International Survey on Voltage Harmonic Unbalance in Low Voltage Networks

This paper presents the analysis of the unbalance in voltage harmonics in low voltage networks. Data from 55 locations from 12 countries have been analysed to study the voltage harmonic unbalance. The locations are classified as industrial, commercial, residential and mix depending on the type of loads. Unbalance is calculated using individual and aggregated unbalance indices. The analysis has shown that the unbalance is present not only in fundamental voltage but also in harmonic voltages and is observed to be highest for triplen harmonics. Also, unbalance increases with the harmonic order. The survey suggests that while performing harmonic studies, unbalance in the harmonics should also be considered to have realistic results.