针对架空配电线路电弧接地故障点定位难题,该文研究架空配电线路故障电弧的电磁辐射特性,探索基于电磁辐射信号的电弧故障定位方法的可行性。通过10 k V配网真型故障模拟试验平台,分析接地电弧电磁辐射的时域与频域特性及传播衰减规律,...针对架空配电线路电弧接地故障点定位难题,该文研究架空配电线路故障电弧的电磁辐射特性,探索基于电磁辐射信号的电弧故障定位方法的可行性。通过10 k V配网真型故障模拟试验平台,分析接地电弧电磁辐射的时域与频域特性及传播衰减规律,结果表明:电弧电流的电磁辐射特征频段为20~30 MHz,该特征频段不会受到中性点接地方式、电弧接地介质与线路结构参数的显著影响,且特征频段内辐射信号在传播过程中衰减较慢。在此基础上,设计一种小型化三角形单极子–环形组合平面天线,工作频率为20~500 MHz。利用自制天线开展小型电弧故障定位实验,为后续配网电弧故障定位的应用研究提供基础。展开更多
This study investigates the groundwater aquifer located in Fayuim oasis. In this study, two of the electromagnetic measurement methods have been used in determining the hydrological situation in the Fayoum oasis. The ...This study investigates the groundwater aquifer located in Fayuim oasis. In this study, two of the electromagnetic measurement methods have been used in determining the hydrological situation in the Fayoum oasis. The first is airborne electromagnetic (AEM) which, sometimes is referred to as Helicopter electromagnetic (HEM) and the second is ground Time-domain Electromagnetic method (TEM). The subsurface consists of four geoelectrical layers with a rough slope towards the center. The third and the fourth layers in the succession are suggested to be the two-groundwater aquifers. The third layer saturates with fresh water overlying saline water which exists in the bottom of the second one. It is worth mentioning that the depth of the fresh water surface undulates between the surface level in two lakes in the study area and 57 meters below the ground, whereas the thickness of the fresh water aquifer varies from 13 to 36 meters. The depth of the saline water surface undulates between 59 and 81 meters below the ground. In general, airborne electromagnetic surveying has the advantage of fast resistivity mapping with high lateral resolution. Groundbased geophysical surveys are often more accurate, but they are definitely slower than airborne surveys. It depends on targets of interest, time, budget, and manpower available by the method or the combination of methods that will be chosen. A combination of different methods is useful to obtain a detailed understanding of the subsurface resistivity distribution.展开更多
文摘针对架空配电线路电弧接地故障点定位难题,该文研究架空配电线路故障电弧的电磁辐射特性,探索基于电磁辐射信号的电弧故障定位方法的可行性。通过10 k V配网真型故障模拟试验平台,分析接地电弧电磁辐射的时域与频域特性及传播衰减规律,结果表明:电弧电流的电磁辐射特征频段为20~30 MHz,该特征频段不会受到中性点接地方式、电弧接地介质与线路结构参数的显著影响,且特征频段内辐射信号在传播过程中衰减较慢。在此基础上,设计一种小型化三角形单极子–环形组合平面天线,工作频率为20~500 MHz。利用自制天线开展小型电弧故障定位实验,为后续配网电弧故障定位的应用研究提供基础。
文摘This study investigates the groundwater aquifer located in Fayuim oasis. In this study, two of the electromagnetic measurement methods have been used in determining the hydrological situation in the Fayoum oasis. The first is airborne electromagnetic (AEM) which, sometimes is referred to as Helicopter electromagnetic (HEM) and the second is ground Time-domain Electromagnetic method (TEM). The subsurface consists of four geoelectrical layers with a rough slope towards the center. The third and the fourth layers in the succession are suggested to be the two-groundwater aquifers. The third layer saturates with fresh water overlying saline water which exists in the bottom of the second one. It is worth mentioning that the depth of the fresh water surface undulates between the surface level in two lakes in the study area and 57 meters below the ground, whereas the thickness of the fresh water aquifer varies from 13 to 36 meters. The depth of the saline water surface undulates between 59 and 81 meters below the ground. In general, airborne electromagnetic surveying has the advantage of fast resistivity mapping with high lateral resolution. Groundbased geophysical surveys are often more accurate, but they are definitely slower than airborne surveys. It depends on targets of interest, time, budget, and manpower available by the method or the combination of methods that will be chosen. A combination of different methods is useful to obtain a detailed understanding of the subsurface resistivity distribution.
