Measurements of neutral currents and voltages on a distribution feeder

eutral currents flow in four-wire distribution systems due to linear load unbaliiiices and triplen liaiinonics associated with niahily tlie niagnetizing currents of (distribution) trausfoimiers. It is known that high levels of neutral currents can lead to overloadedlbunied neutral conductors, coninion-mode noise problems, derating of trmsfoliiiers and/or excessive voltage distortion. The proliferation of noilllnear loads which inject harmonic currents into the distribution system has brought more attention upon the levels of neutral currents and voltages found in distribution systems. To this end, this paper evaluates ineasurenients taken on tlie neutral conductors of a distribution feeder at two different sites. The analysis of the nieasurenients focuses on tlie niagnitudes of the tiiplen-harmonic currents and voltages relative to their corresponding phase rms values in order to separate the inipact on the neuti~cl onductois of nonlinear loads and hear load unbalances.