TIME-VARYING HARMONICS - PART I - CHARACTERIZING MEASURED DATA

This paper represents Part I of a two-part article which summarizes th e probabilistic aspects of harmonics in electric distribution systems. This fist part reviews the problems associated with direct applicatio n of the Fast Fourier Transform to compute harmonic levels of non-stea dy state distorted waveforms, and various ways to describe recorded da ta in statistical terms. Each statistical description is applied to a set of recently recorded data for illustration purposes. Part II of th is article, to be reported in the future, will cover problems associat ed with summation of harmonics generated by time-varying loads, comput ation of harmonic power flow, and some applications.