Robust Distributed Control of DC Microgrids with Time-Varying Power Sharing
For power electronics engineers designing DC microgrids, this work provides a control framework that overcomes limitations of prior designs by enabling time-varying power sharing and quantifiable performance analysis.
This paper proposes a distributed control architecture for DC microgrids that achieves output voltage regulation and time-varying power sharing among sources, with performance guarantees that improve with better communication but remain viable without it. Case studies with battery, PV, and generic sources demonstrate enhanced performance.
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.