Decentralized Stability Conditions for DC Microgrids: Beyond Passivity Approaches

TL;DR

This paper develops decentralized stability conditions for DC microgrids that go beyond traditional passivity-based methods, using input-output properties and homotopy arguments to reduce conservatism.

Contribution

It introduces novel decentralized stability criteria for DC microgrids derived from subsystem decompositions, surpassing passivity-based approaches.

Findings

Conditions are formulated as input-output properties of local subsystems.

Homotopy arguments enable combining stability conditions with reduced conservatism.

Examples demonstrate the effectiveness and applicability of the proposed methods.

Abstract

We consider the problem of ensuring stability in a DC microgrid by means of decentralized conditions. Such conditions are derived which are formulated as input-output properties of locally defined subsystems. These follow from various decompositions of the microgrid and corresponding properties of the resulting representations. It is shown that these stability conditions can be combined together by means of appropriate homotopy arguments, thus reducing the conservatism relative to more conventional decentralized approaches that often rely on a passivation of the bus dynamics. Examples are presented to demonstrate the efficiency and the applicability of the results derived.