Regulador suplementar para o controle auxiliar de frequência em microrredes ilhadas

Abstract

Islanded microgrids and geographically isolated microgrids, with penetration of wind and solar generation, usually have a low equivalent moment of inertia associated with the distributed synchronous generators. Because of this low equivalent inertia, typical load variations in the microgrid generally result in large frequency deviations. In this case, the great operational challenge is to maintain the microgrid frequency within permissible limits, preventing the action of the protection system and the consequent microgrid shutdown. In this context, this paper proposes a supplementary frequency control to assist the frequency control in islanded and isolated microgrids with low equivalent inertia. The proposed control takes advantage of the fact that the power of the typical loads varies according to the voltage magnitude of the system. The proposed supplementary control loop, added to the reference of the synchronous generator voltage regulator, varies the generator voltage reference in a limited way in order to modify the magnitude of the voltage applied to system loads. The proposed control structure is relatively simple and the designed controller was effective in the auxiliary control of the microgrid frequency, significantly reducing the magnitude of the frequency deviations and settling time of the microgrid frequency.