Survey of harmonic levels on the American Electric Power distribution system

The authors results of a research project involving the investigation of power-system harmonic levels on selected distribution circuits of differing load composition on the American Electric Power system (AEP). Over a four-year period, beginning in 1984, the harmonic levels on seven selected distribution circuits were recorded and analyzed providing valuable information on the characteristics of specific loads as well as typical harmonic levels on the three classes of distribution circuits: residential, commercial, and industrial. Analysis of the data obtained through these field measurements indicates typical harmonic distortion levels present during operation of the distribution system. Based on monitored information from the selected circuits, the voltage distortion on the AEP 12.47/7.2 kV distribution system is near 1% at minimum and can be expected to exceed 5% in a small percentage of measurements. In the voltage distortion measurements which exceeded 5% voltage distortion, the fifth harmonic is the major component