Computer loads and systems can be found in all of society's industrial
, commercial, and residential sectors, The nature of these loads is su
ch that they distort the line-current waveforms and, in some cases, ca
n significantly distort the supply-voltage waveforms causing disruptio
n in computer system performance, The voltage (i.e., line-to-line, lin
e-to-neutral and neutral-to-ground) and the phase current waveform cha
racteristics of many computer loads are similar and reported in the li
terature [1]-[6]. Some waveform patterns remain fairly stable during l
oading cycles, while other vary significantly and randomly, This paper
will present several case studies to reveal the unique power quality
characteristics of several commonly used computer systems (e.g., works
tations, heating plant process computers, and electron microscopes), T
he dominant even- and odd-harmonic components of the waveforms will be
presented and discussed in some detail. This paper will also discuss
the impact of the computer loads on the supply voltage waveforms.