A decentralized scalable approach to voltage control of DC islanded microgrids

TL;DR

This paper introduces a decentralized, scalable voltage control method for DC islanded microgrids that ensures stability and plug-and-play capability, allowing easy addition or removal of generation units without destabilizing the system.

Contribution

It presents a novel decentralized control scheme with plug-and-play design that guarantees stability and scalability in DC microgrids, using only local information for controller synthesis.

Findings

Controllers maintain stability during plug-and-play operations.

Simulation results demonstrate effective voltage regulation.

The approach scales with system size and component changes.

Abstract

We propose a new decentralized control scheme for DC Islanded microGrids (ImGs) composed by several Distributed Generation Units (DGUs) with a general interconnection topology. Each local controller regulates to a reference value the voltage of the Point of Common Coupling (PCC) of the corresponding DGU. Notably, off-line control design is conducted in a Plug-and-Play (PnP) fashion meaning that (i) the possibility of adding/removing a DGU without spoiling stability of the overall ImG is checked through an optimization problem; (ii) when a DGU is plugged in or out at most neighbouring DGUs have to update their controllers and (iii) the synthesis of a local controller uses only information on the corresponding DGU and lines connected to it. This guarantee total scalability of control synthesis as the ImG size grows or DGU gets replaced. Yes, under mild approximations of line dynamics, we formally guarantee stability of the overall closed-loop ImG. The performance of the proposed controllers is analyzed simulating different scenarios in PSCAD.