In this paper, a robust single primary control loop is proposed for ac microgrids. There are no work in primary control layer which presents a systematic tuning method based on the modelling of the system. As we know, tuning of this loops are very sensitive to their elements’ value of nominal system (like LCL filter and load variations). In other words, tuning of these cascade loops always challenged the designers to close the system appropriately. Lack of a systematic and robust approach to controller design at primary layer, encouraged us to incline and design robust controllers and represent a systematic primary control. Unlike previous works, it is shown that the proposed controller covers all functions of both voltage and current controller loops in primary control. Moreover, with this solution, all the possible uncertainty of a microgrid is considered and the systematic designed controller renders an optimal/suboptimal robust performance. Simulation results in simpower environment of MATLAB validate our claims.
