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Sample records for kane transform fault

  1. VARIATIONS IN CRUSTAL THICKNESS OF THE KANE TRANSFORM IN THE NORTH ATLANTIC OCEAN

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A new approach was taken to investigate the crustal stucture of the Kane transform and its aseismic extension, using high quality bathymetry and gravity data. The gravity signatures associated with variations in crustal thickness of the transform were isolated from the observed free-air anomaly,was continued downward to the mean depth of the crust/mantle interface and converted onto the relief on that surface. The crustal thickness of the transform was then calculated by subtracting seawater depth from the depth of the gravity-inferred crust/mantle interface. 3-D gravity investigation results indicate that the Kane transform and adjacent areas are associated with a crust thinner than normal oceanic crust. The transform trough is largely underlain by a crust less than 4.5km thick and in the nodal basins the crust may be as thin as 3 km. The crust beneath the fracture zone valley is 4 - 5.5 km thick. The rift valleys on the spreading segments are also characterized by thin crust (4 - 5 km thick). Thin oceanic crust extends to 20 - 30 km from the transform axis, except for some localized places such as the inside comer highs adjoining the ridge-transform intersections. These gravity-inferred results match fairly well with limited published seismic results. Thinning of the crust is mainly attributable to a thin layer 3, which in tum may be explained by the combined effects of reduced magma supply at the ends of the spreading segments and tectonic activities in the region.

  2. VARIATIONS IN CRUSTAL THICKNESS OF THE KANE TRANSFORM IN THE NORTH ATLANTIC OCEAN

    Institute of Scientific and Technical Information of China (English)

    PhilipD.Rabinowitz; 胡延昌

    2001-01-01

    A new approach was taken to investigate the crustal stucture of the Kane transform and its aseismic extension, using high quality bathymetry and gravity data. The gravity signatures associated with variations in crustal thickness of the transform were isolated from the observed free-air anomaly,was continued downward to the mean depth of the crust/mantle interface and converted on to the relief onthat surface. The crustal thickness of the transform was then calculated by subtracting seawater depth from the depth of the gravity-inferred crust/mantle interface. 3-D gravity investigation results indicate that the Kane transform and adjacent areas are associated with a crust thinner than normal oceanic crust. The transform trough is largely underlain by a crust less than 4.5kin thick and in the nodal basins the crust may be as thin as 3 kin. The crust beneath the fracture zone valley is 4 - 5.5 km thick. The rift valleys on the spreading segments are also characterized by thin crust (4 - 5 km thick). Thin oceanic crust extends to 20-30 km from the transform axis,except for some localized places such as the inside comerhighs adjoining the ridge-transform intersections. These gravity-inferred results match fairly well with limited published seismic results. Thinning of the crust is mainly attributable to a thin layer 3, which in turn may be explained by the combined effects of reduced magma supply at the ends of the spreading segments and tectonic activities in the region.

  3. Dead sea transform fault system reviews

    CERN Document Server

    Garfunkel, Zvi; Kagan, Elisa

    2014-01-01

    The Dead Sea transform is an active plate boundary connecting the Red Sea seafloor spreading system to the Arabian-Eurasian continental collision zone. Its geology and geophysics provide a natural laboratory for investigation of the surficial, crustal and mantle processes occurring along transtensional and transpressional transform fault domains on a lithospheric scale and related to continental breakup. There have been many detailed and disciplinary studies of the Dead Sea transform fault zone during the last?20 years and this book brings them together.This book is an updated comprehensive coverage of the knowledge, based on recent studies of the tectonics, structure, geophysics, volcanism, active tectonics, sedimentology and paleo and modern climate of the Dead Sea transform fault zone. It puts together all this new information and knowledge in a coherent fashion.

  4. Transformer fault diagnosis using continuous sparse autoencoder.

    Science.gov (United States)

    Wang, Lukun; Zhao, Xiaoying; Pei, Jiangnan; Tang, Gongyou

    2016-01-01

    This paper proposes a novel continuous sparse autoencoder (CSAE) which can be used in unsupervised feature learning. The CSAE adds Gaussian stochastic unit into activation function to extract features of nonlinear data. In this paper, CSAE is applied to solve the problem of transformer fault recognition. Firstly, based on dissolved gas analysis method, IEC three ratios are calculated by the concentrations of dissolved gases. Then IEC three ratios data is normalized to reduce data singularity and improve training speed. Secondly, deep belief network is established by two layers of CSAE and one layer of back propagation (BP) network. Thirdly, CSAE is adopted to unsupervised training and getting features. Then BP network is used for supervised training and getting transformer fault. Finally, the experimental data from IEC TC 10 dataset aims to illustrate the effectiveness of the presented approach. Comparative experiments clearly show that CSAE can extract features from the original data, and achieve a superior correct differentiation rate on transformer fault diagnosis.

  5. Initiation of Ridges and Transform Faults

    Science.gov (United States)

    Nyst, M.; Thompson, G. A.; Parsons, T.

    2004-12-01

    No clear consensus has emerged to explain initiation of the strikingly regular pattern of ocean ridges and transform faults. The question is important on the continents also, because a less regular pattern of step-overs on faults such as the San Andreas influences the sources of earthquakes. We explore the question by finite element modeling and a study of observational data on ridges and transforms. We focus on the simplest case, where ridges and transforms seem to self-organize at new plate boundaries as soon as new oceanic (magmatic) crust forms. The South Atlantic supplies a clear example. Continental South America and Africa separated along an irregular break, whose general shape is still preserved in the Mid-Atlantic Ridge. In detail, however, the sea floor magnetic anomalies and satellite gravity show that traces of the ridges and transforms extend to the base of the continental slope, i.e. they formed quickly in the new oceanic crust. The Gulf of California provides another clear example and is notable because of its northward transition into the continental San Andreas fault system. In continental crust, dike segments connected by transform faults provide the clearest analogues of oceanic ridges and transforms. Remarkably, the ridge-transform pattern has been simulated by pulling the crust on molten wax [Oldenburg and Brune, JGR, 80, 1975] and also observed in the crust of a molten lava lake [Duffield, JGR, 77, 1972]. In neither of these models, however, do the spatial and temporal scales permit investigation of the dikes whose repeated emplacement and inflation builds layer 3 of the ocean crust. It is well established that, under a buoyant head of magma, dikes tend to fracture and intrude the crust in planes perpendicular to the least horizontal stress, and they relieve the stress difference as they inflate [e.g. Parsons and Thompson, Science, 253, 1991]. Dikes are commonly used as stress-direction indicators analogous to artificial hydraulic fractures

  6. The Singular Kane Oscillator

    Institute of Scientific and Technical Information of China (English)

    Babayev A.M.; Cakmaktepe (S).

    2006-01-01

    The energy spectrum of carriers in narrow band gap semiconductor nanocrystals are studied theoretically taking into account the nonparabolicity of charge carriers dispersion laws. The confinement potential of nanocrystals is approximated to be λr2 +λ1r-2, and the dispersion laws are considered within the framework of the three-band Kane model.

  7. A Dynamic Integrated Fault Diagnosis Method for Power Transformers

    Directory of Open Access Journals (Sweden)

    Wensheng Gao

    2015-01-01

    Full Text Available In order to diagnose transformer fault efficiently and accurately, a dynamic integrated fault diagnosis method based on Bayesian network is proposed in this paper. First, an integrated fault diagnosis model is established based on the causal relationship among abnormal working conditions, failure modes, and failure symptoms of transformers, aimed at obtaining the most possible failure mode. And then considering the evidence input into the diagnosis model is gradually acquired and the fault diagnosis process in reality is multistep, a dynamic fault diagnosis mechanism is proposed based on the integrated fault diagnosis model. Different from the existing one-step diagnosis mechanism, it includes a multistep evidence-selection process, which gives the most effective diagnostic test to be performed in next step. Therefore, it can reduce unnecessary diagnostic tests and improve the accuracy and efficiency of diagnosis. Finally, the dynamic integrated fault diagnosis method is applied to actual cases, and the validity of this method is verified.

  8. A New Method of Improving Transformer Restricted Earth Fault Protection

    Directory of Open Access Journals (Sweden)

    KRSTIVOJEVIC, J. P.

    2014-08-01

    Full Text Available A new method of avoiding malfunctioning of the transformer restricted earth fault (REF protection is presented. Application of the proposed method would eliminate unnecessary operation of REF protection in the cases of faults outside protected zone of a transformer or a magnetizing inrush accompanied by current transformer (CT saturation. On the basis of laboratory measurements and simulations the paper presents a detailed performance assessment of the proposed method which is based on digital phase comparator. The obtained results show that the new method was stable and precise for all tested faults and that its application would allow making a clear and precise difference between an internal fault and: (i external fault or (ii magnetizing inrush. The proposed method would improve performance of REF protection and reduce probability of maloperation due to CT saturation. The new method is robust and characterized by high speed of operation and high reliability and security.

  9. Application of extension method to fault diagnosis of transformer

    Institute of Scientific and Technical Information of China (English)

    DENG Hong-gui; CAO Jian; LUO An; XIA Xiang-yang

    2007-01-01

    A novel extension diagnosis method was proposed for enhancing the diagnosis ability of the conventional dissolved gas analysis. Based on the extension theory a matter-element model was established for qualitatively and quantitatively describing the fault diagnosis problem of power transformers. The degree of relation based on the dependent functions WaS employed to determine then ature and the grade of the faults in a transformer system.And the proposed method was verified with the experimental data.The results show that accuracy rate of the diagnosis method exceeds 90% and two kinds of faults call be detected at the same time.

  10. Research on Transformer Fault Based on Probabilistic Neural Network

    Directory of Open Access Journals (Sweden)

    Li Yingshun

    2015-01-01

    Full Text Available With the development of computer science and technology, and increasingly intelligent industrial production, the application of big data in industry also advances rapidly, and the development of artificial intelligence in the aspect of fault diagnosis is particularly prominent. On the basis of MATLAB platform, this paper constructs a fault diagnosis expert system of artificial intelligence machine based on the probabilistic neural network, and it also carries out a simulation of production process by the use of bionic algorithm. This paper makes a diagnosis of transformer fault by the use of an expert system developed by this paper, and verifies that the probabilistic neural network has a good convergence, fault-tolerant ability and big data handling capability in the fault diagnosis. It is suitable for industrial production, which can provide a reliable mathematical model for the construction of fault diagnosis expert system in the industrial production.

  11. Transform faults and large horizontal displacements of the ocean floor

    Directory of Open Access Journals (Sweden)

    G. RANALLI

    1968-06-01

    Full Text Available The evidence concerning the existence of transform
    faults and the occurrence of sea-floor spreading is reviewed and discussed.
    Available fault-plane solutions indicate that the direction of motion along
    some oceanic fracture zones is opposite to that which would be expected
    in case of transcurrent faults. The support for the sea-floor spreading hypothesis
    comes mainly from magnetic investigations. The problem, however,
    presents formidable dynamic and rheological aspects, and is far from being
    completely solved.

  12. Allegheny County Kane Regional Center Census

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — Total number of residents in each Kane Regional Center facility by race and gender. The Kane Regional Centers are skilled nursing and rehabilitation centers run by...

  13. Battery Fault Detection with Saturating Transformers

    Science.gov (United States)

    Davies, Francis J. (Inventor); Graika, Jason R. (Inventor)

    2013-01-01

    A battery monitoring system utilizes a plurality of transformers interconnected with a battery having a plurality of battery cells. Windings of the transformers are driven with an excitation waveform whereupon signals are responsively detected, which indicate a health of the battery. In one embodiment, excitation windings and sense windings are separately provided for the plurality of transformers such that the excitation waveform is applied to the excitation windings and the signals are detected on the sense windings. In one embodiment, the number of sense windings and/or excitation windings is varied to permit location of underperforming battery cells utilizing a peak voltage detector.

  14. DATA TRANSFORMATION OF FAULT TREE BY USING MATRIX OPERATION

    Institute of Scientific and Technical Information of China (English)

    Cai Jiakun; Chen Jinshui

    2003-01-01

    On the base of study of the correlation of fault tree's main data-minimum cut sets, minimum path sets, non-intersect minimum cut sets and non-intersect minimum path sets, transformation method among main data are found, i.e. the transformation can be realized by the operation of cut sets matrixes. This method provides a new way to reduce "NP" difficulty and simplify FTA.

  15. Investigation of a marine magnetic polarity reversal boundary in cross section at the northern boundary of the Kane Megamullion, Mid-Atlantic Ridge, 23°40'N

    Science.gov (United States)

    Xu, Min; Tivey, M. A.

    2016-05-01

    Near-bottom magnetic field measurements made by the submersible Nautile during the 1992 Kanaut Expedition define the cross-sectional geometry of magnetic polarity reversal boundaries and the vertical variation of crustal magnetization in lower oceanic crust exposed along the Kane Transform Fault (TF) at the northern boundary of the Kane Megamullion (KMM). The KMM exposes lower crust and upper mantle rocks on a low-angle normal fault that was active between 3.3 Ma and 2.1 Ma. The geometry of the polarity boundaries is estimated from an inversion of the submarine magnetic data for crustal magnetization. In general, the polarity boundaries dip away from the ridge axis along the Kane TF scarp, with a west dipping angle of ~45° in the shallow (isotherms and isochrons. We also test the effects of the rotation of this isotherm structure and/or footwall rotation and find that the magnetic polarity boundary geometry is not sensitive to these directional changes.

  16. Software System for Finding the Incipient Faults in Power Transformers

    Directory of Open Access Journals (Sweden)

    Nikolina Petkova

    2015-05-01

    Full Text Available In this paper a new software system for finding of incipient faultsis presented.An experiment is made with real measurement of partial discharge(PD that appeared in power transformer. The software system usesacquisition data to define the real state of this transformer. One of the most important criteria for the power transformer’s state is the presence of partial discharges. The wave propagation caused by partial discharge depends on scheme of the winding and construction of the power equipment. In all cases, the PD source had a specific position so the wave measured from the PD –coupling device had a specific waveform. The waveform is different when PDcoupling device is put on a specific place. The waveform and the time of propagation are criteria for the localization of the source of incipient faults in the volume of power transformer.

  17. Fault location in underground cables using ANFIS nets and discrete wavelet transform

    Directory of Open Access Journals (Sweden)

    Shimaa Barakat

    2014-12-01

    Full Text Available This paper presents an accurate algorithm for locating faults in a medium voltage underground power cable using a combination of Adaptive Network-Based Fuzzy Inference System (ANFIS and discrete wavelet transform (DWT. The proposed method uses five ANFIS networks and consists of 2 stages, including fault type classification and exact fault location. In the first part, an ANFIS is used to determine the fault type, applying four inputs, i.e., the maximum detailed energy of three phase and zero sequence currents. Other four ANFIS networks are utilized to pinpoint the faults (one for each fault type. Four inputs, i.e., the maximum detailed energy of three phase and zero sequence currents, are used to train the neuro-fuzzy inference systems in order to accurately locate the faults on the cable. The proposed method is evaluated under different fault conditions such as different fault locations, different fault inception angles and different fault resistances.

  18. Resource requirements for a fault-tolerant quantum Fourier transform

    Science.gov (United States)

    Goto, Hayato; Nakamura, Satoshi; Kujiraoka, Mamiko; Ichimura, Kouichi

    2015-03-01

    The quantum Fourier transform (QFT) is a basic subroutine for most quantum algorithms providing an exponential speedup over classical ones. We investigate resource requirements for a fault-tolerant QFT. To implement single-qubit rotations for a QFT in a fault-tolerant manner, we examine three types of approaches: ancilla-free gate synthesis, ancilla-assisted gate synthesis, and state distillation. While the gate synthesis approximates single-qubit rotations with basic quantum operations, the state distillation enables to perform specific single-qubit rotations required for the QFT exactly. It is unknown, however, which approach is better for the QFT. We estimated the resource requirement for a QFT in each case, where the resource is measured by the total number of the π / 8 gates denoted by T, which is called the T count. Contrary to the initial expectation, the total T count for the state distillation is considerably larger than those for the ancilla-free and ancilla-assisted gate synthesis. Thus, we conclude that the ancilla-assisted gate synthesis is the best for a fault-tolerant QFT so far.

  19. A Method for Incipient Fault Diagnosis of Roller Bearings Based on the Wavelet Transform Correlation Filter and Hilbert Transform

    Institute of Scientific and Technical Information of China (English)

    ZENG Qing-hu; QIU Jing; LIU Guan-jun

    2007-01-01

    Noise is the biggest obstacle that makes the incipient fault diagnosis results of roller bearings uncorrected; a new method for diagnosing incipient fault of roller bearings based on the Wavelet Transform Correlation Filter and Hilbert Transform was proposed. First, the weak fault information features are picked up from the roller bearings fault vibration signals by use of a de-noising characteristic of the Wavelet Transform Correlation Filter as the preprocessing of the Hilbert Envelope Analysis. Then, in order to get fault features frequency, de-noised wavelet coefficients of high scales which represent high frequency signal were analyzed by Hilbert Envelope Spectrum Analysis. The simulation signals and diagnosing examples analysis results reveal that the proposed method is more effective than the method of direct wavelet coefficients-Hilbert Transform in de-noising and clarifying roller bearing incipient fault.

  20. Rheology and friction along the Vema transform fault (Central Atlantic) inferred by thermal modeling

    Science.gov (United States)

    Cuffaro, Marco; Ligi, Marco

    2016-04-01

    We investigate with 3-D finite element simulations the temperature distribution beneath the Vema transform that offsets the Mid-Atlantic Ridge by ~300 km in the Central Atlantic. The developed thermal model includes the effects of mantle flow beneath a ridge-transform-ridge geometry and the lateral heat conduction across the transform fault, and of the shear heating generated along the fault. Numerical solutions are presented for a 3-D domain, discretized with a non-uniform tetrahedral mesh, where relative plate kinematics is used as boundary condition, providing passive mantle upwelling. Mantle is modelled as a temperature-dependent viscous fluid, and its dynamics can be described by Stokes and advection-conduction heat equations. The results show that shear heating raises significantly the temperature along the transform fault. In order to test model results, we calculated the thermal structure simulating the mantle dynamics beneath an accretionary plate boundary geometry that duplicates the Vema transform fault, assuming the present-day spreading rate and direction of the Mid Atlantic Ridge at 11 °N. Thus, the modelled heat flow at the surface has been compared with 23 heat flow measurements carried out along the Vema Transform valley. Laboratory studies on the frictional stability of olivine aggregates show that the depth extent of oceanic faulting is thermally controlled and limited by the 600 °C isotherm. The depth of isotherms of the thermal model were compared to the depths of earthquakes along transform faults. Slip on oceanic transform faults is primarily aseismic, only 15% of the tectonic offset is accommodated by earthquakes. Despite extensive fault areas, few large earthquakes occur on the fault and few aftershocks follow large events. Rheology constrained by the thermal model combined with geology and seismicity of the Vema Transform fault allows to better understand friction and the spatial distribution of strength along the fault and provides

  1. Transformation of fault slip modes in laboratory experiments

    Science.gov (United States)

    Martynov, Vasilii; Alexey, Ostapchuk; Markov, Vadim

    2017-04-01

    Slip mode of crust fault can vary because of many reasons. It's well known that fault structure, material of fault gouge, pore fluid et al. in many ways determines slip modes from creep and slow slip events to mega-earthquakes [1-3]. Therefore, the possibility of fault slip transformation due to external action is urgent question. There is popular and developing approach of fluid injection into central part of fault. The phenomenon of earthquakes induced due to pumping of water was investigated on small and large scales [4, 5]. In this work the laboratory experiments were conducted to study the evolution of the experimental fault slip when changing the properties of the interstitial fluid. The scheme of experiments is the classical slider-model set-up, in which the block under the shear force slips along the interface. In our experiments the plexiglas block 8x8x3 cm3 in size was put on the plexiglas base. The contact of the blocks was filled with a thin layer (about 3 mm thick) of a granular material. The normal load varied from 31 to 156 kPa. The shear load was applied through a spring with stiffness 60 kN/m, and the rate of spring deformation was 20 or 5 mcm/s. Two parameters were recorded during experiments: the shear force acting on the upper block (with an accuracy of 1 N) and its displacement relatively the base (with an accuracy of 0.1 μm). The gouge was composed of quartz sand (97.5%) and clay (2.5%). As a moisturizer were used different fluids with viscosity varying from 1 to 103 mPa x s. Different slip modes were simulated during slider-experiments. In our experiments slip mode is the act of instability manifested in an increase of slip velocity and a drop of shear stress acting on a movable block. The amplitude of a shear stress drop and the peak velocity of the upper block were chosen as the characteristics of the slip mode. In the laboratory experiments, slip events of one type can be achieved either as regularly recurring (regular mode) or as random

  2. NEW METHOD FOR WEAK FAULT FEATURE EXTRACTION BASED ON SECOND GENERATION WAVELET TRANSFORM AND ITS APPLICATION

    Institute of Scientific and Technical Information of China (English)

    Duan Chendong; He Zhengjia; Jiang Hongkai

    2004-01-01

    A new time-domain analysis method that uses second generation wavelet transform (SGWT) for weak fault feature extraction is proposed. To extract incipient fault feature, a biorthogonal wavelet with the characteristics of impact is constructed by using SGWT. Processing detail signal of SGWT with a sliding window devised on the basis of rotating operation cycle, and extracting modulus maximum from each window, fault features in time-domain are highlighted. To make further analysis on the reason of the fault, wavelet package transform based on SGWT is used to process vibration data again. Calculating the energy of each frequency-band, the energy distribution features of the signal are attained. Then taking account of the fault features and the energy distribution, the reason of the fault is worked out. An early impact-rub fault caused by axis misalignment and rotor imbalance is successfully detected by using this method in an oil refinery.

  3. Seismic zonation of the Dead Sea Transform Fault area

    Directory of Open Access Journals (Sweden)

    E. E. Papadimitriou

    2000-06-01

    Full Text Available The Dead Sea Transform Fault constitutes the northwestern boundary of the Arabian plate, accommodating the plate’s lateral movement relative to the African plate. A complete and homogeneous catalogue of historical earthquakes has been compiled and used in the subdivision of the fault area into the following segments: 1 Araba segment, which extends along Wadi Araba and the southernmost part of the Dead Sea (29.5°-31.3°N and trends SSW-NNE with scarce historical and instrumental seismicity; 2 Jordan-valley segment, which extends along the central and northern parts of the Dead Sea and the Jordan valley to the Huleh depression (31.3°-33.1° N and trends S-N with moderate historical seismicity; 3 Beqa’a segment, which extends along the western margin of the Beqa’a valley in Lebanon (33.1°-34.5°N and trends SSW-NNE with strong historical seismicity; 4 El-Ghab segment, which extends along the eastern flank of the coastal mountain range of Syria (34.5°-35.8°N and trends S-N with moderate historical seismicity; 5 Karasu segment, which extends along the Karasu valley in SE Turkey (35.8°-37.3°N and trends SSW-NNE, exhibiting the strongest historical seismicity of the area. Probabilities for the generation of strong (M > 6.0 earthquakes in these segments during the next decade are given, by the application of the regional time and magnitude predictable model.

  4. The relationship between oceanic transform fault segmentation, seismicity, and thermal structure

    Science.gov (United States)

    Wolfson-Schwehr, Monica

    Mid-ocean ridge transform faults (RTFs) are typically viewed as geometrically simple, with fault lengths readily constrained by the ridge-transform intersections. This relative simplicity, combined with well-constrained slip rates, make them an ideal environment for studying strike-slip earthquake behavior. As the resolution of available bathymetric data over oceanic transform faults continues to improve, however, it is being revealed that the geometry and structure of these faults can be complex, including such features as intra-transform pull-apart basins, intra-transform spreading centers, and cross-transform ridges. To better determine the resolution of structural complexity on RTFs, as well as the prevalence of RTF segmentation, fault structure is delineated on a global scale. Segmentation breaks the fault system up into a series of subparallel fault strands separated by an extensional basin, intra-transform spreading center, or fault step. RTF segmentation occurs across the full range of spreading rates, from faults on the ultraslow portion of the Southwest Indian Ridge to faults on the ultrafast portion of the East Pacific Rise (EPR). It is most prevalent along the EPR, which hosts the fastest spreading rates in the world and has undergone multiple changes in relative plate motion over the last couple of million years. Earthquakes on RTFs are known to be small, to scale with the area above the 600°C isotherm, and to exhibit some of the most predictable behaviors in seismology. In order to determine whether segmentation affects the global RTF scaling relations, the scalings are recomputed using an updated seismic catalog and fault database in which RTF systems are broken up according to their degree of segmentation (as delineated from available bathymetric datasets). No statistically significant differences between the new computed scaling relations and the current scaling relations were found, though a few faults were identified as outliers. Finite element

  5. Detailed Simulation of Transformer Internal Fault in Power System by Diakoptical Concept

    Directory of Open Access Journals (Sweden)

    KOUHSARI, S. M.

    2010-08-01

    Full Text Available This paper presents a novel method for modeling internal faults in a power transformer. This method uses a distributed computing approach for analysis of internal fault in transient stability (T/S studies of electrical networks using Diakoptics and large change sensitivity (LCS concepts. The combination of these concepts by phase frame model of transformer will be used here to develop an internal fault simulation of transformers. This approach leads to a model which is compatible with commercial phasor-based software packages. Consequently, it enables calculation of fault currents in any branch of the network due to a winding fault of a power transformer. The proposed method is implemented successfully and validated by time domain software and GEC group measurement results.

  6. Mine-hoist fault-condition detection based on the wavelet packet transform and kernel PCA

    Institute of Scientific and Technical Information of China (English)

    XIA Shi-xiong; NIU Qiang; ZHOU Yong; ZHANG Lei

    2008-01-01

    A new algorithm was developed to correctly identify fault conditions and accurately monitor fault development in a mine hoist. The new method is based on the Wavelet Packet Transform (WPT) and kernel PCA (Kernel Principal Component Analysis, KPCA). For non-linear monitoring systems the key to fault detection is the extracting of main features. The wavelet packet transform is a novel technique of signal processing that possesses excellent characteristics of time-frequency localization. It is suitable for analysing time-varying or transient signals. KPCA maps the original input features into a higher dimension feature space through a non-linear mapping. The principal components are then found in the higher dimension feature space. The KPCA transformation was applied to extracting the main nonlinear features from experimental fault feature data after wavelet packet transformation. The results show that the proposed method affords credible fault detection and identification.

  7. Transformer Incipient Fault Prediction Using Combined Artificial Neural Network and Various Particle Swarm Optimisation Techniques.

    Directory of Open Access Journals (Sweden)

    Hazlee Azil Illias

    Full Text Available It is important to predict the incipient fault in transformer oil accurately so that the maintenance of transformer oil can be performed correctly, reducing the cost of maintenance and minimise the error. Dissolved gas analysis (DGA has been widely used to predict the incipient fault in power transformers. However, sometimes the existing DGA methods yield inaccurate prediction of the incipient fault in transformer oil because each method is only suitable for certain conditions. Many previous works have reported on the use of intelligence methods to predict the transformer faults. However, it is believed that the accuracy of the previously proposed methods can still be improved. Since artificial neural network (ANN and particle swarm optimisation (PSO techniques have never been used in the previously reported work, this work proposes a combination of ANN and various PSO techniques to predict the transformer incipient fault. The advantages of PSO are simplicity and easy implementation. The effectiveness of various PSO techniques in combination with ANN is validated by comparison with the results from the actual fault diagnosis, an existing diagnosis method and ANN alone. Comparison of the results from the proposed methods with the previously reported work was also performed to show the improvement of the proposed methods. It was found that the proposed ANN-Evolutionary PSO method yields the highest percentage of correct identification for transformer fault type than the existing diagnosis method and previously reported works.

  8. Transformer Incipient Fault Prediction Using Combined Artificial Neural Network and Various Particle Swarm Optimisation Techniques.

    Science.gov (United States)

    Illias, Hazlee Azil; Chai, Xin Rui; Abu Bakar, Ab Halim; Mokhlis, Hazlie

    2015-01-01

    It is important to predict the incipient fault in transformer oil accurately so that the maintenance of transformer oil can be performed correctly, reducing the cost of maintenance and minimise the error. Dissolved gas analysis (DGA) has been widely used to predict the incipient fault in power transformers. However, sometimes the existing DGA methods yield inaccurate prediction of the incipient fault in transformer oil because each method is only suitable for certain conditions. Many previous works have reported on the use of intelligence methods to predict the transformer faults. However, it is believed that the accuracy of the previously proposed methods can still be improved. Since artificial neural network (ANN) and particle swarm optimisation (PSO) techniques have never been used in the previously reported work, this work proposes a combination of ANN and various PSO techniques to predict the transformer incipient fault. The advantages of PSO are simplicity and easy implementation. The effectiveness of various PSO techniques in combination with ANN is validated by comparison with the results from the actual fault diagnosis, an existing diagnosis method and ANN alone. Comparison of the results from the proposed methods with the previously reported work was also performed to show the improvement of the proposed methods. It was found that the proposed ANN-Evolutionary PSO method yields the highest percentage of correct identification for transformer fault type than the existing diagnosis method and previously reported works.

  9. Undecimated Lifting Wavelet Packet Transform with Boundary Treatment for Machinery Incipient Fault Diagnosis

    Directory of Open Access Journals (Sweden)

    Lixiang Duan

    2016-01-01

    Full Text Available Effective signal processing in fault detection and diagnosis (FDD is an important measure to prevent failure and accidents of machinery. To address the end distortion and frequency aliasing issues in conventional lifting wavelet transform, a Volterra series assisted undecimated lifting wavelet packet transform (ULWPT is investigated for machinery incipient fault diagnosis. Undecimated lifting wavelet packet transform is firstly formulated to eliminate the frequency aliasing issue in traditional lifting wavelet packet transform. Next, Volterra series, as a boundary treatment method, is used to preprocess the signal to suppress the end distortion in undecimated lifting wavelet packet transform. Finally, the decomposed wavelet coefficients are trimmed to the original length as the signal of interest for machinery incipient fault detection. Experimental study on a reciprocating compressor is performed to demonstrate the effectiveness of the presented method. The results show that the presented method outperforms the conventional approach by dramatically enhancing the weak defect feature extraction for reciprocating compressor valve fault diagnosis.

  10. EMD and Wavelet Transform Based Fault Diagnosis for Wind Turbine Gear Box

    Directory of Open Access Journals (Sweden)

    Qingyu Yang

    2013-01-01

    Full Text Available Wind turbines are mainly located in harsh environment, and the maintenance is therefore very difficult. The wind turbine faults are mostly from the gear box, and the fault signal is generally nonlinear and nonstationary. The traditional fault diagnosis methods such as Fast Fourier transform (FFT and the inverted frequency spectrum identification method based on FFT are not satisfactory in processing this kind of signal. This paper proposes a hybrid fault diagnosis method which combines the empirical mode decomposition (EMD and wavelet transform. The vibration signal is analyzed through wavelet transform, and the aliasing in high-frequency signals is then addressed by conducting EMD to the original signals. The experimental results based on a specific wind turbine gear box demonstrate that this method can diagnose the faults and locate their positions accurately.

  11. Double Fault Detection of Cone-Shaped Redundant IMUs Using Wavelet Transformation and EPSA

    Directory of Open Access Journals (Sweden)

    Wonhee Lee

    2014-02-01

    Full Text Available A model-free hybrid fault diagnosis technique is proposed to improve the performance of single and double fault detection and isolation. This is a model-free hybrid method which combines the extended parity space approach (EPSA with a multi-resolution signal decomposition by using a discrete wavelet transform (DWT. Conventional EPSA can detect and isolate single and double faults. The performance of fault detection and isolation is influenced by the relative size of noise and fault. In this paper; the DWT helps to cancel the high frequency sensor noise. The proposed technique can improve low fault detection and isolation probability by utilizing the EPSA with DWT. To verify the effectiveness of the proposed fault detection method Monte Carlo numerical simulations are performed for a redundant inertial measurement unit (RIMU.

  12. Wavelet Transform and Neural Networks in Fault Diagnosis of a Motor Rotor

    Institute of Scientific and Technical Information of China (English)

    RONG Ming-xing

    2012-01-01

    In the motor fault diagnosis technique, vibration and stator current frequency components of detection are two main means. This article will discuss the signal detection method based on vibration fault. Because the motor vibration signal is a non-stationary random signal, fault signals often contain a lot of time-varying, burst proper- ties of ingredients. The traditional Fourier signal analysis can not effectively extract the motor fault characteristics, but are also likely to be rich in failure information but a weak signal as noise. Therefore, we introduce wavelet packet transforms to extract the fault characteristics of the signal information. Obtained was the result as the neural network input signal, using the L-M neural network optimization method for training, and then used the BP net- work for fault recognition. This paper uses Matlab software to simulate and confirmed the method of motor fault di- agnosis validity and accuracy

  13. Fault Detection in Complex Distribution Network Based on Hilbert-Huang Transform

    Directory of Open Access Journals (Sweden)

    Zhongjian Kang

    2013-01-01

    Full Text Available Traditional distribution network fault location methods often cannot be effectively applied for the structure of the branch in complex distribution network. A new accurate fault location for the single-phase-ground fault in complex distribution network with structure of the branch based on Hilbert-Huang transform was proposed in this paper. First, the distribution network was modeled. The faults on each branch were simulated. The energy characteristics under the branch in a particular frequency band were identified by HHT. Then these energy characteristics were used to train artificial neural networks (ANN.When the energy characteristics of actual fault are inputted, the trained neural network can output the malfunction branch. When the fault branch was determined, using the online fault feature matching method, combined with the genetic algorithm, the precise determination of the distance to fault location in the fault branch can be completed. With combinations of signal processing-Hilbert-Huang transform, artificial neural network and genetic algorithm, the entirely new method was proposed to deal with the problem of fault location in distribution network in this article. The results showed that the method has a good precision and apply to the small current grounding system.

