In this paper,we present a single-ended principal-component-analysis-(PCA-)based fault-section identification method for a hybrid distribution line(non-effective grounding system),which is an overhead line combined wi...In this paper,we present a single-ended principal-component-analysis-(PCA-)based fault-section identification method for a hybrid distribution line(non-effective grounding system),which is an overhead line combined with an under-ground cable when a single-line-to-ground(SLG)fault occurs.Ground-mode currents are extracted from the single-ended measuring points when faults occur in underground cables or overhead lines,and then the method of fault-section identification based on PCA is utilized to deal with the ground-mode or aerial-mode currents to realize the fault-section identification of the hybrid system.First,a loading plot of PCA is used to compare the projection of ground-mode currents on the PC1 coordinate axis to 0.Then,Euclidean distance is used to realize the fault-section identification to improve the reliability of criterion and avoid threshold setting in the PCA method.The performance of the method is tested in 35 kV hybrid distribution lines for a distribution system based on PSCAD/EMTDC for different fault locations,different fault inception angles(FIAs),and fault resistances with satisfactory results.The impact of distributed generation(DG)and lengths of cable and overhead lines on the accuracy of the proposed method is also investigated.展开更多
线缆混合输电线路故障时将出现更加复杂的行波折反射现象,对于故障测距带来不小的难度。为解决此类问题,根据电缆与架空线各自的结构、特性的不同,在输电线路上安装分布式的行波检测装置将线路分成若干区间。应用皮尔逊相关系数的相关...线缆混合输电线路故障时将出现更加复杂的行波折反射现象,对于故障测距带来不小的难度。为解决此类问题,根据电缆与架空线各自的结构、特性的不同,在输电线路上安装分布式的行波检测装置将线路分成若干区间。应用皮尔逊相关系数的相关性原理,确定故障发生的区间。通过详细的公式推导,抵消掉波速对测距精度的影响,利用第二个SVD(singular value decomposition)分量标定出信号奇异点的脉冲模极大值,推导出分区间不含波速的混合线路故障定位算法。通过PSCAD仿真及MATLAB数据处理结果表明,与常规的单双端测距法应用于线缆组成的混合输电线路相比,可进一步提高测距精度。展开更多
横跨色尔腾山山前断裂布设一条长10.77 km的浅层地震勘探测线L1,结果发现,色尔腾山山前断裂在剖面上清晰可见,其主断裂在上部存在分叉,由断层F_(P1.1)和F_(P1)组成,均为正断层,视倾向南;结合地质地貌调查认为,F_(P1.1)断层的最新活动时...横跨色尔腾山山前断裂布设一条长10.77 km的浅层地震勘探测线L1,结果发现,色尔腾山山前断裂在剖面上清晰可见,其主断裂在上部存在分叉,由断层F_(P1.1)和F_(P1)组成,均为正断层,视倾向南;结合地质地貌调查认为,F_(P1.1)断层的最新活动时代为全新世。针对色尔腾山山前断裂的F_(P1)断层开展钻孔联合地质剖面探测,划分出Fa、Fb两个断层,结合光释光测年结果发现,断层Fa和Fb为全新世断层,其最新活动时代晚于2.5±0.6 ka BP。色尔腾山山前断裂在近地表呈叉状结构,是该断裂在晚第四纪具有多次活动的反映。展开更多
基金This work was supported by the National Natural Science Foundation of China under Grant No.51667010 and 51807084.
文摘In this paper,we present a single-ended principal-component-analysis-(PCA-)based fault-section identification method for a hybrid distribution line(non-effective grounding system),which is an overhead line combined with an under-ground cable when a single-line-to-ground(SLG)fault occurs.Ground-mode currents are extracted from the single-ended measuring points when faults occur in underground cables or overhead lines,and then the method of fault-section identification based on PCA is utilized to deal with the ground-mode or aerial-mode currents to realize the fault-section identification of the hybrid system.First,a loading plot of PCA is used to compare the projection of ground-mode currents on the PC1 coordinate axis to 0.Then,Euclidean distance is used to realize the fault-section identification to improve the reliability of criterion and avoid threshold setting in the PCA method.The performance of the method is tested in 35 kV hybrid distribution lines for a distribution system based on PSCAD/EMTDC for different fault locations,different fault inception angles(FIAs),and fault resistances with satisfactory results.The impact of distributed generation(DG)and lengths of cable and overhead lines on the accuracy of the proposed method is also investigated.
文摘线缆混合输电线路故障时将出现更加复杂的行波折反射现象,对于故障测距带来不小的难度。为解决此类问题,根据电缆与架空线各自的结构、特性的不同,在输电线路上安装分布式的行波检测装置将线路分成若干区间。应用皮尔逊相关系数的相关性原理,确定故障发生的区间。通过详细的公式推导,抵消掉波速对测距精度的影响,利用第二个SVD(singular value decomposition)分量标定出信号奇异点的脉冲模极大值,推导出分区间不含波速的混合线路故障定位算法。通过PSCAD仿真及MATLAB数据处理结果表明,与常规的单双端测距法应用于线缆组成的混合输电线路相比,可进一步提高测距精度。
文摘横跨色尔腾山山前断裂布设一条长10.77 km的浅层地震勘探测线L1,结果发现,色尔腾山山前断裂在剖面上清晰可见,其主断裂在上部存在分叉,由断层F_(P1.1)和F_(P1)组成,均为正断层,视倾向南;结合地质地貌调查认为,F_(P1.1)断层的最新活动时代为全新世。针对色尔腾山山前断裂的F_(P1)断层开展钻孔联合地质剖面探测,划分出Fa、Fb两个断层,结合光释光测年结果发现,断层Fa和Fb为全新世断层,其最新活动时代晚于2.5±0.6 ka BP。色尔腾山山前断裂在近地表呈叉状结构,是该断裂在晚第四纪具有多次活动的反映。
