Evaluation of Harmonic Distortion from Multiple Renewable Sources at a Distribution Substation

Abstract

Harmonic emission assessment in a distribution network with existing background voltage harmonics is a challenge for Renewable Power Producers (RPP) aiming to achieve grid code compliance. Dynamic interaction of harmonic sources at a Point of Common Coupling (PCC) renders the general summation law in IEC 61000-3-6 impractical, as harmonic phasors do not conform to the addition of rms values using alpha factors. The dynamic interaction of different PV plants and non-linear traction loads connected to the same 132 kV PCC is analyzed to validate the practical constraints in assessing grid code compliance requirements It is demonstrated that an innovative application of phasor aggregation, albeit scientifically challenged, could present a pragmatic approach for engineers tasked with network Power Quality performance.