Title: Robust Distributed Control of DC Microgrids with Time-Varying Power Sharing,
Abstract: This paper addresses the problem of output voltage regulation for multiple
DC/DC converters connected to a microgrid, and prescribes a scheme for sharing
power among different sources. This architecture is structured in such a way
that it admits quantifiable analysis of the closed-loop performance of the
network of converters; the analysis simplifies to studying closed-loop
performance of an equivalent {\em single-converter} system. The proposed
architecture allows for the proportion in which the sources provide power to
vary with time; thus overcoming limitations of our previous designs.
Additionally, the proposed control framework is suitable to both centralized
and decentralized implementations, i.e., the same control architecture can be
employed for voltage regulation irrespective of the availability of common
load-current (or power) measurement, without the need to modify controller
parameters. The performance becomes quantifiably better with better
communication of the demanded load to all the controllers at all the converters
(in the centralized case); however guarantees viability when such communication
is absent. Case studies comprising of battery, PV and generic sources are
presented and demonstrate the enhanced performance of prescribed optimal
controllers for voltage regulation and power sharing.