The paper presents several power quality issues in an islanded microgrid, regarding the frequency regulation. A load-frequency control technique has been implemented, which consists in a special device, named dump load (DL) that draws the extra power from the generators, transforming it into heat through a power electronics device. This paper compares more DL topologies from the power quality point of view, and suggests a new DL configuration developed by the authors. The simulations and experimental results show the effectiveness of the solution.

Keywords: Microgrid (MG), Power quality, Dump load, Frequency control.