  14. Magnetic character of a large continental transform: an aeromagnetic survey of the Dead Sea Fault

    Science.gov (United States)

    ten Brink, Uri S.; Rybakov, Michael; Al-Zoubi, Abdallah S.; Rotstein, Yair

    2007-01-01

    New high-resolution airborne magnetic (HRAM) data along a 120-km-long section of the Dead Sea Transform in southern Jordan and Israel shed light on the shallow structure of the fault zone and on the kinematics of the plate boundary. Despite infrequent seismic activity and only intermittent surface exposure, the fault is delineated clearly on a map of the first vertical derivative of the magnetic intensity, indicating that the source of the magnetic anomaly is shallow. The fault is manifested by a 10–20 nT negative anomaly in areas where the fault cuts through magnetic basement and by a

  15. Interaction between transform faults and rift systems: a combined field and experimental approach

    Directory of Open Access Journals (Sweden)

    Alessandro eTibaldi

    2016-04-01

    Full Text Available We present a detailed field structural survey of the area of interaction between the active NW-striking transform Husavik-Flatey Fault (HFF and the N-S Theystareykir Fissure Swarm (TFS, in North Iceland, integrated by analogue scaled models. Field data contribute to a better understanding of how transform faults work, at a much higher detail than classical marine geophysical studies. Analogue experiments are conducted to analyse the fracture patterns resulting from different possible cases where transform faulting accompanies or postpones the rift motions; different tectonic block configurations are also considered. West of the intersection between the transform fault (HFF and the rift zone (TFS, the former splays with a gradual bending giving rise to a leading extensional imbricate fan. The westernmost structure of the rift, the N-S Gudfinnugja Fault (GF, is divided into two segments: the southern segment makes a junction with the HFF and is part of the imbricate fan; north of the junction instead, the northern GF appears right-laterally offset by about 20 m. Southeast of the junction, along the possible prolongation of the HFF across the TFS, the strike of the rift faults rotates in an anticlockwise direction, attaining a NNW-SSE orientation. Moreover, the TFS faults north of the HFF prolongation are fewer and have smaller offsets than those located to the south. Through the comparison between the structural data collected in the field at the HFF-TFS connection zone and a set of scaled experiments, we confirm a prolongation of the HFF through the rift, although here the transform fault has a much lower slip-rate than west of the junction. Our data suggest that transform fault terminations may be more complex than previously known, and propagate across a rift through a modification of the rift pattern.

  16. Series transformer based diode-bridge-type solid state fault current limiter

    Institute of Scientific and Technical Information of China (English)

    Amir HEIDARY; Hamid RADMANESH; Seyed Hamid FATHI; G B GHAREHPETIAN

    2015-01-01

    We propose a novel series transformer based diode-bridge-type solid state fault current limiter (SSFCL). To control the fault current, a series RLC branch is connected to the secondary side of an isolation series transformer. Based on this RLC branch, two current limiting modes are created. In the first mode, R and C are bypassed via a paralleled power electronic switch (insulated-gate bipolar transistor, IGBT) and L remains connected to the secondary side of the transformer as a DC reactor. In the second mode, the series reactor impedance is not enough to limit the fault current. In this case, the fault current can be con-trolled by selecting a proper on-off duration of the parallel IGBT, across the series damping resistor (R) and capacitor, which inserts high impedance into the line to limit the fault current. Then, by controlling the magnitude of the DC reactor current, the fault current is reduced and the voltage of the point of common coupling (PCC) is kept at an acceptable level. In addition, in the new SSFCL, the series RC branch, connected in parallel with the IGBT, serves as a snubber circuit for decreasing the transient recovery voltage (TRV) of the IGBT during on-off states. Therefore, the power quality indices can be improved. The measure-ment results of a built prototype are presented to support the simulation and theoretical studies. The proposed SSFCL can limit the fault current without any delay and successfully smooth the fault current waveform.

  17. New method for online interturn faults detection in power transformer with using probabilistic neural network

    Directory of Open Access Journals (Sweden)

    S. hajiaghasi

    2014-07-01

    Full Text Available In recent years with notice increase reliability in power system and Intelligent Systems and also notice that transformers are one of the main part of the transmission and distribution systems, online monitoring of these equipment in power system are require. In this paper, a new method for online interturn fault detection base on leakage flux in power transformer are propose. When an interturn fault occur the symmetry of flux destruction and leakage flux increase or decrease and for various location and severity of fault leakage flux is different and it can be used for fault detection. In this paper for measure these flux we using search coils that mounted on HV winding. To fault detection and classify we using probabilistic neural network. and for decrease the information volume PCA is used. The simulation results are compare and verified with experimental result and show that this propose method is very good.

  18. FAULT DIAGNOSIS APPROACH FOR ROLLER BEARINGS BASED ON EMPIRICAL MODE DECOMPOSITION METHOD AND HILBERT TRANSFORM

    Institute of Scientific and Technical Information of China (English)

    Yu Dejie; Cheng Junsheng; Yang Yu

    2005-01-01

    Based upon empirical mode decomposition (EMD) method and Hilbert spectrum, a method for fault diagnosis of roller bearing is proposed. The orthogonal wavelet bases are used to translate vibration signals of a roller bearing into time-scale representation, then, an envelope signal can be obtained by envelope spectrum analysis of wavelet coefficients of high scales. By applying EMD method and Hilbert transform to the envelope signal, we can get the local Hilbert marginal spectrum from which the faults in a roller bearing can be diagnosed and fault patterns can be identified. Practical vibration signals measured from roller bearings with out-race faults or inner-race faults are analyzed by the proposed method. The results show that the proposed method is superior to the traditional envelope spectrum method in extracting the fault characteristics of roller bearings.

  19. Diagnosis of airgap eccentricity fault in the inverter driven induction motor drives by transformative techniques

    Directory of Open Access Journals (Sweden)

    Khadim Moin Siddiqui

    2016-09-01

    Full Text Available In the present paper, the airgap eccentricity fault of the induction motor has been diagnosed by digital signal processing transformative techniques in the inverter driven induction motor drives. The airgap eccentricity fault has been diagnosed in the transient condition by time domain as well as time-frequency domain techniques with the help of a proposed dynamic simulation model. In the past, many signal processing techniques had been used for various induction motor fault detection purpose such as fast Fourier transform, Hilbert transform, short term Fourier transform, etc. But, all techniques faced some sort of disadvantages. Therefore, in this paper, all shortcomings of the previous used signal processing techniques have been solved by newly wavelet transform's approximation signal. The low frequency approximation signal has been used to diagnose the eccentricity fault in the transient condition. Therefore, early fault diagnosis of the motor is possible and averted the motor before reaching in the ruinous conditions. As a result, the industries may save large revenues and unexpected failure conditions. The obtained results clearly demonstrate that the developed diagnostic technique may reliably separate airgap eccentricity fault in many stages.

  20. A Combined Fault Diagnosis Method for Power Transformer in Big Data Environment

    Directory of Open Access Journals (Sweden)

    Yan Wang

    2017-01-01

    Full Text Available The fault diagnosis method based on dissolved gas analysis (DGA is of great significance to detect the potential faults of the transformer and improve the security of the power system. The DGA data of transformer in smart grid have the characteristics of large quantity, multiple types, and low value density. In view of DGA big data’s characteristics, the paper first proposes a new combined fault diagnosis method for transformer, in which a variety of fault diagnosis models are used to make a preliminary diagnosis, and then the support vector machine is used to make the second diagnosis. The method adopts the intelligent complementary and blending thought, which overcomes the shortcomings of single diagnosis model in transformer fault diagnosis, and improves the diagnostic accuracy and the scope of application of the model. Then, the training and deployment strategy of the combined diagnosis model is designed based on Storm and Spark platform, which provides a solution for the transformer fault diagnosis in big data environment.

  1. INVESTIGATION OF MICROPROCESSOR TRANSFORMER CURRENT PROTECTION IN SHORT CIRCUIT FAULT MODES

    Directory of Open Access Journals (Sweden)

    M. S. Loman

    2014-01-01

    Full Text Available The paper presents an investigation on transformer current protection with blocking against magnetizing inrush current in short circuit fault modes. It has been shown that the proposed magnetizing in-rush current blocking algorithm can be implemented in microprocessor current protections of transformers.

  2. Support Vector Machine for Discrimination Between Fault and Magnetizing Inrush Current in Power Transformer

    Directory of Open Access Journals (Sweden)

    V. Malathi

    2007-01-01

    Full Text Available This study presents a novel technique based on Support Vector Machine (SVM for the classification of transient phenomena in power transformer. The SVM is a powerful method for statistical classification of data. The input data to this SVM for training comprises fault current and magnetizing inrush current. SVM classifier produces significant accuracy for classification of transient phenomena in power transformer.

  3. Fault interaction and stresses along broad oceanic transform zone: Tjörnes Fracture Zone, north Iceland

    Science.gov (United States)

    Homberg, C.; Bergerat, F.; Angelier, J.; Garcia, S.

    2010-02-01

    Transform motion along oceanic transforms generally occurs along narrow faults zones. Another class of oceanic transforms exists where the plate boundary is quite large (˜100 km) and includes several subparallel faults. Using a 2-D numerical modeling, we simulate the slip distribution and the crustal stress field geometry within such broad oceanic transforms (BOTs). We examine the possible configurations and evolution of such BOTs, where the plate boundary includes one, two, or three faults. Our experiments show that at any time during the development of the plate boundary, the plate motion is not distributed along each of the plate boundary faults but mainly occurs along a single master fault. The finite width of a BOT results from slip transfer through time with locking of early faults, not from a permanent distribution of deformation over a wide area. Because of fault interaction, the stress field geometry within the BOTs is more complex than that along classical oceanic transforms and includes stress deflections close to but also away from the major faults. Application of this modeling to the 100 km wide Tjörnes Fracture Zone (TFZ) in North Iceland, a major BOT of the Mid-Atlantic Ridge that includes three main faults, suggests that the Dalvik Fault and the Husavik-Flatey Fault developed first, the Grismsey Fault being the latest active structure. Since initiation of the TFZ, the Husavik-Flatey Fault accommodated most of the plate motion and probably persists until now as the main plate structure.

  4. Implementation of Transformer Protection by Intelligent Electronic Device for Different Faults

    Directory of Open Access Journals (Sweden)

    Y V Aruna, Beena S

    2015-01-01

    Full Text Available Protection of power system equipments was traditionally done by using electromagnetic relay, static relays, and numerical relays. At present the microprocessor based relays are replacing the old Electromagnetic relays because of their high level accuracy and fast operation. RET670(Transformer protection relay , an IED (INTELLIGENT ELECTRONIC DEVICE provides fast and selective protection, monitoring, and control of all types of transformer. The configured IED is tested under different fault conditions simulated by using mobile test kit to ensure IED’s reliable operation on site. With preconfigured algorithms, the IED will automatically reconfigure the network in case of a fault, and a service restoration is carried out within milliseconds by giving trip signal to the corresponding Circuit breakers. On receiving the trip signal the circuit breaker operates providing quicker isolation of transformers under the fault condition. This enables to have a complete and an adequate protection to the specified power transformer.

  5. Induction motor rotor fault diagnosis method based on double PQ transformation

    Institute of Scientific and Technical Information of China (English)

    HUANG Jin; NIU Faliang; YANG Jiaqiang

    2007-01-01

    This Paper presents a new rotor fault diagnosis method for induction motors which is based on the double PQ transformation.We construct the PQ transformation matrix with the positive sequence fundamental voltage components and their Hilbert transformation as elements.The active power P and the reactive power Q are obtained through the PO transformation of the stator currents.As both P and Q are constant for a healthy motor,they are represented by a dot on the PQ plane.Whereas the P and Q for a rotor broken bar motor are represented by an ellipse because they comprise an additional frequency component 2sfs (s is the slip and js is the supply frequency).Thus,by distinguishing these two different patterns.the rotor broken bar fault is detected.We use the major radius of the ellipse as the fault indicator and the distance between the point of no-load condition and the center of the ellipse on the PQ plane as its normalization value.We thus arrive at the fault severity factor which is fairly independent of the load level and the inertia value of the induction motors.Experimental results have demonstrated that the proposed method is effective in identifying the rotor-broken-bars fault and at determining the severity of the fault.

  6. Transformer fault diagnosis based on chemical reaction optimization algorithm and relevance vector machine

    Directory of Open Access Journals (Sweden)

    Luo Wei

    2017-01-01

    Full Text Available Power transformer is one of the most important equipment in power system. In order to predict the potential fault of power transformer and identify the fault types correctly, we proposed a transformer fault intelligent diagnosis model based on chemical reaction optimization (CRO algorithm and relevance vector machine(RVM. RVM is a powerful machine learning method, which can solve nonlinear, high-dimensional classification problems with a limited number of samples. CRO algorithm has well global optimization and simple calculation, so it is suitable to solve parameter optimization problems. In this paper, firstly, a multi-layer RVM classification model was built by binary tree recognition strategy. Secondly, CRO algorithm was adopted to optimize the kernel function parameters which could enhance the performance of RVM classifiers. Compared with IEC three-ratio method and the RVM model, the CRO-RVM model not only overcomes the coding defect problem of IEC three-ratio method, but also has higher classification accuracy than the RVM model. Finally, the new method was applied to analyze a transformer fault case, Its predicted result accord well with the real situation. The research provides a practical method for transformer fault intelligent diagnosis and prediction.

  7. Modification of Duval Triangle for Diagnostic Transformer Fault through a Procedure of Dissolved Gases Analysis

    Directory of Open Access Journals (Sweden)

    Sobhy Serry Dessouky

    2016-08-01

        The evaluation is carried out on DGA data obtained from three different groups of transformers. A Matlab program was developed to automate the evaluation of  Duval Triangle graph to numerical modification, Also the fault gases can be generated due to oil decomposing effected by transformer over excitation which increasing thetransformer exciting current lead to rising the temperature inside transformer core beside the other causes.

  8. Thermal Constraints on the Rheology of Segmented Oceanic Transform Fault Systems

    Science.gov (United States)

    Wolfson-Schwehr, M. L.; Boettcher, M. S.; Behn, M. D.

    2012-12-01

    Mid-ocean ridge transform fault (RTF) systems may be comprised of two or more fault segments that are physically offset by an extensional basin or intra-transform spreading center. These intra-transform offsets affect the thermal structure underlying the transform fault and may act as barriers to rupture propagation. The seismogenic zone of RTFs is thermally controlled and limited by the 600°C isotherm, as evidenced by earthquake hypocentral depths and laboratory friction experiments. Observations from a recent ocean bottom seismic study found that RTF earthquakes rarely occur above ~2 km depth. These findings suggest that the seismogenic zone on RTFs likely extends from ~2 km to the 600°C isotherm. Here we utilize finite element analysis to model the thermal structure of a RTF system comprised of two transform fault segments separated by an extensional offset. The mantle is assumed to have a visco-plastic rheology to simulate brittle failure at temperatures bounded by areas of increased microseismicity, which act as barriers to large rupture propagation. Previously, we used well-located earthquakes recorded on a NOAA hydrophone array together with a relative relocation technique to determine the absolute positions for the five rupture patches on Discovery, which host 5.4 ≤ Mw ≤ 6.0 earthquakes. In this study, we combine absolute locations of the largest earthquakes, our detailed analysis of the fault trace of Discovery, and our thermal modeling results to assess how intra-transform offsets on Discovery affect the subsurface thermal structure. Along the 6 km intra-transform spreading center we find the 600°C isotherm is shallower than 2 km, suggesting that the thermal structure of this offset creates a rupture barrier between the adjoining fault segments. By contrast, intra-transform offsets surface trace of each segment only minimally affect the depth of the 600°C isotherm, resulting in a continuous seismogenic zone between the fault segments. This

  9. Current Limiting Performance of Three-Phase Concentric Transformer Type SFCL at Unbalanced Fault Conditions

    OpenAIRE

    Shirai, Yasuyuki; Noda, Syo; Yamabe, Kenta; Hattori, Keisuke; Baba, Jumpei; Nishihara, Taichi; Nitta, Tanzo; Kobayashi, Shinichi; Sato, Kenichi

    2013-01-01

    We have proposed a transformer type SFCL whose primary and secondary superconducting coils have rewound structure. The primary coil is connected to a power line. The secondary one is short-circuited and has fewer turns than the primary coil. For small fault current, only the secondary coil turns to normal state. Inductive component of impedance at the primary terminal mainly appears. For larger fault current, the primary coil also turns to normal state, resistive component additively appears....

  10. DETECTION OF INCIPIENT LOCALIZED GEAR FAULTS IN GEARBOX BY COMPLEX CONTINUOUS WAVELET TRANSFORM

    Institute of Scientific and Technical Information of China (English)

    Han Zhennan; Xiong Shibo; Li Jinbao

    2003-01-01

    As far as the vibration signal processing is concerned, composition of vibration signal resulting from incipient localized faults in gearbox is too weak to be detected by traditional detecting technology available now. The method, which includes two steps: vibration signal from gearbox is first processed by synchronous average sampling technique and then it is analyzed by complex continuous wavelet transform to diagnose gear fault, is introduced. Two different kinds of faults in the gearbox, i.e.shaft eccentricity and initial crack in tooth fillet, are detected and distinguished from each other successfully.

  11. Entropy-Based Bagging for Fault Prediction of Transformers Using Oil-Dissolved Gas Data

    Directory of Open Access Journals (Sweden)

    Weigen Chen

    2011-08-01

    Full Text Available The development of the smart grid has resulted in new requirements for fault prediction of power transformers. This paper presents an entropy-based Bagging (E-Bagging method for prediction of characteristic parameters related to power transformers faults. A parameter of comprehensive information entropy of sample data is brought forward to improve the resampling process of the E-Bagging method. The generalization ability of the E-Bagging is enhanced significantly by the comprehensive information entropy. A total of sets of 1200 oil-dissolved gas data of transformers are used as examples of fault prediction. The comparisons between the E-Bagging and the traditional Bagging and individual prediction approaches are presented. The results show that the E-Bagging possesses higher accuracy and greater stability of prediction than the traditional Bagging and individual prediction approaches.

  12. The influence of transformers, induction motors and fault resistance regarding propagation voltage sags

    Directory of Open Access Journals (Sweden)

    Jairo Blanco

    2011-07-01

    Full Text Available This article presents an analysis of voltage sag propagation. The ATPDraw tool was selected for simulating the IEEE 34 node test feeder. It takes into account both voltage sags caused by electrical fault network, as well as voltage sag propagation characteristics caused by induction motor starting and transformer energising. The analysis was aimed at assessing the influence of transformer winding connections, the impedance of these transformers, lines and cables, summarising the effects on disturbance magnitude and phase. The study shows that the influence of an induction motor on voltage sag propagation results in increased voltage sag severity. Voltage sags caused by induction motor starting and transformer energising have no zero-sequence component, so they are only affected by type 3 transformers. The influence of fault resistance on voltage sag magnitude and phase characteristics is examined and some aspects of interest in characterising these electromagnetic disturbances is identified.

  13. Distinctive diamagnetic fabrics in dolostones evolved at fault cores, the Dead Sea Transform

    Science.gov (United States)

    Braun, D.; Weinberger, R.; Eyal, Y.; Feinstein, S.; Harlavan, Y.; Levi, T.

    2015-08-01

    We resolve the anisotropy of magnetic susceptibility (AMS) axes along fault planes, cores and damage zones in rocks that crop out next to the Dead Sea Transform (DST) plate boundary. We measured 261 samples of mainly diamagnetic dolostones that were collected from 15 stations. To test the possible effect of the iron content on the AMS we analyzed the Fe concentrations of the samples in different rock phases. Dolostones with mean magnetic susceptibility value lower than -4 × 10-6 SI and iron content less than ∼1000 ppm are suitable for diamagnetic AMS-based strain analysis. The dolostones along fault planes display AMS fabrics that significantly deviate from the primary "sedimentary fabric". The characteristics of these fabrics include well-grouped, sub-horizontal, minimum principal AMS axes (k3) and sub-vertical magnetic foliations commonly defined by maximum and intermediate principal AMS axes (k1 and k2 axes, respectively). These fabrics are distinctive along fault planes located tens of kilometers apart, with strikes ranging between NNW-SSE and NNE-SSW and different senses of motion. The obtained magnetic foliations (k1-k2) are sub-parallel (within ∼20°) to the fault planes. Based on rock magnetic and geochemical analyses, we interpret the AMS fabrics as the product of both shape and crystallographic anisotropy of the dolostones. Preferred shape alignment evolves due to mechanical rotation of subordinate particles and rock fragments at the fault core. Preferred crystallographic orientation results from elevated frictional heating (>300 °C) during faulting, which enhances c-axes alignment in the cement-supported dolomite breccia due to crystal-plastic processes. The penetrative deformation within fault zones resulted from the local, fault-related strain field and does not reflect the regional strain field. The analyzed AMS fabrics together with fault-plane kinematics provide valuable information on faulting characteristics in the uppermost crust.

  14. Faults

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Through the study of faults and their effects, much can be learned about the size and recurrence intervals of earthquakes. Faults also teach us about crustal...

  15. Induced Voltages Ratio-Based Algorithm for Fault Detection, and Faulted Phase and Winding Identification of a Three-Winding Power Transformer

    Directory of Open Access Journals (Sweden)

    Byung Eun Lee

    2014-09-01

    Full Text Available This paper proposes an algorithm for fault detection, faulted phase and winding identification of a three-winding power transformer based on the induced voltages in the electrical power system. The ratio of the induced voltages of the primary-secondary, primary-tertiary and secondary-tertiary windings is the same as the corresponding turns ratio during normal operating conditions, magnetic inrush, and over-excitation. It differs from the turns ratio during an internal fault. For a single phase and a three-phase power transformer with wye-connected windings, the induced voltages of each pair of windings are estimated. For a three-phase power transformer with delta-connected windings, the induced voltage differences are estimated to use the line currents, because the delta winding currents are practically unavailable. Six detectors are suggested for fault detection. An additional three detectors and a rule for faulted phase and winding identification are presented as well. The proposed algorithm can not only detect an internal fault, but also identify the faulted phase and winding of a three-winding power transformer. The various test results with Electromagnetic Transients Program (EMTP-generated data show that the proposed algorithm successfully discriminates internal faults from normal operating conditions including magnetic inrush and over-excitation. This paper concludes by implementing the algorithm into a prototype relay based on a digital signal processor.

  16. Scaling Relations for the Thermal Structure of Segmented Oceanic Transform Faults

    Science.gov (United States)

    Wolfson-Schwehr, M.; Boettcher, M. S.; Behn, M. D.

    2015-12-01

    Mid-ocean ridge-transform faults (RTFs) are a natural laboratory for studying strike-slip earthquake behavior due to their relatively simple geometry, well-constrained slip rates, and quasi-periodic seismic cycles. However, deficiencies in our understanding of the limited size of the largest RTF earthquakes are due, in part, to not considering the effect of short intra-transform spreading centers (ITSCs) on fault thermal structure. We use COMSOL Multiphysics to run a series of 3D finite element simulations of segmented RTFs with visco-plastic rheology. The models test a range of RTF segment lengths (L = 10-150 km), ITSC offset lengths (O = 1-30 km), and spreading rates (V = 2-14 cm/yr). The lithosphere and upper mantle are approximated as steady-state, incompressible flow. Coulomb failure incorporates brittle processes in the lithosphere, and a temperature-dependent flow law for dislocation creep of olivine activates ductile deformation in the mantle. ITSC offsets as small as 2 km affect the thermal structure underlying many segmented RTFs, reducing the area above the 600˚C isotherm, A600, and thus the size of the largest expected earthquakes, Mc. We develop a scaling relation for the critical ITSC offset length, OC, which significantly reduces the thermal affect of adjacent fault segments of length L1 and L2. OC is defined as the ITSC offset that results in an area loss ratio of R = (Aunbroken - Acombined)/Aunbroken - Adecoupled) = 63%, where Aunbroken = C600(L1+L2)1.5V-0.6 is A600 for an RTF of length L1 + L2; Adecoupled = C600(L11.5+L21.5)V-0.6 is the combined A600 of RTFs of lengths L1 and L2, respectively; and Acombined = Aunbroken exp(-O/ OC) + Adecoupled (1-exp(-O/ OC)). C600 is a constant. We use OC and kinematic fault parameters (L1, L2, O, and V) to develop a scaling relation for the approximate seismogenic area, Aseg, for each segment of a RTF system composed of two fault segments. Finally, we estimate the size of Mc on a fault segment based on Aseg. We

  17. A Fault Feature Extraction Method for Rolling Bearing Based on Pulse Adaptive Time-Frequency Transform

    Directory of Open Access Journals (Sweden)

    Jinbao Yao

    2016-01-01

    Full Text Available Shock pulse method is a widely used technique for condition monitoring of rolling bearing. However, it may cause erroneous diagnosis in the presence of strong background noise or other shock sources. Aiming at overcoming the shortcoming, a pulse adaptive time-frequency transform method is proposed to extract the fault features of the damaged rolling bearing. The method arranges the rolling bearing shock pulses extracted by shock pulse method in the order of time and takes the reciprocal of the time interval between the pulse at any moment and the other pulse as all instantaneous frequency components in the moment. And then it visually displays the changing rule of each instantaneous frequency after plane transformation of the instantaneous frequency components, realizes the time-frequency transform of shock pulse sequence through time-frequency domain amplitude relevancy processing, and highlights the fault feature frequencies by effective instantaneous frequency extraction, so as to extract the fault features of the damaged rolling bearing. The results of simulation and application show that the proposed method can suppress the noises well, highlight the fault feature frequencies, and avoid erroneous diagnosis, so it is an effective fault feature extraction method for the rolling bearing with high time-frequency resolution.

  18. Power transformer fault diagnosis model based on rough set theory with fuzzy representation

    Institute of Scientific and Technical Information of China (English)

    Li Minghua; Dong Ming; Yan Zhang

    2007-01-01

    Objective Due to the incompleteness and complexity of fault diagnosis for power transformers, a comprehensive rough-fuzzy scheme for solving fault diagnosis problems is presented. Fuzzy set theory is used both for representation of incipient faults' indications and producing a fuzzy granulation of the feature space. Rough set theory is used to obtain dependency rules that model indicative regions in the granulated feature space. The fuzzy membership functions corresponding to the indicative regions, modelled by rules, are stored as cases. Results Diagnostic conclusions are made using a similarity measure based on these membership functions. Each case involves only a reduced number of relevant features making this scheme suitable for fault diagnosis. Conclusion Superiority of this method in terms of classification accuracy and case generation is demonstrated.

  19. Recurrence Behaviors of Earthquakes along the Kefallinia Transform Fault, Ionian Sea, Greece

    Institute of Scientific and Technical Information of China (English)

    Qi Cheng; Athanassios Ganas; Huang Fuqiong; Chen Yong; George Drakato

    2007-01-01

    We examined the whole strong earthquake recurrence behaviors of two fault zones along the Kefallinia Transform, Ionian Sea, Greece, using seismological data and statistical methods.Our data include 29 events with M > 5.5 for the period 1636 ~ 2003. We found different recurrence behaviors for the Kefallinia Fault Zone (clustering and time-predictable recurrence behaviors) and the Lefkada Fault Zone (near random and non-slip-predictable or non-timepredictable recurrence nature). The different modes may be attributed to: (a) segment interaction along-strike (Kefallinia) by static triggering and (b) the influence of fault systems to the north and east on the recurrence on Lefkada. Within the active periods, earthquake recurrence intervals are distributed in a more dispersed fashion, and can be fitted well by a Weibull distribution. In contrast, the distribution of the quiet periods is relatively less dispersed and difficult to describe by suitable probability functions.

  20. Detection and classification of winding faults in windmill generators using Wavelet Transform and ANN

    Energy Technology Data Exchange (ETDEWEB)

    Gketsis, Zacharias E.; Zervakis, Michalis E.; Stavrakakis, George [Department of Electronics and Computer Engineering, Technical University of Crete, Chania 73100 (Greece)

    2009-11-15

    This paper exploits the Wavelet Transform (WT) analysis along with Artificial Neural Networks (ANN) for the diagnosis of electrical machines winding faults. A novel application is presented exploring the problem of automatically identifying short circuits of windings, which often appear during machine manufacturing and operation. Such faults are usually resulting from electrodynamics forces generated during the flow of large short circuit currents, as well as forces occurring when the machines are transported. The early detection and classification of winding failures is of particular importance, as these kinds of defects can lead to winding damage due to overheating, imbalance, etc. Application results and investigations of windmill generator winding turn-to-turn faults between adjacent winding wires are presented. The ANN approach is proven effective in detecting and classifying faults based on WT features extracted from high frequency measurements of the admittance, current, or voltage responses. (author)

  1. Earthquake cycle on a transform fault in the Gulf of California, Mexico.

    Science.gov (United States)

    Malservisi, Rocco; Hackl, Matthias; Plattner, Christina; Suarez Vidal, Francisco; Gonzales Garcia, Javier; Amelung, Falk

    2010-05-01

    South of the San Andreas Fault system, ~90% of the North America/Pacific plate motion is accommodated along the Gulf of California. Here the plate boundary deformation is partitioned in deep basins formation, often resulting in production of new oceanic crust, connected by long transform faults. In the central part of the Gulf, one of these transform faults, the Ballenas fault, is localized in the Canal de Ballenas, a ~30 km wide channel between Isla Angel de la Garda and mainland Baja California in an area where full oceanic crust is still not generated. The presence of land on both the sides of this "quasi marine" transform fault give the unique opportunity to perform geodetic studies across its trace. On August 3rd 2009, a series of seismic strike slip events (including a M6.9) happened along this segment of plate boundary allowing a combined study of co- and inter-seismic deformation. Here we present the results from 5 years of EGPS along a transect perpendicular to the plate motion direction at approximately 29 degrees North. These surveys include at least 3 occupations before the seismic event and at least 2 occupations after the earthquake. The analysis of the inter-seismic data shows that ~46 mm/yr of relative motion is accommodated within the Canal de Ballenas. Co-seismic data show displacements up to 25 cm on the two sites closest to the event and a pattern compatible with the finite fault model computed by USGS (although the USGS location of the hypocenter is probably 100 km too much to the East). The geodetically estimated fault location is also compatible with multibeam bathymetry. The data collected after the earthquake show also the possibility to identify postseismic displacement from the campaign data. They also show the possibility that the postseismic behavior of the "marine" side is different from the one of the on land side.

  2. Fault Diagnosis in Transformer Based on Weighted Degree of Grey Slope Incidence of Optimized Entropy

    Directory of Open Access Journals (Sweden)

    Zhang Anping

    2016-01-01

    Full Text Available Dissolved gas analysis (DGA is an important method to find the hidden or incipient insulation faults of oil-immersed power transformer. However, code deficiency exists in the gas ratio methods specified by the IEC standard and complexity of fault diagnosis for power transformer. Hence a new model based on optimized weighted degree of grey slope incidence was put forward. Firstly, the entropy weight is used to determine objective weight of indices; then the model fault types are obtained by weighted degree of grey slope incidence. The combination of entropy weight with grey slope incidence analysis can fully utilize over all information of DGA and give full play to the superiority of grey slope incidence, which overcomes shortcomings of original grey slope incidence analysis. The experimental results also demonstrate that the improved method has higher accuracy compared with three-ratio method and general grey slope incidence analysis method. The diagnosis accuracy is 92.8%.

  3. EXPERIMENTAL INVESTIGATION FOR FAULT DI AGNOSIS BASED ON FFT AND WAVELET TRANSFORM

    Directory of Open Access Journals (Sweden)

    MIHAIL PRICOP

    2016-06-01

    Full Text Available Belts are components of the mechanical systems of rotation commonly used for mechanical power transmission and changes in rotational speeds in the shafts. Various failures of the drive belts (foot shear, tooth wear, hollowed teeth, back cracks are common in rotating machines and can cause economic losses. To increase efficiency, reliability and safety of the machines the use of new fault diagnosis techniques of belts, identification and classification is required. In this paper Fast Fourier Transform (FFT and Wavelet transform complementary methods are used for fault monitoring of drive belts, analyzing in this way the limitations and advantages of using these methods. Experimental investigations for the fault diagnosis of drive belts are made using experimental platform and Bruel & Kjaer equipment for measuring vibration and PULSE and MATLAB software for recorded signal processing. The results were analyzed and presented.

