Stability and steady state analysis of distributed cooperative droop controlled DC microgrids

TL;DR

This paper analyzes the stability and steady state behavior of distributed cooperative droop control in DC microgrids, providing conditions for stability and insights into steady state performance through theoretical analysis and simulation.

Contribution

It offers a novel stability analysis framework for distributed cooperative droop control in DC microgrids, linking stability to semistability of second-order matrix systems.

Findings

Stability is equivalent to semistability of certain matrix systems.

Provided sufficient conditions for stability.

Validated results with a three-node microgrid simulation.

Abstract

Distributed cooperative droop control consisting of the primary decentralized droop control and the {secondary} distributed correction control is studied in this paper, which aims to achieve an exact current sharing between generators, worked in the voltage control mode, of DC microgrids. For the DC microgrids with the distributed cooperative droop control, the dynamic stability has not been well investigated although its steady performance has been widely reported. This paper focuses on the stability problem and shows it is equivalent to the semistability problem of a class of second-order matrix systems. Some further sufficient conditions as well followed. The steady state is analyzed deeply for some special cases. A DC microgrid of three nodes is simulated on the Matlab/Simulink platform to illustrate the efficacy of analytic results.