Frequency Characteristics of Overhead Power Lines of Distribution Power Grids with Isolated Neutral and Their Using for Determination of Single-Phase Ground Faults

Abstract

This paper show research of the dependence of the spectral composition of current and voltage depending on the place of occurrence single-phase intermittent arcing fault on overhead power lines in electrical grids with complex topology. Theoretical bases are considered of displays of higher harmonic components of voltage and current and method of their selection RSCAD. Paper show the effectiveness of pre-suppression in the information signal of the main harmonic of current (voltage) which allows with the required sensitivity to allocate a spectrum of higher harmonics in the area of up to ten kilohertz and above. This fact gives access for using high order resonant harmonics which practically do not depend on the load of substations, but are directly related to the distance to the place of single-phase ground fault. The results of field experiments are presented on modeling different variants of single-phase arc faults including when with a tree faults in existing electrical grids. It is shown that the resonant harmonics of current and voltage in overhead power lines arising from single-phase ground faults are a reliable indicator of the fact of the fault mode and a marker of the location of single-phase ground fault from the power center buses.