  4. Intelligent Fault Diagnosis in Power Transformer with Using Dissolved Gas Analysis in different Standards by Fuzzy Logic

    Directory of Open Access Journals (Sweden)

    Rahmat Houshmand

    2007-09-01

    Full Text Available The power electric transformer fault diagnosis is based on dissolved gas-in-oil analysis (DGA. the conventional fault diagnosis methods, i.e. the ratio methods (Rogers, Dornenburg and IEC and the key gas method, have limitations such as the “no decision” problem. Various artificial intelligence techniques may help solve the problems and present a better solution. In this paper present a fuzzy systems to fault diagnosis in power electric transformer by dissolved we gas analysis.

  5. Transforming incomplete fault tree to Ishikawa diagram as an alternative method for technology transfer

    Science.gov (United States)

    Batzias, Dimitris F.

    2012-12-01

    Fault Tree Analysis (FTA) can be used for technology transfer when the relevant problem (called 'top even' in FTA) is solved in a technology centre and the results are diffused to interested parties (usually Small Medium Enterprises - SMEs) that have not the proper equipment and the required know-how to solve the problem by their own. Nevertheless, there is a significant drawback in this procedure: the information usually provided by the SMEs to the technology centre, about production conditions and corresponding quality characteristics of the product, and (sometimes) the relevant expertise in the Knowledge Base of this centre may be inadequate to form a complete fault tree. Since such cases are quite frequent in practice, we have developed a methodology for transforming incomplete fault tree to Ishikawa diagram, which is more flexible and less strict in establishing causal chains, because it uses a surface phenomenological level with a limited number of categories of faults. On the other hand, such an Ishikawa diagram can be extended to simulate a fault tree as relevant knowledge increases. An implementation of this transformation, referring to anodization of aluminium, is presented.

  6. Distinctive Features of Faults for Use in Power Transformer Differential Protection

    Directory of Open Access Journals (Sweden)

    Glazyrin V.E.

    2017-04-01

    Full Text Available The aim of the work is to study the change in instantaneous values of the differential current in power transformer differential protection circuits under conditions of magnetizing inrush when the unloaded transformer is energized and under conditions of a fault within the protection zone. Saturation of measuring current transformers during the transient process leads to distortion of signals in their secondary windings, which can cause a long delay in the disconnection of the protected object and the development of an accident in the power system if traditional protective algorithms are used. Taking into account the peculiarities of the change in the instantaneous values of the differential current while developing the protection algorithm makes it possible to recognize faults with maximum speed before the moment of the first saturation of electromagnetic current transformers and thus avoid a delay in the operation of the protection. For quick and correct recognition of a fault within the protection zone authors proposed to monitor the maximum value of the derivative of the differential current and the duration of its monotonous change from the moment of the onset of the transient process. This is because the monitored parameters in the emergency and normal operation of the power transformer can vary significantly. Application of traditional protection algorithms together with proposed methods allows increasing the speed of differential protection response in different operation modes of the power system. Mathematical simulation has been used to study the magnetizing inrush and short circuits within the protection zone.

  7. Gravity field over the Sea of Galilee: Evidence for a composite basin along a transform fault

    Science.gov (United States)

    Ben-Avraham, Zvi; ten Brink, Uri; Bell, Robin; Reznikov, Margaret

    1996-01-01

    The Sea of Galilee (Lake Kinneret) is located at the northern portion of the Kinneret-Bet Shean basin, in the northern Dead Sea transform. Three hundred kilometers of continuous marine gravity data were collected in the lake and integrated with land gravity data to a distance of more than 20 km around the lake. Analyses of the gravity data resulted in a free-air anomaly map, a variable density Bouguer anomaly map, and a horizontal first derivative map of the Bouguer anomaly. These maps, together with gravity models of profiles across the lake and the area south of it, were used to infer the geometry of the basins in this region and the main faults of the transform system. The Sea of Galilee can be divided into two units. The southern half is a pull-apart that extends to the Kinarot Valley, south of the lake, whereas the northern half was formed by rotational opening and transverse normal faults. The deepest part of the basinal area is located well south of the deepest bathymetric depression. This implies that the northeastern part of the lake, where the bathymetry is the deepest, is a young feature that is actively subsiding now. The pull-apart basin is almost symmetrical in the southern part of the lake and in the Kinarot Valley south of the lake. This suggests that the basin here is bounded by strike-slip faults on both sides. The eastern boundary fault extends to the northern part of the lake, while the western fault does not cross the northern part. The main factor controlling the structural complexity of this area is the interaction of the Dead Sea transform with a subperpendicular fault system and rotated blocks.

  8. Automatic fault feature extraction of mechanical anomaly on induction motor bearing using ensemble super-wavelet transform

    Science.gov (United States)

    He, Wangpeng; Zi, Yanyang; Chen, Binqiang; Wu, Feng; He, Zhengjia

    2015-03-01

    Mechanical anomaly is a major failure type of induction motor. It is of great value to detect the resulting fault feature automatically. In this paper, an ensemble super-wavelet transform (ESW) is proposed for investigating vibration features of motor bearing faults. The ESW is put forward based on the combination of tunable Q-factor wavelet transform (TQWT) and Hilbert transform such that fault feature adaptability is enabled. Within ESW, a parametric optimization is performed on the measured signal to obtain a quality TQWT basis that best demonstrate the hidden fault feature. TQWT is introduced as it provides a vast wavelet dictionary with time-frequency localization ability. The parametric optimization is guided according to the maximization of fault feature ratio, which is a new quantitative measure of periodic fault signatures. The fault feature ratio is derived from the digital Hilbert demodulation analysis with an insightful quantitative interpretation. The output of ESW on the measured signal is a selected wavelet scale with indicated fault features. It is verified via numerical simulations that ESW can match the oscillatory behavior of signals without artificially specified. The proposed method is applied to two engineering cases, signals of which were collected from wind turbine and steel temper mill, to verify its effectiveness. The processed results demonstrate that the proposed method is more effective in extracting weak fault features of induction motor bearings compared with Fourier transform, direct Hilbert envelope spectrum, different wavelet transforms and spectral kurtosis.

  9. Feature Extraction Using Discrete Wavelet Transform for Gear Fault Diagnosis of Wind Turbine Gearbox

    Directory of Open Access Journals (Sweden)

    Rusmir Bajric

    2016-01-01

    Full Text Available Vibration diagnosis is one of the most common techniques in condition evaluation of wind turbine equipped with gearbox. On the other side, gearbox is one of the key components of wind turbine drivetrain. Due to the stochastic operation of wind turbines, the gearbox shaft rotating speed changes with high percentage, which limits the application of traditional vibration signal processing techniques, such as fast Fourier transform. This paper investigates a new approach for wind turbine high speed shaft gear fault diagnosis using discrete wavelet transform and time synchronous averaging. First, the vibration signals are decomposed into a series of subbands signals with the use of a multiresolution analytical property of the discrete wavelet transform. Then, 22 condition indicators are extracted from the TSA signal, residual signal, and difference signal. Through the case study analysis, a new approach reveals the most relevant condition indicators based on vibrations that can be used for high speed shaft gear spalling fault diagnosis and their tracking abilities for fault degradation progression. It is also shown that the proposed approach enhances the gearbox fault diagnosis ability in wind turbines. The approach presented in this paper was programmed in Matlab environment using data acquired on a 2 MW wind turbine.

  10. Application of Wavelets Transform to Fault Detection in Rotorcraft UAV Sensor Failure

    Institute of Scientific and Technical Information of China (English)

    Jun-tong Qi; Jian-da Han

    2007-01-01

    This paper describes a novel wavelet-based approach to the detection of abrupt fault of Rotorcraft Unmanned Aerial Vehicle (RUAV) sensor system. By use of wavelet transforms that accurately localize the characteristics of a signal both in the time and frequency domains, the occurring instants of abnormal status of a sensor in the output signal can be identified by the multi-scale representation of the signal. Once the instants are detected, the distribution differences of the signal energy on all decomposed wavelet scales of the signal before and after the instants are used to claim and classify the sensor faults.

  11. A novel algorithm for discrimination between inrush current and internal faults in power transformer differential protection based on discrete wavelet transform

    Energy Technology Data Exchange (ETDEWEB)

    Eldin, A.A. Hossam; Refaey, M.A. [Electrical Engineering Department, Alexandria University, Alexandria (Egypt)

    2011-01-15

    This paper proposes a novel methodology for transformer differential protection, based on wave shape recognition of the discriminating criterion extracted of the instantaneous differential currents. Discrete wavelet transform has been applied to the differential currents due to internal fault and inrush currents. The diagnosis criterion is based on median absolute deviation (MAD) of wavelet coefficients over a specified frequency band. The proposed algorithm is examined using various simulated inrush and internal fault current cases on a power transformer that has been modeled using electromagnetic transients program EMTDC software. Results of evaluation study show that, proposed wavelet based differential protection scheme can discriminate internal faults from inrush currents. (author)

  12. Fault diagnostics in power transformer model winding for different alpha values

    Directory of Open Access Journals (Sweden)

    G.H. Kusumadevi

    2015-09-01

    Full Text Available Transient overvoltages appearing at line terminal of power transformer HV windings can cause failure of winding insulation. The failure can be from winding to ground or between turns or sections of winding. In most of the cases, failure from winding to ground can be detected by changes in the wave shape of surge voltage appearing at line terminal. However, detection of insulation failure between turns may be difficult due to intricacies involved in identifications of faults. In this paper, simulation investigations carried out on a power transformer model winding for identifying faults between turns of winding has been reported. The power transformer HV winding has been represented by 8 sections, 16 sections and 24 sections. Neutral current waveform has been analyzed for same model winding represented by different number of sections. The values of α (‘α’ value is the square root of total ground capacitance to total series capacitance of winding considered for windings are 5, 10 and 20. Standard lightning impulse voltage (1.2/50 μs wave shape have been considered for analysis. Computer simulations have been carried out using software PSPICE version 10.0. Neutral current and frequency response analysis methods have been used for identification of faults within sections of transformer model winding.

  13. Discrimination of Inrush Currents from Faults Current in Power Transformers using Gravitational Search Algorithm (GSA

    Directory of Open Access Journals (Sweden)

    Mohamad Kazem Daryabari

    2011-01-01

    Full Text Available The magnetizing inrush current phenomenon is a large transient condition, which occurs when a transformer is energized. The inrush current magnitude may be as high as ten times of transformer rated current that causes mal-operation of protection systems. Indeed, the similarity between signatures of Inrush current and internal fault condition make this failure. So, for safe running of a transformer, it is necessary to distinguish inrush current from fault currents. In this project, an Artificial Neural Network (ANN which is trained by two different swarm based algorithms; Gravitational Search Algorithm (GSA and Particle Swarm Optimization (PSO have been used to discriminate inrush current from fault currents in power transformers. GSA works based on gravity laws and in opposite of other swarm based algorithms, particles have identity and PSO is based on behaviors of bird flocking. Proposed approach has two general stages, in first step, obtained data from simulation have been processed and applied to ANN, and then in step two, using training data considered ANN has been trained by GSA & PSO. Proposed method has been compared with one of the common training approach which is called Back Propagation (BP and Results show that proposed method is so quick and can do discrimination very accurate.

  14. Is the Troodos ophiolite (Cyprus) a complete, transform fault-bounded Neotethyan ridge segment?

    Science.gov (United States)

    Morris, Antony; Maffione, Marco

    2016-04-01

    We report new paleomagnetic data from the sheeted dike complex of the Troodos ophiolite (Cyprus) that indicate a hitherto unrecognized oceanic transform fault system marks its northern limit. The style, magnitude and scale of upper crustal fault block rotations in the northwestern Troodos region mirror those observed adjacent to the well-known Southern Troodos Transform Fault Zone along the southern edge of the ophiolite. A pattern of increasing clockwise rotation toward the north, coupled with consistent original dike strikes and inclined net rotation axes across this region, is compatible with distributed deformation adjacent to a dextrally-slipping transform system with a principal displacement zone just to the north of the exposed ophiolite. Combined with existing constraints on the spreading fabric, this implies segmentation of the Troodos ridge system on length scales of ~40 km, and suggests that a coherent strip of Neotethyan lithosphere, bounded by transforms and containing a complete ridge segment, has been uplifted to form the currently exposed Troodos ophiolite. Moreover, the inferred length scale of the ridge segment is consistent with formation at a slow-spreading rate during Tethyan seafloor spreading and with a supra-subduction zone environment, as indicated by geochemical constraints.

  15. Analysis and Simulation of Fault Characteristics of Power Switch Failures in Distribution Electronic Power Transformers

    Directory of Open Access Journals (Sweden)

    Dan Wang

    2013-08-01

    Full Text Available This paper presents research on the voltage and current distortion in the input stage, isolation stage and output stage of Distribution Electronic Power transformer (D-EPT after the open-circuit and short-circuit faults of its power switches. In this paper, the operational principles and the control methods for input stage, isolation stage and output stage of D-EPT, which work as a cascaded H-bridge rectifier, DC-DC converter and inverter, respectively, are introduced. Based on conclusions derived from the performance analysis of D-EPT after the faults, this paper comes up with the effects from its topology design and control scheme on the current and voltage distortion. According to the EPT fault characteristics, since the waveforms of relevant components heavily depend on the location of the faulty switch, it is very easy to locate the exact position of the faulty switch. Finally, the fault characteristics peculiar to D-EPT are analyzed, and further discussed with simulation on the Saber platform, as well as a fault location diagnosis algorithm.

  16. Fast Fourier and discrete wavelet transforms applied to sensorless vector control induction motor for rotor bar faults diagnosis.

    Science.gov (United States)

    Talhaoui, Hicham; Menacer, Arezki; Kessal, Abdelhalim; Kechida, Ridha

    2014-09-01

    This paper presents new techniques to evaluate faults in case of broken rotor bars of induction motors. Procedures are applied with closed-loop control. Electrical and mechanical variables are treated using fast Fourier transform (FFT), and discrete wavelet transform (DWT) at start-up and steady state. The wavelet transform has proven to be an excellent mathematical tool for the detection of the faults particularly broken rotor bars type. As a performance, DWT can provide a local representation of the non-stationary current signals for the healthy machine and with fault. For sensorless control, a Luenberger observer is applied; the estimation rotor speed is analyzed; the effect of the faults in the speed pulsation is compensated; a quadratic current appears and used for fault detection.

  17. A Novel Association Rule Mining with IEC Ratio Based Dissolved Gas Analysis for Fault Diagnosis of Power Transformers

    Directory of Open Access Journals (Sweden)

    Ms. Kanika Shrivastava

    2012-06-01

    Full Text Available Dissolved gas Analysis (DGA is the most importantcomponent of finding fault in large oil filledtransformers. Early detection of incipient faults intransformers reduces costly unplanned outages. Themost sensitive and reliable technique for evaluatingthe core of transformer is dissolved gas analysis. Inthis paper we evaluate different transformercondition on different cases. This paper usesdissolved gas analysis to study the history ofdifferent transformers in service, from whichdissolved combustible gases (DCG in oil are usedas a diagnostic tool for evaluating the condition ofthe transformer. Oil quality and dissolved gassestests are comparatively used for this purpose. In thispaper we present a novel approach which is basedon association rule mining and IEC ratio method.By using data mining concept we can categorizefaults based on single and multiple associations andalso map the percentage of fault. This is an efficientapproach for fault diagnosis of power transformerswhere we can find the fault in all obviousconditions. We use java for programming andcomparative study.

  18. A fault location method using Lamb waves and discrete wavelet transform

    OpenAIRE

    Souza, Pablo Rodrigo de; Nobrega, Eurípedes Guilherme de Oliveira

    2012-01-01

    Non-destructive evaluation methods and signal process techniques are important steps in structural health monitoring systems to assess the structure integrity. This paper presents a method for fault location in aluminum beams based on time of flight of Lamb waves. The dynamic response signal captured from the structure was processed using the discrete wavelet transform. The information accuracy obtained from the processed signal depends on the correct choice of the mother wavelet. The best mo...

  19. [Application of optimized parameters SVM based on photoacoustic spectroscopy method in fault diagnosis of power transformer].

    Science.gov (United States)

    Zhang, Yu-xin; Cheng, Zhi-feng; Xu, Zheng-ping; Bai, Jing

    2015-01-01

    In order to solve the problems such as complex operation, consumption for the carrier gas and long test period in traditional power transformer fault diagnosis approach based on dissolved gas analysis (DGA), this paper proposes a new method which is detecting 5 types of characteristic gas content in transformer oil such as CH4, C2H2, C2H4, C2H6 and H2 based on photoacoustic Spectroscopy and C2H2/C2H4, CH4/H2, C2H4/C2H6 three-ratios data are calculated. The support vector machine model was constructed using cross validation method under five support vector machine functions and four kernel functions, heuristic algorithms were used in parameter optimization for penalty factor c and g, which to establish the best SVM model for the highest fault diagnosis accuracy and the fast computing speed. Particles swarm optimization and genetic algorithm two types of heuristic algorithms were comparative studied in this paper for accuracy and speed in optimization. The simulation result shows that SVM model composed of C-SVC, RBF kernel functions and genetic algorithm obtain 97. 5% accuracy in test sample set and 98. 333 3% accuracy in train sample set, and genetic algorithm was about two times faster than particles swarm optimization in computing speed. The methods described in this paper has many advantages such as simple operation, non-contact measurement, no consumption for the carrier gas, long test period, high stability and sensitivity, the result shows that the methods described in this paper can instead of the traditional transformer fault diagnosis by gas chromatography and meets the actual project needs in transformer fault diagnosis.

  20. Power Transformer Partial Discharge Fault Diagnosis Based on Multidimensional Feature Region

    Directory of Open Access Journals (Sweden)

    Rong Jia

    2016-01-01

    Full Text Available Effectively extracting power transformer partial discharge (PD signals feature is of great significance for monitoring power transformer insulation condition. However, there has been lack of practical and effective extraction methods. For this reason, this paper suggests a novel method for the PD signal feature extraction based on multidimensional feature region. Firstly, in order to better describe differences in each frequency band of fault signals, empirical mode decomposition (EMD and Hilbert-Huang transform (HHT band-pass filter wave for raw signal is carried out. And the component of raw signals on each frequency band can be obtained. Secondly, the sample entropy value and the energy value of each frequency band component are calculated. Using the difference of each frequency band energy and complexity, signals feature region is established by the multidimensional energy parameters and the multidimensional sample entropy parameters to describe PD signals multidimensional feature information. Finally, partial discharge faults are classified by sphere-structured support vector machines algorithm. The result indicates that this method is able to identify and classify different partial discharge faults.

  1. Current limiting behavior in three-phase transformer-type SFCLs using an iron core according to variety of fault

    Science.gov (United States)

    Cho, Yong-Sun; Jung, Byung-Ik; Ha, Kyoung-Hun; Choi, Soo-Geun; Park, Hyoung-Min; Choi, Hyo-Sang

    To apply the superconducting fault current limiter (SFCL) to the power system, the reliability of the fault-current-limiting operation must be ensured in diverse fault conditions. The SFCL must also be linked to the operation of the high-speed recloser in the power system. In this study, a three-phase transformer-type SFCL, which has a neutral line to improve the simultaneous quench characteristics of superconducting elements, was manufactured to analyze the fault-current-limiting characteristic according to the single, double, and triple line-to-ground faults. The transformer-type SFCL, wherein three-phase windings are connected to one iron core, reduced the burden on the superconducting element as the superconducting element on the sound phase was also quenched in the case of the single line-to-ground fault. In the case of double or triple line-to-ground faults, the flux from the faulted phase winding was interlinked with other faulted or sound phase windings, and the fault-current-limiting rate decreased because the windings of three phases were inductively connected by one iron core.

  2. A New Method for Recognition of Arcing Faults in Transmission Lines using Wavelet Transform and Correlation Coefficient

    Directory of Open Access Journals (Sweden)

    Navid Ghaffarzadeh

    2013-03-01

    Full Text Available In this paper a novel method based on discrete wavelet transform and correlation coefficient is presented for distinguishing between arcing and permanent faults. The algorithm includes offline and online processing. In the offline, discrete wavelet transform is used to decompose typical faulted phase voltage waveforms during arcing faults. An index is then defined and computed. The index is based on the normalised energy of detail coefficients at resolution levels 1 to 14. The online processing consists of capturing the faulted phase voltage waveform using a 20 kHz sampling rate, and decomposing it by db4. Finally, arcing faults are distinguished from permanent faults based on correlation coefficient of the computed index of the pre-stored typical arcing faults and a recorded indistinct signal. The effectiveness of the approach has been tested for numerous arcing and permanent fault conditions on a transmission line using the Electromagnetic transient Program (EMTP software tool. The simulation results show the capability of the proposed method in distinguishing between arcing faults from permanent faults.

  3. A Novel Association Rule Mining with IEC Ratio Based Dissolved Gas Analysis for Fault Diagnosis of Power Transformers

    Directory of Open Access Journals (Sweden)

    Kanika Shrivastava

    2012-06-01

    Full Text Available Dissolved gas Analysis (DGA is the most important component of finding fault in large oil filled transformers. Early detection of incipient faults in transformers reduces costly unplanned outages. The most sensitive and reliable technique for evaluating the core of transformer is dissolved gas analysis. In this paper we evaluate different transformer condition on different cases. This paper uses dissolved gas analysis to study the history of different transformers in service, from which dissolved combustible gases (DCG in oil are used as a diagnostic tool for evaluating the condition of the transformer. Oil quality and dissolved gasses tests are comparatively used for this purpose. In this paper we present a novel approach which is based on association rule mining and IEC ratio method. By using data mining concept we can categorize faults based on single and multiple associations and also map the percentage of fault. This is an efficient approach for fault diagnosis of power transformers where we can find the fault in all obvious conditions. We use java for programming and comparative study.

  4. A Poisson-Fault Model for Testing Power Transformers in Service

    Directory of Open Access Journals (Sweden)

    Dengfu Zhao

    2014-01-01

    Full Text Available This paper presents a method for assessing the instant failure rate of a power transformer under different working conditions. The method can be applied to a dataset of a power transformer under periodic inspections and maintenance. We use a Poisson-fault model to describe failures of a power transformer. When investigating a Bayes estimate of the instant failure rate under the model, we find that complexities of a classical method and a Monte Carlo simulation are unacceptable. Through establishing a new filtered estimate of Poisson process observations, we propose a quick algorithm of the Bayes estimate of the instant failure rate. The proposed algorithm is tested by simulation datasets of a power transformer. For these datasets, the proposed estimators of parameters of the model have better performance than other estimators. The simulation results reveal the suggested algorithms are quickest among three candidates.

  5. Incipient fault diagnosis of power transformers using optical spectro-photometric technique

    Science.gov (United States)

    Hussain, K.; Karmakar, Subrata

    2015-06-01

    Power transformers are the vital equipment in the network of power generation, transmission and distribution. Mineral oil in oil-filled transformers plays very important role as far as electrical insulation for the winding and cooling of the transformer is concerned. As transformers are always under the influence of electrical and thermal stresses, incipient faults like partial discharge, sparking and arcing take place. As a result, mineral oil deteriorates there by premature failure of the transformer occurs causing huge losses in terms of revenue and assets. Therefore, the transformer health condition has to be monitored continuously. The Dissolved Gas Analysis (DGA) is being extensively used for this purpose, but it has some drawbacks like it needs carrier gas, regular instrument calibration, etc. To overcome these drawbacks, Ultraviolet (UV) -Visible and Fourier Transform Infrared (FTIR) Spectro-photometric techniques are used as diagnostic tools for investigating the degraded transformer oil affected by electrical, mechanical and thermal stresses. The technique has several advantages over the conventional DGA technique.

  6. Global rates of mantle serpentinization and H2 release at oceanic transform faults

    Science.gov (United States)

    Ruepke, Lars; Hasenclever, Joerg

    2017-04-01

    The cycling of seawater through the ocean floor is the dominant mechanism of biogeochemical exchange between the solid earth and the global ocean. Crustal fluid flow appears to be typically associated with major seafloor structures, and oceanic transform faults (OTF) are one of the most striking yet poorly understood features of the global mid-ocean ridge systems. Fracture zones and transform faults have long been hypothesized to be sites of substantial biogeochemical exchange between the solid Earth and the global ocean. This is particularly interesting with regard to the ocean biome. Deep ocean ecosystems constitute 60% of it but their role in global ocean biogeochemical cycles is much overlooked. There is growing evidence that life is supported by chemosynthesis at hydrothermal vents but also in the crust, and therefore this may be a more abundant process than previously thought. In this context, the serpentine forming interaction between seawater and cold lithospheric mantle rocks is particularly interesting as it is also a mechanism of abiotic hydrogen and methane formation. Interestingly, a quantitative global assessment of mantle serpentinization at oceanic transform faults in the context of the biogeochemical exchange between the seafloor and the global ocean is still largely missing. Here we present the results of a set of 3-D thermo-mechanical model calculations that investigate mantle serpentinization at OTFs for the entire range of globally observed slip rates and fault lengths. These visco-plastic models predict the OTF thermal structure and the location of crustal-scale brittle deformation, which is a prerequisite for mantle serpentinization to occur. The results of these simulations are integrated with information on the global distribution of OTF lengths and slip rates yielding global estimates on mantle serpentinization and associated H2 release. We find that OTFs are potentially sites of intense crustal fluid flow and are in terms of H2 release

  7. Sub-module Short Circuit Fault Diagnosis in Modular Multilevel Converter Based on Wavelet Transform and Adaptive Neuro Fuzzy Inference System

    DEFF Research Database (Denmark)

    Liu, Hui; Loh, Poh Chiang; Blaabjerg, Frede

    2015-01-01

    for continuous operation and post-fault maintenance. In this article, a fault diagnosis technique is proposed for the short circuit fault in a modular multi-level converter sub-module using the wavelet transform and adaptive neuro fuzzy inference system. The fault features are extracted from output phase voltage...

  8. Incipient Stator Insulation Fault Detection of Permanent Magnet Synchronous Wind Generators Based on Hilbert–Huang Transformation

    DEFF Research Database (Denmark)

    Wang, Chao; Liu, Xiao; Chen, Zhe

    2014-01-01

    Incipient stator winding fault in permanent magnet synchronous wind generators (PMSWGs) is very difficult to be detected as the fault generated variations in terminal electrical parameters are very weak and chaotic. This paper simulates the incipient stator winding faults at different degree...... of insulation degradation of one turn in the winding of a PMSWG. Cosimulation method by combining finite element model and external circuits is used. Hilbert–Huang transformation is applied to detect the very early stage fault in interturn insulation by analyzing the stator current. Detection results show...

  9. Wavelet transform based on inner product in fault diagnosis of rotating machinery: A review

    Science.gov (United States)

    Chen, Jinglong; Li, Zipeng; Pan, Jun; Chen, Gaige; Zi, Yanyang; Yuan, Jing; Chen, Binqiang; He, Zhengjia

    2016-03-01

    As a significant role in industrial equipment, rotating machinery fault diagnosis (RMFD) always draws lots of attention for guaranteeing product quality and improving economic benefit. But non-stationary vibration signal with a large amount of noise on abnormal condition of weak fault or compound fault in many cases would lead to this task challenging. As one of the most powerful non-stationary signal processing techniques, wavelet transform (WT) has been extensively studied and widely applied in RMFD. Numerous publications about the study and applications of WT for RMFD have been presented to academic journals, technical reports and conference proceedings. Many previous publications admit that WT can be realized by means of inner product principle of signal and wavelet base. This paper verifies the essence on inner product operation of WT by simulation and field experiments. Then the development process of WT based on inner product is concluded and the applications of major developments in RMFD are also summarized. Finally, super wavelet transform as an important prospect of WT based on inner product are presented and discussed. It is expected that this paper can offer an in-depth and comprehensive references for researchers and help them with finding out further research topics.

  10. Late Quaternary sinistral slip rate along the Altyn Tagh fault and its structural transformation model

    Institute of Scientific and Technical Information of China (English)

    XU; Xiwei; P.; Tapponnier; J.; Van; Der; Woerd; F.; J.; Ryer

    2005-01-01

    Based on technical processing of high-resolution SPOT images and aerophotos,detailed mapping of offset landforms in combination with field examination and displacement measurement, and dating of offset geomorphic surfaces by using carbon fourteen (14C), cosmogenic nuclides (10Be+26Al) and thermoluminescence (TL) methods, the Holocene sinistral slip rates on different segments of the Altyn Tagh Fault (ATF) are obtained. The slip rates reach 17.5±2 mm/a on the central and western segments west of Aksay Town, 11±3.5 mm/a on the Subei-Shibaocheng segment, 4.8± 1.0 mm/a on the Sulehe segment and only 2.2± 0.2 mm/a on the Kuantanshan segment, an easternmost segment of the ATF. The sudden change points for loss of sinistral slip rates are located at the Subei, Shibaocheng and Shulehe triple junctions where NW-trending active thrust faults splay from the ATF and propagate southeastward. Slip vector analyses indicate that the loss of the sinistral slip rates from west to east across a triple junction has structurally transformed into local crustal shortening perpendicular to the active thrust faults and strong uplifting of the thrust sheets to form the NW-trending Danghe Nanshan,Daxueshan and Qilianshan Ranges. Therefore, the eastward extrusion of the northern Qinghai-Tibetan Plateau is limited and this is in accord with "the imbricated thrusting transformation-limited extrusion model".

  11. Support vector machine based decision for mechanical fault condition monitoring in induction motor using an advanced Hilbert-Park transform.

    Science.gov (United States)

    Ben Salem, Samira; Bacha, Khmais; Chaari, Abdelkader

    2012-09-01

    In this work we suggest an original fault signature based on an improved combination of Hilbert and Park transforms. Starting from this combination we can create two fault signatures: Hilbert modulus current space vector (HMCSV) and Hilbert phase current space vector (HPCSV). These two fault signatures are subsequently analysed using the classical fast Fourier transform (FFT). The effects of mechanical faults on the HMCSV and HPCSV spectrums are described, and the related frequencies are determined. The magnitudes of spectral components, relative to the studied faults (air-gap eccentricity and outer raceway ball bearing defect), are extracted in order to develop the input vector necessary for learning and testing the support vector machine with an aim of classifying automatically the various states of the induction motor.

  12. Oceanic Transform Fault-Zone Geomorphology in the Gulf of California from High-Resolution Bathymetric Data

    Science.gov (United States)

    Hilley, G. E.; Aron, F.; Baden, C. W.; Castillo, C. M.; Johnstone, S. A.; Nevitt, J. M.; McHargue, T.; Paull, C. K.; Sare, R.; Shumaker, L.; Young, H.

    2015-12-01

    We use high-resolution, deep-water bathymetry to examine the structure of, and offset along, transform faults in the Gulf of California. These data provide detailed observations of fault-zone geomorphology of an active transform fault hosted in an area transitioning from continental to oceanic crust. Bathymetric data were collected by an autonomous underwater vehicle deployed by the Monterey Bay Aquarium Research Institute in 2012. Dense ocean-bottom point clouds allowed construction of an ~1-m-resolution digital terrain model, which provides comparable spatial resolution to early airborne laser swath mapping surveys. The data reveal a set of complex, multi-stranded fault zones, whose morphologies suggest a temporal migration of deformation between individual strands contained within an up to 1 km wide zone, similar to complex fault zones observed within continental crust in subaerial environments. Individual fault strands show restraining steps that create positive relief along the ocean floor in their vicinity. Although the depositional nature of these deep-water systems makes identification of offset features challenging, we found a series of offset fans along a fault strand with consistent right-lateral offsets of 17-21 m. These are likely multi-event offsets, given the length of the transform segments and magnitudes of historically recorded earthquakes in the region. The consistency of these multi-event offsets suggests that an external process predating the displacement of the fans, such as seismic shaking due to large earthquakes, may be responsible for the synchroneity of these features. Our study demonstrates that the fault-zone geomorphology of oceanic transform faults in the Gulf of California bears resemblance to that of terrestrial strike-slip faults hosted in continental crust, and that high-resolution, deep water bathymetry can provide information about the earthquake history of these environments.

  13. Dynamic triggering and earthquake swarms on East Pacific Rise transform faults

    Science.gov (United States)

    Cattania, Camilla; McGuire, Jeffrey J.; Collins, John A.

    2017-01-01

    While dynamic earthquake triggering has been reported in several continental settings, offshore observations are rare. Oceanic transform faults share properties with continental geothermal areas known for dynamic triggering: high geothermal gradients, high seismicity rates, and frequent swarms. We study dynamic triggering along the East Pacific Rise by analyzing 1 year of seismicity recorded by Ocean Bottom Seismographs. By comparing the response to teleseismic waves from global earthquakes, we find triggering to be most sensitive to changes in normal stress and to preferentially occur above 0.25 kPa. The clearest example of triggering occurs on the Quebrada and Gofar faults after the Mw8.0 Wenchuan earthquake. On Gofar, triggered seismicity occurs between the rupture areas of large earthquakes, within a zone characterized by aseismic slip, abundant microseismicity, frequent swarms, and low Vp. We infer that lithological properties inhibiting rupture propagation, such as high porosity and fluid content, also favor dynamic triggering.

