Results 31 to 40 of about 2,130 (150)
Gaoya dianqi, 2018 为实现油浸式电力变压器绕组运行温度的分布式测量,及早发现绕组异常温升等问题,文中提出了一种基于Raman光时域反射计（ROTDR）的变压器绕组温度测量方法。该方法通过在变压器绕组中预埋分布式光纤,并依据拉曼散射原理来直接测量绕组温度。设计并研制了敷设分布式光纤的电磁线和绕组模型,并根据测量要求对电磁线结构和绕组绕制工艺进行了改进,利用分布式光纤测温系统对敷设分布式光纤的电磁线温度传感性能和绕组模型进行了试验。试验结果表明:基于该方法的温度测量误差≤2℃,满足变压器绕组温度测量的要求 ...
张重远 +6 more
doaj
Study on the temperature prediction model of residual coal in goaf based on ACO-KELM [PDF]
Existing studies on the temperature prediction of residual coal in goafs have mainly focused on the relationship between temperature and gas concentration, with limited attention given to the complex nonlinear relationships between the residual coal ...
HAO Le +5 more
core +1 more source
Guangtongxin yanjiu, 2006 光纤光栅传感器以其波长编码的独有优势适用于准分布式测量网络。文章介绍了光纤光栅传感器的解调方法,分析了其工作原理、性能和特点。提出了几种常用的光纤光栅复用方案,比较了它们的优缺点和组网规模,并指出准分布式传感网络的发展前景。
胡家艳, 印新达
doaj
Conception and practice of resource utilization, energization and functionalization of coal mining subsidence areas with high groundwater level [PDF]
Underground coal mining often leads to surface subsidence and water accumulation, changes in the ecological environment, as well as in the spatial pattern of land and water resources, in high groundwater level mining areas.
Liang YUAN, Liangji XU
core +1 more source
Gaoya dianqi, 2020 绕组变形是变压器内部的常见故障之一,严重威胁电力系统的安全运行。目前绕组变形检测均属于离线检测,无法准确定位变形故障;带电检测由于受现场复杂电磁环境的干扰,且无法进行变形故障定位。为有效提高绕组变形在线检测的准确性,本文提出了基于分布式光纤传感的变压器绕组变形故障定位方法。搭建内置分布式光纤连续式绕组模型模拟绕组变形,当绕组发生局部形变时,利用布里渊光时域反射计（BOTDR）,对光纤应变进行测量。实验结果表明,分布式光纤传感技术能够准确的实现绕组变形的故障定位,具有良好的应用前景。
杨照光 +5 more
doaj
Coal wall deformation monitoring and concentrated load inversion technology based on intelligent support devices [PDF]
Coal wall spalling is a major factor restricting the safe and efficient development of coal mining. Accurate monitoring of coal wall support conditions is essential to improving wall stability and ensuring safe mining.
LI Lianghui +5 more
core +1 more source
Prevention and control of land subsidence and earth fissures in Suzhou–Wuxi–Changzhou region [PDF]
Objective The Suzhou–Wuxi–Changzhou region is one of the most severely affected areas by land subsidence, both in China and globally. In the early 1970s, land subsidence occurred and resulted in the formation of ground fissures caused by differential ...
GONG Xulong +13 more
core +1 more source
Guangtongxin yanjiu, 2018 围绕下一代光纤通信系统中轨道角动量（OAM）复用技术的关键问题,基于环状光纤中携带OAM的模式基础理论,仿真分析了环状光纤的不圆度对矢量合成OAM模式的本征奇模和偶模的有效折射率、走离长度以及模场强度分布的影响。结果表明,环状光纤不圆度会使得本征模式奇偶模之间的有效折射率差增大,走离长度减小,导致相应OAM模式在环状光纤中传输时稳定性下降。同时,不圆度的存在还会使矢量合成OAM模式的各本征模式的模场强度分布发生畸变,模场泄漏加剧。
张丽丽, 张霞, 白成林
doaj
Guangtongxin yanjiu, 2018 为了利用分布式光纤振动传感技术进行光纤复合海底电缆（简称为海缆）锚害故障检测,开展了海缆运行现场的锚害试验。用550吨的货船和1 000kg的船锚模拟了锚砸和拖曳事件,用基于相位敏感光时域反射计（Ф-OTDR）技术的分布式光纤振动传感设备对3.3km三芯海缆内的光纤进行了实时监测,获得了海面平静、锚砸和船锚拖曳3种情况下,光纤振动信号的能量和快速傅里叶变换幅度谱在时间和空间上的分布数据,并对其进行了分析。结果表明,海面平静时能量和幅度都很小,锚砸时能量和幅度会产生短时上升且频率成分丰富 ...
汪洋 +5 more
doaj
Gaoya dianqi, 2023 变压器的正常运行对电力系统的稳定至关重要。因此，对变压器进行实时状态监测并基于其进行故障分析具有重要意义。光纤传感因其灵敏度高、抗电磁干扰、耐高温等优势广泛应用于变压器监测中。文中首先介绍了光纤光栅传感、分布式光纤传感及荧光光纤传感等技术的原理和特点。详细分析了光纤传感技术在油浸式电力变压器温升、振动、局部放电和油中溶解气体4种状态监测的原理和研究进展。最后对其后续研究方向进行了展望。
杨志, 黄雯利, 赵丽娟
doaj