Fuzzy secondary controller applied to autonomous operated AC microgrid

The present work addresses the AC microgrid control issue using hierarchical control structure and droop controllers for load sharing. Once the droop controllers impose an operation with frequency and voltage deviations, depending on the load and droop parameters, a hierarchical control structure must be added to change the droop controller operating points. The hierarchical controllers operate with local measurements and shared signals from communication links among the distributed generating systems connected to the microgrid. Depending on the size of the microgrid, the communication links can be economically unviable. This work proposes the development of a fuzzy secondary controller to AC microgrids to reduced the link communication dependency and using only local measurements. It is expected the deviations be fixed as happens with the conventional secondary controllers when the microgrid is operating as stand-alone mode, and can provide a certain amount of power to the connected utility bus operating as grid-connected mode.