Effect of magnetic field on partial discharge parameters in power cables and on the breakdown characteristics of impregnated paper insulation

摘要

This article demonstrates that parameters of partial discharges in power cables and impregnated paper insulation breakdown characteristics vary in presence of grid-frequency alternating magnetic field. Experimental and theoretical demonstrations confirm that magnetic field affects the probability of partial discharges in air cavities inside inhomogeneous insulation. Based on the developed method, the impact of magnetic field on breakdown probability and on Weibull distribution parameters that approximate experimental breakdown voltage data is estimated. The differences in chemical and structural properties of the breakdown area in electrical and electromagnetic fields are determined using scanning electron microscopy and energy dispersive spectroscopy.