Distributed Pinning Droop Control in Isolated AC Microgrids

This paper presents a distributed pinning droop control mechanism for accurate active and reactive power sharing in isolated converter-fed microgrids (MG). Under this framework, both power converters and loads in the MG are treated as agents in a multiagent system (MAS). Since only a fraction of the agents in the network have access to critical information, the required communication bandwidth and control cost can be significantly reduced without degrading the dynamical performance of the power sharing compared to consensus-based droop control techniques. Theoretical studies of this pinning-based distributed droop control, including pinning localization, grid partition, and convergence criteria, will be explored in detail. In order to validate the feasibility and the correctness of the proposed distributed droop control method, an MAS platform is developed for a test-bed MG system in Taiwan. Simulation tests under normal conditions, loading conditions, and plug-in and plug-out scenarios are investigated in MATLAB/Simulink and the Java Agent Development Framework. Simulation results demonstrate that the proposed pinning-based distributed droop control can indeed improve autonomous operations of an isolated ac MG.