针对配电网线路径向分布、分支线复杂特性,存在多重估计的问题,提出一种基于孤立森林算法与大数据挖掘的配电网故障距离估计方法。首先,构建“云-管-边-端”新型配电物联网架构,实现数据的高效管理。然后,在配电边缘代理装置中引入孤立...针对配电网线路径向分布、分支线复杂特性,存在多重估计的问题,提出一种基于孤立森林算法与大数据挖掘的配电网故障距离估计方法。首先,构建“云-管-边-端”新型配电物联网架构,实现数据的高效管理。然后,在配电边缘代理装置中引入孤立森林算法提取故障时电压电流异常特征数据。最后,基于配电云主站汇集并获取海量装置中提取的异常特征数据集,利用基于代码库的大数据挖掘技术(Big data mining base on code repositories,BDMBCR)搜索故障事件间的关联关系,根据数据相似性归类分支分组,估算故障发生的具体位置。采用IEEE 34测试仿真系统进行试验。结果表明,提出的方法能够挖掘复杂数据特性,两相和三相接地故障多重估计长度相应减少了24%~27%和16%~20%,单相接地的故障影响距离仅为1.2 km,优于其他对比方法。展开更多
Cubic and hexagonal sodium yttrium fluoride were successfully synthesized from yttrium nitrate, sodium fluoride and polyethanediol in propanetriol solvent under a facile hydrothermal route. By regulating the molar rat...Cubic and hexagonal sodium yttrium fluoride were successfully synthesized from yttrium nitrate, sodium fluoride and polyethanediol in propanetriol solvent under a facile hydrothermal route. By regulating the molar ratio of yttrium and fluoride, hydrothermal temperature and reaction time, the phase and shape of sodium yttrium fluoride were commendably controlled. The as-prepared products were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM） and energy dispersive X-ray spectrum （EDS） techniques. It was revealed that the hollow-structured Na（Y1.5Na0.5）F6 nanotubes self-assembled and arrayed orientedly to be bamboo raft-shaped. The formation of hexagonal Na（Y1.5Na0.5）F6 nanotube arrays was attributed to solid-liquid-solid process and Oswald ripening. This study provided a simple method to prepare hexagonal bamboo raft-shaped Na（Y1.5Na0.5）F6 on a large scale, which broadened their practical applications.展开更多
文摘针对配电网线路径向分布、分支线复杂特性,存在多重估计的问题,提出一种基于孤立森林算法与大数据挖掘的配电网故障距离估计方法。首先,构建“云-管-边-端”新型配电物联网架构,实现数据的高效管理。然后,在配电边缘代理装置中引入孤立森林算法提取故障时电压电流异常特征数据。最后,基于配电云主站汇集并获取海量装置中提取的异常特征数据集,利用基于代码库的大数据挖掘技术(Big data mining base on code repositories,BDMBCR)搜索故障事件间的关联关系,根据数据相似性归类分支分组,估算故障发生的具体位置。采用IEEE 34测试仿真系统进行试验。结果表明,提出的方法能够挖掘复杂数据特性,两相和三相接地故障多重估计长度相应减少了24%~27%和16%~20%,单相接地的故障影响距离仅为1.2 km,优于其他对比方法。
基金Project supported by National Natural Science Foundation of China (51202066)China Postdoctoral Science Foundation Project (20100480947,201104510)+2 种基金Scientific Research Found of Hunan Provincial Education Department (12A047)State Key Laboratory Program of Inorganic Synthesis and Preparative Chemistry of China (2013-26)Doctoral Start-up Research Fund of Hunan University of Science and Technology (E51079)
文摘Cubic and hexagonal sodium yttrium fluoride were successfully synthesized from yttrium nitrate, sodium fluoride and polyethanediol in propanetriol solvent under a facile hydrothermal route. By regulating the molar ratio of yttrium and fluoride, hydrothermal temperature and reaction time, the phase and shape of sodium yttrium fluoride were commendably controlled. The as-prepared products were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM） and energy dispersive X-ray spectrum （EDS） techniques. It was revealed that the hollow-structured Na（Y1.5Na0.5）F6 nanotubes self-assembled and arrayed orientedly to be bamboo raft-shaped. The formation of hexagonal Na（Y1.5Na0.5）F6 nanotube arrays was attributed to solid-liquid-solid process and Oswald ripening. This study provided a simple method to prepare hexagonal bamboo raft-shaped Na（Y1.5Na0.5）F6 on a large scale, which broadened their practical applications.
