
38-1
38.1 Introduction
Power quality is generally evaluated in terms of harmonic content in both supply voltage and current.
For an ideal system, harmonics are typically caused by the use of nonlinear loads found in domestic
equipment such as switch-mode power electronics converters, ballast for uorescent lamps, computers,
televisions, and other nonlinear loads used in tertiary and industrial applications such as power elec-
tronics operated adjustable speed drives, arc furnaces, and welding equipment [1]. e nonlinear loads
draw nonsinusoidal current from the network, an important harmonic content of the supply voltage
with regards to the