Stability of the Small-Scale Interconnected DC Grids via Output-Feedback Control


A decentralized nonlinear model and controller is proposed to stabilize the interconnected small-scale islanded dc grids in the presence of renewable energy sources with proven stability in this paper. The dc interconnected network comprises dc sources along with resistive and constant-power loads (CPLs). Though the dc sources are photovoltaic (PV) in this paper, the proposed controller can be applied to other types of low-inertia intermittent sources as well. All sources and/or CPL loads are connected to the grid through simple dc-dc converters (DDCs) to avoid power electronic complexities. The negative-resistance CPLs can destabilize the grid in the presence of the DDC dynamical components. The decentralized nonlinear output-feedback controller mitigates rapid voltage and power oscillations caused by the disturbances and measurement noises, and stabilizes the grid. Since the proposed output-feedback controller needs only partial knowledge of the local converter states, the number of measure points reduces leading to a simple implementation. Simulation results on a small-scale dc grid are provided to show the performance of the proposed controller.


Electrical and Computer Engineering

Research Center/Lab(s)

Intelligent Systems Center


This work was supported by NSF CAREER ECCS under Grant 1151141.

Keywords and Phrases

Controllers; DC-DC converters; Decentralized control; Electric inverters; Electric power system control; Electric power system interconnection; Electric power transmission networks; Feedback control; Power converters; Renewable energy resources; Constant power load (CPLs); DC distribution system; Micro grid; Neural networks (NN); Nonlinear output feedback controller; Output feedback; Output feedback controller; Output feedback controls; Feedback; Microgrids

International Standard Serial Number (ISSN)

2168-6777; 2168-6785

Document Type

Article - Journal

Document Version


File Type





© 2017 Institute of Electrical and Electronics Engineers (IEEE), All rights reserved.

Publication Date

01 Sep 2017