Table of Contents
ISRN Renewable Energy
Volume 2012, Article ID 261325, 12 pages
Research Article

Analytical Assessment of DC Components Generated by Renewable Energy Resources with Inverter-Based Interconnection System due to Even Harmonics

1Department of Electrical Engineering, Technological Educational Institute of Larissa, 41110 Larrisa, Greece
2Department of Natural Resources & Environment, Technological Educational Institute of Crete, Romanou 3 Street, 73133 Chania, Crete, Greece

Received 29 April 2012; Accepted 7 August 2012

Academic Editors: E. R. Bandala, S. Dai, and G. Namkoong

Copyright © 2012 Marios N. Moschakis et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


This paper deals with the assessment of DC components generated by renewable energy resources with inverter-based interconnection system to the electric grid. DC injection is a critical issue related to power quality of distribution network systems with high penetration of inverter-based interconnection systems. This type of interface systems may improve the performance of the electric generation unit and affect positively or negatively the power quality of the distribution network depending on the proper or improper designation. The investigation of the various causes of DC components and the analytical assessment of their maximum levels are crucial for the proper operation of inverter-based interface systems and the limitation of DC injection. A method based on analytical calculations using a computer software has been implemented for the assessment of DC components contained on an inverter's output voltage when even harmonics are present on the network voltage. Moreover, a simulation package was used to demonstrate the existence of DC components under various conditions. It was proved by the current analysis that the amounts of DC components generated when even harmonics are present on the network voltage can be high under abnormalities on the power grid but they are not considerable under normal operating conditions.