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The widely used QUICKEST method with ULTIMATE flux limiter is not capable of solving the charge transport problems with a very steep wavefront accurately, due to the wide stencil adopted. Furthermore, the splitting process of separating the convection and the reaction terms in the method introduces additional errors. To solve such problems accurately, a novel numerical method based on the Runge–Kutta discontinuous Galerkin (RKDG) method is introduced in this paper, which has high-order resolution and weak correlation between cells. The bipolar charge transport under dc voltage in solid dielectrics with trapping and recombination is simulated using this new method. The results of charge profiles provided by the method are obviously different from the simulation results in the existing literature. The method was verified by problems with analytical solution and experimental observations.

This paper focuses on the effect of nanoparticle surface modification on the charge transport characteristics in XLPE/SiO 2 nanocomposites. A titanate coupling agent (TC9) and a 3-(Methacryloyloxy)propyltrimethoxysilane (KH570) were used for the surface modification of SiO 2 nanoparticles. It was found that both KH570 and TC9 coupling agents improve the nanoparticle dispersion compared with unmodified SiO 2 nanoparticles. The improvement in dispersion was found to be due to increased surface hydrophobicity of the treated SiO 2 nanoparticles. In addition, it was found that the surface modification improved the DC conductivity, dielectric characteristics, and space charge properties as compared to XLPE or XLPE/SiO 2 nanocomposites without surface modification. The results of the TSC measurements showed that the introduction of SiO 2 nanoparticles into XLPE increased the trap density and produced more trap energy levels. Improving the nanoparticle dispersion was found to further increase the corresponding trap depth and trap density. The trapped homocharge formed an independent electric field and reduced the effective electric field, which reduced charge injection and increased the charge injection barrier height. Therefore, the space charge formation in the material bulk was suppressed.

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