Mohammad T. Dehghani - Department of Power Engineering, Saveh Branch, Islamic Azad University, Saveh, Iran
Abolfazl Vahedi - Center of Excellence for Power System Automation and Operation, Iran University of Science and Technology, Iran
Mehdi Savaghebi - Department of Electronics Engineering, Karaj Branch, Islamic Azad University, Karaj, Iran
Josep M. Guerrero - Department of Automatic Control and Industrial Informatics, Technical University of Catalonia, Spain

The aim of this paper is to improve voltage quality at the terminals of distributed generators (DGs) in an islanded microgrid. To achieve this goal, it is proposed to include separate voltage and current control loops for the fundamental and harmonics frequencies. This way, it is not necessary to consider additional controllers to provide voltage harmoniccompensation. The proposed control system can be implemented in a very simple way. The control structure ofevery single DG unit consists of active and reactive power droop controllers and voltage and current control loops. Simulation results are provided in order to show the effectiveness of the proposed control approach.

Distributed generator (DG), microgrid,voltage harmonics