Methods for estimating customer voltage harmonic emission levels

The definition and determination of harmonic emission levels in accordance with the new draft edition of the IEC Techical Report 61000-3-6 is presented in this paper. The paper deals with contributions to the voltage harmonic distortion and, in addition, discuses an alternative method for estimating customer harmonic emission levels at the point of common coupling. This method is based on the harmonic vector method where reference impedances are introduced. The results of the harmonic vector method are compared with the results of the method based on the definitions in the IEC Techical Report. The presented harmonic vector method with reference impedances allows calculation of harmonic emission levels without any switching maneuvers or without knowing the actual impedances.