Survey of harmonic levels on the Southwestern Electric Power Company system

A survey of current and voltage distortion levels measured at 76 different sites is presented. Over 5000 pairs of current and voltage waveforms were recorded and analyzed for this study. In addition to summarizing the harmonic levels at the various industrial, commercial, and substation sites, the authors use data at a particular nonlinear load site to show how US utilities may be failing to collect the correct revenues from power factor penalty clauses. The instrumentation used to collect the field data is briefly described. The results of the field measurements are discussed, with particular emphasis on the problem sites identified during the project