Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Harmonic considerations for electrical distribution feeders

Technical Report ·
OSTI ID:5321868
Harmonics on the electric power distribution system can cause motor overheating, capacitor failures, watthour meter error, and relay malfunctions. The degree of problems caused by harmonics is greatly dependent on the characteristics of the distribution feeder. A typical distribution feeder can absorb a considerable percentage of its capacity in harmonic currents without ill effects. However, power factor correction capacitors can cause resonances near harmonic voltages that can result in intolerable distortion. Both motor loads and resistive loads can decrease the effet of resonance significatnly. This report describes useful techniques to analyze, suppress, and measure harmonics on distribution feeders. Applicable areas for manual analysis and computer analysis are explained. The basic formulae are presented as well as sophisticated omputer methods. Emphasis is placed on the fundamental principle. Models of harmonic-producing devices are presented and their limitations discussed. Most distribution feeder harmonics analyses can be performed using simple current source models. Filtering of specific loads and general, dispersed load is discussed. The fundamental principle in filtering distribution feeders is to shorten the harmonic current path. 3-dimensional plots enhance the understanding of the filtering action. Equipment and procedures for making measurements are described.
Research Organization:
Cooper Industries, Inc., Canonsburg, PA (USA). McGraw-Edison Power Systems Div.
DOE Contract Number:
AC05-84OR21400
OSTI ID:
5321868
Report Number(s):
ORNL/Sub-81-95011/4; ON: DE88007849
Country of Publication:
United States
Language:
English