Dynamic droop based inverter control for autonomous microgrid

Developments in the renewable generation along with the power electronic converters gave huge scope of research in microgrid through which there can be little chance of meeting the load demand. Integration of microgrids into the existing system leads to lots of changes in the power system. So detail analysis is required for the microgrid level to achieve better performance in the existing system. In this paper the systematic small signal modeling of an islanded AC microgrid operating under various kinds of loading conditions is discussed. From the small-signal dynamic analysis of the microgrid, it can be observed as the loading condition changes, the low-frequency modes of the power sharing dynamics drifts to new locations and the damping of the system varies according to the real power load which affects relative stability of the system, and eventually may lead to instability. To avoid this instability a dynamic droop settings is proposed in this work which modifies its droop in accord to the inverter output current.