A method for computing non-localized harmonic propagation and resonance in the electric energy systems

This paper concerns propagation of harmonics within the electric energy systems. Sufficient conditions for localized propagation are stated. The propagation for harmonic is illustrated on a simple linear RLC network by showing that when these conditions are satisfied the effect of harmonics is confined to the vicinity of the harmonic source. However, when these conditions are not met, it is possible to have a hard-to-predict electrically distant harmonic resonance which may lead to the unacceptably high distortion. The same network is used to illustrate this problem. The possibility of non-localized harmonic propagation and resonance requires systematic tools for: (1) identifying causes of harmonics within an electrically vast system; (2) prediction of most likely resonance locations; (3) effective placement of filters for eliminating harmonics at the most sensitive system locations; and, (4) pricing for providing adequate power quality. This paper presents preliminary findings related to (1) through (4). More importantly, the paper points out the need to study the power quality problem as a network systems problem, instead of as a problem limited to a single location within the grid.