Modeling and sensitivity analysis of consensus algorithm based distributed hierarchical control for DC microgrids

Distributed control methods for microgrid systems become a popular topic in recent years. Distributed algorithms, such as consensus algorithms, can be applied for distributed information sharing. However, by using this kind of algorithms the stability analysis becomes a critical issue since the dynamics of electrical and communication systems interact with each other. Apart from that, the communication characteristics also affect the dynamics of the system. Due to discrete nature of information exchange in communication network, Laplace domain analysis is not accurate enough for this kind of dynamic study. The aim of this paper is to model the complete DC microgrid system in z-domain and perform sensitivity analysis for the complete system. A generalized modeling method is proposed and the system dynamics under different control parameters, communication topologies and communication speed are studied. The responses derived from the analytical model are verified by comparing them with Simulink/PLECS based simulation results.