A power consensus algorithm for DC microgrids

TL;DR

This paper introduces a novel power consensus algorithm for DC microgrids, enabling coordinated power sharing and voltage preservation through a nonlinear differential-algebraic system analyzed with Lyapunov functions.

Contribution

It presents a new consensus algorithm for DC microgrids that guarantees convergence and voltage preservation, applicable to various load types.

Findings

Convergence to weighted consensus power vectors.

Preservation of the weighted geometric mean of voltages.

Applicable to networks with different load types.

Abstract

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. A second graph represents the communication network over which the source nodes exchange information about the instantaneous powers, which is used to adjust the injected current accordingly. This give 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 consisting of weighted consensus power vectors 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.