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Zhenlian An - IEEE Xplore Author Profile

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304 stainless steel electrodes together with the stainless steel sheets of the same material were surface fluorinated in the laboratory using the fluorine source of 12.5% \text{F}_{{2}} in \text{N}_{{2}} at 0.1 MPa and 250 °C for 10 h, to investigate the effects of the electrode fluorination on the insulator flashover voltage and the gap breakdown voltage between two electrodes. DC flashov...Show More
Due to many desired properties, liquid silicone rubber (LSR) is the first choice for external insulation of all kinds of bushing in substations or converter stations. This report compares basic electrical properties and hydrophobicity of three commercial LSRs before and after direct fluorination. They are fluorinated in a laboratory reactor with the same fluorination temperature, pressure and time...Show More
Various composite films with high energy storage performance and/or dielectric strength have been fabricated. However, due to some reasons, few of them have been used in practice, and biaxially oriented polypropylene (BOPP) film is still regarded as the state-of-the-art capacitor dielectric film. Previous work has indicated that direct fluorination can improve the dielectric strength of BOPP films...Show More
This report summarizes previous studies on direct fluorination of ATH-free silicone rubbers (SRs) with different types or formulations to improve the outdoor application performance of SR, and gives overall improvements in the outdoor performance of ATH-free SRs by direct fluorination. The overall performance improvements contain the hydrophobicity, moisture barrier properties, dc flashover perfor...Show More
Under HVDC, insulator surface tends to accumulate charge. Excessive charge build-up on the insulator surface can distort the electric field and pose a serious challenge to the safe and reliable performance of the insulation system. Direct fluorination has become an important means of surface modification of the insulating material due to its simple process, mature technology and low cost, providin...Show More
In order to provide further evidence for the improvement in tracking and erosion resistance of alumina trihydrate (ATH)-free silicone rubbers (SRs) by direct fluorination and to explore the improvement mechanisms, the ATH-free SR samples containing 15-parts per hundred parts of rubber by weight (phr) melamine cyanurate and 18-phr fumed silica were prepared, and then they were surface fluorinated u...Show More
In order to verify the effectiveness of direct fluorination in improving the dc flashover performance of gas insulated switchgear (GIS) actual spacers and explore the effect of fluorination conditions, 126-kV disk spacers were surface fluorinated in the laboratory at the different temperatures of 35 °C, 55 °C, or 80 °C. The evaluation of surface physicochemical characteristics and basic electrical...Show More
Several fluorinated polyethylene surface studies have proved that the fluorination reaction can effectively prevent charge from being injected into polyethylene. Therefore, this paper explores the influence of fluorinated electrode on space charge behavior in polyethylene. In this study, the space charge distribution inside polyethylene is measured by laser-PWP (Pressure Wave Propagation) method w...Show More
Several researches has proved that surface fluorination of polyethylene has a significant barrier effect of space charge, so whether the surface fluorination treatment of poly (ethylene-co-vinyl acetate) (EVA) loaded with carbon black particles electrode has the same effect? In this study, the space charge distribution in polyethylene under different electrode fluorination conditions was measured ...Show More
In order to promote the possible application of direct fluorination for the performance improvement of capacitor dielectric film, the commercial BOPP film was fluorinated. Surface physicochemical characteristics and basic properties of the fluorinated PP film were investigated. ATR-IR analysis shows an obvious difference in surface chemistry, and SEM observation gives direct information on the thi...Show More
In this paper, space charge accumulation in bilayer dielectrics composed of two metalized biaxially oriented polypropylene (BOPP) films thermally coupled by thin heat transfer oil (dibenzyltoluene, DBT) is investigated by thermal pulse method. An improved thermal pulse method for in-situ double-sided measurements is proposed to achieve higher spatial resolution. The accumulation and decay of the i...Show More
In this study, direct fluorination is used to modify the surface of silicone rubber. Moisture barrier properties of the SIR surface layers fluorinated at different temperatures are evaluated by moisture absorption experiments at a temperature of 30 or 60°C and at a relative humidity of 75 or 97%. Physicochemical characteristics of the fluorinated SIR surface layers are investigated on the basis of...Show More
