Investigation of harmonic distortion and losses in distribution systems with non-linear loads

Many studies have revealed that large non-linear loads are the main contributors to distribution system harmonics. On the other hand, the proliferation of small nonlinear loads such as electronically-switched devices has the potential to greatly elevate harmonic distortion levels on distribution systems. To study this harmonic distortion, we performed field measurements on a variety of home appliances. Field data from a number of 0.4 kV urban loads show that such nonlinear loads can have a dominant effect on distortion power and power factor. A comprehensive investigation on the neutral and phase current distortion levels behind the low voltage transformer has been carried out in the realistic distribution systems. In this paper we also estimate the increase of losses due to non-linear loads.