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Li C.M.,Harbin University of Science and Technology | Han B.Z.,Harbin University of Science and Technology | Han B.Z.,Far East Holding Group Co. | Zhao L.,Harbin University of Science and Technology | Yin C.P.,Harbin University of Science and Technology
Advanced Materials Research

Nonlinear insulated materials can uniform electric field distribution in non-uniform electric field. In order to inhibit the electric tree initiation and propagation inside high-voltage cross-linked polyethylene (XLPE) insulated cable, a kind of 220kV high-voltage XLPE insulated cable with new structure is designed by embedding nonlinear shielding layer into XLPE insulation layer of high-voltage cable with traditional structure in this study. Experimental and simulation results indicate that the nonlinear shielding layer can effectively inhibit electrical tree propagation inside the XLPE specimens, and obviously extend the breakdown time caused by electric tree propagation. When the electrical tree propagates into the nonlinear shielding layer sandwiched between insulation layers of cable, the electric field distribution near the tip of electrical tree is obviously improved. These findings prove the feasibility and the effectivity of inhibiting electrical tree propagation inside high-voltage cable by adding nonlinear shielding layer into the insulation layer. © (2014) Trans Tech Publications, Switzerland. Source

Shi H.,Xian Jiaotong University | Gao N.,Xian Jiaotong University | Jin H.,Xian Jiaotong University | Jin H.,Far East Holding Group Co.
Materials Science Forum

The reported enhancement in dielectric properties obtained for polymer nano-composite seemed to be very encouraging. To further understand the dielectric behavior of epoxy nano-composite, aluminum oxide (Al 2O3) nano-particles were incorporated into bisphenol A epoxy resin, and the dependence of nano-particle content and the dielectric properties was investigated in this study. Results showed that, when nano-particle contents was no more than 10phr, relative permittivity (εr) decreased to be lower than that of monolithic epoxy, and the minimum value appeared in 4phr nano-particle filled composite. The minimum value of tan delta (tanδ) appeared in 6phr nano-particle filled composite. DC volume resistivity (ρv) increased due to the introduction of nano-particles when the filler content is very small (about 2phr). © (2010) Trans Tech Publications. Source

Li H.,Xian Jiaotong University | Zhang Q.,Xian Jiaotong University | Jin Z.,Xian Jiaotong University | Jin H.,Xian Jiaotong University | Jin H.,Far East Holding Group Co.
Materials Science Forum

SiC/C (graphite) composite ceramics with 20vol% flake graphite were fabricated by Plasma Activated Sintering (PAS) firstly; the composites treated by silicon infiltration in surface were oxidized from 800°C to 1500°C. Effect of silicon infiltration on the oxidation resistance of SiC/C (graphite) composites was characterized by TG/DTA, SEM and XRD. The results show that the graphite in surface of composites reacted with silicon to form a dense SiC film about 30μm-in-thickness. The oxidation resistance temperature was increased from 600°C to 1300°C. Below 1300°C, the surface of composites by silicon filtration was oxidized to form a dense continuous oxide film to hider the oxidation of graphite in matrix. At 1500°C, the surface oxide film was heavy damaged, and many micropores were produced; inner graphite was oxidized above 1300°C again. © (2010) Trans Tech Publications. Source

Jin H.,Xian Jiaotong University | Jin H.,Far East Holding Group Co. | Shi H.,Xian Jiaotong University | He B.,Xian Jiaotong University | And 2 more authors.
Materials Science Forum

AlN filled epoxy composites were fabricated. The microstructure of composites was observed by SEM. The thermal conductivity was also measured. The results showed that microstructure of AlN/ epoxy composites was different with monolithic epoxy, it had some crystal-like characteristics. The grain size of AlN/ epoxy composites decreased with increasing AlN contents, and the thermal conductivity of composites increased with increasing AlN content. The thermal conductivity of 40wt. % AlN/ epoxy was about 3 times of monolithic epoxy. © (2010) Trans Tech Publications. Source

Jin H.,Xian Jiaotong University | Jin H.,Far East Holding Group Co. | Huang Y.,Xian Jiaotong University | Feng D.,Xian Jiaotong University | And 2 more authors.
IOP Conference Series: Materials Science and Engineering

Both AlN/ nano h-BN composites and AlN/ micro h-BN composites were fabricated. The high temperature oxidation behaviors were investigated at 1000°C and 1300°C using a cycle-oxidation method. The results showed that there were little changes of both nano composites and monolithic AlN ceramic at temperature of 1000°C. And at 1300°C, the oxidation dynamics curve of composites could be divided into two courses: a slowly weight increase and a rapid weight decrease, but the oxidation behavior of nano composites was better than micro composites. It was due to that the uniform distribution of oxidation production (Al18B4O33) surround the AlN grains in nano composites and the oxidation proceeding was retarded. The XRD analysis and SEM observations showed that there was no BN remained in the composites surface after 1300°C oxidation and the micropores remain due to the vaporizing of B2O3 oxidized by BN. © Published under licence by IOP Publishing Ltd. Source

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