On distributed control of voltage source inverters in island AC microgrids

This paper presents a new distributed control framework to coordinate inverter-interfaced distributed energy resources (DERs) in island microgrids. We show that under bounded load uncertainties, the proposed control method can steer the microgrid to a desired steady state with synchronized inverter frequency across the network and proportional sharing of both active and reactive powers among the inverters. We also show that such convergence can be achieved while respecting constraints on voltage level and branch angle differences. In addition, the proposed controller has several other appealing features, including being robust to microgrid parameters variations and applicable to lossy mesh microgrids with heterogeneous R/X distribution lines. Realistic simulation results are also provided to show the effectiveness of the proposed control method.