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Xiaohong Zhang - IEEE Xplore Author Profile

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Low-density polyethylene is one of the most comprehensive used as insulation materials in the power equipment. How to improve dielectric properties by doping inorganic particles in LDPE has always been concerned by many researchers. In this paper, SiO2 particles and MMT particles were added to LDPE, the order of adding particles was changed, and different micro-nano composites was made. The crysta...Show More
In order to investigate the effect of the addition of different morphologies of zinc oxide (ZnO) on the electrical properties of the polymer. In this paper, low density polyethylene (LDPE) was used as a matrix material, spherical and needle zinc oxide were added to LDPE respectively, and composite material were prepared by a two-step method. The effect of different morphologies of zinc oxide on th...Show More
The effect of moisture absorption on the dielectric properties of polypropylene-polyolefin elastomer blend was investigated. It was found that the crystalline structure was influenced by elastomer blended. However, the blending had few effected on the melting and crystallization behavior. The DC breakdown strength, electrical conductivity, and space charge distribution were influenced by moisture ...Show More
Polymers containing inorganic nanoparticles have been found to exhibit improved to excellent performance for electrical engineering applications. It was found that nanoparticles with surface chemical modifications displayed improved compatibility with the polymer matrix. After tailoring the nanometric interface between the nanoparticles and the polymer matrix and employing the appropriate compound...Show More
To investigate characteristics of the electrical trees propagation in PE, the low-density polyethylene (LDPE) samples with electrical trees were cut into slices using ultramicrotome, then the slices are etched by potassium permanganate solution. Finally, the crystalline structure and propagation path of electrical trees were observed by polarized light microscopy (PLM). The observation results sho...Show More
In order to investigate the effect of adding micro- and nano- inorganic particles in the polymer on the morphology and dielectric properties, the low density polyethylene (LDPE) was used as the matrix, the inorganic micro and nano silicon dioxide (SiO2) were selected as inorganic fillers, origin LDPE and M-SiO2 and N-SiO2 and MN-SiO2 composite materials were respectively prepared by melt blending,...Show More
Surface charge on insulator polymers in breakers, gas insulated switchgears and other electrical apparatuses, plays a dominant role in the insulation performance of power system. Meanwhile, the surface potential on the functional dielectric can be one of the criteria in the evaluation of the charge storage performance when the dipoles formed in polymer are taken into consideration during corona po...Show More
Electrical tree occurring in polymer insulation limits the applications and reduces the service lifetime of power equipment. To improve electrical tree resistance in polymer insulation, polyethylene (PE) nanocomposites with nano-montmorillonite (MMT)- layered fillers are compounded and investigated in terms of electrical tree characteristics. By an organization process, intercalation and coupling ...Show More
The dielectric properties of Nano-composites has attract tremendous attention during the past decade. In present paper, the silane coupling agent (KH-570) and titanate coupling agent (105, 101, TC-F) is used as modifiers. The nanometer zinc oxide which has been modified by KH-570 or TC-F etc is added to the low density polyethylene. In the end, the electrical breakdown properties of the composites...Show More
The phenomenon of electrical tree in polyethylene affects its service life and application in widely field. Our previous research works have showed that montmorillonite (MMT) introduced can improve electrical tree performance of polyethylene. In the present paper, organic processing methods by using intercalation agent and coupling agent are selected to modify spacing between laminar layers and su...Show More
Space charge existed in polymer subjected DC high electrical stress has attracted more and more attention over the world. Various methods of inhibiting space charge generation and accumulation had been attempted in order to reduce insulation deterioration. In the present paper, the polyethylene/montmorillonite nanocomposites are prepared by melting intercalation process. The distribution of space ...Show More
The partial discharge is one of the major failure mechanisms for insulation of power equipments subjected to high electrical stress. In order to understand the service conditions of insulating materials, it is very important to investigate on partial discharge characteristic in electrical apparatus. In the present paper, a set of acquisition system for acoustic signal generated by partial discharg...Show More
Epoxy/organic-montmorillonite nanocomposites were prepared with different organic-montmorillonite and content of montmorillonite by diglycidyl ether of bisphenol A. Chemical composition of different organic-montmorillonite was analyzed by Fourier Transition Infrared(FTIR). The temperature properties of resistivity of composites were measured by Megger. The temperature dependence of composites diel...Show More
The power cable is an important component in the power system, and crosslinked polyethylene is widely applied to power cables, electrical tree of XLPE is a troubled one of the reasons widely used XLPE. In the paper crosslinked polyethylene/montmorillonite composites were prepared by peroxide crosslinking method and melting intercalation process, and the processes of electrical tree in initiation a...Show More
On the basis of statistical theory, a method to determine quantitatively the reliability of multi-parameter diagnosis and to optimize the algorithm of multi-parameter diagnosis is put forward. Moreover, as an example, this method is applied to the estimation of residual breakdown voltage of generator bars and the optimized multi-parameter diagnosis algorithm is determined on the basis of actual da...Show More
Dielectric loss factor (tanδ), largest repeatedly occurring PD magnitude and breakdown voltage of large generator stator bars with different internal corona protection were studied in this paper. It was found the electric properties which, the increment of tanδ, breakdown voltage and partial discharge magnitude etc. of the bars with internal corona protection were excelled than the bars without th...Show More
The dielectric properties of nanometric dielectrics have attracted much attention since John Lewis published the article; the title is ldquoNanometric Dielectricsrdquo, on IEEE transactions on dielectric and electrical insulation in 1994. However, the majority of works reported in the literature were involved in comparing the dielectric properties of polymer/inorganic nano-particles composites tho...Show More
Montmorillonite modified with alkyl ammonium ions was dispersed in an epoxy/methyl nadic anhydride systems to form epoxy/organo-montmorillonite (oMMT) nanocomposites. Different systems of epoxy montmorillonite nanocomposites materials were prepared by mixing at different temperature before curing. These systems were characterized by X-ray diffraction (XRD), scanning electric microscopy (SEM) and a...Show More
Epoxy/Organic-Montmorillonite (O-MMT) nanocomposites were prepared through melting intercalation and solvent intercalation processes, respectively. The interplanar spacing of montmorillonite before/after the intercalation treatment, the fracture morphology of the nanocomposites and the dispersion condition of the o-MMT were investigated by XRD (X-ray diffraction) and SEM (scanning electron microsc...Show More