This paper proposes a method for transformer fault detection system based on GSM network, through the current transformer, voltage sensor information, the known fault information attribute conditions, and the feedback...This paper proposes a method for transformer fault detection system based on GSM network, through the current transformer, voltage sensor information, the known fault information attribute conditions, and the feedback weighted coefficient through the adaptive feed forward, that can obtain high fault information attributes, thus filtering interference factors and timely get fault information properties. It solves the traditional transformer can only judge general fault and fault real-time alarm by GSM network, the system also can measure the transformer oil temperature and oil temperature alarm in super high temperature, to detect the power transformer operation parameters, and the fault running state （over-current, over-voltage, under-voltage, warning）. The actual test system show that, diagnosis ability of fault signal separation ability and small signal identification increases 17%. also meet the requirements of real-time.展开更多
During the compaction of a road subgrade, the mechanical parameters of the soil mass change in real time, but current research assumes that these parameters remain unchanged. In order to address this discrepancy, this...During the compaction of a road subgrade, the mechanical parameters of the soil mass change in real time, but current research assumes that these parameters remain unchanged. In order to address this discrepancy, this paper establishes a relationship between the degree of compaction K and strain ε. The relationship between the compaction degree K and the shear strength of soil(cohesion c and frictional angle φ) was clearly established through indoor experiments. The subroutine UMAT in ABAQUS finite element numerical software was developed to realize an accurate calculation of the subgrade soil compaction quality. This value was compared and analyzed against the assumed compaction value of the model, thereby verifying the accuracy of the intelligent compaction calculation results for subgrade soil. On this basis, orthogonal tests of the influential factors(frequency, amplitude, and quality) for the degree of compaction and sensitivity analysis were carried out. Finally, the ‘acceleration intelligent compaction value’, which is based on the acceleration signal, is proposed for a compaction meter value that indicates poor accuracy. The research results can provide guidance and basis for further research into the accurate control of compaction quality for roadbeds and pavements.展开更多
文摘This paper proposes a method for transformer fault detection system based on GSM network, through the current transformer, voltage sensor information, the known fault information attribute conditions, and the feedback weighted coefficient through the adaptive feed forward, that can obtain high fault information attributes, thus filtering interference factors and timely get fault information properties. It solves the traditional transformer can only judge general fault and fault real-time alarm by GSM network, the system also can measure the transformer oil temperature and oil temperature alarm in super high temperature, to detect the power transformer operation parameters, and the fault running state （over-current, over-voltage, under-voltage, warning）. The actual test system show that, diagnosis ability of fault signal separation ability and small signal identification increases 17%. also meet the requirements of real-time.
基金Project(51878164) supported by the National Natural Science Foundation of ChinaProjects(BK20161421, BK20140109) supported by the Natural Science Foundation of Jiangsu Province, China+4 种基金Project(141076) supported by the Huoyingdong Foundation of the Ministry of Education of ChinaProject(BZ2017011) supported by the Science and Technology Support Project of Jiangsu Province, ChinaProject(2242015R30027) supported by the Fundamental Research Funds for the Central Universities, ChinaProject(grant number KFJ170106) supported by the Changsha University of Science & Technology via Open Fund of National Engineering Laboratory of Highway Maintenance Technology, ChinaProject(2018B51) supported by the Science and Technology Support Project of Qilu Transportation Development Group, China。
文摘During the compaction of a road subgrade, the mechanical parameters of the soil mass change in real time, but current research assumes that these parameters remain unchanged. In order to address this discrepancy, this paper establishes a relationship between the degree of compaction K and strain ε. The relationship between the compaction degree K and the shear strength of soil(cohesion c and frictional angle φ) was clearly established through indoor experiments. The subroutine UMAT in ABAQUS finite element numerical software was developed to realize an accurate calculation of the subgrade soil compaction quality. This value was compared and analyzed against the assumed compaction value of the model, thereby verifying the accuracy of the intelligent compaction calculation results for subgrade soil. On this basis, orthogonal tests of the influential factors(frequency, amplitude, and quality) for the degree of compaction and sensitivity analysis were carried out. Finally, the ‘acceleration intelligent compaction value’, which is based on the acceleration signal, is proposed for a compaction meter value that indicates poor accuracy. The research results can provide guidance and basis for further research into the accurate control of compaction quality for roadbeds and pavements.
