Estimation of power components for non-sinusoidal currents and voltages regarded as power quality indices

Abstract

This  paper  deals  with  the  computation  of  power components  of  distorted  signals  seen  as  power  quality  indices. The  proliferation  of  nonlinear  devices  into  the  power  system results    in    nonlinear    voltages    and    currents    whereas    this unfortunate trend is supposed to increase. The  prime  tool  for  spectral  analysis  is  the  Discrete  Fourier Transform,   establishing   the   preliminary   step   in   the   power components  computation  of  distorted  signals.  Power  definitions proposed   by   Budeanu   and   afterwards   by   Shepherd   and Zakikhani  require  spectral  components  as  input.  Windowing, leakage  and  other  DFT  properties  and  limitations  influence significantly the assessment of power components. The  power  definition  proposed  by  Skopec  and  Stec  is  totally confined to signals represented in time domain. Similar idea was firstly  outspoken  by  Fryze  and  entirely by-passed  the  issue  of spectral components computation. The  authors  made  an  attempt  to  apply  practically  different approaches    to    power    components    computation    for    non-sinusoidal currents and voltages.