Power Utilization Factor (PUF)

Abstract

It is shown that, in case of feeding loads with high levels of harmonic distortion, the RMS values of voltage and current no longer provide a reliable representation of the load, either in terms of its actual power efficiency or its tendency to introduce distortion. To cope with this sort of scenario, the use of a Power Utilization Factor (PUF), in addition to the usual Power Factor and Cos Phi, is suggested on analytical and experimental grounds. The use of the PUF enables a more reliable analysis of high distortion loads, as it better describes the relationship between the load and the power supply. Practical case studies are presented for a variety of loads, including the so called low consumption lamps, typical domestic loads (sorted as low consumption lamps, incandescent lamps, and common appliances) showing also the effect of these type of loads on step-down transformer. It is shown that the use of the PUF allows to keep track and quantify the relationship between distortion-producing loads and the ensuing distorted regulation of the electrical system.