  14. Investigations on Incipient Fault Diagnosis of Power Transformer Using Neural Networks and Adaptive Neurofuzzy Inference System

    Directory of Open Access Journals (Sweden)

    Nandkumar Wagh

    2014-01-01

    Full Text Available Continuity of power supply is of utmost importance to the consumers and is only possible by coordination and reliable operation of power system components. Power transformer is such a prime equipment of the transmission and distribution system and needs to be continuously monitored for its well-being. Since ratio methods cannot provide correct diagnosis due to the borderline problems and the probability of existence of multiple faults, artificial intelligence could be the best approach. Dissolved gas analysis (DGA interpretation may provide an insight into the developing incipient faults and is adopted as the preliminary diagnosis tool. In the proposed work, a comparison of the diagnosis ability of backpropagation (BP, radial basis function (RBF neural network, and adaptive neurofuzzy inference system (ANFIS has been investigated and the diagnosis results in terms of error measure, accuracy, network training time, and number of iterations are presented.

  15. En echelon knolls in the Nosappu Fracture Zone, NW Pacific: A possible leaky transform fault zone

    Science.gov (United States)

    Ogawa, Y.; Hirano, N.; Shipboard Scientific Party Kr03-07, .

    2003-12-01

    During JAMSTEC R/V KAIREI cruise KR03-07, we mapped significant en echelon arrays of knolls and ridges on the NNW-trending Nosappu Fracture Zone between Hokkaido and Shatsky Rise, NW Pacific. This fracture zone has been known to be irregular, including a deep-sea channel, the Nakwe Channel, enigmatic for inside the wide oceanic plate. Considering the previously recognized magnetic lineament dislocation, the fracture zone has long (more than 150 km) left-lateral strike-slip component as a ridge-ridge transform fault zone between the Izanagi and Pacific plates during Early Cretaceous. Detail multi-narrowbeam mapping around 37 N latitude, 150 E longitude (covering 78 km x 137 km), indicated many small knolls and ridges that form en echelon arrangement. Some are boomerang, sock or E-letter in shape. The two dominant directions of ridges are recognized, one is parallel to the fracture zone and the other is in left-handed en echelon fashion. Besides these ridges, there are other types of ridges or conical knolls lower than 500 m in relief; one is a group of rather large knolls extending to NE, roughly perpendicular to the fracture zone direction, and the other is independent small knolls, summing up to five or six in number. Another expression of a depression zone was recognized with a moderate angle to the fracture zone in a crank fashion. This may correspond to the so-called _gNakwe Channel_h which has been wrongly mistaken. Such en echelon arrays are involved in a 50 km wide NNW-SSE zone, which is sharply demarcated by fault scarps. These characteristics in the fracture zone area and associated knolls suggest that this part of the Nosappu Fracture Zone might have developed in a fault interaction area which has a left-lateral component of leaky transform faulting close to the spreading ridge.

  16. Numerical Methods for the Analysis of Power Transformer Tank Deformation and Rupture Due to Internal Arcing Faults.

    Science.gov (United States)

    Yan, Chenguang; Hao, Zhiguo; Zhang, Song; Zhang, Baohui; Zheng, Tao

    2015-01-01

    Power transformer rupture and fire resulting from an arcing fault inside the tank usually leads to significant security risks and serious economic loss. In order to reveal the essence of tank deformation or explosion, this paper presents a 3-D numerical computational tool to simulate the structural dynamic behavior due to overpressure inside transformer tank. To illustrate the effectiveness of the proposed method, a 17.3 MJ and a 6.3 MJ arcing fault were simulated on a real full-scale 360MVA/220kV oil-immersed transformer model, respectively. By employing the finite element method, the transformer internal overpressure distribution, wave propagation and von-Mises stress were solved. The numerical results indicate that the increase of pressure and mechanical stress distribution are non-uniform and the stress tends to concentrate on connecting parts of the tank as the fault time evolves. Given this feature, it becomes possible to reduce the risk of transformer tank rupture through limiting the fault energy and enhancing the mechanical strength of the local stress concentrative areas. The theoretical model and numerical simulation method proposed in this paper can be used as a substitute for risky and costly field tests in fault overpressure analysis and tank mitigation design of transformers.

  17. Numerical Methods for the Analysis of Power Transformer Tank Deformation and Rupture Due to Internal Arcing Faults.

    Directory of Open Access Journals (Sweden)

    Chenguang Yan

    Full Text Available Power transformer rupture and fire resulting from an arcing fault inside the tank usually leads to significant security risks and serious economic loss. In order to reveal the essence of tank deformation or explosion, this paper presents a 3-D numerical computational tool to simulate the structural dynamic behavior due to overpressure inside transformer tank. To illustrate the effectiveness of the proposed method, a 17.3 MJ and a 6.3 MJ arcing fault were simulated on a real full-scale 360MVA/220kV oil-immersed transformer model, respectively. By employing the finite element method, the transformer internal overpressure distribution, wave propagation and von-Mises stress were solved. The numerical results indicate that the increase of pressure and mechanical stress distribution are non-uniform and the stress tends to concentrate on connecting parts of the tank as the fault time evolves. Given this feature, it becomes possible to reduce the risk of transformer tank rupture through limiting the fault energy and enhancing the mechanical strength of the local stress concentrative areas. The theoretical model and numerical simulation method proposed in this paper can be used as a substitute for risky and costly field tests in fault overpressure analysis and tank mitigation design of transformers.

  18. Comparison of the quench and fault current limiting characteristics of the flux-coupling type SFCL with single and three-phase transformer

    Science.gov (United States)

    Jung, Byung Ik; Cho, Yong Sun; Park, Hyoung Min; Chung, Dong Chul; Choi, Hyo Sang

    2013-01-01

    The South Korean power grid has a network structure for the flexible operation of the system. The continuously increasing power demand necessitated the increase of power facilities, which decreased the impedance in the power system. As a result, the size of the fault current in the event of a system fault increased. As this increased fault current size is threatening the breaking capacity of the circuit breaker, the main protective device, a solution to this problem is needed. The superconducting fault current limiter (SFCL) has been designed to address this problem. SFCL supports the stable operation of the circuit breaker through its excellent fault-current-limiting operation [1-5]. In this paper, the quench and fault current limiting characteristics of the flux-coupling-type SFCL with one three-phase transformer were compared with those of the same SFCL type but with three single-phase transformers. In the case of the three-phase transformers, both the superconducting elements of the fault and sound phases were quenched, whereas in the case of the single-phase transformer, only that of the fault phase was quenched. For the fault current limiting rate, both cases showed similar rates for the single line-to-ground fault, but for the three-wire earth fault, the fault current limiting rate of the single-phase transformer was over 90% whereas that of the three-phase transformer was about 60%. It appears that when the three-phase transformer was used, the limiting rate decreased because the fluxes by the fault current of each phase were linked in one core. When the power loads of the superconducting elements were compared by fault type, the initial (half-cycle) load was great when the single-phase transformer was applied, whereas for the three-phase transformer, its power load was slightly lower at the initial stage but became greater after the half fault cycle.

  19. Use of Fourier Transformation for Detection of Faults in Underground Power Cables

    Institute of Scientific and Technical Information of China (English)

    Abhishek Pandey; Nicolas H. Younan

    2011-01-01

    An analysis of underground power cables is performed using Fourier analysis with the objective of detecting fault and average life of the cables. Three types of cables are used in this experiment: a normal cable, a shorted cable, and a cable with holes. The impedance in each case is computed and Fourier transformation is applied so that the re- suiting impedance magnitude and impedance phase can be examined in the frequency domain. Various windowing tech- niques are applied to the experimental data to eliminate any interference. Fourier analysis is then applied to the imped- ance data calculated from both the sending end voltage and differential voltage. This analysis reveals differences in the frequency response of the three different types of a cable and can eventually be used as a measure for fault detection. Preliminary results reveal the differences in the frequency response. Accordingly, Fourier type methods can be effectively used as low cost and viable solutions to identify and detect faults in underground cables.

  20. Sarah Kane y el espectáculo del dolor

    Directory of Open Access Journals (Sweden)

    Carolina Brnci'c

    2006-11-01

    Full Text Available Este artículo analiza las principales características de la dramaturgia de Sarah Kane en su dimensión textual y escénica. Se establecen los vínculos con la corriente teatral inglesa 'in yer face'de los años 90 y se precisan las influencias de Antonin Artaud en la concepción de Kane del teatro como espectáculo del dolor. El análisis se centra principalmente en la obra Phaedra's love, proyectando los aspectos más relevantes a otras piezas de la autoraThis article analyses the chief characteristics of Sarah Kane' dramaturgy in both its textual and scenic dimensions. Links are established with the English theatrical trend of the 90', known as 'in yer face', and the influences of Antonin Artaud on Kane' conception of theatre as 'a spectacle of pain'comes under consideration. This study basically focuses on Kane' piece, Phaedra' Love, while considering other pieces of the playwight

  1. Verification of Transformer Restricted Earth Fault Protection by using the Monte Carlo Method

    Directory of Open Access Journals (Sweden)

    KRSTIVOJEVIC, J. P.

    2015-08-01

    Full Text Available The results of a comprehensive investigation of the influence of current transformer (CT saturation on restricted earth fault (REF protection during power transformer magnetization inrush are presented. Since the inrush current during switch-on of unloaded power transformer is stochastic, its values are obtained by: (i laboratory measurements and (ii calculations based on the input data obtained by the Monte Carlo (MC simulation. To make a detailed assessment of the current transformer performance the uncertain input data for the CT model were obtained by applying the MC method. In this way, different levels of remanent flux in CT core are taken into consideration. By the generated CT secondary currents, the algorithm for REF protection based on phase comparison in time domain is tested. On the basis of the obtained results, a method of adjustment of the triggering threshold in order to ensure safe operation during transients, and thereby improve the algorithm security, has been proposed. The obtained results indicate that power transformer REF protection would be enhanced by using the proposed adjustment of triggering threshold in the algorithm which is based on phase comparison in time domain.

  2. Stress fields of the San Andreas and Queen Charlotte transform faults

    Science.gov (United States)

    Kilty, Kevin T.

    1981-08-01

    Analytic solutions to the stress fields resulting from the San Andreas and Queen Charlotte transform faults may be found by applying conformal mappings to the generalized plane stress solution of stresses in a half-plane. The mean stress fields (one-half the trace of the stress tensor) found in this manner show a similarity to the deformation found in western Canada and the western United States. The results refute the hypothesis that Alaska acts as a continental buttress against deformation of the Canadian Cordillera. Moreover, these results imply that the differences in the tectonics of major transform boundaries are caused primarily by differences in lithospheric structure and differences in stress distribution along the plate boundaries.

  3. Identification of Magnetizing Inrush and Internal Short-Circuit Fault Current in V/x-Type Traction Transformer

    Directory of Open Access Journals (Sweden)

    Y. H. Li

    2013-01-01

    Full Text Available This paper deals with the fault diagnosis methodology for the V/x-type traction transformer in railway passenger-dedicated lines. A kind of the protection methodology to combine empirical mode decomposition (EMD, energy weight, and information entropy is proposed. This method can sensitively reflect the dynamic information changes of traction transformer differential current, so it can not only effectively identify internal short-circuit fault current from magnetizing inrush but also better identify fault current accompanied with magnetizing inrush. In this method, the differential current is decomposed by EMD and the energy weight of each intrinsic mode function (IMF is calculated, and the feature vector of the fault pattern recognition is obtained by constructing IMF energy entropy. The field-measured data illustrate that the new method not only has the advantages of high sensitivity, faster identification speed, and clear concept but also is available for the diagnosis of the complicated dynamic system.

  4. Adaptive Redundant Lifting Wavelet Transform Based on Fitting for Fault Feature Extraction of Roller Bearings

    Directory of Open Access Journals (Sweden)

    Huaqing Wang

    2012-03-01

    Full Text Available A least square method based on data fitting is proposed to construct a new lifting wavelet, together with the nonlinear idea and redundant algorithm, the adaptive redundant lifting transform based on fitting is firstly stated in this paper. By variable combination selections of basis function, sample number and dimension of basis function, a total of nine wavelets with different characteristics are constructed, which are respectively adopted to perform redundant lifting wavelet transforms on low-frequency approximate signals at each layer. Then the normalized lP norms of the new node-signal obtained through decomposition are calculated to adaptively determine the optimal wavelet for the decomposed approximate signal. Next, the original signal is taken for subsection power spectrum analysis to choose the node-signal for single branch reconstruction and demodulation. Experiment signals and engineering signals are respectively used to verify the above method and the results show that bearing faults can be diagnosed more effectively by the method presented here than by both spectrum analysis and demodulation analysis. Meanwhile, compared with the symmetrical wavelets constructed with Lagrange interpolation algorithm, the asymmetrical wavelets constructed based on data fitting are more suitable in feature extraction of fault signal of roller bearings.

  5. Improved probabilistic neural networks with self-adaptive strategies for transformer fault diagnosis problem

    Directory of Open Access Journals (Sweden)

    Jiao-Hong Yi

    2016-01-01

    Full Text Available Probabilistic neural network has successfully solved all kinds of engineering problems in various fields since it is proposed. In probabilistic neural network, Spread has great influence on its performance, and probabilistic neural network will generate bad prediction results if it is improperly selected. It is difficult to select the optimal manually. In this article, a variant of probabilistic neural network with self-adaptive strategy, called self-adaptive probabilistic neural network, is proposed. In self-adaptive probabilistic neural network, Spread can be self-adaptively adjusted and selected and then the best selected Spread is used to guide the self-adaptive probabilistic neural network train and test. In addition, two simplified strategies are incorporated into the proposed self-adaptive probabilistic neural network with the aim of further improving its performance and then two versions of simplified self-adaptive probabilistic neural network (simplified self-adaptive probabilistic neural networks 1 and 2 are proposed. The variants of self-adaptive probabilistic neural networks are further applied to solve the transformer fault diagnosis problem. By comparing them with basic probabilistic neural network, and the traditional back propagation, extreme learning machine, general regression neural network, and self-adaptive extreme learning machine, the results have experimentally proven that self-adaptive probabilistic neural networks have a more accurate prediction and better generalization performance when addressing the transformer fault diagnosis problem.

  6. Iterative generalized synchrosqueezing transform for fault diagnosis of wind turbine planetary gearbox under nonstationary conditions

    Science.gov (United States)

    Feng, Zhipeng; Chen, Xiaowang; Liang, Ming

    2015-02-01

    The synchrosqueezing transform can effectively improve the readability of time-frequency representation of mono-component and constant frequency signals. However, for multi-component and time-variant frequency signals, it still suffers from time-frequency blurs. In order to address this issue, the synchrosqueezing transform is improved using iterative generalized demodulation. Firstly, the complex nonstationary signal is decomposed into mono-components of constant frequency by iterative generalized demodulation. Then, the instantaneous frequency of each mono-component is accurately estimated via the synchrosqueezing transform, by exploiting its merit of enhanced time-frequency resolution. Finally, the time-frequency representation of the original signal is obtained by superposing the time-frequency representations of all the mono-components with restored instantaneous frequency. This proposed method generalizes the synchrosqueezing transform to multi-component and time-variant frequency signals, and it has fine time-frequency resolution and is free of cross-term interferences. The proposed method was validated using both numerically simulated and lab experimental vibration signals of planetary gearboxes under nonstationary conditions. The time-variant planetary gearbox characteristic frequencies were effectively identified, and the gear faults were correctly diagnosed.

  7. Generalized stepwise demodulation transform and synchrosqueezing for time-frequency analysis and bearing fault diagnosis

    Science.gov (United States)

    Shi, Juanjuan; Liang, Ming; Necsulescu, Dan-Sorin; Guan, Yunpeng

    2016-04-01

    The energy concentration level is an important indicator for time-frequency analysis (TFA). Weak energy concentration would result in time-frequency representation (TFR) diffusion and thus leading to ambiguous results or even misleading signal analysis results, particularly for nonstationary multicomponent signals. To improve the energy concentration level, this paper proposes a generalized stepwise demodulation transform (GSDT). The rationale of the proposed method is that (1) the generalized demodulation (GD) can map the original signal into an analytic signal with constant instantaneous frequency (IF) and improve the energy concentration level on time-frequency plane, and (2) focusing on a short window around the time instant of interest, a backward demodulation operation can recover the original frequency at the time instant without affecting the improved energy concentration level. By repeating the backward demodulation at every time instant of interest, the TFR of the entire signal can be attained with enhanced energy concentration level. With the GSDT, an iterative GSDT (IGSDT) is developed to analyze multicomponent signal that is subjected to different modulating sources for their constituent components. The IGSDT iteratively demodulates each constituent component to attain its TFR and the TFR of the whole signal is derived from superposing all the resulting TFRs of constituent components. The cross-term free and more energy concentrated TFR of the signal is, therefore, obtained, and the diffusion in the TFR can be reduced. The GSDT-based synchrosqueezing transform is also elaborated to further enhance the GSDT(IGSDT) yielded TFR. The effectiveness of the proposed method in TFA is tested using both simulated monocomponent and multicomponent signals. The application of the proposed method to bearing fault detection is explored. Bearing condition and fault pattern can be revealed by the proposed method resulting TFR. The main advantages of the proposed method

  8. Correction to Kane et al. (2016).

    Science.gov (United States)

    Kane, Michael J; Meier, Matt E; Smeekens, Bridget A; Gross, Georgina M; Chun, Charlotte A; Silvia, Paul J; Kwapil, Thomas R

    2016-12-01

    Reports an error in "Individual differences in the executive control of attention, memory, and thought, and their associations with schizotypy" by Michael J. Kane, Matt E. Meier, Bridget A. Smeekens, Georgina M. Gross, Charlotte A. Chun, Paul J. Silvia and Thomas R. Kwapil (Journal of Experimental Psychology: General, 2016[Aug], Vol 145[8], 1017-1048). There were errors in Table 3 and Table 7 (these transcription errors were limited to descriptive statistics in the Tables and did not affect any inferential statistics). In Table 3, the ARRO-TUT and LETT-TUT variables had incorrect values for Mean [95% CI], SD, Skew, Kurtosis, and N. In Table 7, the same values (plus Min and Max) were incorrect for the SEM-SART variable. The correct values for these measures are presented in the correction (the values for Min and Max were correct as set in Table 3, but are repeated below for clarity). (The following abstract of the original article appeared in record 2016-29680-001.) A large correlational study took a latent-variable approach to the generality of executive control by testing the individual-differences structure of executive-attention capabilities and assessing their prediction of schizotypy, a multidimensional construct (with negative, positive, disorganized, and paranoid factors) conveying risk for schizophrenia. Although schizophrenia is convincingly linked to executive deficits, the schizotypy literature is equivocal. Subjects completed tasks of working memory capacity (WMC), attention restraint (inhibiting prepotent responses), and attention constraint (focusing visual attention amid distractors), the latter 2 in an effort to fractionate the "inhibition" construct. We also assessed mind-wandering propensity (via in-task thought probes) and coefficient of variation in response times (RT CoV) from several tasks as more novel indices of executive attention. WMC, attention restraint, attention constraint, mind wandering, and RT CoV were correlated but separable

  9. Evidence for ground-rupturing earthquakes on the Northern Wadi Araba fault at the archaeological site of Qasr Tilah, Dead Sea Transform fault system, Jordan

    Science.gov (United States)

    Haynes, Jeremy M.; Niemi, Tina M.; Atallah, Mohammad

    2006-10-01

    The archaeological site of Qasr Tilah, in the Wadi Araba, Jordan is located on the northern Wadi Araba fault segment of the Dead Sea Transform. The site contains a Roman-period fort, a late Byzantine Early Umayyad birkeh (water reservoir) and aqueduct, and agricultural fields. The birkeh and aqueduct are left-laterally offset by coseismic slip across the northern Wadi Araba fault. Using paleoseismic and archaeological evidence collected from a trench excavated across the fault zone, we identified evidence for four ground-rupturing earthquakes. Radiocarbon dating from key stratigraphic horizons and relative dating using potsherds constrains the dates of the four earthquakes from the sixth to the nineteenth centuries. Individual earthquakes were dated to the seventh, ninth and eleventh centuries. The fault strand that slipped during the most recent event (MRE) extends to just below the modern ground surface and juxtaposes alluvial-fan sediments that lack in datable material with the modern ground surface, thus preventing us from dating the MRE except to constrain the event to post-eleventh century. These data suggest that the historical earthquakes of 634 or 659/660, 873, 1068, and 1546 probably ruptured this fault segment.

  10. The Queen Charlotte Fault, British Columbia: seafloor anatomy of a transform fault and its influence on sediment processes

    Science.gov (United States)

    Barrie, J. Vaughn; Conway, Kim W.; Harris, Peter T.

    2013-08-01

    The Queen Charlotte Fault Zone (QCFZ) off western Canada is the northern equivalent to the San Andreas Fault Zone, the Pacific-North American plate boundary. Geomorphologic expression and surface processes associated with the QCFZ system have been revealed in unprecedented detail by recent seabed mapping surveys. Convergence of the Pacific and North American plates along northern British Columbia is well known, but how the QCFZ accommodates this convergence is still a subject of controversy. The multibeam sonar bathymetry data reveal, for the first time, evidence of a fault valley with small depressions on the upper slope, offshore central Haida Gwaii (Queen Charlotte Islands). The depressions form where strike-slip right-step offsets have realigned the fault due to oblique convergence. Core stratigraphy and radiocarbon dating of sediments within the fault valley and small depressions suggest that these features are recent in origin. In addition, the development of the fault valley and dislocation of submarine canyons control sediment migration from the continental shelf through to the lower slope. This interpretation of the geomorphic expression of major plate tectonic processes along the QCFZ can now be tested with new surveys subsequent to the October 2012 magnitude 7.7 earthquake.

  11. Novel indices for broken rotor bars fault diagnosis in induction motors using wavelet transform

    Science.gov (United States)

    Ebrahimi, Bashir Mahdi; Faiz, Jawad; Lotfi-fard, S.; Pillay, P.

    2012-07-01

    This paper introduces novel indices for broken rotor bars diagnosis in three-phase induction motors based on wavelet coefficients of stator current in a specific frequency band. These indices enable to diagnose occurrence and determine number of broken bars in different loads precisely. Besides thanks to the suitability of wavelet transform in transient conditions, it is possible to detect the fault during the start-up of the motor. This is important in the case of start-up of large induction motors with long starting time and also motors with frequent start-up. Furthermore, broken rotor bars in induction motor are detected using spectra analysis of the stator current. It is also shown that rise of number of broken bars and load levels increases amplitude of the particular side-band components of the stator currents in the faulty case. An induction motor with 1, 2, 3 and 4 broken bars at the rated load and the motor with 4 broken bars at no-load, 33%, 66%, 100% and 133% rated load are investigated. Time stepping finite element method is used for modeling broken rotor bars faults in induction motors. In this modeling, effects of the stator winding distribution, stator and rotor slots, geometrical and physical characteristics of different parts of the motor and non-linearity of the core materials are taken into account. The simulation results are are verified by the experimental results.

  12. Research of converter transformer fault diagnosis based on improved PSO-BP algorithm

    Science.gov (United States)

    Long, Qi; Guo, Shuyong; Li, Qing; Sun, Yong; Li, Yi; Fan, Youping

    2017-09-01

    To overcome those disadvantages that BP (Back Propagation) neural network and conventional Particle Swarm Optimization (PSO) converge at the global best particle repeatedly in early stage and is easy trapped in local optima and with low diagnosis accuracy when being applied in converter transformer fault diagnosis, we come up with the improved PSO-BP neural network to improve the accuracy rate. This algorithm improves the inertia weight Equation by using the attenuation strategy based on concave function to avoid the premature convergence of PSO algorithm and Time-Varying Acceleration Coefficient (TVAC) strategy was adopted to balance the local search and global search ability. At last the simulation results prove that the proposed approach has a better ability in optimizing BP neural network in terms of network output error, global searching performance and diagnosis accuracy.

  13. Incipient Gearbox Fault Diagnosis Based on the Reverse State Transformation of the Chaotic Duffing Oscillator and Sampling Integral Technology

    Directory of Open Access Journals (Sweden)

    Li Jie

    2015-01-01

    Full Text Available Incipient fault for a gearbox diagnosis is difficult because the signals with low signal-to-noise ratio (SNR are corrupted with background noise. A method based on chaos theory and sampling integral technology will be presented to detect the incipient fault of gearbox according to the characters of the gearbox vibration signals. Sampling integral technology was used to improve the tracking ability of fault signals with lower SNR. The small changes in the sidebands of meshing frequency can be detected by the transformation of chaotic phase diagram and its Hu moment invariants, and on this basis the incipient faults can be diagnosed. The results based on gearboxes experiment justify the effectiveness of the method.

  14. Net Slip across the Ballenas Transform Fault Measured from Offset Ignimbrite Deposits

    Science.gov (United States)

    Stock, J. M.; Martín, A.; Chapman, A.; López-Martínez, M.

    2008-12-01

    The Ballenas Transform Fault in the Gulf of California separates the Baja California Peninsula (to the W on the Pacific Plate) from Isla Angel de la Guarda (to the E on the North America plate). This active right-lateral fault originated in a Pliocene plate boundary reorganization when part of the rift margin jumped westward into the Baja California peninsula, transferring Isla Angel de la Guarda from the Pacific plate to the North America plate. The net slip along the Ballenas transform fault system is expected to be less than the 250-300 km of post-Miocene opening of the northern Gulf of California basins. Here we constrain the net slip using geological similarities between the west coast of the island and the east coast of Baja California. Reconnaissance geological mapping on Isla Angel de la Guarda reveals the presence of a middle Miocene high-silica rhyolite ignimbrite with an Ar/Ar age of 11.8±0.2 Ma on sanidine. This deposit is preserved in a paleo-low in Cretaceous (?) granitic rocks in the central part of the island. The major and trace element compositions are similar to those of the Tuff of San Felipe, identified in Sonora and Baja California, but not previously recognized on Isla Angel de la Guarda. The deposit from the island exhibits a paleomagnetic remanence vector toward the SW and nearly horizontal, similar to that of the Tuff of San Felipe, and far outside of the expected paleomagnetic remanence direction. The ignimbrite on Isla Angel de la Guarda has an age younger than that previously reported for the Tuff of San Felipe, but within the range of ages from other outcrops of the Tuff of San Felipe in Sonora (Vidal-Solano et al., 2008). We correlate this ignimbrite to a similar unit preserved in isolated locations northwest of Cataviña on the Baja California peninsula, for which paleomagnetic work shows a very similar remanence direction. Using the SE limit of these outcrops against the granitic rocks in both locations yields an estimate of ~130

  15. Fault feature extraction of gearbox by using overcomplete rational dilation discrete wavelet transform on signals measured from vibration sensors

    Science.gov (United States)

    Chen, Binqiang; Zhang, Zhousuo; Sun, Chuang; Li, Bing; Zi, Yanyang; He, Zhengjia

    2012-11-01

    Gearbox fault diagnosis is very important for preventing catastrophic accidents. Vibration signals of gearboxes measured by sensors are useful and dependable as they carry key information related to the mechanical faults in gearboxes. Effective signal processing techniques are in necessary demands to extract the fault features contained in the collected gearbox vibration signals. Overcomplete rational dilation discrete wavelet transform (ORDWT) enjoys attractive properties such as better shift-invariance, adjustable time-frequency distributions and flexible wavelet atoms of tunable oscillation in comparison with classical dyadic wavelet transform (DWT). Due to these advantages, ORDWT is presented as a versatile tool that can be adapted to analysis of gearbox fault features of different types, especially in analyzing the non-stationary and transient characteristics of the signals. Aiming to extract the various types of fault features confronted in gearbox fault diagnosis, a fault feature extraction technique based on ORDWT is proposed in this paper. In the routine of the proposed technique, ORDWT is used as the pre-processing decomposition tool, and a corresponding post-processing method is combined with ORDWT to extract the fault feature of a specific type. For extracting periodical impulses in the signal, an impulse matching algorithm is presented. In this algorithm, ORDWT bases of varied time-frequency distributions and varied oscillatory natures are adopted, moreover an improved signal impulsiveness measure derived from kurtosis is developed for choosing optimal ORDWT bases that perfectly match the hidden periodical impulses. For demodulation purpose, an improved instantaneous time-frequency spectrum (ITFS), based on the combination of ORDWT and Hilbert transform, is presented. For signal denoising applications, ORDWT is enhanced by neighboring coefficient shrinkage strategy as well as subband selection step to reveal the buried transient vibration contents. The

  16. New Bathymetry Reveals Detailed History of Transform Fault Segmentation at the Clarion Fracture Zone

    Science.gov (United States)

    Morrow, T. A.; Kim, S. S.; Mittelstaedt, E. L.; Olive, J. A. L.; Howell, S. M.

    2016-12-01

    Between 150°W and 135°W, the Clarion Fracture Zone (FZ) coalesces from six discrete FZ traces to a single FZ over a period of 30 million years, coinciding with a change in plate motion that placed the associated transform fault (TF) in compression. Although FZ observations suggest segmented TFs may unify to a single TF as a response to tectonic compression, little is known about the timing of this process, as well as how it may alter lithosphere structure. Using new bathymetry and gravity data from the Clarion FZ, we investigate this process through interpreted structural maps of the seafloor, numerical simulations of a segmented FZ, and modeling of gravitational anomalies. From 3154 mapped volcanic ridges and faults, we observe temporally correlated changes in intra-transform spreading center (ITSC) fabrics and plate motions that suggest that ITSC fabrics further from the center of the FZ responded to compressional changes in plate motion sooner (up to 5 million years) than ITSC fabrics located near the center of the FZ. Using the 2D finite-difference, visco-elastic-plastic code SiStER, we simulate the tectonic evolution of a differentially cooling lithosphere broken by several FZs and subject to compression or extension. We vary parameters such as the number of initial ITSC segments (0-4) and the rate of compression or extension (0-4.5 mm/year). In some model cases, we also vary the strength of the initial FZ offset by introducing small, low-viscosity weaknesses in the modeled lithosphere at the FZ. Gravity anomalies are calculated from the simulated lithospheric structure by using Talwani's 2D polygon algorithm. We then compare model predicted and existing satellite-derived gravity anomalies over the segmented Clarion FZ to constrain the relative timing of compressional changes along individual transform segment traces and structural changes within the FZ. Our observations suggest that compression and extension are not uniformly distributed across a segmented

  17. Early fault feature extraction of rolling bearing based on ICD and tunable Q-factor wavelet transform

    Science.gov (United States)

    Li, Yongbo; Liang, Xihui; Xu, Minqiang; Huang, Wenhu

    2017-03-01

    When a fault occurs on bearings, the measured bearing fault signals contain both high Q-factor oscillation component and low Q-factor periodic impact component. TQWT is the improvement of the traditional single Q-factor wavelet transform, which is very suitable for separating the low Q-factor component from the high Q-factor component. However, the accuracy of its decomposition heavily depended on the selection of Q-factors. There is no reported simple but effective method to select the Q-factors with enough accuracy. This study aims to develop a strategy to diagnostic the early fault of rolling bearings. In this paper, a characteristic frequency ratio (CFR) is used to optimize Q-factors of TQWT (OTQWT). However, directly application of OTQWT is difficult to extract fault signatures at early stage due to the weak fault symptoms and strong noise. A strategy of combination of intrinsic characteristic-scale decomposition (ICD) and TQWT is proposed. ICD owns significant advantages on computation efficiency and alleviation of mode mixing. The effectiveness of the proposed strategy is tested with both simulated and experimental vibration signals. Meanwhile, comparisons are conducted between the proposed method and other methods like: envelope demodulation and EEMD-TQWT. Results show that the proposed method has superior performance in extracting fault features of defective bearings at an early stage.

  18. New constraints on seismic anisotropy along the Dead Sea transform fault

    Science.gov (United States)

    Kaviani, A.; Rumpker, G.; Asch, G.

    2009-12-01

    We study seismic anisotropy along the Dead Sea Transform fault (DST) by shear-wave splitting analysis of SKS and SKKS waveforms recorded at a dense network of broad-band and short-period stations of the DESIRE experiment. The DST accommodates the relative motion between Africa and Arabia through a sinistral strike-slip motion. The Dead Sea is a pull-apart basin formed along the DST as a result of stepwise fault-normal displacement. The DESIRE array of stations cover this portion of the DST. We measured the splitting parameters (delay times between the fast and slow components of the shear wave and fast polarization direction) in different period bands. We observed consistent fast polarization directions varying from N14W to N19E at different stations and delay times ranging between 1.0 and 2.5 s. Our preliminary examination reveals that the splitting parameters do not exhibit significant frequency dependence. However, we observe variations in the splitting parameters (mostly delay times) along an E-W profile crossing the DST, with smaller delay times in the middle of the profile, within the surface exposure of the DST shear zone, and with two lobes of relatively large delay times on both sides of the central region. The fast polarization directions along this profile change from a dominant NNW trend in the western side of the DST to a general N-S orientation in the central part and a dominant NNE trend to the east. Waveform modeling is required to infer the lateral and depth variations of the strength and orientation of anisotropy in the crust and upper mantle from these observations. We will also complement our results with the data from the DESERT experiment to provide an overall pattern of seismic anisotropy and structural fabric beneath the DST and surrounding regions from the north of the Dead Sea down to the Red sea.