Thermal pulse method (TPM) is a powerful tool for probing space charge behavior in thin polymer films, whose data analysis involves the solution of the Fredholm integral equation of the first kind. This is an ill-conditioned problem with multiple solutions. The method based on regularization algorithms have been proved to be an effective way in analyzing thermal-pulse data, but the solution is sen...Show More
Several fluorinated polyethylene surface studies have proved that the fluorination reaction can effectively prevent charge from injecting into the sample. Therefore, this paper explores a new question: Whether the surface fluorination treatment of poly(ethylene-co-vinyl acetate) (EVA) electrode loaded with carbon black particles can effectively suppress the injection of charge from the electrode i...Show More
In this report, liquid silicone rubber (LSR) was fluorinated and studied. ATR-IR and XPS results clearly indicate the presence of Si-F bonds as well as C-F bonds in the fluorinated layer. The fluorination of the LSR is not a simple substitution of fluorine atoms for hydrogen atoms of methyl groups or for methyl groups, and during the fluorination besides fluorine atoms there are other reactive spe...Show More
Thin polymer films are widely used as dielectrics in devices operating in the field of electrical engineering or power electronics, such as capacitors, and the thermal property of the films is of great importance for the heat dissipation of involved devices. Thermal diffusivity (D) is one of the crucial parameters concerned with heat conduction. The existing methods, however, have some difficultie...Show More
Our previous results have shown that surface hydrophobicity of a high temperature vulcanized silicone rubber can be significantly enhanced by direct fluorination. In this report, the surface fluorinated sample together with the virgin sample as a reference have been investigated on their water vapor barrier properties at 30 °C or 60 °C in a humidity environment of 75% or 97% RH. The experimental r...Show More
Polyethylene is widely used in submarine DC cables, but polymers have the problem of space charge accumulation. Long-term exposure to high electric field will cause space charge accumulation in polymers which will lead to severe problems. And the space charge injection will be affected by the pressure of the sea. Using the Piezoelectric pressure wave propagation method to investigate the effect of...Show More
Aiming to improve the tracking and erosion resistance of the addition-cure liquid silicone rubber (LSR) without using alumina trihydrate, LSR samples with different mass fractions of fumed silica were prepared. The tracking and erosion resistance of all the samples was evaluated by the Inclined-Plane Test. The test results showed that increasing the mass fraction of fumed silica can improve the tr...Show More
Polyethylene is widely used in high-voltage DC cables, but prolonged exposure to high-voltage electric field will result in space charge accumulation in insulation layers, which could lead to electric field distortion or even breakdown of cables. The addition of carbon black (CB) in semi-conducting layer plays an important role in homogenizing electric field and preventing insulation damage. In th...Show More
Effective suppression of charge accumulation on epoxy spacers in high voltage gas insulated systems is one of the most concerned problems for the researchers and engineers in the field of electrical insulation, being of great significance for the development of HVDC/HVAC GIL or GIS. In order to suppress charge accumulation on the epoxy insulator and to improve its dc flashover performance, the fir...Show More
In this work, a direct space charge calculation method for thermal pulse method data analysis is proposed. Combining the equation of temperature in the tested film with the heat conduction equation, the Fredholm integral equation of the first kind with the direct goal of space charge distribution in the frequency domain is deduced. This ill-posed equation is solved by approximation algorithm with ...Show More
Liquid silicone rubber (LSR) sheet samples of a commercial formulation and surface fluorinated using a F2/N2 mixture at various temperatures are studied in this work. The intrinsic DC flashover of the surface fluorinated samples is evaluated using a sheet sample/finger electrode configuration and under a stepwise increasing voltage. The tests show an increase up to 64% in the intrinsic DC flashove...Show More
In view of the significant performance improvement of unfilled epoxy insulators by direct fluorination, and the fact that all spacers in SF6 gas insulated systems are alumina-filled epoxy composites, to promote the application of the method for improving the performance of epoxy spacers, in this paper, alumina-filled epoxy (composite) and unfilled epoxy (pure) samples were prepared with the same f...Show More
In order to promote the possible application of direct fluorination for the performance improvement of epoxy spacers, the alumina-filled composite epoxy samples were prepared with the same formulation and technology as those for commercial epoxy spacers and were fluorinated. Surface physicochemical characteristics and basic properties of the fluorinated epoxy sample layer were investigated. ATR-IR...Show More