Distributed Secondary Control for Reactive Power Sharing of Inverter-based DGs in Microgrids

A self-organizing distributed secondary control method is proposed by applying cooperative control theory of multi-agent systems to reactive power proportionally sharing according to their power ratings for large-scale distributed generators (DGs) microgrids. The designed distributed control under signal communications between DGs is able to make the reactive power of large-scale DGs exact sharing. The proposed distributed control scheme is able to effectively control a large number of DGs which exchange information among their neighboring DGs intermittently in the switching communication network with time-varying communication delays, respectively. Sufficient conditions on the requirements for the network connectivity and the delays boundedness which guarantees the stability and synchronization of the controlled heterogeneous lossy microgrid systems are presented. The feasibility of the proposed control methodology is verified by the simulation of a given lossy microgrid test system.