  19. A combined method for triplex pump fault diagnosis based on wavelet transform, fuzzy logic and neuro-networks

    Science.gov (United States)

    Kong, Fansen; Chen, Ruheng

    2004-01-01

    A new combined method based on wavelet transformation, fuzzy logic and neuro-networks is proposed for fault diagnosis of a triplex. The failure characteristics of the fluid- and dynamic-end can be divided into wavelet transform in different scales at the same time (in: Jun Zhu et al. (Eds.), Proceedings of an International Conference on Condition Monitoring. National Defense Industry Press, Beijing, 1997, pp. 271-275). Therefore, the characteristic variables can be constructed making use of the coefficients of Edgeworth asymptotic spectrum expansion formula and fuzzified to train the neuro-network to identify the faults of fluid- and dynamic-end of triplex pump in fuzzy domain. Tests indicate that the information of wavelet transformation in scale 2 is related to the meshing state of the gear and the information in scales 4 and 5 is related to the running state of fluid-end. Good agreement between analytical and experimental results has been obtained.

  20. Bearing Fault Diagnosis Using a Novel Classifier Ensemble Based on Lifting Wavelet Packet Transforms and Sample Entropy

    Directory of Open Access Journals (Sweden)

    Lei Zhang

    2016-01-01

    Full Text Available In order to improve the fault detection accuracy for rolling bearings, an automated fault diagnosis system is presented based on lifting wavelet packet transform (LWPT, sample entropy (SampEn, and classifier ensemble. Bearing vibration signals are firstly decomposed into different frequency subbands through a three-level LWPT, resulting in a total of 8 frequency-band signals throughout the third layers of the LWPT decomposition tree. The SampEns of all the 8 components are then calculated as feature vectors. Such a feature extraction paradigm is expected to depict complexity, irregularity, and nonstationarity of bearing vibrations. Moreover, a novel classifier ensemble is proposed to alleviate the effect of initial parameters on the performance of member classifiers and to improve classification effectiveness. Experiments were conducted on electric motor bearings considering various set of fault categories and fault severity levels. Experimental results demonstrate the proposed diagnosis system can effectively improve bearing fault recognition accuracy and stability in comparison with diagnosis methods based on a single classifier.

  1. Discrete wavelet transform-based fault diagnosis for driving system of pipeline detection robot arm

    Institute of Scientific and Technical Information of China (English)

    Deng Huiyu; Wang Xinli; Ma Peisun

    2005-01-01

    A real-time wavelet multi-resolution analysis (MRA)-based fault detection algorithm is proposed. The first stage detailed MRA signals extracted from the original signals were used as the criteria for fault detection. By measuring sharp variations in the detailed MRA signals, faults in the motor driving system of pipeline detection robot arm could be detected. The fault type was then identified by comparison of the three-phase MRA sharp variations. The effects of the faults were examined. The simulation results show that this algorithm is effective and robust, it is promising for fault detection in a robot's joint driving system. The method is simple, rapid and it can operate in real time.

  2. A Novel Characteristic Frequency Bands Extraction Method for Automatic Bearing Fault Diagnosis Based on Hilbert Huang Transform

    Directory of Open Access Journals (Sweden)

    Xiao Yu

    2015-11-01

    Full Text Available Because roller element bearings (REBs failures cause unexpected machinery breakdowns, their fault diagnosis has attracted considerable research attention. Established fault feature extraction methods focus on statistical characteristics of the vibration signal, which is an approach that loses sight of the continuous waveform features. Considering this weakness, this article proposes a novel feature extraction method for frequency bands, named Window Marginal Spectrum Clustering (WMSC to select salient features from the marginal spectrum of vibration signals by Hilbert–Huang Transform (HHT. In WMSC, a sliding window is used to divide an entire HHT marginal spectrum (HMS into window spectrums, following which Rand Index (RI criterion of clustering method is used to evaluate each window. The windows returning higher RI values are selected to construct characteristic frequency bands (CFBs. Next, a hybrid REBs fault diagnosis is constructed, termed by its elements, HHT-WMSC-SVM (support vector machines. The effectiveness of HHT-WMSC-SVM is validated by running series of experiments on REBs defect datasets from the Bearing Data Center of Case Western Reserve University (CWRU. The said test results evidence three major advantages of the novel method. First, the fault classification accuracy of the HHT-WMSC-SVM model is higher than that of HHT-SVM and ST-SVM, which is a method that combines statistical characteristics with SVM. Second, with Gauss white noise added to the original REBs defect dataset, the HHT-WMSC-SVM model maintains high classification accuracy, while the classification accuracy of ST-SVM and HHT-SVM models are significantly reduced. Third, fault classification accuracy by HHT-WMSC-SVM can exceed 95% under a Pmin range of 500–800 and a m range of 50–300 for REBs defect dataset, adding Gauss white noise at Signal Noise Ratio (SNR = 5. Experimental results indicate that the proposed WMSC method yields a high REBs fault

  3. Fault Detection and Location by Static Switches in Microgrids Using Wavelet Transform and Adaptive Network-Based Fuzzy Inference System

    Directory of Open Access Journals (Sweden)

    Ying-Yi Hong

    2014-04-01

    Full Text Available Microgrids are a highly efficient means of embedding distributed generation sources in a power system. However, if a fault occurs inside or outside the microgrid, the microgrid should be immediately disconnected from the main grid using a static switch installed at the secondary side of the main transformer near the point of common coupling (PCC. The static switch should have a reliable module implemented in a chip to detect/locate the fault and activate the breaker to open the circuit immediately. This paper proposes a novel approach to design this module in a static switch using the discrete wavelet transform (DWT and adaptive network-based fuzzy inference system (ANFIS. The wavelet coefficient of the fault voltage and the inference results of ANFIS with the wavelet energy of the fault current at the secondary side of the main transformer determine the control action (open or close of a static switch. The ANFIS identifies the faulty zones inside or outside the microgrid. The proposed method is applied to the first outdoor microgrid test bed in Taiwan, with a generation capacity of 360.5 kW. This microgrid test bed is studied using the real-time simulator eMegaSim developed by Opal-RT Technology Inc. (Montreal, QC, Canada. The proposed method based on DWT and ANFIS is implemented in a field programmable gate array (FPGA by using the Xilinx System Generator. Simulation results reveal that the proposed method is efficient and applicable in the real-time control environment of a power system.

  4. Mourir/survivre. Lumières de Sarah Kane

    Directory of Open Access Journals (Sweden)

    Martine Delvaux

    2012-01-01

    Full Text Available L’article propose une lecture de la première et de la dernière œuvres de la dramaturge britannique Sarah Kane, Blasted et 4.48 Psychosis, afin de réfléchir sur son legs théâtral. En s’appuyant sur Survivance des lucioles de Georges Didi-Huberman (2009, le texte met en lumière le rapport à l’espoir qui émane de l’œuvre de Kane et de son pessimisme apparent. Delvaux voit, dans l’écriture fragmentée, sarcastique et provocante, non pas le testament d’une artiste cliniquement dépressive mais plutôt un ultime outil de résistance à la noirceur, un refus radical de cette posture cynique que lui attribuait la critique. This article offers a reading of British dramaturge Sarah Kane’s first and last pieces, Blasted and 4.48 Psychosis, in order to reflect on her dramatic heritage. Drawing upon Georges Didi-Huberman’s Survivance des lucioles (2009, the text sheds light on the question of hope in what has been seen as pessimism in Kane’s work. Rather than understanding Kane’s fragmented, sarcastic and provocative writing as a testament of a clinically depressed author, Delvaux sees it as a work of resistance, a desire to see the light in an all-encompassing cultural darkness, suggesting that Kane, in fact, refuses the cynical posturethat critics have associated with her work.

  5. Four-Dimensional Transform Fault Processes: Evolution of Step-Overs and Bends at Different Scales

    Science.gov (United States)

    Wakabayashi, J.; Hengesh, J. V.; Sawyer, T. L.

    2002-12-01

    Many bends or step-overs along strike-slip faults may evolve by propagation of the strike-slip fault on one side of the structure and progressive shut off of the strike-slip fault on the other side. In such a process, new transverse structures form, old ones become inactive, and the bend or step-over region migrates with respect to materials that were once affected by it. This process is the progressive asymmetric development of a strike-slip duplex. Consequences of this type of step-over evolution include the following: 1. the amount of vertical structural relief in restraining step-over or bend regions is less than expected (apatite fission track ages associated with these step-over regions predate the strike-slip faulting); 2. pull-apart basin deposits are left outside of the active basin and commonly subjected to contractional deformation and uplift; and 3. local basin inversion occurs that is not linked to regional plate motion changes. This type of evolution of step-overs and bends may be common along the dextral San Andreas fault system of California. Examples of pull-apart basin deposits related to migrating releasing () bends or step-overs are the Plio-Pleistocene Merced Formation (tens of km along strike), the Pleistocene Olema Creek Formation (several km along strike) along the San Andreas fault in the San Francisco Bay area, and an inverted colluvial graben exposed in a paleoseismic trench across the Miller Creek fault (meters to tens of meters along strike) in the eastern San Francisco Bay area. Examples of migrating restraining bends or step-overs include the transfer of slip from the Calaveras to Hayward fault in the Mission Peak area, and the Greenville to the Concord fault at Mount Diablo (10 km or more along strike), the offshore San Gregorio fold and thrust belt (40 km along strike), and the progressive transfer of slip from the eastern faults of the San Andreas system to the migrating Mendocino triple junction (over 150 km along strike). Another

  6. Level of Construal, Mind Wandering, and Repetitive Thought: Reply to McVay and Kane (2010)

    Science.gov (United States)

    Watkins, Edward R.

    2010-01-01

    In this reply to the comment of McVay and Kane (2010), I consider their argument concerning how Watkins's (2008) elaborated control theory informs their perspective on the role of executive control in mind wandering. I argue that although in a number of places the elaborated control theory is consistent with the perspective of McVay and Kane that…

  7. Transport of Antarctic bottom water through the Kane Gap, tropical NE Atlantic Ocean

    NARCIS (Netherlands)

    Morozov, E.G.; Tarakanov, R.Y.; van Haren, H.

    2013-01-01

    We study low-frequency properties of the Antarctic Bottom Water (AABW) flow through the Kane Gap (9° N) in the Atlantic Ocean. The measurements in the Kane Gap include five visits with CTD (Conductivity-Temperature-Depth) sections in 2009–2012 and a year-long record of currents on a mooring using th

  8. Transport of Antarctic bottom water through the Kane Gap, tropical NE Atlantic Ocean

    NARCIS (Netherlands)

    Morozov, E.G.; Tarakanov, R.Y.; van Haren, H.

    2013-01-01

    We study low-frequency properties of the Antarctic Bottom Water (AABW) flow through the Kane Gap (9° N) in the Atlantic Ocean. The measurements in the Kane Gap include five visits with CTD (Conductivity-Temperature-Depth) sections in 2009–2012 and a year-long record of currents on a mooring using th

  9. Induction motor broken rotor bar fault location detection through envelope analysis of start-up current using Hilbert transform

    Science.gov (United States)

    Abd-el-Malek, Mina; Abdelsalam, Ahmed K.; Hassan, Ola E.

    2017-09-01

    Robustness, low running cost and reduced maintenance lead Induction Motors (IMs) to pioneerly penetrate the industrial drive system fields. Broken rotor bars (BRBs) can be considered as an important fault that needs to be early assessed to minimize the maintenance cost and labor time. The majority of recent BRBs' fault diagnostic techniques focus on differentiating between healthy and faulty rotor cage. In this paper, a new technique is proposed for detecting the location of the broken bar in the rotor. The proposed technique relies on monitoring certain statistical parameters estimated from the analysis of the start-up stator current envelope. The envelope of the signal is obtained using Hilbert Transformation (HT). The proposed technique offers non-invasive, fast computational and accurate location diagnostic process. Various simulation scenarios are presented that validate the effectiveness of the proposed technique.

  10. Four-dimensional transform fault processes: progressive evolution of step-overs and bends

    Science.gov (United States)

    Wakabayashi, John; Hengesh, James V.; Sawyer, Thomas L.

    2004-11-01

    Many bends or step-overs along strike-slip faults may evolve by propagation of the strike-slip fault on one side of the structure and progressive shut-off of the strike-slip fault on the other side. In such a process, new transverse structures form, and the bend or step-over region migrates with respect to materials that were once affected by it. This process is the progressive asymmetric development of a strike-slip duplex. Consequences of this type of step-over evolution include: (1) the amount of structural relief in the restraining step-over or bend region is less than expected; (2) pull-apart basin deposits are left outside of the active basin; and (3) local tectonic inversion occurs that is not linked to regional plate boundary kinematic changes. This type of evolution of step-overs and bends may be common along the dextral San Andreas fault system of California; we present evidence at different scales for the evolution of bends and step-overs along this fault system. Examples of pull-apart basin deposits related to migrating releasing (right) bends or step-overs are the Plio-Pleistocene Merced Formation (tens of km along strike), the Pleistocene Olema Creek Formation (several km along strike) along the San Andreas fault in the San Francisco Bay area, and an inverted colluvial graben exposed in a paleoseismic trench across the Miller Creek fault (meters to tens of meters along strike) in the eastern San Francisco Bay area. Examples of migrating restraining bends or step-overs include the transfer of slip from the Calaveras to Hayward fault, and the Greenville to the Concord fault (ten km or more along strike), the offshore San Gregorio fold and thrust belt (40 km along strike), and the progressive transfer of slip from the eastern faults of the San Andreas system to the migrating Mendocino triple junction (over 150 km along strike). Similar 4D evolution may characterize the evolution of other regions in the world, including the Dead Sea pull-apart, the Gulf

  11. Seismicity of the diffusive Iberian/African plate boundary at the eastern terminus of the Azores-Gibraltar Transform fault

    Science.gov (United States)

    Lange, D.; Grevemeyer, I.; Matias, L. M.

    2014-12-01

    The plate boundary at the eastern terminus of the Azores-Gibraltar transform fault between Africa and Iberia is poorly defined. The deformation in the area is forced by the slow NW-SE convergence of 4 mm/yr between the oceanic domains of Iberia/Eurasia and Africa and is accommodated over a 200 km broad tectonically-active deformation zone. The region, however, is also characterized by large earthquakes, such as the 1969 Mw=7.9 Horseshoe event and the November 1, 1755 Great Lisbon earthquake with an estimated magnitude of Mw~8.5. The exact location of the source of the 1755 Lisbon earthquake is still unknown. Recent work may suggest that the event occurred in the vicinity of the Horseshoe fault, an oblique thrust fault. However, estimates of tsunami arrival times suggested a source near the Gorringe Bank, a ~180 km-long and ~70 km-wide ridge that has a relieve of ~5000 m. Deep Sea Drilling (DSDP) and rock samples indicated that the bank is mainly composed of serpentinized peridotites with gabbroic intrusions, perhaps being created by overthrusting of the Horseshoe Abyssal Plain onto the Tagus Abyssal Plain in NW direction. Further, the Horseshoe Abyssal Plain is marked by the presence of compressive structures with a roughly NE-SW orientation and E-W trending, segmented, crustal-scale, strike slip faults that extend from the Gorringe Bank to the Gibraltar Arc in the eastern Gulf of Cadiz, which were called "South West Iberian Margin" or SWIM faults. The fault system may mark a developing Eurasia-Africa plate boundary. Two local seismic networks were operated in the area. First, a network of 14 ocean-bottom seismometers (OBS) was operated between April and October 2012 in the vicinity of the Horseshoe fault between 10°W to 11°W, and 35°50'N to 36°10'N. From October 2013 to March 2014 a second network of 15 OBS monitored seismicity at the Gorringe Bank. Both networks benefitted from seismic stations operated in Portugal. The first network provided in the order of

  12. Fault kinematics of the Magallanes-Fagnano fault system, southern Chile; an example of diffuse strain and sinistral transtension along a continental transform margin

    Science.gov (United States)

    Betka, Paul; Klepeis, Keith; Mosher, Sharon

    2016-04-01

    A system of left-lateral faults that separates the South American and Scotia plates, known as the Magallanes-Fagnano fault system, defines the modern tectonic setting of the southernmost Andes and is superimposed on the Late Cretaceous - Paleogene Patagonian fold-thrust belt. Fault kinematic data and crosscutting relationships from populations of thrust, strike-slip and normal faults from Peninsula Brunswick adjacent to the Magallanes-Fagnano fault system, presented herein, show kinematic and temporal relationships between thrust faults and sets of younger strike-slip and normal faults. Thrust fault kinematics are homogeneous in the study area and record subhorizontal northeast-directed shortening. Strike-slip faults record east-northeast-directed horizontal shortening, west-northwest-directed horizontal extension and form Riedel and P-shear geometries compatible with left-lateral slip on the main splay of the Magallanes-Fagnano fault system. Normal faults record north-south trending extension that is compatible with the strike-slip faults. The study area occurs in a releasing step-over between overlapping segments of the Magallanes-Fagnano fault system, which localized on antecedent sutures between basement terranes with differing geological origin. Results are consistent with regional tectonic models that suggest sinistral shearing and transtension in the southernmost Andes was contemporaneous with the onset of seafloor spreading in the Western Scotia Sea during the Early Miocene.

  13. Paleoseismic observations of an onshore transform boundary: the Magallanes-Fagnano fault, Tierra del Fuego Argentina

    Directory of Open Access Journals (Sweden)

    C.H. Costa

    2006-12-01

    Full Text Available We present preliminary information on the geomorphologic features and paleoseismic record associated with the ruptures of two Ms 7.8 earthquakes that struck Tierra del Fuego and the southernmost continental margin of South America on December 17, 1949. The fault scarp was surveyed in several places east of Lago Fagnano and a trench across a secondary fault trace of the Magallanes-Fagnano fault `was excavated at the Río San Pablo. The observed deformation in a 9 kyr-old peat bog sequence suggests evidence for two, and possibly three pre- 1949 paleoearthquakes is preserved in the stratigraphy. The scarp reaches heights up to 11 m in late Pleistocene-Holocene(? deposits, but the vertical component of the 1949 events was always less than ~1 m. This observation also argues for the occurrence of previous events during the Quaternary. Along the part of the fault we investigated east of Lago Fagnano, the horizontal component of the 1949 rupture does not exceed 4 m and is likely lower than 0.4 m, which is consistent with the kinematics of a local releasing bend, or at the end of a strike-slip rupture zone.

  14. Paleoseismic observations of an onshore transform boundary: The Magallanes-Fagnano fault, Tierra del Fuego, Argentina

    Science.gov (United States)

    Costa, C.H.; Smalley, R.; Schwartz, D.P.; Stenner, Heidi D.; Ellis, M.; Ahumada, E.A.; Velasco, M.S.

    2006-01-01

    We present preliminary information on the geomorphologic features and paleoseismic record associated with the ruptures of two Ms 7.8 earthquakes that struck Tierra del Fuego and the southernmost continental margin of South America on December 17, 1949. The fault scarp was surveyed in several places cast of Lago Fagnano and a trench across a secondary fault trace of the Magallanes-Fagnano fault was excavated at the Ri??o San Pablo. The observed deformation in a 9 kyr-old peat bog sequence suggests evidence for two, and possibly three pre-1949 paleoearthquakes is preserved in the stratigraphy. The scarp reaches heights up to 11 m in late Pleistocene-Holocence(?) deposits, but the vertical component of the 1949 events was always less than ???1 m. This observation also argues for the occurrence of previous events during the Quaternary. Along die part of the fault we investigated east of Lago Fagnano, the horizontal component of the 1949 rupture does not exceed 4 m and is likely lower than 0.4 m, which is consistent with the kinematics of a local releasing bend, or at the end of a strike-slip rupture zone. ?? 2006 Revista de la Asociacio??n Geolo??gica Argentina.

  15. Acoustic emission partial discharge detection technique applied to fault diagnosis: Case studies of generator transformers

    Directory of Open Access Journals (Sweden)

    Shanker Tangella Bhavani

    2016-01-01

    Full Text Available In power transformers, locating the partial discharge (PD source is as important as identifying it. Acoustic Emission (AE sensing offers a good solution for both PD detection and PD source location identification. In this paper the principle of the AE technique, along with in-situ findings of the online acoustic emission signals captured from partial discharges on a number of Generator Transformers (GT, is discussed. Of the two cases discussed, the first deals with Acoustic Emission Partial Discharge (AEPD tests on two identical transformers, and the second deals with the AEPD measurement of a transformer carried out on different occasions (years. These transformers are from a hydropower station and a thermal power station in India. Tests conducted in identical transformers give the provision for comparing AE signal amplitudes from the two transformers. These case studies also help in comprehending the efficacy of integrating Dissolved Gas is (DGA data with AEPD test results in detecting and locating the PD source.

  16. Rough set and radial basis function neural network based insulation data mining fault diagnosis for power transformer

    Institute of Scientific and Technical Information of China (English)

    DONG Li-xin; XIAO Deng-ming Xiao; LIU Yi-lu

    2007-01-01

    Rough set (RS) and radial basis function neural network (RBFNN) based insulation data mining fault diagnosis for power transformer is proposed. On the one hand rough set is used as front of RBFNN to simplify the input of RBFNN and mine the rules. The mined rules whose "confidence" and "support" is higher than requirement are used to offer fault diagnosis service for power transformer directly. On the other hand the mining samples corresponding to the mined rule, whose "confidence and support" is lower than requirement,are used to be training samples set of RBFNN and these samples are clustered by rough set. The center of each clustering set is used to be center of radial basis function, i.e. , as the hidden layer neuron. The RBFNN is structured with above base, which is used to diagnose the case that can not be diagnosed by mined simplified valuable rules based on rough set. The advantages and effectiveness of this method are verified by testing.

  17. A robust algorithm based on a failure-sensitive matrix for fault diagnosis of power systems: an application on power transformers

    OpenAIRE

    2015-01-01

    In this paper, a robust algorithm for fault diagnosis of power system equipment based on a failure-sensitive matrix (FSM) is presented. The FSM is a dynamic matrix structure updated by multiple measurements (online) and test results (offline) on the systems. The algorithm uses many different artificial intelligence and expert system methods for adaptively detecting the location of faults, emerging failures, and causes of failures. In this algorithm, all data obtained from the power transforme...

  18. A "Kane's Dynamics" Model for the Active Rack Isolation System

    Science.gov (United States)

    Hampton, R. D.; Beech, G. S.; Rao, N. N. S.; Rupert, J. K.; Kim, Y. K.

    2001-01-01

    Many microgravity space science experiments require vibratory acceleration levels unachievable without active isolation. The Boeing Corporation's Active Rack Isolation System (ARIS) employs a novel combination of magnetic actuation and mechanical linkages to address these isolation requirements on the International Space Station (ISS). ARIS provides isolation at the rack (International Standard Payload Rack (ISPR)) level. Effective model-based vibration isolation requires: (1) an appropriate isolation device, (2) an adequate dynamic (i.e., mathematical) model of that isolator, and (3) a suitable, corresponding controller. ARIS provides the ISS response to the first requirement. This paper presents one response to the second, in a state space framework intended to facilitate an optimal-controls approach to the third. The authors use "Kane's Dynamics" to develop a state-space, analytical (algebraic) set of linearized equations of motion for ARIS.

  19. A "Kanes's Dynamics" Model for the Active Rack Isolation System

    Science.gov (United States)

    Hampton, R. David; Beech, Geoffrey

    1999-01-01

    Many microgravity space-science experiments require vibratory acceleration levels unachievable without active isolation. The Boeing Corporation's Active Rack Isolation System (ARIS) employs a novel combination of magnetic actuation and mechanical linkages, to address these isolation requirements on the International Space Station (ISS). ARIS provides isolation at the rack (international Standard Payload Rack, or ISPR) level. Effective model-based vibration isolation requires (1) an appropriate isolation device, (2) an adequate dynamic (i.e., mathematical) model of that isolator, and (3) a suitable, corresponding controller. ARIS provides the ISS response to the first requirement. This paper presents one response to the second, in a state-space framework intended to facilitate an optimal-controls approach to the third. The authors use "Kane's Dynamics" to develop an state-space, analytical (algebraic) set of linearized equations of motion for ARIS.

  20. 2008 USGS Lidar: Twelve County, Illinois (Grundy, Kane, McHenry only)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This LiDAR data is within Illinois Department of Transportation districts 1 and 3 covering Grundy, Kane and McHenry counties. The data is updated from its original...

  1. Power transformer fault diagnosis model based on rough set theory with fuzzy representation

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Inthis paper,rough-fuzzy hybridizationis usedfor synthetic fault diagnosis of power transfor mers.Each diagnostic method s result is represented by itsfuzzy membership with respect to three credible de-gree sets as:Low,Middle,orHigh,thereby gen-erating a fuzzy granulation of the feature space thatcontains granules with otherwiseill-defined bounda-ries.Discernibility of the granulated objects inter ms of attributes is thencomputedinthe for mof adiscernibility matrix.Using rough set theory,anumber of decision...

  2. Detection of weak transient signals based on wavelet packet transform and manifold learning for rolling element bearing fault diagnosis

    Science.gov (United States)

    Wang, Yi; Xu, Guanghua; Liang, Lin; Jiang, Kuosheng

    2015-03-01

    The kurtogram-based methods have been proved powerful and practical to detect and characterize transient components in a signal. The basic idea of the kurtogram-based methods is to use the kurtosis as a measure to discover the presence of transient impulse components and to indicate the frequency band where these occur. However, the performance of the kurtogram-based methods is poor due to the low signal-to-noise ratio. As the weak transient signal with a wide spread frequency band can be easily masked by noise. Besides, selecting signal just in one frequency band will leave out some transient features. Aiming at these shortcomings, different frequency bands signal fusion is adopted in this paper. Considering that manifold learning aims at discovering the nonlinear intrinsic structure which embedded in high dimensional data, this paper proposes a waveform feature manifold (WFM) method to extract the weak signature from waveform feature space which obtained by binary wavelet packet transform. Minimum permutation entropy is used to select the optimal parameter in a manifold learning algorithm. A simulated bearing fault signal and two real bearing fault signals are used to validate the improved performance of the proposed method through the comparison with the kurtogram-based methods. The results show that the proposed method outperforms the kurtogram-based methods and is effective in weak signature extraction.

  3. An improved fault detection classification and location scheme based on wavelet transform and artificial neural network for six phase transmission line using single end data only.

    Science.gov (United States)

    Koley, Ebha; Verma, Khushaboo; Ghosh, Subhojit

    2015-01-01

    Restrictions on right of way and increasing power demand has boosted development of six phase transmission. It offers a viable alternative for transmitting more power, without major modification in existing structure of three phase double circuit transmission system. Inspite of the advantages, low acceptance of six phase system is attributed to the unavailability of a proper protection scheme. The complexity arising from large number of possible faults in six phase lines makes the protection quite challenging. The proposed work presents a hybrid wavelet transform and modular artificial neural network based fault detector, classifier and locator for six phase lines using single end data only. The standard deviation of the approximate coefficients of voltage and current signals obtained using discrete wavelet transform are applied as input to the modular artificial neural network for fault classification and location. The proposed scheme has been tested for all 120 types of shunt faults with variation in location, fault resistance, fault inception angles. The variation in power system parameters viz. short circuit capacity of the source and its X/R ratio, voltage, frequency and CT saturation has also been investigated. The result confirms the effectiveness and reliability of the proposed protection scheme which makes it ideal for real time implementation.

  4. Slip history of the La Cruz fault: Development of a late Miocene transform in response to increased rift obliquity in the northern Gulf of California

    Science.gov (United States)

    Bennett, Scott E. K.; Oskin, Michael E.; Iriondo, Alexander; Kunk, Michael J.

    2016-12-01

    The Gulf of California rift has accommodated oblique divergence of the Pacific and North America plates in northwestern México since Miocene time. Due to its infancy, its rifted margins preserve a rare onshore record of early continental break-up processes and an opportunity to investigate the role of rift obliquity in strain localization. We map rift-related structures and syn-tectonic basins on southern Isla Tiburón, a proximal onshore exposure of the rifted North America margin. We integrate analysis and geochronology of syn-tectonic sedimentary basins and mapping of crosscutting relationships to characterize the style and timing of fault activity. On southern Isla Tiburón, an early phase of extension initiated between 19-17 Ma and 12.2 Ma. Subsequently, these normal faults and related basins were cut by the La Cruz strike-slip fault and buried by deposits of the La Cruz basin, an elongate, fault-controlled trough coextensive with the La Cruz fault. Crosscutting relationships show that the NW-striking La Cruz fault accrued 5 ± 2 km of dextral slip 8-4 Ma. The La Cruz fault and parallel Tiburón transform were kinematically linked to detachment faulting that accommodated latest Miocene to Pliocene oblique opening of the offshore Upper Tiburón pull-apart basin. The onset of strike-slip faulting on Isla Tiburón was synchronous with the 8-6 Ma onset of transform faulting and basin formation along > 1000 km of the reconstructed Pacific-North America plate boundary. This transition coincides with the commencement of a clockwise azimuthal shift in Pacific-North America relative plate motion that increased the obliquity of the Gulf of California rift and formed the Gulf of California shear zone. The record from the proto-Gulf of California illustrates how highly oblique rift geometries, where transform faults are kinematically linked to pull-apart basins, enhance the ability of continental lithosphere to rupture and, ultimately, hasten the formation of new oceanic

  5. Quaternary tectonic activity in NW Jordan: Insights for a new model of transpression-transtension along the southern Dead Sea Transform Fault

    Science.gov (United States)

    Al-Awabdeh, M.; Pérez-Peña, J. V.; Azañón, J. M.; Booth-Rea, G.; Abed, A.; Atallah, M.; Galve, J. P.

    2016-12-01

    The Dead Sea Transform Fault (DSTF) constitutes the transform plate boundary between the African and Arabian plates. The southern part of this fault has been traditionally divided into two main segments, the Wadi Araba Fault (WAF) and the Jordan Valley Fault (JVF), connected through the Dead Sea continental pull-apart basin. Active tectonic studies in NW Jordan have traditionally focused on these DSTF structures and have neglected other prominent structures in the region, such as the Amman Hallabat Structure (AHS) and Shueib Structure (SHS) fault systems, which have been considered inactive since the Cretaceous. However, some recent studies have suggested a possible local reactivation of the southern parts of these structures. In this work, we carried out a detailed geological study of the NE Dead Sea Basin to analyze the Quaternary activity of the AHS and SHS based on field observations and structural analyses. Our findings have revealed that the AHS and SHS structures present clear Quaternary activity and accommodate a small part of the deformation of the southern DSTF. In the Quaternary, the southwestern part of the AHS has acted as the northernmost continuation of the WAF, whereas the SHS has acted as a transfer fault associated with NW-SE normal faults with low to moderate throws (meters to decameters) that connect this structure to the JVF. These NW-SE normal faults constitute the northeastern border of the Dead Sea depression (Jericho Valley). They produce a topographic front and separate the sediments of the Jordan Valley in the hanging wall from the Mesozoic sedimentary sequence located in the footwall.

  6. Paleoseismic observations of an onshore transform boundary: the Magallanes-Fagnano fault, Tierra del Fuego Argentina

    Directory of Open Access Journals (Sweden)

    C.H. Costa

    2006-12-01

    Full Text Available We present preliminary information on the geomorphologic features and paleoseismic record associated with the ruptures of two Ms 7.8 earthquakes that struck Tierra del Fuego and the southernmost continental margin of South America on December 17, 1949. The fault scarp was surveyed in several places east of Lago Fagnano and a trench across a secondary fault trace of the Magallanes-Fagnano fault `was excavated at the Río San Pablo. The observed deformation in a 9 kyr-old peat bog sequence suggests evidence for two, and possibly three pre- 1949 paleoearthquakes is preserved in the stratigraphy. The scarp reaches heights up to 11 m in late Pleistocene-Holocene(? deposits, but the vertical component of the 1949 events was always less than ~1 m. This observation also argues for the occurrence of previous events during the Quaternary. Along the part of the fault we investigated east of Lago Fagnano, the horizontal component of the 1949 rupture does not exceed 4 m and is likely lower than 0.4 m, which is consistent with the kinematics of a local releasing bend, or at the end of a strike-slip rupture zone.Se presenta información sobre las evidencias geomorfológicas y paleosísmicas observadas al este del lago Fagnano, relacionadas con dos terremotos de Ms 7,8, que ocurrieron en Tierra del Fuego el 17 de diciembre de 1949. Se efectuaron relevamientos en las escarpas observadas en los alrededores de Tolhuin y Estancia La Correntina-Río San Pablo. En este último sitio, se excavó una trinchera en un trazo secundario de la falla Magallanes-Fagnano con el propósito de analizar el registro paleosísmico de esta estructura. Con el apoyo de dataciones radiocarbónicas se reconoció la estratigrafía correspondiente a los últimos 9 ka, interpretándose por lo menos dos eventos sísmicos con rupturas superficiales previos al sismo de 1949 en este trazo de la falla. Se reconocieron escarpas asociadas de hasta 11 m de altura en depósitos atribuibles al

  7. Transformer Protection by Using FL Based Artificial Intelligent Buchholz Relay against Incipient Faults

    Directory of Open Access Journals (Sweden)

    SOUMYADEEP SAMONTO

    2016-03-01

    Full Text Available Switchgear and Protection are the two vital terminology of Electrical power system. Normally the components of any switchgear needs better protection schemes to be set for a composite power system. Many explorers worked on artificial intelligent breaker but an indulgence of fuzzy theory is nevertheless very absent in case of buchholz relay. Here in this paper discussion has been drawn in favor of the Artificial Intelligent Buchholz (AIB relay where inputs are level of transformer oil and rate of oil rising due to over current. To fit with the transformer tank it is needed to measure level of transformer oil and the rate at which volume increasing. The constructional feature of a rate of rise pressure relay is taken into account in this work along with the working principle of a buchholz relay. The change in the inputs will give a crisp output to change the contacts state from normally closed to normally open by tripping via alarm circuit indeed like the basic buchholz relay does. The entire concept has been developed under MATLAB environment using Mamdani based Fuzzy Inference System. Experimental output data validates the implementation of Transformer Protection by Using Fuzzy Logic Based Artificial Intelligent Buchholz Relay.

