Keywords: power quality, harmonics, harmonic assessment, electrical power systems, harmonic distortion, harmonic analysis, complex power systems
Harmonic assessment of electrical power systems
Advances in semiconductor technology have resulted in an escalation in the numbers and power ratings of non-linear loads connected to the power system. At all voltage levels, equipment is being installed which generates harmonics. At transmission levels, FACTS devices are being installed for controlling power flow, HVDC links are used to transfer real power between AC systems and large industries (aluminium smelters, steel manufacturing, etc.) are connected at these voltage levels, all of which introduce harmonics. At the other end of the scale, the increasing use of heat pumps, microwave ovens, PC, printers, stereos, TVs, compact fluorescent lamps in homes and commercial premises represents a dramatic increase in small harmonic sources. The effect of these harmonic sources needs to be assessed and this paper provides an overview of the techniques currently available for the analysis of harmonic distortion in a large and complex electrical power system.