Table of Contents Author Guidelines Submit a Manuscript
The Scientific World Journal
Volume 2017, Article ID 1393476, 13 pages
https://doi.org/10.1155/2017/1393476
Research Article

An Optimal Current Controller Design for a Grid Connected Inverter to Improve Power Quality and Test Commercial PV Inverters

Electrical Electronics Engineering Department, Sirte University, Sirte, Libya

Correspondence should be addressed to Ali Algaddafi; moc.oohay@etrisila

Received 19 December 2016; Revised 1 March 2017; Accepted 2 April 2017; Published 30 April 2017

Academic Editor: Chi-Wai Chow

Copyright © 2017 Ali Algaddafi 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.

Abstract

Grid connected inverters play a crucial role in generating energy to be fed to the grid. A filter is commonly used to suppress the switching frequency harmonics produced by the inverter, this being passive, and either an L- or LCL-filter. The latter is smaller in size compared to the L-filter. But choosing the optimal values of the LCL-filter is challenging due to resonance, which can affect stability. This paper presents a simple inverter controller design with an L-filter. The control topology is simple and applied easily using traditional control theory. Fast Fourier Transform analysis is used to compare different grid connected inverter control topologies. The modelled grid connected inverter with the proposed controller complies with the IEEE-1547 standard, and total harmonic distortion of the output current of the modelled inverter has been just 0.25% with an improved output waveform. Experimental work on a commercial PV inverter is then presented, including the effect of strong and weak grid connection. Inverter effects on the resistive load connected at the point of common coupling are presented. Results show that the voltage and current of resistive load, when the grid is interrupted, are increased, which may cause failure or damage for connecting appliances.