Harmonic emission level estimation based on measurements at the point of evaluation

Two methods for determination of harmonic emission levels at the point of evaluation are discussed in this paper. A method based on harmonic voltage and current phasor measurements is compared with the method based on long duration measurements of harmonic current and voltage magnitudes. One-week measurements were carried out to estimate customer harmonic emission levels using the two methods, and results were compared. Both methods produced comparable results and enabled the assessment of harmonic emission levels without switching maneuvers or disturbing the operation of any customer load. However, the method based on harmonic current magnitude measurements shows certain advantages as it does not require harmonic phase angle information. Both methods require the network harmonic impedance information, although reference impedances can be used to estimate the harmonic emission levels.