A power consensus algorithm for DC microgrids

A novel power consensus algorithm for DC microgrids is proposed and analyzed. DC microgrids are networks composed of DC sources, loads, and interconnecting lines. They are represented by differential algebraic equations connected over an undirected weighted graph that models the electrical circuit. The proposed algorithm features a second graph, which represents the communication network over which the source nodes exchange information about the instantaneous powers, and which is used to adjust the injected current accordingly. This gives rise to a nonlinear consensus-like system of differential algebraic equations that is analyzed via Lyapunov functions inspired by the physics of the system. We establish convergence to the set of equilibria, where weighted power consensus is achieved, as well as preservation of the weighted geometric mean of the source voltages. The results apply to networks with constant impedance, constant current and constant power loads. (C) 2018 Elsevier Ltd. All rights reserved.