Stability, power sharing, & distributed secondary control in droop-controlled microgrids

John W. Simpson-Porco, Florian Dorfler, Francesco Bullo, Qobad Shafiee, Josep M. Guerrero
2013 2013 IEEE International Conference on Smart Grid Communications (SmartGridComm)  
Motivated by the recent and growing interest in microgrids, we study the operation of droop-controlled DC/AC inverters in an islanded microgrid. We present a necessary and sufficient condition for the existence of a synchronized steady state that is unique and locally exponentially stable. We discuss a selection of controller gains which leads to a sharing of power among the generators, show that this proportional selection enforces actuation constraints for the inverters. Moreover, we propose
more » ... distributed integral controller based on averaging algorithms which dynamically regulates the system frequency in the presence of a time-varying load. Remarkably, this distributedaveraging integral controller has the additional property that it maintains the power sharing properties of the primary droop controller. Finally, we present experimental results validating our controller design, along with simulations of extended scenarios. Our results hold without assumptions on uniform line admittances or voltage magnitudes.
doi:10.1109/smartgridcomm.2013.6688036 dblp:conf/smartgridcomm/Simpson-PorcoDBSG13 fatcat:brm6uty3ifgqpim5fiitax3foa