  8. Pd-Doped SnO2-Based Sensor Detecting Characteristic Fault Hydrocarbon Gases in Transformer Oil

    Directory of Open Access Journals (Sweden)

    Weigen Chen

    2013-01-01

    Full Text Available Methane (CH4, ethane (C2H6, ethylene (C2H4, and acetylene (C2C2 are important fault characteristic hydrocarbon gases dissolved in power transformer oil. Online monitoring these gaseous components and their generation rates can present the operational state of power transformer timely and effectively. Gas sensing technology is the most sticky and tricky point in online monitoring system. In this paper, pure and Pd-doped SnO2 nanoparticles were synthesized by hydrothermal method and characterized by X-ray powder diffraction, field-emission scanning electron microscopy, and energy dispersive X-ray spectroscopy, respectively. The gas sensors were fabricated by side-heated preparation, and their gas sensing properties against CH4, C2H6, C2H4, and C2H2 were measured. Pd doping increases the electric conductance of the prepared SnO2 sensors and improves their gas sensing performances to hydrocarbon gases. In addition based on the frontier molecular orbital theory, the highest occupied molecular orbital energy and the lowest unoccupied molecular orbital energy were calculated. Calculation results demonstrate that C2H4 has the highest occupied molecular orbital energy among CH4, C2H6, C2H4, and C2H2, which promotes charge transfer in gas sensing process, and SnO2 surfaces capture a relatively larger amount of electric charge from adsorbed C2H4.

  9. Constraining the shear zone along the Dead Sea transform fault in the crust and upper mantle using seismic anisotropy

    Science.gov (United States)

    Kaviani, Ayoub; Rümpker, Georg; Asch, Günter; Desire Group

    2010-05-01

    We study seismic anisotropy along the Dead Sea Transform fault (DST) by shear-wave splitting analysis of SKS and SKKS waveforms recorded at a dense network of broad-band and short-period stations of the DESIRE experiment. The DST accommodates the relative motion between Africa and Arabia through a sinistral strike-slip motion. The Dead Sea is a pull-apart basin formed along the DST as a result of stepwise fault-normal displacement. The DESIRE array of stations cover this portion of the DST. We measured the splitting parameters (delay times between the fast and slow components of the shear wave and fast polarization direction) in different period bands. We observed consistent fast polarization directions varying from N14W to N19E at different stations and delay times ranging between 1.0 and 2.5 s. Our preliminary examination reveals that the splitting parameters do not exhibit significant frequency dependence. However, we observe variations in the splitting parameters (mostly delay times) along an E-W profile crossing the DST, with smaller delay times in the middle of the profile, within the surface exposure of the DST shear zone, and with two lobes of relatively large delay times on both sides of the central region. The fast polarization directions along this profile change from a dominant NNW trend in the western side of the DST to a general N-S orientation in the central part and a dominant NNE trend to the east. Waveform modeling is required to infer the lateral and depth variations of the strength and orientation of anisotropy in the crust and upper mantle from these observations. We will also complement our results with the data from the DESERT experiment to provide an overall pattern of seismic anisotropy and structural fabric beneath the DST and surrounding regions from the north of the Dead Sea down to the Red sea.

  10. Margaret E. O'Kane on healthcare accreditation. Interview by Wanda Bishop and Kevin C. Park.

    Science.gov (United States)

    O'Kane, M E

    2001-01-01

    Since 1990, Margaret E. O'Kane has served as president of the National Committee for Quality Assurance (NCQA), an independent, not-for-profit organization whose mission is to improve the quality of healthcare everywhere. Under O'Kane's leadership, NCQA has developed broad support among the employer and health plan communities; today many Fortune 100 companies will do business only with NCQA-accredited health plans. About three quarters of the nation's largest employers use Health Plan Employer Data and Information Set (HEDIS) data to evaluate the plans that serve their employees. O'Kane was named Health Person of the Year in 1996 by the journal Medicine & Health. She also received a 1997 Founder's Award from the American College of Medical Quality, recognizing NCQA's efforts to improve managed care quality. In 1999, O'Kane was elected a member of the Institute of Medicine. In 2000, she received the Centers for Disease Control and Prevention (CDC) Champion of Prevention award, the agency's highest honor. CDC names a Champion of Prevention infrequently and only when an individual has made a truly notable contribution to advancing preventive healthcare. O'Kane began her career in healthcare as a respiratory therapist and has a master's degree in health administration and planning from Johns Hopkins University.

  11. Transformer Fault Diagnosis Based on Support Vector Machines%基于支持向量机的变压器故障诊断

    Institute of Scientific and Technical Information of China (English)

    刘义艳; 陈晨; 亢旭红; 巨永锋

    2011-01-01

    Due to lack of typical damage samples in the transformer fault diagnosis, a new fault diagnosis method based on support vector machines (SVMs) is presented. According to the method, the five characteristic gases dissolved in transformer oil are extracted by the K-means clustering (KMC) method as feature vectors, which are input into multi-classified SVMs for training, and then the SVMs diagnosis model is established to implement fault samples classification. The results of experiment and analysis show that with KMC algorithm, the diagnosis information are concentrated and the great time consumption in parameter determination is remitted effectively. The presented method can detect the faults in transformer with a high correct judgment rate and can reach the purpose of automation diagnosis for transformer faults under the condition of few samples.%针对变压器故障诊断中缺少实际典型故障样本的问题,提出了支持向量机(SVMs)变压器故障诊断方法.该方法采用K均值聚类(KMC)对变压器油中5种特征气体样本进行预选取作为特征向量,输入到多分类支持向量机中进行训练,建立SVMs诊断模型,实现对故障样本的诊断分类.实例分析表明,KMC算法浓缩了故障信息,有效地解决了确定模型参数时耗时巨大的问题.该方法在有限样本情况下,能够达到较高的故障正判率,满足变压器故障自动诊断的目的.

  12. Assessment Method for the Reliability of Power Transformer Based on Fault-tree Analysis%基于粒子群优化支持向量机的变压器故障诊断

    Institute of Scientific and Technical Information of China (English)

    费胜巍; 苗玉彬; 刘成良

    2009-01-01

    Accurate assessment of system reliability with limited or insufficient statistical data is difficult. At present, to assess the reliability of the transformers primarily depend on the statistics data, and the result of the assessment does not accurately reflect the reliability of a transformer. Fault tree is a powerful tool for depicting the logical relationships between the faults system. However, for a sophisticated reliability system, like power transformer,fault analysis is hard or infeasible because of the complexities of the equipment configuration and its faults. This paper presents a method which overcomes the drawbacks of traditional fault-tree analysis (FTA) by using FTA based on fault probability and equivalent calculation of each failure mode. Based on the further analysis of typical failure modes and influences of power transformer, the fault-tree of transformer is set up by using FTA techniques and the assessment method for the reliability of transformer is put forward, combined with the index of the importance and the method of improved analytic hierarchy process(IAHP). The assessment examples show the method can deduct the failure modes of transformer clearly, meanwhile, find out the weaknesses in time during the operation and get better assessment results. The method is helpful for the reliability analysis of a sophisticated system.

  13. Stacking faults and phase transformations study in ball milled Co{sub 100-x}Cr{sub x} (x = 0, 20, 50) alloys

    Energy Technology Data Exchange (ETDEWEB)

    Louidi, S., E-mail: louidisof@yahoo.fr [Laboratoire de Magnetisme et de Spectroscopie des Solides (LM2S), Departement de Physique, Faculte des Sciences, Universite de Annaba, B.P. 12, 23000 Annaba (Algeria); Departement des Sciences de la Matiere, Faculte des Sciences, Universite 20 Aout de Skikda (Algeria); Bentayeb, F.-Z.; Tebib, W. [Laboratoire de Magnetisme et de Spectroscopie des Solides (LM2S), Departement de Physique, Faculte des Sciences, Universite de Annaba, B.P. 12, 23000 Annaba (Algeria); Sunol, J.J.; Escoda, L. [Dep. Fisica, Universitat Girona, Campus Montilivi, 17071 Girona (Spain); Mercier, A.M. [Laboratoire des Fluorures, UMR CNRS 6010, Universite du Maine, F-72085 Le Mans Cedex 9 (France)

    2012-02-15

    Highlights: Black-Right-Pointing-Pointer We investigate the induced phase transformations fcc {r_reversible} hcp in Co{sub 100-x}Cr{sub x} (x = 0, 20, 50) alloys during milling. Black-Right-Pointing-Pointer The investigation is carried out by the Rietveld refinement of the XRD patterns. Black-Right-Pointing-Pointer The structural parameters of different phases are determined. Black-Right-Pointing-Pointer Ball milling induces fcc {yields} hcp and hcp {yields} fcc phase transformations in the first and the last stage of milling, respectively Black-Right-Pointing-Pointer The induced phase transformations are correlated with the stacking faults accumulation in fcc and hcp structures. - Abstract: The structural evolution and the phase transformations occurred during milling process of Co{sub 100-x}Cr{sub x} (x = 0, 20, 50) alloys are investigated by X-ray diffraction. Microstructural parameters such as the crystallites size, the microstrains, the stacking faults, the dislocation density and the phase fraction were determined from the Rietveld refinement of the X-ray diffraction patterns. The results show the formation of nanostructured alloys which depend on the initial composition of the mixture. In addition, X-ray diffraction indicates that the ball milling induces the fcc to hcp phase transformation in the first stage of milling and the reverse hcp to fcc phase transformation at the end of milling. On the basis of Warren's model, these allotropic transformations were explained by the presence of dislocations and the accumulation of stacking faults in the hcp and the fcc structures.

  14. Orson Welles. Ciudadano Kane. Estudio Crítico [Introducció

    OpenAIRE

    Rey-Reguillo, Antonia del

    2002-01-01

    La película "Ciudano Kane" nació marcada por polémicas y escándalos que ni siquiera las entusiastas críticas lograron aminorar. Desde entonces, los años transcurridos han hecho de ella uno de los grandes clásicos del cine, porque su deslumbrante envoltorio formal está puesto al servicio de un contenido tan pródigo en significados que aún hoy sigue suscitando nuevas interpretaciones y reflexiones de los estudiosos. The film ciudano Kane was born marked by controversies and scandals that eve...

  15. Fault Diagnosis of Transformer Based on D-S Evidence Theory%基于D-S证据理论的变压器故障诊断

    Institute of Scientific and Technical Information of China (English)

    王日彬; 佘彩绮; 刘新东; 周锦龙

    2012-01-01

    Because the relationship between fault symptom and failure cause of power transformer is complex and the fault of transformer is not always diagnosed accurately by using single method, a new fault diagnosis method by combining grey association entropy method and weighted K-NN algorithm is proposed based on the D-S Evidence Theory in this paper. On the basis of the dissolved gases analysis (DGA), the basic credit assignment function of evidence theory is built by grey association entropy algorithm and weighted K-NN algorithm. Then, more reliable evidence information is generated by using of evidence combination rule. In the end, the fault of transformer is diagnosed according to the maximum basic credit value. The example of fault diagnosis of transformer testifies the feasibility and effectiveness of proposed algorithm, which can accurately diagnose the transformer fault.%针对电力变压器故障征兆与原因之间错综复杂的关系,以及单一变压器故障诊断算法精度有限的问题,本文提出一种在D-S证据理论的基础上,结合灰关联熵法和加权K邻近算法的变压器故障诊断新方法.该算法以油中溶解气体分析方法(Dissolved Gases Analysis,简称DGA)为基础,通过灰关联熵法和加权K邻近算法构建证据理论的基本可信度赋值函数,然后利用证据组合规则产生更为可靠的证据信息;最后根据基本可信数最大值确定变压器故障类型.变压器故障诊断实例结果表明该算法能够准确判断出变压器的故障类型,证明了该算法的可行性和有效性.

  16. Special Case Analysis of A Large Transformer Oil Dielectric Loss Fault%大型变压器油介损超标现场特例分析

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    The fault analysis and special solution to a transformer oil dielectric loss were given .Then some ignored reasons for oil dielectric loss were presented in the prodution of transformers .%  介绍了大型变压器油介质损耗因数(简称介损)超标的故障及典型处理方法,以及变压器生产制造过程中容易忽视的可能导致介损超标的一些细节因素。

  17. Geochronology Constraints on Transformation Age from Ductile to Brittle Deformation of the Shangma Fault and Its Tectonic Significance, Dabieshan, Central China

    Institute of Scientific and Technical Information of China (English)

    Wang Guocan; Wang Pu; Liu Chao; Wang An; Ye Runqing

    2008-01-01

    By a detailed investigation of geometry and kinematics of the Shangma (商麻) fault in Dabieshan (大别山),three different crust levels of extension movement have been recognized in sequence from the deep to the shallow:① low-angle ductile detachment shearing with top to the NW; ② low-angle normal fault with top to the NW or NWW in brittle or brittle-ductile transition domain; ③high-angle brittle normal fault with top to the W or NWW. Two samples were chosen for zircon U-Pb age dating to constrain the activity age of the Shangma fault. A bedding intrusive granitoid pegmatite vein that is parallel to the foliation of the low-angle ductile detachment shear zone of the country rock exhibits a lotus-joint type of boudinage deformation,showing syn-tectonic emplacing at the end of the ductile deformation period and deformation in the brittle-ductile transition domain. The zircon U-Pb dating of this granitoid pegmatite vein gives an age of (125.9±4.2) Ma,which expresses the extension in the brittle-ductile transition domain of the Shangma fault. The other sample,which is collected from a granite pluton cutting the foliation of the low-angle ductile detachment shear zone, gives a zircon U-Pb age of (118.8±4.1) Ma,constraining the end of the ductile detachment shearing. Then the transformation age from ductile to brittle deformation can be constrained between 126-119 Ma.Combined with the previous researches,the formation of the Luotian (罗田) dome,which is located to the east of the Shangma fault,can beconstrained during 150-126 Ma. This study gives a new time constraint to the evolution of the Dabie orogenic belt.

  18. 75 FR 36149 - Union Pacific Railroad Company-Abandonment Exemption-in Kane County, IL.

    Science.gov (United States)

    2010-06-24

    ....30, near St. Charles, in Kane County, Ill. The line traverses United States Postal Service Zip Code... salvage of the line, the line may be suitable for other public use, including interim trail use. Any..., Office of Proceedings. Jeffrey Herzig, Clearance Clerk. BILLING CODE 4915-01-P...

  19. Establishing an Improved Kane Dynamic Model for the 7-DOF Reconfigurable Modular Robot

    Directory of Open Access Journals (Sweden)

    Xiao Li

    2017-01-01

    Full Text Available We propose an improved Kane dynamic model theory for the 7-DOF modular robot in this paper, and the model precision is improved by the improved function T′it. We designed three types of progressive modular joints for reconfigurable modular robot that can be used in industrial robot, space robot, and special robot. The Kane dynamic model and the solid dynamic model are established, respectively, for the 7-DOF modular robot. After that, the experimental results are obtained from the simulation experiment of typical task in the established dynamic models. By the analysis model of error, the equation of the improved torque T′it is derived and proposed. And the improved Kane dynamic model is established for the modular robot that used T′it. Based on the experimental data, the undetermined coefficient matrix is five-order linear that was proved in 7-DOF modular robot. And the explicit formulation is solved of the Kane dynamic model and can be used in control system.

  20. A Novel Method for Inverter Faults Detection and Diagnosis in PMSM Drives of HEVs based on Discrete Wavelet Transform

    Directory of Open Access Journals (Sweden)

    AKTAS, M.

    2012-11-01

    Full Text Available The paper proposes a novel method, based on wavelet decomposition, for detection and diagnosis of faults (switch short-circuits and switch open-circuits in the driving systems with Field Oriented Controlled Permanent Magnet Synchro?nous Motors (PMSM of Hybrid Electric Vehicles. The fault behaviour of the analyzed system was simulated by Matlab/SIMULINK R2010a. The stator currents during transients were analysed up to the sixth level detail wavelet decomposition by Symlet2 wavelet. The results prove that the proposed fault diagnosis system have very good capabilities.

  1. 基于BP神经网络的变压器内部故障保护%Internal fault protection based on BP neural network transformer

    Institute of Scientific and Technical Information of China (English)

    苏美玲; 邹晓松; 何杰

    2016-01-01

    本文研究了基于BP神经网络方法的变压器内部故障保护。运用MATLAB/SUMILINK对变压器励磁涌流、励磁涌流与故障电流的差异进行了数字仿真。利用MATLAB的人工神经网络工具箱,建立了BP神经网络模型,对励磁涌流和故障电流的样本进行训练及测试并对训练好的网络进行验证。表明BP神经网络可以较为正确地区分励磁涌流和故障电流,用于变压器内部故障保护。%This paper discussed a transformer protection based on Back- Propagation Network .Digital simulation were made on the inrush current of the transformer and on the comparison between the inrush current and the fault current of the transformer. Back- Propagation Network model was set up by using the MATLAB artificial neural network toolbox. The results show that the Back- Propagation Network almost can correctly distinguish between excitation inrush current and the fault current of the transformer.

  2. Bearing fault diagnosis under variable rotational speed via the joint application of windowed fractal dimension transform and generalized demodulation: A method free from prefiltering and resampling

    Science.gov (United States)

    Shi, Juanjuan; Liang, Ming; Guan, Yunpeng

    2016-02-01

    The conventional way for bearing fault diagnosis under variable rotational speed generally includes prefiltering, resampling based on shaft rotating frequency and order spectrum analysis. However, its application is confined by three major obstacles: a) knowledge-demanding parameter determination required by prefiltering, b) unavailable shaft rotating frequency for resampling as it is coupled with instantaneous fault characteristic frequency (IFCF) by a fault characteristic coefficient (FCC) which cannot be decided without knowing what fault actually exists, and c) complicated and error-prone resampling process. As such, we propose a new method to address these problems. The proposed method free from prefiltering and resampling mainly contains the following steps: a) extracting envelope by windowed fractal dimension (FD) transform, requiring no prefiltering, b) with the envelope signal, performing short time Fourier transform (STFT) to get a clear time frequency representation (TFR), from which the IFCF and the basic demodulator for generalized demodulation (GD) can be obtained, c) applying the generalized demodulation to the envelope signal with the current demodulator, converting the trajectory of the current time-frequency component into a linear path parallel to the time axis, d) frequency analyzing the demodulated signal, followed by searching the amplitude of the constant frequency where the linear path is situated. Updating demodulator via multiplying the basic demodulator by different real numbers (i.e., coefficient λ) and repeating the steps (c)-(d), the resampling-free order spectrum is then obtained. Based on the resulting spectrum, the final diagnosis decision can be made. The proposed method for its implementation on the example of simulated data is presented. Finally, experimental data are employed to validate the effectiveness of the proposed technique.

  3. Road and Street Centerlines, Kane Springs, Published in 2007, 1:24000 (1in=2000ft) scale, Iron County.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — , published at 1:24000 (1in=2000ft) scale, was produced all or in part from Other information as of 2007. It is described as 'Kane Springs'. The extent of these...

  4. DIAGNOSIS OF INSIDIOUS FAULT INSIDE POWER TRANSFORMER%变压器内部潜伏性故障的诊断方法

    Institute of Scientific and Technical Information of China (English)

    倪健

    2001-01-01

    Some common-used methods and measuring instruments by gas chromatography are described in this paper for the fault diagnosis inside transformer. The feature and the demerit of gas chromatography are stated.%介绍了用于判断变压器内部故障的几种常用的气相色谱分析法及其常用测试仪器,指出了气相色谱法的特点和不足。

  5. Precarious rock and overturned transformer evidence for ground shaking in the Ms 7.7 Kern County earthquake: An analog for disastrous shaking from a major thrust fault in the Los Angeles basin

    Science.gov (United States)

    Brune, J.N.; Anooshehpoor, A.; Shi, B.; Zheng, Yen

    2004-01-01

    Precariously balanced rocks and overturned transformers in the vicinity of the White Wolf fault provide constraints on ground motion during the 1952 Ms 7.7 Kern County earthquake, a possible analog for an anticipated large earthquake in the Los Angeles basin (Shaw et al., 2002; Dolan et al., 2003). On the northeast part of the fault preliminary estimates of ground motion on the footwall give peak accelerations considerably lower than predicted by standard regression curves. On the other hand, on the hanging-wall, there is evidence of intense ground shattering and lack of precarious rocks, consistent with the intense hanging-wall accelerations suggested by foam-rubber modeling, numerical modeling, and observations from previous thrust fault earthquakes. There is clear evidence of the effects of rupture directivity in ground motions on the hanging-wall side of the fault (from both precarious rocks and numerical simulations). On the southwest part of the fault, which is covered by sediments, the thrust fault did not reach the surface ("blind" thrust). Overturned and damaged transformers indicate significant transfer of energy from the hanging wall to the footwall, an effect that may not be as effective when the rupture reaches the surface (is not "blind"). Transformers near the up-dip projection of the fault tip have been damaged or overturned on both the hanging-wall and footwall sides of the fault. The transfer of energy is confirmed in a numerical lattice model and could play an important role in a similar situation in Los Angeles. We suggest that the results of this study can provide important information for estimating the effects of a large thrust fault rupture in the Los Angeles basin, specially given the fact that there is so little instrumental data from large thrust fault earthquakes.

  6. Implementation of Kane's Method for a Spacecraft Composed of Multiple Rigid Bodies

    Science.gov (United States)

    Stoneking, Eric T.

    2013-01-01

    Equations of motion are derived for a general spacecraft composed of rigid bodies connected via rotary (spherical or gimballed) joints in a tree topology. Several supporting concepts are developed in depth. Basis dyads aid in the transition from basis-free vector equations to component-wise equations. Joint partials allow abstraction of 1-DOF, 2-DOF, 3-DOF gimballed and spherical rotational joints to a common notation. The basic building block consisting of an "inner" body and an "outer" body connected by a joint enables efficient organization of arbitrary tree structures. Kane's equation is recast in a form which facilitates systematic assembly of large systems of equations, and exposes a relationship of Kane's equation to Newton and Euler's equations which is obscured by the usual presentation. The resulting system of dynamic equations is of minimum dimension, and is suitable for numerical solution by computer. Implementation is ·discussed, and illustrative simulation results are presented.

  7. A Novel Method of Fault Diagnosis for Rolling Bearing Based on Dual Tree Complex Wavelet Packet Transform and Improved Multiscale Permutation Entropy

    Directory of Open Access Journals (Sweden)

    Guiji Tang

    2016-01-01

    Full Text Available A novel method of fault diagnosis for rolling bearing, which combines the dual tree complex wavelet packet transform (DTCWPT, the improved multiscale permutation entropy (IMPE, and the linear local tangent space alignment (LLTSA with the extreme learning machine (ELM, is put forward in this paper. In this method, in order to effectively discover the underlying feature information, DTCWPT, which has the attractive properties as nearly shift invariance and reduced aliasing, is firstly utilized to decompose the original signal into a set of subband signals. Then, IMPE, which is designed to reduce the variability of entropy measures, is applied to characterize the properties of each obtained subband signal at different scales. Furthermore, the feature vectors are constructed by combining IMPE of each subband signal. After the feature vectors construction, LLTSA is employed to compress the high dimensional vectors of the training and the testing samples into the low dimensional vectors with better distinguishability. Finally, the ELM classifier is used to automatically accomplish the condition identification with the low dimensional feature vectors. The experimental data analysis results validate the effectiveness of the presented diagnosis method and demonstrate that this method can be applied to distinguish the different fault types and fault degrees of rolling bearings.

  8. INVESTIGATION ON KANE DYNAMIC EQUATIONS BASED ON SCREW THEORY FOR OPENCHAIN MANIPULATORS

    Institute of Scientific and Technical Information of China (English)

    LIU Wu-fa; GONG Zhen-bang; WANG Qin-que

    2005-01-01

    First, screw theory, product of exponential formulas and Jacobian matrix are introduced. Then definitions are given about active force wrench, inertial force wrench, partial velocity twist, generalized active force, and generalized inertial force according to screw theory. After that Kane dynamic equations based on screw theory for open-chain manipulators have been derived. Later on how to compute the partial velocity twist by geometrical method is illustrated. Finally the correctness of conclusions is verified by example.

  9. Magneto-Optical Signature of Massless Kane Electrons in Cd3 As2

    Science.gov (United States)

    Akrap, A.; Hakl, M.; Tchoumakov, S.; Crassee, I.; Kuba, J.; Goerbig, M. O.; Homes, C. C.; Caha, O.; Novák, J.; Teppe, F.; Desrat, W.; Koohpayeh, S.; Wu, L.; Armitage, N. P.; Nateprov, A.; Arushanov, E.; Gibson, Q. D.; Cava, R. J.; van der Marel, D.; Piot, B. A.; Faugeras, C.; Martinez, G.; Potemski, M.; Orlita, M.

    2016-09-01

    We report on optical reflectivity experiments performed on Cd3 As2 over a broad range of photon energies and magnetic fields. The observed response clearly indicates the presence of 3D massless charge carriers. The specific cyclotron resonance absorption in the quantum limit implies that we are probing massless Kane electrons rather than symmetry-protected 3D Dirac particles. The latter may appear at a smaller energy scale and are not directly observed in our infrared experiments.

  10. Transformer Winding Common Fault and Processing Method Analysis%变压器绕组常见故障及处理方法探析

    Institute of Scientific and Technical Information of China (English)

    段成琳

    2012-01-01

      The power system transformer is very main a equipment, transformer in good operating safety of power grid has a very important significance. Although transformer the operation reliability of rising, but its winding trigger fault or frequent. Transformer winding in the event of failure will cause transformer decommissioning, at the same time for the safety of power grid operation and production brings the serious influence.%  电力系统中变压器是非常主要的一次设备,变压器的良好运行对电网安全具有非常重要的意义。虽然变压器运行的可靠性不断提升,但其绕组引发的故障还是频繁发生。变压器绕组如果发生故障将引起变压器的停运,同时对电网的安全运行和生产带来严重影响。

  11. The Alarcón Rise: detail mapping and preliminary results on the geometry, distribution and kinematics of faults and fissures on a ridge-transform system

    Science.gov (United States)

    Spelz, R. M.; Fletcher, J. M.; Nieves-Cardoso, C.; Santa Rosa-del Rio, M.; Caress, D. W.; Clague, D. A.; Paduan, J. B.; Martin, J. F.; Guardado-France, R.

    2012-12-01

    The Alarcón Rise, the northernmost segment of the East Pacific Rise before it enters the Gulf of California, is the oldest and perhaps most active spreading ridge-transform system along the oblique-divergent Pacific-North America plate boundary in the southern Gulf of California. Magnetic anomalies along the main ridge axis, which stretches for nearly 50 km long in a NE-SW (034o) direction, suggest that spreading with new oceanic crust was fully established ca. 2.5 Ma, and that its modern configuration as the main plate boundary initiated ca. 2 Ma (Umhoefer, P.J. et al., 2007 Basin Research). High resolution (1m lateral/0.2m vertical) bathymetry data and direct observations of the entire ridge segment, collected and performed by MBARI's autonomous underwater vehicle (AUV) and ROV dives, respectively, during the 2012 Expedition to the Gulf of California, have revealed the presence of an intense array of fault-scarps and fissures displacing numerous neovolcanic landforms such as huge lava domes and smaller cones, pillow mounds and large sheet flows along the entire ridge. The relative age of the surface ruptures is wide-ranging. At some places the fractures appear to be relatively recent, as evident by the apparent young age of the fractured flows, based on having few sessile organisms and/or relatively thin sediment cover. In contrast, fractures and fault-scarps elsewhere are observed to have been partially or totally overrun by lava flows, suggesting their preexistence and relatively older age. The ridge parallel faults and fissures change orientation dramatically as they approach and wrap around the bordering Pescadero and Tamayo fracture zones, which limit the northern and southern flanks of the rise, respectively, giving the ridge a sigmoidal geometry with a Z-shaped symmetry. Moreover, the presence of an en echelon volcanic fissure system near the southern end of the ridge, measuring several kilometers long and oriented somewhat obliquely (~15o clockwise) to

  12. 基于小波变换的电力电缆故障测距研究%Research of Power Cable Fault Location Based on Wavelet Transform

    Institute of Scientific and Technical Information of China (English)

    廖晓辉; 梁恒娜; 丁倩

    2013-01-01

    With wide application of power cable in transmission and distribution systems,the demand for cable fault location accuracy is improved.In order to locate cable fault accurately,the wavelet transform is applied in detecting the traveling wave signal of power cable.According to the principle of singularity detection of signals,the traveling wave starting pulse and reflection pulse time point is determined by searching modulus maximum,and then locating by single terminal traveling wave method for the online fault location.The experimen tal results show that the traveling wave singularity point can be detected by using localized time-frequencycharacteristic of wavelet transform,thereby the accurate time of pulse arrival is obtained.This method is not affected by fault type and the range error is small,which can achieve a higher fault location accuracy.%随着电力电缆的广泛应用,对电缆故障测距的精确度要求也日益提高.为了实现电缆故障的精确定位,引入小波变换的方法对电缆故障行波信号进行检测和分析,根据信号的奇异性检测原理,采用搜索模极大值的方法确定行波信号起始脉冲和反射脉冲时间点,应用单端行波在线故障测距方法进行测距,实验结果表明,利用小波变换的时频局部化特性可有效聚焦到电缆行波信号的奇异点,从而得到精确的脉冲到达时刻.该方法不受电缆故障类型的影响,测距误差小,可获得较高的故障定位精度.

  13. Temperature-driven massless Kane fermions in HgCdTe crystals

    Science.gov (United States)

    Teppe, F.; Marcinkiewicz, M.; Krishtopenko, S. S.; Ruffenach, S.; Consejo, C.; Kadykov, A. M.; Desrat, W.; But, D.; Knap, W.; Ludwig, J.; Moon, S.; Smirnov, D.; Orlita, M.; Jiang, Z.; Morozov, S. V.; Gavrilenko, V. I.; Mikhailov, N. N.; Dvoretskii, S. A.

    2016-08-01

    It has recently been shown that electronic states in bulk gapless HgCdTe offer another realization of pseudo-relativistic three-dimensional particles in condensed matter systems. These single valley relativistic states, massless Kane fermions, cannot be described by any other relativistic particles. Furthermore, the HgCdTe band structure can be continuously tailored by modifying cadmium content or temperature. At critical concentration or temperature, the bandgap collapses as the system undergoes a semimetal-to-semiconductor topological phase transition between the inverted and normal alignments. Here, using far-infrared magneto-spectroscopy we explore the continuous evolution of band structure of bulk HgCdTe as temperature is tuned across the topological phase transition. We demonstrate that the rest mass of Kane fermions changes sign at critical temperature, whereas their velocity remains constant. The velocity universal value of (1.07+/-0.05) × 106 m s-1 remains valid in a broad range of temperatures and Cd concentrations, indicating a striking universality of the pseudo-relativistic description of the Kane fermions in HgCdTe.

  14. Modeling of a space flexible probe–cone docking system based on the Kane method

    Directory of Open Access Journals (Sweden)

    Zhang Xiang

    2014-04-01

    Full Text Available Recent developments in micro- and nano-satellites have attracted the interest of the research community worldwide. Many colleges and corporations have launched their satellites in space. Meanwhile, the space flexible probe–cone docking system for micro- and nano-satellites has become an attractive topic. In this paper, a dynamic model of a space flexible probe–cone docking system, in which the flexible beam technology is applied, is built based on the Kane method. The curves of impact force versus time are obtained by the Lagrange model, the Kane model, and the experimental method. The Lagrange model was presented in the reference and verified by both finite element simulation and experiment. The results of the three methods show good agreements on the condition that the beam flexibility and the initial relative velocity change. It is worth mentioning that the introduction of vectorial mechanics and analytical mechanics in the Kane method leads to a large reduction of differential operations and makes the modeling process much easier than that of the Lagrange method. Moreover, the influences of the beam flexibility and the initial relative velocity are discussed. It is concluded that the initial relative velocity of space docking operation should be controlled to a certain value in order to protect the docking system.

