Next Article in Journal
Impact of Scheduling Flexibility on Demand Profile Flatness and User Inconvenience in Residential Smart Grid System
Previous Article in Journal
Optimal Scheduling for the Complementary Energy Storage System Operation Based on Smart Metering Data in the DC Distribution System
Previous Article in Special Issue
Decentralized and Real-Time Power Dispatch Control for an Islanded Microgrid Supported by Distributed Power Sources
Article Menu

Export Article

Open AccessArticle
Energies 2013, 6(12), 6586-6607; doi:10.3390/en6126586

Three-Phase Primary Control for Unbalance Sharing between Distributed Generation Units in a Microgrid

Department of Electrical Energy, Systems & Automation, Ghent University, Sint-Pietersnieuwstraat 41, 9000 Gent, Belgium
Author to whom correspondence should be addressed.
Received: 3 October 2013 / Revised: 11 November 2013 / Accepted: 12 December 2013 / Published: 18 December 2013
(This article belongs to the Special Issue Smart Grid and the Future Electrical Network)
View Full-Text   |   Download PDF [586 KB, 17 March 2015; original version 17 March 2015]   |  


For islanded microgrids, droop-based control concepts have been developed both in single and three-phase variants. The three-phase controllers often assume a balanced network; hence, unbalance sharing and/or mitigation remains a challenging issue. Therefore, in this paper, unbalance is considered in a three-phase islanded microgrid in which the distributed generation (DG) units are operated by the voltage-based droop (VBD) control. For this purpose, the VBD control, which has been developed for single-phase systems, is extended for a three-phase application and an additional control loop is added for unbalance mitigation and sharing. The method is based on an unbalance mitigation scheme by DG units in grid-connected systems, which is altered for usage in grid-forming DG units with droop control. The reaction of the DG units to unbalance is determined by the main parameter of the additional control loop, viz., the distortion damping resistance, Rd. The effect of Rd on the unbalance mitigation is studied in this paper, i.e., dependent on Rd, the DG units can be resistive for unbalance (RU) or they can contribute in the weakest phase (CW). The paper shows that the RU method decreases the line losses in the system and achieves better power equalization between the DG unit’s phases. However, it leads to a larger voltage unbalance near the loads. The CW method leads to a more uneven power between the DG unit’s phases and larger line losses, but a better voltage quality near the load. However, it can negatively affect the stability of the system. In microgrids with multiple DG units, the distortion damping resistance is set such that the unbalanced load can be shared between multiple DG units in an actively controlled manner rather than being determined by the microgrid configuration solely. The unit with the lowest distortion damping resistance provides relatively more of the unbalanced currents.
Keywords: distributed generation; droop controllers; microgrid; unbalance sharing distributed generation; droop controllers; microgrid; unbalance sharing
This is an open access article distributed under the Creative Commons Attribution License (CC BY 3.0).

Scifeed alert for new publications

Never miss any articles matching your research from any publisher
  • Get alerts for new papers matching your research
  • Find out the new papers from selected authors
  • Updated daily for 49'000+ journals and 6000+ publishers
  • Define your Scifeed now

SciFeed Share & Cite This Article

MDPI and ACS Style

Vandoorn, T.L.; De Kooning, J.D.M.; Van de Vyver, J.; Vandevelde, L. Three-Phase Primary Control for Unbalance Sharing between Distributed Generation Units in a Microgrid. Energies 2013, 6, 6586-6607.

Show more citation formats Show less citations formats

Related Articles

Article Metrics

Article Access Statistics



[Return to top]
Energies EISSN 1996-1073 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top