气体绝缘金属封闭开关设备(gas insulated metal enclosed switchgear,GIS)机械缺陷是导致设备故障的重要因素,针对单测点、单证据机械缺陷诊断模型信息缺失和精度不足问题,该文提出一种多层融合振动数据分析的GIS设备机械缺陷诊断方法...气体绝缘金属封闭开关设备(gas insulated metal enclosed switchgear,GIS)机械缺陷是导致设备故障的重要因素,针对单测点、单证据机械缺陷诊断模型信息缺失和精度不足问题,该文提出一种多层融合振动数据分析的GIS设备机械缺陷诊断方法。首先,基于真型GIS设备振动模拟平台试验研究测点位置与缺陷类型对振动行为的影响特性;然后,联合统计分析、模态分解、尺度变换方法提出机械振动信号整体与局部信息关注的复合参数分析方法,引入主成分分析开展多测点振动信息的特征层融合降维;最后,提出改进放缩权重的Dempster-Shafer(DS)证据理论和Bagging投票机制的强/弱基学习器决策层融合机制,联合构建多层融合振动数据分析的GIS设备机械缺陷诊断模型。结果表明:不同类型机械缺陷信号的响应幅值、特征频点和畸变程度存在显著差异,复合特征参量大小及分散程度各不相同;同时,测点位置对缺陷信号的复合振动特征参量的表现形式及分布区间也具有一定影响;基于多层融合数据分析的诊断模型实现缺陷有效识别,辨识准确率为98.66%,相比单一分类器诊断效果提升5.83%。该文可为GIS设备机械缺陷诊断方法提供有价值的参考。展开更多
文章在常规TOPSIS(technique for order preference by similarity to ideal solution)模型的基础上提出空间TOPSIS模型,以安徽省休宁县为例,采用地理信息系统(geographic information system,GIS)技术对安徽省休宁县的滑坡易发性进行...文章在常规TOPSIS(technique for order preference by similarity to ideal solution)模型的基础上提出空间TOPSIS模型,以安徽省休宁县为例,采用地理信息系统(geographic information system,GIS)技术对安徽省休宁县的滑坡易发性进行评价。研究表明:基于GIS的空间TOPSIS模型的滑坡易发性评价,能够处理和分析滑坡评价因子以及滑坡易发性的空间变化特征;评价结果与休宁县境内已经发生滑坡的空间分布较为吻合,评价结果较好。基于GIS的空间TOPSIS模型在滑坡易发性评价中具有较好的适用性。展开更多
River bank erosion is a natural process that occurs when the water flow of a river exceeds the bank’s ability to withstand it. It is a common phenomenon that causes extensive land damage, displacement of people, loss...River bank erosion is a natural process that occurs when the water flow of a river exceeds the bank’s ability to withstand it. It is a common phenomenon that causes extensive land damage, displacement of people, loss of crops, and infrastructure damage. The Gorai River, situated on the right bank of the Ganges, is a significant branch of the river that flows into the Bay of Bengal via the Mathumati and Baleswar rivers. The erosion of the banks of the Gorai River in Kushtia district is not a recent occurrence. Local residents have been dealing with this issue for the past hundred years, and according to the elderly members of the community, the erosion has become more severe activities. Therefore, the main objective of this research is to quantify river bank erosion and accretion and bankline shifting from 2003 to 2022 using multi-temporal Landsat images data with GIS and remote sensing technique. Bank-line migration occurs as a result of the interplay and interconnectedness of various factors such as the degree of river-related processes such as erosion, transportation, and deposition, the amount of water in the river during the high season, the geological and soil makeup, and human intervention in the river. The results show that the highest eroded area was 4.6 square kilometers during the period of 2016 to 2019, while the highest accreted area was 7.12 square kilometers during the period of 2013 to 2016. However, the erosion and accretion values fluctuated from year to year.展开更多
