期刊文献+
共找到2篇文章
< 1 >
每页显示 20 50 100
地电波方法在金属封闭式开关柜放电故障诊断中的应用(英文) 被引量:11
1
作者 任明 董明 +3 位作者 任重 彭华东 李洪杰 邱爱慈 《高电压技术》 EI CAS CSCD 北大核心 2011年第11期2672-2679,共8页
In order to solve the problems of TEV(transient earth voltage) utilization,such as single judgment criterion and low reliability of PD detection in HV switchboard,this paper discussed the method on how to make a bette... In order to solve the problems of TEV(transient earth voltage) utilization,such as single judgment criterion and low reliability of PD detection in HV switchboard,this paper discussed the method on how to make a better utilization of TEV in PD detection of metal-enclosed switchgears.Through discussing the relationship among the temporal phase,number of pulses and threshold of measuring and extracting the features corresponding to different typical defects,test results showed that the needle discharge distributed in 0°~90°and 200°~340°with low appearance probability above high measurement threshold;internal discharge distributed in 0°~90°and 270°~315°,and showed a similar decreasing trend under increasing of the threshold in the two regions;suspended discharge distributed in 0°~135°and 180°~315°where the PD in negative half periods decreased more seriously than those in positive half with increasing threshold.These results followed the doctrine of consistency with the conclusions that were obtained by using the traditional pulse current method.The possibility of using TEV method to make identification of PD defects has been proved to prepare for further research. 展开更多
关键词 metal-enclosed switchgear identification of defects transient earth voltage(TEV) PD detection
下载PDF
Effect of La_2O_3 on electrical friction and wear properties of Cu-graphite composites 被引量:6
2
作者 莫飞 凤仪 +4 位作者 陈阳明 王雨晴 钱刚 豆亚坤 张学斌 《Journal of Rare Earths》 SCIE EI CAS CSCD 2015年第3期327-333,共7页
Sliding friction and wear experiments using Cu-La2O3-graphite composites against Cu-5 wt.%Ag alloy ring were conducted at a constant sliding speed of 10 m/s, a current density of 10 A/cm2 and a load of 2.5 N/cm2. Thes... Sliding friction and wear experiments using Cu-La2O3-graphite composites against Cu-5 wt.%Ag alloy ring were conducted at a constant sliding speed of 10 m/s, a current density of 10 A/cm2 and a load of 2.5 N/cm2. These composites with different La2O3 and graphite contents were fabricated by hot-pressing. Physical and mechanical properties of the composites were examined. Morphologies of the worn surface of composites were observed using optical microscopy. X-ray photoelectron spectroscopy spectra were used to study compositions of the lubricating film. The results showed that with the increasing addition of La2O3, hardness, flexural strength and electrical resistivity increased, but the relative density dropped. The friction coefficient increased with the increasing addition of La2O3. Composite containing 3 vol.% of La2O3 and 37 vol.% of graphite showed the best wear resistance. The main wear mechanisms of composites were abrasive wear, oxidative wear and adhesive wear. 展开更多
关键词 Cu-La2O3-graphite composites electrical contacts contact voltage drop friction wear rare earths
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部