  15. Research of Magnetizing Inrush Current and Fault Current Identification Based on Wavelet Transform in Transformer Protection%基于小波变换的变压器励磁涌流和故障电流识别研究

    Institute of Scientific and Technical Information of China (English)

    张晓; 张建文; 潘磊落

    2012-01-01

    变压器差动保护是变压器的重要保护之一,在变压器差动保护中,励磁涌流的准确识别是保护可靠动作的保证,也是变压器保护的难点之一.本文利用Matlab/Simulink建立模型进行仿真,得到了励磁涌流与内部故障电流的波形.通过快速傅里叶变换对其进行分析,总结了励磁涌流的波形特点;对其进行小波分解,发现两者小波分解后第三尺度的细节信号有较大不同,并得到了用于区分两者的判据,可用于变压器差动保护中励磁涌流的识别.%Differential protection is one of important protective schemes for transformers, accurate identification of magnetizing inrush current is the guarantee for reliable action, and it is also one of hard problems in transformers differential protection. The waveforms of magnetizing inrush current and fault current are obtained by modeling and simulating in Matlab/Simulink. Utilizing FFT, the waveform features of magnetizing inrush current are analyzed; and the level 3 detailed signal of magnetizing inrush current and fault current are detected different by wavelet transform. A wavelet transform method is proposed to recognize magnetizing inrush current and can be used in transformers differential protection.

  16. The Mw6.5 earthquake of 17 November 2015 in Lefkada Island and the seismotectonics in the Cephalonia Transform Fault (Ionian Sea, Greece)

    Science.gov (United States)

    Papadopoulos, Gerassimos A.; Agalos, Apostolos; Bocchini, Gian Maria; Chousianitis, Konstantinos; Karastathis, Vassilis; Triantafyllou, Ioanna; Kontoes, Charis; Papoutsis, Ioannis; Svigkas, Nikos; Koukouvelas, Ioannis; Zygouri, Vasiliki; Tselentis, Akis

    2016-04-01

    inversion method, which is capable of estimating the distributions of both the spatial slip and rise time on the ruptured fault, was applied using the Harvard CMT focal mechanism solution. The above velocity model was used to create the subfault synthetics. It was found that the earthquake had a not very complex source time function with nearly 78 cm maximum slip with source duration of ~13 s. Most of the slip is concentrated on a 14 km x 7 km fault rupture. The rupture propagated from the mainshock focal depth of 12 km upwards and southwards. Taking into account together the Cephalonia Jan.-Febr. 2014 seismic sequence and the Lefkada 2015 sequence, the overall seismotectonic picture is that the northern (Lefkada) branch of the Cephalonia Transform Fault (CTF) continues towards SW intersecting western Cephalonia. Also, it is likely that the 2015 earthquake fits the characteristic earthquake model suggested for the area after the 2003 Lefkada earthquake by considering also the historical seismicity of the area. This research is a contribution to the EU-FP7 ITN research project ZIP (Zooming In between Plates, grant agreement no: 604713, 2013.

  17. Possible Interactions between the 2012 Mw 7.8 Haida Gwaii Subduction Earthquake and the Transform Queen Charlotte Fault

    Science.gov (United States)

    Hobbs, T. E.; Cassidy, J. F.; Dosso, S. E.

    2014-12-01

    This paper examines the effect of the October 2012 Mw 7.8 Haida Gwaii earthquake on aftershock nodal planes and the neighboring Queen Charlotte Fault (QCF) through Coulomb modeling and directivity analysis. The Haida Gwaii earthquake was the largest thrust event recorded in this region and ruptured an area of ~150 by 40 km on a gently NE-dipping fault off the west coast of Moresby Island, British Columbia. It is particularly interesting as it is located just to the west of the QCF, the predominantly right-lateral strike-slip fault separating the Pacific and North American plates. The QCF was the site of the largest recorded earthquake in Canada: the 1949 Ms 8.1 strike-slip earthquake whose rupture extended as far south as this 2012 event and roughly as far north as an Mw7.5 strike slip event at Craig, Alaska, which occurred just two months later in January 2013. The 75 km long portion of the QCF south of the 1949 rupture has not had a large (M ≥ 7) earthquake in over 116 years, representing a significant seismic gap. Coulomb stress transfer analysis is performed using finite fault models which incorporate seismic and geodetic data. Static stress changes are projected onto aftershock nodal planes and the QCF, including an inferred southern seismic gap. We find up to 86% of aftershocks are consistent with triggering, and as high as 96% for normal faulting events. The QCF experiences static stress changes greater than the empirically-determined threshold for triggering, with positive stress changes predicted for roughly half of the seismic gap region. Added stress from the mainshock and a lack of post-mainshock events make this seismic gap a likely location for future earthquakes. Empirical Green's function and directivity analyses are also performed to constrain rupture kinematics of the mainshock using systematic azimuthal variations in relative source time functions. Results indicate rupture progressed mainly to the northwest within 15o of the direction of the

  18. The mechanics of gravity-driven faulting

    OpenAIRE

    L. Barrows; V. Barrows

    2010-01-01

    Faulting can result from either of two different mechanisms. These involve fundamentally different energetics. In elastic rebound, locked-in elastic strain energy is transformed into the earthquake (seismic waves plus work done in the fault zone). In force-driven faulting, the forces that create the stress on the fault supply work or energy to the faulting process. Half of this energy is transformed into the earthquake and half goes into an increase in locked-in elastic strain. In elastic reb...

  19. Seismicity as a key to Understanding the Dead Sea Transform Fault - Results From a Temporary Dense Seismic Network in the Southern Dead Sea Basin

    Science.gov (United States)

    Braeuer, B.; Weber, M. H.; Asch, G.; Haberland, C. A.; Hofstetter, A.; El-Kelani, R.; Darwish, Y.

    2009-12-01

    Knowledge of the seismicity distribution gives a great contribution to understand the processes at transform faults. The analysis of the regional network catalog (Begin & Steinitz, 2005) could not produce a clear image of the distribution of the seismicity. Furthermore, the seismic energy release over the 20 years suggests a continuous decrease of the seismic activity. Therefore, a very dense (station distance 2 - 5km) local seismological network was operated in the southern Dead Sea area within the framework of the international project DESIRE (Dead Sea Integrated Research Project). During its operation time more than 500 local events were registered, which is about five times more than previously estimated. These events give a detailed picture of the distribution of seismicity. The mainly microseismic activity is generally concentrated on the eastern and western faults limiting the Dead Sea basin (DSB). Most of the seismic events occurred in the uppermost 15 km, while the overall depth limit was at 30km. One of the dominant features observed in the dataset was a cluster of 115 earthquakes, occurring in February 2007. For precise relative locations of the events in the cluster Double-Difference location HypoDD (Waldhauser 2001) procedure was applied. We observe a vertical distribution of the events in the cluster. Very shallow events are found in the center of the study area. They are related to activity of the Lisan salt dome beneath that area. Furthermore, the local events were used to refine the picture of the P- and S- wave velocity distribution.

  20. Subsurface imaging in a sector of Cerro Prieto transform fault near to pull-apart basin, Mexicali Valley, Baja California, Mexico, based on crooked lines 2D seismic reflection.

    Science.gov (United States)

    Mares-Agüero, M. A.; González-Escobar, M.; Arregui, S.

    2016-12-01

    In the transition zone between San Andres continental transformation system and the coupled transform faults system and rifting of Gulf of California is located the Cerro Prieto pull-apart basin delimitated by Imperial fault (northeast) and Cerro Prieto fault (CPF) (southwest), this last, is the limit west of Cerro Prieto geothermic field (CPGF). Crooked lines 2D seismic reflection, covering a portion near the intersection of CPF and CPGF are processed and interpreted. The seismic data were obtained in the early 80's by Petróleos Mexicanos (PEMEX). By decades, technical and investigation works in Cerro Prieto geothermic field and its vicinity had mapped faults at several depths but do not stablish a clear limit where this faults and CPF interact due the complex hydrothermal effects imaging the subsurface. The profiles showing the presence of a zone of uplift effect due to CPF. Considering the proximity of the profiles to CPF, it is surprising almost total absence of faults. A strong reflector around 2 km of depth, it is present in all profiles. This seismic reflector is considered a layer of shale, result of the correlation with a well located in the same region.

  1. 功率谱逆变换对数在齿轮箱故障诊断中的应用%Application of Logarithm of Fourier Inverse Transform of Signal Power Spectrum in Gearbox Fault Diagnosis

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    According to the nature and characteristic of frequency spectrum analysis ,this paper puts forward applying frequency spectrum analysis method to gearbox fault diagnosis ,for improving the signal-to-noise ratio in fault diagnosis .The feasibility of using the logarithm of Fourier inverse transform of signal power spectrum in gear box fault diagnosis is verified , and the characteristics of gear box fault are obtained .%  根据频谱分析的性质和特点,提出在故障诊断中提高信噪比的频谱分析方法。将功率谱傅里叶逆变换对数应用在齿轮箱故障诊断中,并分析了齿轮箱的故障特征。

  2. Valence bond phases in S = 1/2 Kane-Mele-Heisenberg model.

    Science.gov (United States)

    Zare, Mohammad H; Mosadeq, Hamid; Shahbazi, Farhad; Jafari, S A

    2014-11-12

    The phase diagram of the Kane-Mele-Heisenberg model in a classical limit [47] contains disordered regions in the coupling space, as the result of competition between different terms in the Hamiltonian, leading to frustration in finding a unique ground state. In this work we explore the nature of these phases in the quantum limit, for a S = 1/2. Employing exact diagonalization in Sz and nearest neighbour valence bond bases, and bond and plaquette valence bond mean field theories, we show that the disordered regions are divided into ordered quantum states in the form of plaquette valence bond crystals and staggered dimerized phases.

  3. Analytic evaluation of Kane fermion magneto-optics in two and three dimensions

    Science.gov (United States)

    Malcolm, J. D.; Nicol, E. J.

    2016-12-01

    We calculate and present an analytic form of the magneto-optical conductivity for the gapped low-energy Kane model in two and three dimensions separately. The two-dimensional case maps onto the α -T3 model at a particular value of α =1 /√{3 } . In two dimensions, two chiral sectors exist, between which there are no optically activated transitions. In three dimensions, the extra dimension of dispersion mixes the two sectors so that intra- and intersector transitions can occur. The latter type of transition can be separated out via circular polarizations of light, and it shows a distinct signature in the transverse conductivity.

  4. Sizeable Kane-Mele-like spin orbit coupling in graphene decorated with iridium clusters

    Science.gov (United States)

    Qin, Yuyuan; Wang, Siqi; Wang, Rui; Bu, Haijun; Wang, Xuefeng; Wang, Xinran; Song, Fengqi; Wang, Baigeng; Wang, Guanghou

    2016-05-01

    The spin-orbit coupling strength of graphene can be enhanced by depositing iridium nanoclusters. Weak localization is intensely suppressed near zero fields after the cluster deposition, rather than changing to weak anti-localization. Fitting the magnetoresistance gives the spin relaxation time, which increases by two orders with the application of a back gate. The spin relaxation time is found to be proportional to the electronic elastic scattering time, demonstrating the Elliot-Yafet spin relaxation mechanism. A sizeable Kane-Mele-like coupling strength of over 5.5 meV is determined by extrapolating the temperature dependence to zero.

  5. 变压器几种常见故障产生原因和其处理方法解析%Several Common Causes of Transformer Fault and Its Processing Method Analysis

    Institute of Scientific and Technical Information of China (English)

    宋加波

    2015-01-01

    The factors affected by the transformer structure, process, operation mode, transformer failure often occurs in the process of operation, which have a great impact on normal operation of transformer. Through the analysis and the causes of common faults of transformer in operation, put forward the corresponding fault processing method.%受变压器结构、工艺、运维方式等因素的影响,变压器在运行过程中经常发生故障,这对变压器的正常运行有很大的影响。通过分析变压器运行中的常见故障及其产生原因,提出了相应的故障处理方法。

  6. TRANSFORMATION

    Energy Technology Data Exchange (ETDEWEB)

    LACKS,S.A.

    2003-10-09

    Transformation, which alters the genetic makeup of an individual, is a concept that intrigues the human imagination. In Streptococcus pneumoniae such transformation was first demonstrated. Perhaps our fascination with genetics derived from our ancestors observing their own progeny, with its retention and assortment of parental traits, but such interest must have been accelerated after the dawn of agriculture. It was in pea plants that Gregor Mendel in the late 1800s examined inherited traits and found them to be determined by physical elements, or genes, passed from parents to progeny. In our day, the material basis of these genetic determinants was revealed to be DNA by the lowly bacteria, in particular, the pneumococcus. For this species, transformation by free DNA is a sexual process that enables cells to sport new combinations of genes and traits. Genetic transformation of the type found in S. pneumoniae occurs naturally in many species of bacteria (70), but, initially only a few other transformable species were found, namely, Haemophilus influenzae, Neisseria meningitides, Neisseria gonorrheae, and Bacillus subtilis (96). Natural transformation, which requires a set of genes evolved for the purpose, contrasts with artificial transformation, which is accomplished by shocking cells either electrically, as in electroporation, or by ionic and temperature shifts. Although such artificial treatments can introduce very small amounts of DNA into virtually any type of cell, the amounts introduced by natural transformation are a million-fold greater, and S. pneumoniae can take up as much as 10% of its cellular DNA content (40).

  7. Transformation

    DEFF Research Database (Denmark)

    Peters, Terri

    2011-01-01

    Artiklen diskuterer ordet "transformation" med udgangspunkt i dels hvorledes ordet bruges i arkitektfaglig terminologi og dels med fokus på ordets potentielle indhold og egnethed i samme teminologi.......Artiklen diskuterer ordet "transformation" med udgangspunkt i dels hvorledes ordet bruges i arkitektfaglig terminologi og dels med fokus på ordets potentielle indhold og egnethed i samme teminologi....

  8. Transformation

    DEFF Research Database (Denmark)

    Peters, Terri

    2011-01-01

    Artiklen diskuterer ordet "transformation" med udgangspunkt i dels hvorledes ordet bruges i arkitektfaglig terminologi og dels med fokus på ordets potentielle indhold og egnethed i samme teminologi.......Artiklen diskuterer ordet "transformation" med udgangspunkt i dels hvorledes ordet bruges i arkitektfaglig terminologi og dels med fokus på ordets potentielle indhold og egnethed i samme teminologi....

  9. Identification of Transient and Permanent Faults

    Institute of Scientific and Technical Information of China (English)

    李幼仪; 董新洲; 孙元章

    2003-01-01

    A new algorithm was developed for arcing fault detection based on high-frequency current transients analyzed with wavelet transforms to avoid automatic reclosing on permanent faults. The characteristics of arc currents during transient faults were investigated. The current curves of transient and permanent faults are quite similar since current variation from the fault arc is much less than the voltage variation. However, the fault current details are quite different because of the arc extinguishing and reigniting. Dyadic wavelet transforms were used to identify the current variation since wavelet transform has time-frequency localization ability. Many electric magnetic transient program (EMTP) simulations have verified the feasibility of the algorithm.

  10. TRANSMISSION LINE FAULT ANALYSIS USING WAVELET THEORY

    Directory of Open Access Journals (Sweden)

    Ravindra Malkar

    2012-06-01

    Full Text Available This paper describes a Wavelet transform technique to analyze power system disturbance such as transmission line faults with Biorthogonal and Haar wavelets. In this work, wavelet transform based approach,which is used to detect transmission line faults, is proposed. The coefficient of discrete approximation of the dyadic wavelet transform with different wavelets are used to be an index for transmission line fault detection and faulted – phase selection and select which wavelet is suitable for this application. MATLAB/Simulation is used to generate fault signals. Simulation results reveal that the performance of the proposed fault detection indicator is promising and easy to implement for computer relaying application.

  11. Analysis and Treatment of Abnormal Chromatographic Result Fault in 220kV Main Transformer%一台220kV主变色谱异常故障的分析及处理

    Institute of Scientific and Technical Information of China (English)

    孔祥凤; 李进

    2012-01-01

    The abnormal chromatographic result in 220kV main transformer is analyzed. The fault position is diagnosed based on electric test results.%对220kV主变色谱异常结果进行了分析,结合电气试验对故障的位置进行了判断。

  12. TRANSFORMER

    Science.gov (United States)

    Baker, W.R.

    1959-08-25

    Transformers of a type adapted for use with extreme high power vacuum tubes where current requirements may be of the order of 2,000 to 200,000 amperes are described. The transformer casing has the form of a re-entrant section being extended through an opening in one end of the cylinder to form a coaxial terminal arrangement. A toroidal multi-turn primary winding is disposed within the casing in coaxial relationship therein. In a second embodiment, means are provided for forming the casing as a multi-turn secondary. The transformer is characterized by minimized resistance heating, minimized external magnetic flux, and an economical construction.

  13. Classification of fault diagnosis in a gear wheel by used probabilistic neural network, fast Fourier transform and principal component analysis

    Directory of Open Access Journals (Sweden)

    Piotr CZECH

    2007-01-01

    Full Text Available This paper presents the results of an experimental application of artificial neural network as a classifier of the degree of cracking of a tooth root in a gear wheel. The neural classifier was based on the artificial neural network of Probabilistic Neural Network type (PNN. The input data for the classifier was in a form of matrix composedof statistical measures, obtained from fast Fourier transform (FFT and principal component analysis (PCA. The identified model of toothed gear transmission, operating in a circulating power system, served for generation of the teaching and testing set applied for the experiment.

  14. Why the Global Availability of Mind Wandering Necessitates Resource Competition: Reply to McVay and Kane (2010)

    Science.gov (United States)

    Smallwood, Jonathan

    2010-01-01

    When the mind wanders, conscious thoughts come to mind that are only loosely related to the task being performed. This phenomenon produces tension within the cognitive sciences because the interfering nature of these thoughts is at odds with the assumption that such processes are functional in daily life. In their comment, McVay and Kane (2010)…

  15. Why the Global Availability of Mind Wandering Necessitates Resource Competition: Reply to McVay and Kane (2010)

    Science.gov (United States)

    Smallwood, Jonathan

    2010-01-01

    When the mind wanders, conscious thoughts come to mind that are only loosely related to the task being performed. This phenomenon produces tension within the cognitive sciences because the interfering nature of these thoughts is at odds with the assumption that such processes are functional in daily life. In their comment, McVay and Kane (2010)…

  16. Combinational Diagnosis for Transformer Faults Based on Multi-models%基于多模型的变压器故障组合诊断研究

    Institute of Scientific and Technical Information of China (English)

    赵文清; 李庆良; 王德文

    2013-01-01

    Diagnose of power transformer fault is important for normal operation of power system, consequently, combining multiple Bayes classification algorithms, we proposed an assembled model on the basis of support vector machine. During the diagnosis process, firstly, 12 key relative attributes of dissolved gases were selected as inputs of the diagnosis model, and sample data set was obtained after data preprocessing on the attributes. Secondly, according to 13 fault types, the sample data set was diagnosed using a model group formed by several single diagnosis methods, such as naive Bayes model, belief network augmented naive Bayes, semi-naive Bayesian model, and tree augmented naive Bayes model. Thirdly, the diagnosis results were set to be the input of a support vector machine diagnosis model, and then a changeable weights combination diagnosis model was obtained. Furthermore, the procedure and parameters of the proposed combinational diagnosis were discussed in detail. According to comparison with other diagnosis methods, the proposed combinational fault diagnosis model has higher diagnosis accuracy than single model and other common combinational models. Moreover, two practical examples on dissolved gas data of transformers prove the validity and show that this model is effective. Therefore, the proposed model can be adopted in practical projects.%变压器故障诊断是保证整个电力系统正常运行的重要部分,为此提出了一个基于支持向量机并与多种贝叶斯分类算法相结合的组合诊断模型.诊断过程中,首先通过相关统计分析,选择典型油中气体的12个相关属性值作为模型的输入参数,并对其进行数据预处理,生成一次样本.其次,按照变压器常见的13种故障类型,利用多个单一诊断方法如朴素贝叶斯模型、半朴素贝叶斯模型、增强的朴素贝叶斯模型和贝叶斯网络增强模型构成诊断模型群,对一次样本数据进行诊断.最后,把贝叶斯诊断

  17. Realization of the Haldane-Kane-Mele Model in a System of Localized Spins

    Science.gov (United States)

    Kim, Se Kwon; Ochoa, Héctor; Zarzuela, Ricardo; Tserkovnyak, Yaroslav

    2016-11-01

    We study a spin Hamiltonian for spin-orbit-coupled ferromagnets on the honeycomb lattice. At sufficiently low temperatures supporting the ordered phase, the effective Hamiltonian for magnons, the quanta of spin-wave excitations, is shown to be equivalent to the Haldane model for electrons, which indicates the nontrivial topology of the band and the existence of the associated edge state. At high temperatures comparable to the ferromagnetic-exchange strength, we take the Schwinger-boson representation of spins, in which the mean-field spinon band forms a bosonic counterpart of the Kane-Mele model. The nontrivial geometry of the spinon band can be inferred by detecting the spin Nernst effect. A feasible experimental realization of the spin Hamiltonian is proposed.

  18. The topological Anderson insulator phase in the Kane-Mele model.

    Science.gov (United States)

    Orth, Christoph P; Sekera, Tibor; Bruder, Christoph; Schmidt, Thomas L

    2016-04-05

    It has been proposed that adding disorder to a topologically trivial mercury telluride/cadmium telluride (HgTe/CdTe) quantum well can induce a transition to a topologically nontrivial state. The resulting state was termed topological Anderson insulator and was found in computer simulations of the Bernevig-Hughes-Zhang model. Here, we show that the topological Anderson insulator is a more universal phenomenon and also appears in the Kane-Mele model of topological insulators on a honeycomb lattice. We numerically investigate the interplay of the relevant parameters, and establish the parameter range in which the topological Anderson insulator exists. A staggered sublattice potential turns out to be a necessary condition for the transition to the topological Anderson insulator. For weak enough disorder, a calculation based on the lowest-order Born approximation reproduces quantitatively the numerical data. Our results thus considerably increase the number of candidate materials for the topological Anderson insulator phase.

  19. a Six-Link Kinematic Chain Model of Human Body Using Kane's Method

    Science.gov (United States)

    Rambely, A. S.; Fazrolrozi

    A biomechanics model of six-link kinematic chain of human body is developed by using Kane's method. The kinematic data comprise of six segments; foot, calf, thigh, trunk, upper arm and forearm, are obtained through data collection of walking, running and jumping using the Vicon Nexus system. The motion capture system uses 12 Vicon MX-3+ cameras and 12 Vicon MX-F40 cameras, two DV (50 Hz) cameras and a force plate (100 Hz). Inverse dynamics approach is used to obtain the unknown value of torques produced by joint segments during walking, running and jumping activities. The results show that the largest value of torques produced occurs at the foot segment.

  20. A method of online monitoring of transformer fault%变压器故障在线监测的一种方法

    Institute of Scientific and Technical Information of China (English)

    林伟哲; 周伟波

    2015-01-01

    变压器油中气体在线监测技术是以油中溶解气体为监测对象,应用该技术可及时掌握变压器的运行状况,发现和跟踪存在的潜伏性故障。配合计算机系统对故障进行诊断,可以避免部分灾难性事故,实现状态检修、降低维护成本、提高自动化程度,提高变电站运行管理水平。使用开源软件开发了在线监测软件,该软件具有模块化及安全、灵活的数据库操作和跨平台特性,经实验检验达到了设计的目标。%The monitoring technology of gas in oil in the transformer takes the dissolved gases in oil as the monitoring object. The operating condition of the transformer can be monitored timely to discover and track the presence of latent failures. Some catastrophic accident can be prevented with the computer system fault diagnosis, realizing condition-based maintenance, reducing maintenance costs and increasing the degree of automation and improving operational management of the substation. Online monitoring softwareis developed using the open source software, which is modular, has secure, flexible database operations and cross-platform features.The experiment showed that it can satisfy the design goal.

  1. 基于静态小波变换的T型输电线路行波测距方法%Travelling Wave Fault Location for Three-Terminal Transmission ~Line Based on Static Wavelet Transform

    Institute of Scientific and Technical Information of China (English)

    张永健; 胥杰; 孙嘉

    2012-01-01

    In view of the defect in existing travelling wave fault location algorithm that this algorithm is easily affected by wave velocity, a new method for travelling wave fault location of three-terminal transmission line is proposed. Using Clarke's transform the phase currents are turned into independent mode currents, then static wavelet transform (SWT) is applied to mode currents to determine the moments at which travelling wave surges arrive the bus terminals. Firstly the memberships are defined by three initial moments at which the first wave front arrives T-connected buses, and based on the memberships the criterion for distinguishing faulty branch is given. To implement fault location of three-terminal transmission line, based on existing fault location formula for two-terminal transmission line the fault location formula for three-terminal transmission line is derived. Three possible fault conditions near the T-connected node are researched, and a three-time fault location method is put forward to resolve the fault location for the faults occurred near the T-connected node. Comparing with existing fault location methods, due to time-invariance of SWT, making full use of the data measured at three terminals of the three-terminal transmission line and that the wave velocity does not appear in the derived fault location formula, the proposed method can provide more accurate fault location results. Results of simulation using ATP/EMTP show that the proposed fault location method for three-terminal transmission line is simple, reliable and not affected by such factors as transition resistance and fault types and so on.%针对现有T型输电线路行波测距算法易受行波波速影响的不足,提出一种新的T型输电线路行波测距方法。采用Clarke变换将相电流转换为独立的模电流,对模电流进行静态小波变换(staticwavelettransform,SwT)处理,实现各行波浪涌到达各母线端时刻的标定。首先利用

  2. Fault Estimation

    DEFF Research Database (Denmark)

    Stoustrup, Jakob; Niemann, H.

    2002-01-01

    This paper presents a range of optimization based approaches to fault diagnosis. A variety of fault diagnosis prob-lems are reformulated in the so-called standard problem setup introduced in the literature on robust control. Once the standard problem formulations are given, the fault diagnosis pr...... problems can be solved by standard optimization tech-niques. The proposed methods include: (1) fault diagnosis (fault estimation, (FE)) for systems with model uncertainties; (2) FE for systems with parametric faults, and (3) FE for a class of nonlinear systems.......This paper presents a range of optimization based approaches to fault diagnosis. A variety of fault diagnosis prob-lems are reformulated in the so-called standard problem setup introduced in the literature on robust control. Once the standard problem formulations are given, the fault diagnosis...

  3. 基于系统辨识的阻抗匹配平衡变压器故障诊断%Fault Diagnosis of Impedance Matching Balance Transformer Based on System Identification

    Institute of Scientific and Technical Information of China (English)

    李龙; 余楚中; 王鹏飞

    2011-01-01

    Impedance matching balance transformer is tion substation transformer. In order to solve the puzzle often used as the main electrified railway tracthat could not accurately identify the failure in internal or external impedance matching transformer by traditional fauh diagnosis method, based on that the winding resistance and short circuit reactance value have not been changed in normal opera- tion for impedance matching balance transformer or external fault, the paper proposed an identification algorithm of recursive least square parameter estimation on line to distinguish the fault. The curve of experimental simulation demonstrated that it could effectively distinguish to be internal failure or external fault. The research result shows its feasibility to distinguish two sorts of different faults.%阻抗匹配平衡变压器常被用作电气化铁道牵引变电所的主变压器。为解决传统故障诊断方式难以准确鉴别该变压器内外故障,基于正常运行或发生外部故障时绕组电阻和短路电抗值不产生变化,而当出现内部故障时将产生变化的问题,提出了利用最小二乘参数估计递推算法在线辨识其变化以鉴别内外故障。实验仿真曲线证实了采用该算法能有效区分其内外故障,研究结果验证了用该方法鉴别2种不同类型故障的可行性。

  4. Nature and origin of secondary mineral coatings on volcanic rocks of the Black Mountain, Stonewall Mountain, and Kane Springs Wash volcanic centers, southern, Nevada

    Science.gov (United States)

    Taranik, James V.; Hsu, Liang C.; Spatz, David M.; Chenevey, Michael J.

    1989-01-01

    The following subject areas are covered: (1) genetic, spectral, and LANDSAT Thematic Mapper imagery relationship between desert varnish and tertiary volcanic host rocks, southern Nevada; (2) reconnaissance geologic mapping of the Kane Springs Wash Volcanic Center, Lincoln County, Nevada, using multispectral thermal infrared imagery; (3) interregional comparisons of desert varnish; and (4) airborne scanner (GERIS) imagery of the Kane Springs Wash Volcanic Center, Lincoln County, Nevada.

  5. Research on System of Power Transformer Fault Diagnosis Based on WSN and Data Fusion Technology%基于WSN和数据融合技术的电力变压器故障诊断系统的研究

    Institute of Scientific and Technical Information of China (English)

    邵开丽; 王鸿运

    2012-01-01

    The article discusses a method of power transformer fault diagnosis based on data fusion and extension theory, for this method a power transformer fault diagnosis system is constructed and developed by the application of wireless sensor network technology and VS. NET platform. The system applies WSN technology in wireless data acquisition of gases dissolved in power transformer oil, and can achieve real time data transmission. At the same time information fusion technology which is used to optimize the data, not only can reduce network energy consumption and ensure the accurate and objective data. For the coding rules of gas ratio method currently existed is incomplete and single, the extension method, combining quantitative and qualitative, it can make transformer fault diagnosis more refinement. Especially, the visual system can achieve the acquisition, displaying, analysis, storage and playback of gas parameters, and can be used in real-time analyzing and automatic diagnosis of transformer fault. The system of power transformer fault diagnosis can not only resolve the problem of the real-time and remote monitoring of operating personnel , but also greatly improve the performance of the transformer fault diagnosis. It provides a new direction for transformer online monitoring and fault diagnosis technology.%探讨一种基于数据融合和可拓理论的电力变压器故障诊断方法,基于此方法,应用无线传感器网络技术和.NET开发平台构建和开发出一套电力变压器故障诊断系统.该系统将WSN技术用于电力变压器油中溶解气体的无线数据采集,实现变压器油中溶解气体的实时数据采集和传送;同时运用信息融合技术对数据进行优化处理,既可以降低网络能耗又保证了数据的准确和客观;在变压器进行故障诊断时,针对现有电力变压器故障诊断的气体比值法存在的编码规则不完整、诊断故障类型单一等缺陷,使用可拓诊断方法,定

  6. Analysis of the Action of the Fault Protection Action of Multiple Main Transformers in the Circuit Fault%一起线路故障引起多台主变间隙保护动作跳闸事故的分析

    Institute of Scientific and Technical Information of China (English)

    赵亨奎

    2015-01-01

    In order to limit the short-circuit current, and to ensure that the size and distribution of the zero sequence current in the system is not affected by the operation mode of the system, when the single-phase grounding fault and the neutral point is lost, the neutral point of the transformer will be zero sequence voltage or zero sequence current. In this paper, we analyze the causes of the protection action of the main transformer gap protection action caused by the fault of the main transformer and the protection of the ground fault.%为了限制短路电流,并保证系统中零序电流的大小和分布不受系统运行方式变化的影响,当电网发生单相接地故障且失去中性点时,不接地的变压器中性点将出现零序电压或零序电流.针对一起线路接地故障造成的主变间隙保护动作跳闸事故,分析了该间隙保护动作的原因,并对间隙保护相关的整定和配合的问题进行了探究.

  7. A Pore Fluid Study in the Transform Fault System of Western Haiti: Investigating Geochemical Processes and Hydrologic Pathways of the Fluids

    Science.gov (United States)

    Battani, A.; Monnin, C.; Ruffine, L.; Ellouz, N.; Leroy, S. D.

    2014-12-01

    The area of Western Haiti is located between the Enriquillo-Plantain Garden Fault (EPGF) and Ciabao-Oriente Septentrional fault systems. It has been investigated during the Haiti-SIS cruise (November-December 2012) by heat flow measurements and coring. These two strike-slip fault systems accommodate the relative motion between the Caribbean and North American plates. An aftershock study of the MW= 7, 12 January 2010 earthquake indicated that this event originated along the EPGF fault, while the septentrional fault has not been ruptured for about a century. We focused coring operations on specific zones; faults, basin margins, ridge, deep basins delimated using structural/sedimentological surface data. The objective of the pore-fluid study was to determine both the pathways of the fluids and their origin in relation with the fault activity. A total of 14 Kullenberg cores were collected for fluid sampling and sedimentological analyses. Overall, 99 pore fluids were extracted, using Rhizon® samplers. Major and minor dissolved elements were analyzed. The resulting dataset allows us to identify several diagenetic processes occurring within the upper section of the sedimentary column. For the fault-crossing zones, the vertical chloride and sulphate profiles where the dissolved-element concentrations are close to that of normal seawater suggest seawater downward flow (infiltration). There the faults would then act as recharge zones for fluid circulation. On the opposite, for cores recovered in the basins, dissolved element profiles exhibit variable shapes with sulfate concentration decreasing with depth (indicating organic matter oxydation or anaerobic oxidation of methane) These results will be combined with those from the emerged segment of the EPGF (that can be observed on land in Haiti) in order to have a picture of the hydrologic regime of the fault system, its capacity to act as a recharge zone and conversely to supply deep-seated fluids to the surface (discharge

  8. Draft genome sequence of Micrococcus luteus strain O'Kane implicates metabolic versatility and the potential to degrade polyhydroxybutyrates

    Directory of Open Access Journals (Sweden)

    Radwa A. Hanafy

    2016-09-01

    Full Text Available Micrococcus luteus is a predominant member of skin microbiome. We here report on the genomic analysis of Micrococcus luteus strain O'Kane that was isolated from an elevator. The partial genome assembly of Micrococcus luteus strain O'Kane is 2.5 Mb with 2256 protein-coding genes and 62 RNA genes. Genomic analysis revealed metabolic versatility with genes involved in the metabolism and transport of glucose, galactose, fructose, mannose, alanine, aspartate, asparagine, glutamate, glutamine, glycine, serine, cysteine, methionine, arginine, proline, histidine, phenylalanine, and fatty acids. Genomic comparison to other M. luteus representatives identified the potential to degrade polyhydroxybutyrates, as well as several antibiotic resistance genes absent from other genomes.

