Fully Distributed Fixed-Time Optimal Dispatch for Islanded DC Microgrids

This paper presents a fully distributed fixed-time cooperative secondary controller for DC microgrids (MGs) to solve the economic dispatch problem (EDP) in a fixed-time manner. It contains both power optimizer and voltage regulator while a sparse communication network is modeled to convey the information between distributed generators (DGs) using peer-to-peer communication protocol. Based on the equal incremental costs (ICs) scheme, the power optimizer sufficiently guarantees the optimum load power allocation between DGs within a predefined settling time. Additionally, the voltage regulator is mainly answerable to restore MG's average voltage to the nominal value and achieves the equilibrium between generation and demand using fixed-time average consensus protocol. The distinctive advantage of the developed controller is that the objectives can be realized within a fixed-time which is independent on the initial states and possible to be predesigned offline. Small scale islanded DC MG prototype has been developed to verify the efficacy of the proposed controller in case of load variations and communication failures and the plug-and-play capability is demonstrated as well.