ABSTRACT
For the purpose of harmonic load flow and harmonic filter designs, the harmonic emission from the nonlinear loads should be accurately estimated. Online measurement of harmonics will provide reliable results when this analysis is conducted properly over a period of time; however, the measurement techniques cannot be applied for the power systems in the design stage. For simplicity, all the harmonics may be considered cophasial. This does not always give the most conservative results, unless the system has one predominant harmonic; in which case only harmonic magnitudes can be represented. When a predominant harmonic source acts in isolation, it may not be necessary to model the phase angles of the harmonics. For multiple harmonic sources, phase angles should be modeled. When all the nonlinear loads are replaced only with one type, say fluorescent lighting, the calculations with or without modeling the harmonic angles give the same results.
