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

Abstract

Distributed cooperative droop control consisting of the primary decentralised droop control and the secondary distributed control is studied, 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 study focuses on the stability problem of DC microgrids with fixed topology 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 analysed deeply for some special cases. A DC microgrid of four nodes is simulated on the Matlab/Simulink platform to illustrate the efficacy of analytic results.