A study on harmonic current summation using field measurement data

Due to the diversity of harmonic phase angles, the total harmonic current from a combination of loads is lower than the arithmetical sum of their magnitudes, which is also known with the summation effect. Conventionally, the summation effect is analysed through the summation law and expressed as the summation coefficient. In this paper, the summation coefficients are calculated with the field measurement data in several sites and compared with the recommended values of standard. To investigate the performance of summation coefficient, two indices are defined and calculated. More analyses have been done on the phase angles of harmonic currents. Some guidelines about harmonic summation estimation are given.