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基于振动信号的超程变化情况下断路器刚分刚合时刻识别方法研究 被引量:4
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作者 张伟 王冠霖 +5 位作者 谭佳明 蒋佳成 赵依梵 王小华 杨爱军 荣命哲 《高压电器》 CAS CSCD 北大核心 2019年第11期184-190,共7页
在断路器的长期使用过程中,由于触头磨损、螺丝松动等原因,超程将会发生改变,断路器刚分刚合时刻的确定具有较大难度。刚分刚合时刻的判断方法在超程变化情况下的准确性还未有人研究。文中以12 kV交流中压真空断路器为研究对象,搭建了... 在断路器的长期使用过程中,由于触头磨损、螺丝松动等原因,超程将会发生改变,断路器刚分刚合时刻的确定具有较大难度。刚分刚合时刻的判断方法在超程变化情况下的准确性还未有人研究。文中以12 kV交流中压真空断路器为研究对象,搭建了断路器机械状态离线测试试验平台。在模拟多种超程量的条件下,对断路器分合闸过程中的触头换位信号与振动信号进行同步采集,采用短时能量法对振动信号进行处理,准确分析出断路器换位信号提取的分合闸时刻与振动信号提取的特征量间的对应关系。利用振动信号替代换位信号,通过对断路器分合闸过程振动信号的提取,准确判断刚分刚合时刻,获得分合闸时间。测试试验结果表明,该方法在超程改变情况下对分合闸时刻的判断误差在0.5 ms以内,提高了断路器在超程变化时机械数据的准确性,为断路器机械状态的在线监测提供了依据。 展开更多
关键词 中压真空断路器 刚分刚合时刻 超程变化 振动信号 短时能量法
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监视真空开关超程变化的专用装置
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作者 沈聿修 李丰年 《高压电器》 CAS CSCD 北大核心 1998年第5期57-58,共2页
借助结构十分简单的专用装置,可实现对真空开关超程的在线自动监视和报警。
关键词 真空开关 超程变化 监视专用装置 开关
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Dynamics of phase transformation of Cu-Ni-Si alloy with super-high strength and high conductivity during aging 被引量:15
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作者 雷前 李周 +3 位作者 潘志勇 汪明朴 肖柱 陈畅 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2010年第6期1006-1011,共6页
The precipitation behaviors of the Cu-Ni-Si alloys during aging were studied by analyzing the variations of electric conductivity.The Avrami-equation of phase transformation kinetics and the Avrami-equation of electri... The precipitation behaviors of the Cu-Ni-Si alloys during aging were studied by analyzing the variations of electric conductivity.The Avrami-equation of phase transformation kinetics and the Avrami-equation of electric conductivity during aging were established for Cu-Ni-Si alloys,on the basis of linear relationship between the electric conductivity and the volume fraction of precipitates,and the calculation results coincide well with the experiment ones.The transformation kinetics curves were established to characterize the aging process.The characteristics of precipitates in the supersaturated solid solution alloy aged at 723 K were established,and the results show that the precipitates areβ-Ni3Si andδ-Ni2Si phases. 展开更多
关键词 CU Cu-Ni-Si alloy DYNAMICS phase transformation PRECIPITATION electrical conductivity
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Ramanujan's cubic transformation and generalized modular equation
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作者 WANG MiaoKun CHU YuMing SONG YingQing 《Science China Mathematics》 SCIE CSCD 2015年第11期2387-2404,共18页
We study the quotient of hypergeometric functions in the theory of Ramanujan's generalized modular equation for a ∈ (0, 1/2], and find an infinite product for- mula for μ1/3(r) by use of the properties of μ*a... We study the quotient of hypergeometric functions in the theory of Ramanujan's generalized modular equation for a ∈ (0, 1/2], and find an infinite product for- mula for μ1/3(r) by use of the properties of μ*a(r) and Ramanujan's cubic transformation. Besides, a new cubic transformation formula of hypergeometric function is given, which complements the Ramanujan's cubic transformation. 展开更多
关键词 Gaussian hypergeometric function Ramanujan's cubic transformation generalized modular equa-tion infinite product modular function
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