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The generation of abrasive particles is an unavoidable consequence of sliding electrical contact wear in conductive slip rings (SRs). The adhesion of abrasive particles to the insulators may lead to a decrease in flashover voltage, posing a risk to satellite power transmission. In this paper, the effect of abrasive particles on flashover is first studied. Surface abrasive particles can distort the surface electric field of the dielectric, absorb scattered electrons, and then re-emit them, thereby accelerating the development and formation of secondary electron avalanches. Flashover test results indicate that surface abrasive particles lead to a significant reduction in flashover voltage. To mitigate the impact of particle adhesion on flashover, a method of constructing particle traps on the surface of insulators is proposed. The location and structural parameters of the particle trap are further optimized and determined. The flashover test results using planar dielectric samples and SR insulator samples both demonstrate that the optimized particle trap can significantly improve the flashover voltage. The dielectric maintains high electrical strength even when particles are trapped in particle traps. The physical details of the impact of particles on flashover and the effect of particle traps are analyzed utilizing an electron movement simulation, corroborating the experiment from a microscopic aspect. [ABSTRACT FROM AUTHOR]

Frequency Domain Spectroscopy (FDS) is widely used to estimate oil–paper insulation. The high moisture and long aging change the FDS characteristics of the insulating oil–paper, so normalization processing is required. Still, the choice of single activation energy needs further research. This paper studies the FDS characteristic of oil–paper insulation samples with different moisture and aging degrees and improves the traditional temperature correction method. The enhanced Arrhenius model uses the segmented activation energy to make the normalized FDS curve coincide better with the target curve, and the error is reduced. In addition, to verify the method's effectiveness, this paper proposes an iterative correction process. It corrects the tan δ-f curve of the bushing with an aging time of 800 h based on segmented activation energy, and the overall normalization effect is improved. [ABSTRACT FROM AUTHOR]

Atmospheric pressure dielectric barrier discharge (DBD) has abundant application fields, and the influence of the barrier material on DBD characteristics has been the research focus in recent years. In this work, a two-dimensional fluid model is built to investigate the effects of the barrier dielectric surface layer with different permittivity distribution on DBD, including electric parameters, electron distribution, and surface charge evolution. It is demonstrated that higher dielectric permittivity can affect DBD by enhancing the electric field Espace of space charge and weakening electric field Esurf of the surface charge and have a more obvious influence on Esurf, which can make DBD transform from glowlike discharge to streamerlike discharge. The dielectric surface layer with linear distribution of permittivity is introduced in DBD, changing the discharge appearance and discharge channel forming sequence. This work may provide some theoretical experiences for the application of a functionally graded material as a barrier dielectric in DBD. [ABSTRACT FROM AUTHOR]