文摘气体绝缘金属封闭开关设备(gas insulated metal enclosed switchgear,GIS)机械缺陷是导致设备故障的重要因素,针对单测点、单证据机械缺陷诊断模型信息缺失和精度不足问题,该文提出一种多层融合振动数据分析的GIS设备机械缺陷诊断方法。首先,基于真型GIS设备振动模拟平台试验研究测点位置与缺陷类型对振动行为的影响特性;然后,联合统计分析、模态分解、尺度变换方法提出机械振动信号整体与局部信息关注的复合参数分析方法,引入主成分分析开展多测点振动信息的特征层融合降维;最后,提出改进放缩权重的Dempster-Shafer(DS)证据理论和Bagging投票机制的强/弱基学习器决策层融合机制,联合构建多层融合振动数据分析的GIS设备机械缺陷诊断模型。结果表明:不同类型机械缺陷信号的响应幅值、特征频点和畸变程度存在显著差异,复合特征参量大小及分散程度各不相同;同时,测点位置对缺陷信号的复合振动特征参量的表现形式及分布区间也具有一定影响;基于多层融合数据分析的诊断模型实现缺陷有效识别,辨识准确率为98.66%,相比单一分类器诊断效果提升5.83%。该文可为GIS设备机械缺陷诊断方法提供有价值的参考。
文摘文章在常规TOPSIS(technique for order preference by similarity to ideal solution)模型的基础上提出空间TOPSIS模型,以安徽省休宁县为例,采用地理信息系统(geographic information system,GIS)技术对安徽省休宁县的滑坡易发性进行评价。研究表明:基于GIS的空间TOPSIS模型的滑坡易发性评价,能够处理和分析滑坡评价因子以及滑坡易发性的空间变化特征;评价结果与休宁县境内已经发生滑坡的空间分布较为吻合,评价结果较好。基于GIS的空间TOPSIS模型在滑坡易发性评价中具有较好的适用性。
文摘针对现场气体绝缘组合电器(gas insulated substation,GIS)局部放电绝缘缺陷漏报、误报情况频发的问题,文中根据GIS实际运行温度范围对GIS内部常见固体绝缘缺陷开展不同温度下间歇性放电特性试验研究,搭建GIS电-热耦合间歇性放电模拟试验平台,采用脉冲电流法、特高频(ultra high frequency,UHF)法、超声波法和气体特征组分检测法获取不同温度下固体绝缘缺陷间歇性放电特征数据并进行分析。研究发现:UHF法和脉冲电流法在不同温度下均能有效检测到试验缺陷间歇性放电UHF信号,超声波法和气体特征组分检测法无法有效采集到有效放电数据;固体绝缘表面金属污秽缺陷和内部气隙缺陷间歇性放电电压与温度呈负相关,污秽缺陷间歇性放电电压呈较为明显的线性下降趋势,气隙缺陷间歇性放电电压呈先大幅下降后较平缓线性下降趋势;污秽缺陷间歇性放电的平均放电量和UHF信号幅值与温度的升高呈正相关;污秽缺陷放电间歇性在不同温度下随放电时间的增加会增强,而气隙缺陷放电时间间隔在26℃、40℃、50℃下能由秒级发展为毫秒级,存在演变成击穿放电的风险。文中研究成果进一步丰富了GIS间歇性放电理论体系,有助于提升现场GIS间歇性放电的有效诊断率。
文摘River bank erosion is a natural process that occurs when the water flow of a river exceeds the bank’s ability to withstand it. It is a common phenomenon that causes extensive land damage, displacement of people, loss of crops, and infrastructure damage. The Gorai River, situated on the right bank of the Ganges, is a significant branch of the river that flows into the Bay of Bengal via the Mathumati and Baleswar rivers. The erosion of the banks of the Gorai River in Kushtia district is not a recent occurrence. Local residents have been dealing with this issue for the past hundred years, and according to the elderly members of the community, the erosion has become more severe activities. Therefore, the main objective of this research is to quantify river bank erosion and accretion and bankline shifting from 2003 to 2022 using multi-temporal Landsat images data with GIS and remote sensing technique. Bank-line migration occurs as a result of the interplay and interconnectedness of various factors such as the degree of river-related processes such as erosion, transportation, and deposition, the amount of water in the river during the high season, the geological and soil makeup, and human intervention in the river. The results show that the highest eroded area was 4.6 square kilometers during the period of 2016 to 2019, while the highest accreted area was 7.12 square kilometers during the period of 2013 to 2016. However, the erosion and accretion values fluctuated from year to year.
