develops a nonlinear secondary voltage control scheme for a droop-controlled inverter-based islanded microgrid(MG). The proposed secondary voltage control is a distributed scheme that enjoys a simple communication network. Theapplied modified integral backstepping (MIB) controllers restore the voltage of each distribution generation (DG) to theirreference values. An integral term is included in the conventional backstepping method to improve its dynamic performancein tracking a reference signal when voltage deviations and load disturbances exist. The control input law’s design and theclosed-loop system’s stability are realized by the Lyapunov criterion in a step-by-step procedure. The proposed secondaryvoltage control’s effectiveness for a prototype microgrid system is verified by simulating it on MATLAB and comparingthe results with conventional backstepping and sliding mode control (SMC). A considerable improvement in the transientresponse of the MG system and computation time of the input generation is accomplished by applying the proposed MIBtechnique.

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