Analysis of compensation factors influencing the net harmonic current produced by single-phase nonlinear loads

Abstract

The purpose of this paper is to build upon the previous analytical work that has been done on the subject of harmonic cancellation and attenuation and clearly define how an aggregate of single-phase power-electronic-based loads impact the net harmonic current injection. In addition, this paper assesses the way network topologies of low-voltage electric systems in North America and Europe influence harmonic current cancellation. The specific factors that are addressed in this paper are: (i) cancellation factor for harmonic currents due to: transformer phase shift for single-phase loads connected at two different voltage levels; harmonic phase angle difference of single-phase and three-phase loads connected at the same voltage level; harmonic phase angle difference between similar types of loads due to difference in network and load parameters; and cancellation due to phase-angle diversity of different types of loads; and (ii) attenuation factor due to the interaction of voltage harmonics with the current harmonics in switch-mode type loads. In addition to the harmonic compensation factors, this paper addresses the existing load concentration and the potential of new nonlinear load growth by end-users in residential and commercial applications.