Harmonic Virtual Impedance Design for Optimal Management of Power Quality in Microgrids

Challenge and objective

  • Power quality is an important concern for practical microgrid (MG) applications due to the widespread use of nonlinear loads.
  • It is characterized by the implicit trade-off between voltage quality in the MG nodes and harmonic current sharing between distributed generators (DGs).

Work performed

  • Instead of using more costly alternatives as filters, this work addresses the modification of the control system of the DGs that represents a cheaper and more practical solution. Virtual impedances (VIs) can be included in the controller to improve current sharing.

Significant results

  • An optimization algorithm for setting the harmonic VIs of the DGs in a multibus MG is developed where the objective is voltage quality improvement.
  • This optimization algorithm can be  configured for any degree of harmonic current sharing between the DGs.

Impact for distribution system innovation

  • Less costly alternatives will become available to maintain power quality in microgrid applications.
Process for voltage quality improvement
Process for voltage quality improvement

Oddbjørn Gjerde

WP2 Lead
+47 99 730 027
Oddbjørn Gjerde
WP2 Lead


Reference in CINELDI