  9. Simulation Platform of Underwater Quadruped Walking Robot Based on MotionGenesis Kane 5 3 and Central Pattern Generator

    Institute of Scientific and Technical Information of China (English)

    Ke Yang; XuYang Wang; Tong Ge; Chao Wu

    2014-01-01

    It will still in lack of a simulation platform used to learn the walking of underwater quadruped walking robot. In order to alleviate this shortage, a simulation platform for the underwater quadruped walking robot based on Kane dynamic model and CPG-based controller is constructed. The Kane dynamic model of the underwater quadruped walking robot is processed with a commercial package MotionGenesis Kane 5�3. The forces between the feet and ground are represented as a spring and damper. The relation between coefficients of spring and damper and stability of underwater quadruped walking robot in the stationary state is studied. The CPG-based controller consisted of Central Pattern Generator ( CPG) and PD controller is presented, which can be used to control walking of the underwater quadruped walking robot. The relation between CPG parameters and walking speed of underwater quadruped walking robot is investigated. The relation between coefficients of spring and damper and walking speed of underwater quadruped walking robot is studied. The results show that the simulation platform can imitate the stable walking of the underwater quadruped walking robot.

  10. Diagnosis of an Overheat and Oil-leakage Fault of 10 kV Main Side Transformer Bushing%一起10 kV侧主变套管过热及漏油故障的诊断

    Institute of Scientific and Technical Information of China (English)

    赵晓东; 张登宇

    2014-01-01

    The infrared diagnostic technology, which can be used rapidly and in real time to realize the on-line monitoring and diagnosis of most power equipment faults, can early detect equipment defects for taking measures in advance to prevent the power outages caused by equipment malfunction, so, it is one of the effective measures of making the state inspection of power equipment under the charged condition. This paper introduces an overheat and oil-leakage fault of 10 kV main side transformer bushing that was found in time through infrared diagnostic technology. The expanding of the equipment fault was avoided through the diagnosis and analysis on the equipment fault.%红外诊断技术能快速实时地在线监测和诊断电力设备的大多数故障,能及早发现设备缺陷,以提前采取措施,防止设备出现故障造成停电,是电力设备带电条件下进行状态检测的有效手段之一。介绍了一例通过红外诊断技术及时发现的主变10 kV套管过热故障,通过对该故障的诊断分析,避免了设备故障的扩大。

  11. Hadamard Transforms

    CERN Document Server

    Agaian, Sos; Egiazarian, Karen; Astola, Jaakko

    2011-01-01

    The Hadamard matrix and Hadamard transform are fundamental problem-solving tools in a wide spectrum of scientific disciplines and technologies, such as communication systems, signal and image processing (signal representation, coding, filtering, recognition, and watermarking), digital logic (Boolean function analysis and synthesis), and fault-tolerant system design. Hadamard Transforms intends to bring together different topics concerning current developments in Hadamard matrices, transforms, and their applications. Each chapter begins with the basics of the theory, progresses to more advanced

  12. 基于小波变换的鼠笼式异步电动机故障诊断%Research on Squirrel-cage Asynchronous Motor Fault Diagnosis Based on Wavelet Transform

    Institute of Scientific and Technical Information of China (English)

    成函

    2015-01-01

    Wavelet Transform has a good localization capability in the time domain and frequency domain , especially being sensitive to the mutation point of the signal . Due to the multiresolution properties , it can be close to the spectrum , and has outstanding effect on Extraction of fault signal . This paper discussed wavelet analysis and its application in fault diagnosis , and verified the accuracy of the detection method of wavelet transform in squirrel-cage asynchronous motor fault .%小波变换在时域和频域都具有良好的局部化能力,尤其是对信号的突变点很敏感,其多分辨率性质可逼近细化频谱,对故障信号提取有突出的作用。本文通过算例论述了小波分析在故障诊断中的研究和应用,验证了小波变换方法检测鼠笼式异步电动机故障的准确性。

  13. 基于量子遗传改进支持向量机理论的变压器故障诊断%The Fault Diagnosis of Transformers with Support Vector Machine Theory Improved by Quantum Genetic Algorithm

    Institute of Scientific and Technical Information of China (English)

    于虹; 孙鹏

    2011-01-01

    提出了基于量子遗传改进支持向量机理论的变压器故障诊断方法.该算法首先利用粗糙集技术时变压器知识进行属性约简,通过属性表获得变压器故障的最简决策表以作为支持向量机的输入,并利用量子遗传算法获得支持向量机的最优参数设置.实验结果表明,该诊断方法分类性能良好、可靠性高且有效可行.%A new fault diagnosis method is proposed for transformers, which is based on support vector machine theory improved by quantum genetic algorithm. Firstly. The algorithm is as follows: to do attribute reduction to the transformers knowledge with the technologies of rough set, to get the simple decision table for faults and imput the table into the support vector machine, and to achieve the optimum parameters setting of the support vector machine with the quantum genetic algorithm. The experimental results demonstrate that the proposed method works well in the fault classification and is reliable, effective and feasible.

  14. 基于随机森林的变压器故障检测方法的研究∗%Fault Diagnosis for Transformer Based on Random Forests

    Institute of Scientific and Technical Information of China (English)

    陶栋琦; 薄翠梅; 易辉

    2015-01-01

    To study the fault diagnosis of power system,safe and stable operation of the transformer is of great signif-icance. The content of the various characteristics of gases dissolved in transformer oil setting-up for the decision-making analysis is the important methods for the detection of transformer. In view of the single decision tree classifi-cation,its effect is poor,poor in anti-interference ability. The method of using random forests is put forward for fault classification,and a combined classifier model is set up by the combination of classifiers,high precision,strong sta-bility and not fitted,so that the occurrence of fault can be more timely and effectively diagnosed,the normal opera-tion of the transformer can be ensured.%研究变压器的故障检测对电力系统安全稳定运行具有重大意义,对油中溶解的各特征气体含量建立决策器进行分析是变压器故障检测的重要方法,针对单棵决策树的分类效果不良,抗干扰能力差,提出了利用随机森林的方法建立组合分类器模型进行故障分类,该组合分类器精确度高、稳定性强且不会出现过拟合现象,从而使发生的故障能得到更及时有效的诊断,进一步保障变压器的正常运行。

  15. Kane Method Based Dynamics Modeling and Control Study for Space Manipulator Capturing a Space Target

    Directory of Open Access Journals (Sweden)

    Yanhua Han

    2016-01-01

    Full Text Available Dynamics modeling and control problem of a two-link manipulator mounted on a spacecraft (so-called carrier freely flying around a space target on earth’s circular orbit is studied in the paper. The influence of the carrier’s relative movement on its manipulator is considered in dynamics modeling; nevertheless, that of the manipulator on its carrier is neglected with the assumption that the mass and inertia moment of the manipulator is far less than that of the carrier. Meanwhile, we suppose that the attitude control system of the carrier guarantees its side on which the manipulator is mounted points accurately always the space target during approaching operation. The ideal constraint forces can be out of consideration in dynamics modeling as Kane method is used. The path functions of the manipulator’s end-effector approaching the space target as well as the manipulator’s joints control torque functions are programmed to meet the soft touch requirement that the end-effector’s relative velocity to the space target is zero at touch moment. Numerical simulation validation is conducted finally.

  16. Application of Improved Wavelet Neural Network in Fault Diagnosis of Transformer%改进的小波神经网络在变压器故障诊断中的应用

    Institute of Scientific and Technical Information of China (English)

    李晓静; 李杰

    2013-01-01

    为提高变压器油溶解气体分析法的故障诊断能力,以变压器油溶解气体作为研究对象,提出了加动量批处理小波神经网络算法.选取200组油溶解气体含量作为故障识别样本,通过多输入/多输出模式小波神经网络模型的构造,对训练过程和仿真结果进行对比分析.实验结果表明,改进的小波神经网络算法故障检测符合率高达95%,较传统的检测算法提升十几个百分点,从而极大的提高了故障诊断效率,实用性较好.%In order to improve the ability of fault diagnosis for analyzing the dissolved gases in transformer oil,a increased momentum batch wavelet neural network (WNN)algorithm was presented taking dissolved gases in transformer oil as the research objects.After the faults are recognized from 200 practical gas data,comparison and analysis are carried out in training process and simulation results with multiple-input/multiple-output-mode WNN model structure.Experimental results show that the improved algorithm fault detecting coincidence rate reaches as high as 95 %,up to a dozen percentage points than traditional detection algorithm,greatly improving the efficiency of fault diagnosis.The algorithm has better usability.

  17. Application of Dynamic Weighted Fuzzy Clustering Algorithm to Fault Diagnosis of Transformer%动态加权模糊聚类在变压器故障诊断中的应用研究

    Institute of Scientific and Technical Information of China (English)

    刘太洪; 赵永雷

    2016-01-01

    为提高变压器故障诊断准确率,提出了一种基于遗传算法的动态加权模糊C均值聚类算法。该算法使用把聚类中心作为染色体的浮点数的编码方式,染色体长度可变,不同的长度对应于不同的故障聚类数;并使用权值区别不同样本点对故障划分的影响程度。将该算法应用于电力变压器油中溶解气体分析(DGA)数据分析,实现了变压器的故障诊断。经过大量实例分析,并将结果与其他算法进行对比,表明该算法具有较高的诊断精度。%ABSTRACT:In order to improve the correct rate of fault diagnosis of transformer, this paper investigates a dynamic weighted fuzzy c-means clustering algorithm based on genetic algorithm. The algorithm adopts a kind of cluster-center-based floating point encoding mode, in which the variable length chromosomes express cluster prototypes and different length of chromosomes corresponding to different numbers of cluster prototypes;besides,The algorithm utilizes the weights to express the relative degree of the importance of various data in fault partitioning. The algorithm is applied to DGA data analysis, which can accomplish fault diagnosis of the transformer. Examples analysis and comparison results show that the preci-sion of fault diagnosis can be evidently improved.

  18. Source Functions and Path Effects from Earthquakes in the Farallon Transform Fault Region, Gulf of California, Mexico that Occurred on October 2013

    Science.gov (United States)

    Castro, Raúl R.; Stock, Joann M.; Hauksson, Egill; Clayton, Robert W.

    2016-07-01

    We determined source spectral functions, Q and site effects using regional records of body waves from the October 19, 2013 (M w = 6.6) earthquake and eight aftershocks located 90 km east of Loreto, Baja California Sur, Mexico. We also analyzed records from a foreshock with magnitude 3.3 that occurred 47 days before the mainshock. The epicenters of this sequence are located in the south-central region of the Gulf of California (GoC) near and on the Farallon transform fault. This is one of the most active regions of the GoC, where most of the large earthquakes have strike-slip mechanisms. Based on the distribution of the aftershocks, the rupture propagated northwest with a rupture length of approximately 27 km. We calculated 3-component P- and S-wave spectra from ten events recorded by eleven stations of the Broadband Seismological Network of the GoC (RESBAN). These stations are located around the GoC and provide good azimuthal coverage (the average station gap is 39°). The spectral records were corrected for site effects, which were estimated calculating average spectral ratios between horizontal and vertical components (HVSR method). The site-corrected spectra were then inverted to determine the source functions and to estimate the attenuation quality factor Q. The values of Q resulting from the spectral inversion can be approximated by the relations Q_{P} = 48.1 ± 1.1 f^{0.88 ± 0.04} and Q_{S} = 135.4 ± 1.1 f^{0.58 ± 0.03} and are consistent with previous estimates reported by Vidales-Basurto et al. (Bull Seism Soc Am 104:2027-2042, 2014) for the south-central GoC. The stress drop estimates, obtained using the ω2 model, are below 1.7 MPa, with the highest stress drops determined for the mainshock and the aftershocks located in the ridge zone. We used the values of Q obtained to recalculate source and site effects with a different spectral inversion scheme. We found that sites with low S-wave amplification also tend to have low P-wave amplification, except

  19. Source Functions and Path Effects from Earthquakes in the Farallon Transform Fault Region, Gulf of California, Mexico that Occurred on October 2013

    Science.gov (United States)

    Castro, Raúl R.; Stock, Joann M.; Hauksson, Egill; Clayton, Robert W.

    2017-06-01

    We determined source spectral functions, Q and site effects using regional records of body waves from the October 19, 2013 ( M w = 6.6) earthquake and eight aftershocks located 90 km east of Loreto, Baja California Sur, Mexico. We also analyzed records from a foreshock with magnitude 3.3 that occurred 47 days before the mainshock. The epicenters of this sequence are located in the south-central region of the Gulf of California (GoC) near and on the Farallon transform fault. This is one of the most active regions of the GoC, where most of the large earthquakes have strike-slip mechanisms. Based on the distribution of the aftershocks, the rupture propagated northwest with a rupture length of approximately 27 km. We calculated 3-component P- and S-wave spectra from ten events recorded by eleven stations of the Broadband Seismological Network of the GoC (RESBAN). These stations are located around the GoC and provide good azimuthal coverage (the average station gap is 39°). The spectral records were corrected for site effects, which were estimated calculating average spectral ratios between horizontal and vertical components (HVSR method). The site-corrected spectra were then inverted to determine the source functions and to estimate the attenuation quality factor Q. The values of Q resulting from the spectral inversion can be approximated by the relations Q_{{P}} = 48.1 ± 1.1 f^{0.88 ± 0.04} and Q_{{S}} = 135.4 ± 1.1 f^{0.58 ± 0.03} and are consistent with previous estimates reported by Vidales-Basurto et al. (Bull Seism Soc Am 104:2027-2042, 2014) for the south-central GoC. The stress drop estimates, obtained using the ω2 model, are below 1.7 MPa, with the highest stress drops determined for the mainshock and the aftershocks located in the ridge zone. We used the values of Q obtained to recalculate source and site effects with a different spectral inversion scheme. We found that sites with low S-wave amplification also tend to have low P-wave amplification

  20. 基于小波神经网络和D-S证据理论的电力变压器故障诊断研究%Study on Power Transformers Fault Diagnosis Based on Wavelet Neural Network and D-S Evidence Theory

    Institute of Scientific and Technical Information of China (English)

    梁流铭; 陈伟根; 岳彦峰

    2008-01-01

    Transformer faults are quite complicated phenomena and can occur due to a variety of reasons. There have been several methods for transformer fault synthetic diagnosis, but each of them has its own limitations in real fault diagnosis applications. In order to overcome those shortcomings in the existing methods, a new transformer fault diagnosis method based on a wavelet neural network optimized by adaptive genetic algorithm (AGA) and an improved D-S evidence theory fusion technique is proposed in this paper. The proposed method combines the oil chromatogram data and the off-line electrical test data of transformers to carry out fault diagnosis. Based on the fusion mechanism of D-S evidence theory, the comprehensive reliability of evidence is constructed by considering the evidence importance, the outputs of the neural network and the expert experience. The new method increases the objectivity of the basic probability assignment (BPA) and reduces the basic probability assigned for uncertain and unimportant information. The case study results of using the proposed method show that it has a good performance of fault diagnosis for transformers.

  1. 基于多分类相关向量机的变压器故障诊断新方法%New transformer fault diagnosis method based on multi-class relevance vector machine

    Institute of Scientific and Technical Information of China (English)

    尹金良; 朱永利; 俞国勤

    2013-01-01

    The transformer fault diagnosis is naturally a multi-classification problem with few sample data and a lot of uncertainties. Among the existing transformer fault diagnosis methods, a large number of sample data and amount of computation are needed for Bayesian Network (BN), and the adjustment of the coefficient is difficult for support vector machine (SVM). So a new method of transformer fault diagnosis based on multi-class relevance vector machine (M-RVM) is proposed. The method takes ratios of feature gases as inputs and Fast Type-II ML and expectation maximization (EM) are adopted. Diagnostic outputs are probability for each fault category and fault type with the highest probability is taken as diagnosis result. Experimental results show that the diagnosis speed is sufficient for project needs and M-RVM shows higher diagnosis accuracy compared with BN and SVM.%  变压器故障诊断本质为多分类问题,具有故障样本数据少,故障不确定因素多的特点。现有变压器故障诊断方法中,贝叶斯网络(BN)需要大量样本数据且计算量大,支持向量机(SVM)存在规则化系数确定困难的局限。针对此现状,提出基于多分类相关向量机(M-RVM)的变压器故障诊断新方法。该方法以变压器溶解气体含量比值作为M-RVM模型的输入,采用快速type-II 最大似然(Fast Type-II ML)和最大期望估计(EM)的方法进行模型推断,诊断输出为各故障类别的概率,以概率最大的故障类别作为诊断结果。实例分析表明该方法诊断速度较快,能满足工程需要,同基于BN和SVM的变压器故障诊断方法相比,具有较高的诊断正确率。

  2. Transformer Fault Diagnosis Based on C-SVC and Cross-validation Algorithm%基于支持向量机和交叉验证的变压器故障诊断

    Institute of Scientific and Technical Information of China (English)

    张艳; 吴玲

    2012-01-01

    为及时监测变压器潜伏性故障和准确诊断故障,提出基于优化惩罚因子C参数的支持向量机算法(C-SVC:C-support vector classification)和交叉验证算法相结合的变压器故障诊断方法.该方法利用变压器在故障时产生的氢气、甲烷、乙烷、乙烯、乙炔的体积分数数据建立训练集和测试集.在训练集中,该方法能自动优化出(寻找最佳)支持向量机的核函数的参数γ和惩罚因子C,利用优化的参数对训练集进行训练,可得到最佳的支持向量机模型,并用该模型对测试集进行分类,从而诊断出变压器的故障类型.变压器故障诊断实例分析结果证明,该方法可行,有效,且具有较高的故障诊断准确率.%A novel method for power transformer fault diagnosis based on the C-SVC (support vector classification with the optimized penalty parameter C) and cross-validation algorithm is presented, which can monitor and detect latent transformer faults timely and accurately. The training and testing sets of the C-SVC algorithm are built upon the data about the dissolved gases including hydrogen, methyl hydride, ethane, aethylenum and acetylene produced from transformer faults. Through the optimizing process of the penalty parameter and kernel function parameter y in the training set, the optimal support vector machine model can be gotten, with which the classification of data in the testing set can be conducted to determine fault features. The method has been validated by many practical examples to be feasible and efficient with high fault diagnosis accuracy.

  3. 基于双树复小波变换的轴承故障诊断研究%Research on Bearing Fault Diagnosis Based on Dual--tree Complex Wavelet Transform

    Institute of Scientific and Technical Information of China (English)

    艾树峰

    2011-01-01

    提出了一种基于双树复小波变换解调技术的轴承故障诊断新方法。该方法利用双树复小波变换具有近似平移不变性、避免频率混叠和有效降噪的优点,首先对轴承故障振动信号进行双树复小波分解和重构,将振动信号分解成实部和虚部,然后计算振动信号的双树复小波幅值包络和包络谱。齿轮箱轴承故障振动实验信号的分析表明,该方法能在强噪声环境下准确提取轴承故障产生的周期性瞬态冲击信号,能有效消除频率混叠现象和强噪声的影响,能有效识别轴承内圈和外圈故障。%A novel method of bearing fault diagnosis based on demodulation technique of DTCWT. It is demonstrated that the proposed dual-tree complex wavelet transform has better shift invariance, reduced frequency aliasing effect and de-noising ability. The bearing fault vibration signals were firstly decomposed and recostructed using dual-tree complex wavelet transform. Then the real and i maginary parts were obtained and the vibration signals were amplitude demodulated. In the end, the amplitude envelope and wavelet envelope spectrum were computed. Therefore, the characteristics of the bearing faults can be recognized according to the wavelet envelope spectrum. The experimental resuits show that fault diagnosis based on dual-tree complex wavelet transform can diagnose bearing faults effectively under strong noise conditions and reduce spectral aliasing.

  4. 输变电设备监测装置运行故障及可用性分析%Monitoring Device Fault and Availability Analysis of Electric Transmission and Transformation Equipment

    Institute of Scientific and Technical Information of China (English)

    王永奇

    2016-01-01

    In allusion to the current situation of lower availability ratio of electric transmission and transformation equipment online monitor-ing device at present, introduction was made to the practical application of monitoring device. This paper analyzed the fault causes of electric transmission and transformation equipment generated in the respects of communications, power supply, sensors and workstations, and presented fault handling measures, so as to improve the availability of electric transmission and transformation equipment online monitoring device.%针对目前输变电设备在线监测装置可用率较低的现状,介绍了监测装置的实际应用情况,分析了输变电设备在线监测装置在通信、供电电源、传感器及工作站等方面故障产生的原因,并提出了相应的处理措施,以提高输变电设备监测装置的可用率。

  5. 基于HPSO-WNN的牵引变压器故障诊断算法研究%Research on Traction Transformer Faults Diagnosis Algorithm Based on HPSO-WNN

    Institute of Scientific and Technical Information of China (English)

    付强; 陈特放; 朱佼佼

    2012-01-01

    为全面有效地诊断电力机车牵引变压器故障,提出一种基于混合粒子群算法的正交小波神经网络(HP SO-WNN)方法,对牵引变压器进行综合测试和诊断.将色谱数据和电气试验数据作为正交小波神经网络的输 入量,网络隐藏层采用具有正交性的小波函数db4作为基函数,利用混合粒子群算法获得正交小波神经网络的初 始值并优化网络参数.试验结果证明,本文提出的HPSO-WNN确实可有效提高牵引变压器故障诊断速度和准 确度.%In order to diagnose traction transformer faults more effectively and in an all-round way, this paper proposed the method of the orthogonal wavelet neural network based on the hybrid particle swarm optimization algorithm (HPSO-WNN) to be applied in comprehensive tests and diagnoses of electric locomotive traction transformer faults. The chromatographic data and electrical test data worked as the inputs of the orthogonal wavelet neural network, the network's hidden layer used the orthogonal dh4 function as the basis function, and the hybrid particle swarm algorithm was used to obtain the initial values of the orthogonal wavelet neural network and to optimize the network parameters. The test results show that the proposed HPSO-WNN does effectively improve the traction transformer fault diagnosis speed and accuracy.

  6. Simulation research on hydraulic transformer system fault of 300 MN die forging hydraulic press%300MN模锻液压机液压变压系统故障仿真研究

    Institute of Scientific and Technical Information of China (English)

    刘石梅; 谭建平; 陈晖

    2011-01-01

    In order to analyze the fault of hydraulic transformer which failed to work in long-stroke pressurizing because of its too long return time, a simulation model about hydraulic transformer system of 300 MN forging hydraulic press was established based on AMESim software. The influence of opening height of drain valves and pressure of liquidfilled tank on the return time of hydraulic transformer was simulated quantitatively. The condition, which would result in fault, was obtained and used to analyze the actual fault. The result shows that the fault can be eliminated through reducing the space between the cam plunger and drain valve stem by 4. 6 mm.Keywords: die forging hydraulic press; hydraulic transformer; simulationDesign and manufacture of multi-transfer hydraulic press with resistant-bias loading and synchronization mechanismAbstract: Multi-transfer hydraulic press, a kind of hydraulic equipment with the compact structure and high-efficiency,is widely used in sheet metal shaping and forming operations in the developed countries. To the problem appeared in multi-transfer hydraulic press, such as the wide table, serious bias loading and high-precision forming etc., a four-column multi-transfer hydraulic press developed for the forming of auto parts and components was designed and introduced. Through the research and analysis to the mainframe structure style and closed loop electric-hydraulic control system, the stationary motion performances as well as the integrated performances of equipment were improved and the resistant-bias loading capacity was enhanced in order to meet the high accuracy and compaction requirements.%针对300 MN模锻液压机实际生产中存在的变压器回程时间过长而无法长行程加压故障,基于AMESim软件建立了变压系统的仿真模型并进行了故障仿真,定量地得到了变压器操纵分配器排水阀开启度与充液罐压力对回程时间的影响规律.推导出变压器发生无法长行程加压故

  7. 基于双树复小波包变换的滚动轴承故障诊断%Fault diagnosis of rolling bearing based on dual-tree complex wavelet packet transform

    Institute of Scientific and Technical Information of China (English)

    胥永刚; 孟志鹏; 陆明

    2013-01-01

    The operation states of rolling bearings which are the most common and important parts in the mechanical equipment, will affect the whole machine operation condition directly. Due to the working environment of rolling, bearing is complicated, the fault vibration signal of rolling bearing is usually non-stationary, and the strong noise interference is contained in the vibration signal at the same time. So it is important to eliminate the noise interference and extract fault feature information effectively for the rolling bearing. Dual-tree complex wavelet packet transform is a new method of signal processing. Dual-tree complex wavelet packet transform has many good characteristics, for example, approximate shift invariance, good directional selectivity、perfect reconstruction, limited data redundancy, efficient computational efficiency and so on. The high frequency part of dual-tree complex wavelet transform that is not decomposed, is further decomposed by dual-tree complex wavelet packet transform, so as to improve the whole frequency band signal frequency resolution and reduce the loss of information. In view of the above situation, a new fault diagnosis method is proposed based on dual-tree complex wavelet packet transform and threshold de-noising. Firstly, the non-stationary fault signal is decomposed into several different frequency band components through dual-tree complex wavelet packet decomposition. Secondly, Kurtosis and the cross-correlation coefficient of each component are obtained and compared. Due to the kurtosis reflecting the signal variations, if the kurtosis value is bigger, the degree of the change of signal is bigger too. The correlation coefficient can reflect the proximity between the component and the original signal at the same time, the correlation coefficient is bigger, the more similar with the original signal. Finally, the components that have a bigger value are chosen to be de-noised by a soft threshold and reconstructed by dual

  8. 珠海发电厂01启备变内部故障定位分析%Fault Location Analysis of No. 1 Standby Transformer of Zhuhai Power Plant

    Institute of Scientific and Technical Information of China (English)

    孔永科

    2014-01-01

    针对启备变在受电过程中发生的故障,从故障录波图形着手,采用频谱分析的方法,判断出了故障发生的原因,准确而及时地定位了故障点,为事故抢修和及时送电争取了时间,提高了电厂厂用电系统供电的可靠性。%Aiming at the fault occurred in the charging process of the standby transformer,starting from the fault recorder graphics,and by the method of frequency spectrum analysis,this paper found the reason for the failure, timely and accurately located the fault point. This saves time for emergency repair and timely transmission,and im-proves the reliability of power system of power plant.

  9. Study on Spiral Bevel Gear Fault Diagnosis based on Artificial Neural Networks and Wavelet Transform Technique%基于小波神经网络弧齿锥齿轮故障诊断及实验研究

    Institute of Scientific and Technical Information of China (English)

    扶碧波; 方宗德; 沈云波

    2011-01-01

    提出了一种离散小波变换结合神经网络的故障状态识别方法,运用信号特征提取机理对航空用弧齿锥齿轮故障诊断及状态识别进行了研究.建立了孤齿锥齿轮传动系统振动测试试验台,对正常结构和故障结构的齿轮传动进行了试验测试,通过小波阈值去除掉齿轮箱的振动数据信号系统噪声的影响;采用离散小波变换提取信号的能量特征,利用带有反馈算法的神经网络对齿轮系统的故障状态进行了分类识别.结果表明,该方法齿轮故障识别结果的有效率可达100%,为齿轮系统的故障分析提供了一种有效途径.%A fault diagnosis method of discrete wavelet transform and neural networks is proposed, by using signal feature extraction mechanism,aviation spiral bevel gear fault diagnosis and state recognition is studied. A test rig of spiral bevel gear system vibration testing is built, the testing of normal and defective gear transmission is carried out. The influence of noise on gearbox vibration data signal system is removed through the wavelet threshold. By using discrete wavelet transform, the signal energy features is extracted, gear system fault state classification recognition is carried out by using neural networks with feedback algorithm. The results show that the gear fault recognition result effective rate is to 100% . An effective way for gear system fault analysis is provided.

  10. Convolutional-recursive network based current transformer infrared fault image diagnosis%基于卷积递归网络的电流互感器红外故障图像诊断

    Institute of Scientific and Technical Information of China (English)

    林颖; 郭志红; 陈玉峰

    2015-01-01

    Increasing unstructured data of big data in electric system puts forward a new challenge to traditional manual processing mode. As a typical kind of unstructured data, the infrared image is very important for the research of big data in electric system. In order to automatically processing massive infrared fault images, this paper presents a convolutional recursive network based current transformer infrared fault image diagnosis method. The infrared fault images are first segmented by super pixel segmentation method and then we take advantage of the hue information to extract the temperature anomaly area; secondly, a two-level joint convolution recursive neural network is adopted, the fault device position can be identified by training a large number of samples; finally, the fault information is confirmed according to the location information of fault classification. The experimental results show that, this algorithm has better robustness, higher accuracy, and can improve the efficiency of infrared diagnosis, which is also the foundation for the feature representation of unstructured data.%电力大数据中日益增多的非结构化数据为以人工诊断为主的传统处理方式提出了新的挑战。红外故障图像作为一种典型的非结构化数据,对于电力大数据的研究有着至关重要的作用。为了达到自动处理海量红外故障图像的目的,提出了一种基于卷积递归网络的电流互感器红外故障图像诊断方法。对红外故障图像首先进行超像素分割并利用其色度信息提取温度异常区域;然后采用两级联合卷积-递归神经网络,对大量样本信息进行训练学习来指导设备故障部位识别;最后依据部位信息对故障进行分类。实验结果表明,该算法鲁棒性较强,准确性较高,有效地提高了红外检测效率,为非结构化数据的特征提取分析提供了坚实的基础。

  11. Negligible sulfur isotope fractionation during partial melting: Evidence from Garrett transform fault basalts, implications for the late-veneer and the hadean matte

    Science.gov (United States)

    Labidi, J.; Cartigny, P.

    2016-10-01

    We report the quadruple sulfur isotope compositions, sulfur contents and speciation major and trace elements (including copper and chlorine abundances) of eleven basalts collected in the Garrett transform fault. We combine these data to discuss the absence of S isotopic fractionation along both partial melting and low-pressure fractional crystallization. The variations of K2O/TiO2 and La/SmN-ratios (respectively between 0.017 and 0.067, and between 0.31 and 0.59) suggest a range of depletion in Garrett lavas that includes ultra depleted samples (K2O/TiO2 8%) are ∼80 ppm, indistinguishable from MORBs. This requires their mantle sources, variably depleted in incompatible element, to host residual sulfide buffering the Cu content of all erupted melts. We calculate a minimum S content for the source of ultra-depleted Garrett lavas of 100 ± 40ppmS, i.e. roughly a factor of 2 below the MORB mantle source. After exclusion of a single sample with Cl/K ratio >0.1 that likely experienced hydrothermal sulfide assimilation, Garrett ITLs display homogeneous δ34 S, Δ33 S and Δ36 S values with averages of - 0.68 ± 0.08 ‰, + 0.010 ± 0.005 ‰ and - 0.04 ± 0.04 ‰, respectively (all 1σ, n = 10). The δ34 S values display no relationship with either K2O/TiO2 variations or extent sulfide fractionation. From these observations, we derive a 34S/32S fractionation factor between exsolved sulfides and sulfide dissolved in silicate melts of 1.0000 ± 0.0003. The S isotopic fractionation during partial melting can thus be considered as negligible, and both MORBs and ITLs record the 34S/32S ratio of their mantle source. The concept of sulfide melts segregating from the mantle, sinking and being added to the core during planetary differentiation was termed the 'Hadean Matte'. The segregation of sulfides from the mantle to the core during planetary differentiation could account for various geochemical features of the Earth's mantle. Based on S isotopic mass balance, we derive a

  12. The Fault Location for Power System Traveling Wave With Wavelet Transform%小波变换奇异性在电力系统行波故障测距中的应用

    Institute of Scientific and Technical Information of China (English)

    王先明; 陶时伟; 陶冶; 蔡德礼

    2001-01-01

    输电线路行波双端故障测距具有很高的精度,但需要高速A/D采集、大量的数据存储、复杂的行波波头辨识,对近距离故障测量存在困难。提出利用小波变换的时频分析特性,结合行波传输的特点,对行波信号利用小波变换提取故障时行波的故障信息。利用GPS作为同步时钟,测量波头到达测量端的时刻,构成输电线路的行波测量网络,通过调度通信进行故障测距,可以提高测距的可靠性和精度。%The double-end fault location for transmission lines with high precision requires data collection with high speed A/D element,data storage in large quantities and complex identification of the traveling wave crest,so it is difficult to measure a fault in a short distance.This paper shows that the information of fault in the traveling wave signal can be found by the time-frequency analysis characteristics of the wavelet transform and the characteristics of the traveling wave transmission.The time that wave crest reaches the measured-end can be measured by using GPS as a synchronized clock.A network for measuring traveling wave can be formed through dispatch and communications to improve reliability and precision of the fault location.

  13. 基于坐标变换的永磁同步电机电流传感器容错控制∗%Current Sensor Fault Detection and Isolation Technique for Permanent Magnet Synchronous Motor Based on Axes Transformation

    Institute of Scientific and Technical Information of China (English)

    马雷; 陈宇航; 张云峰

    2016-01-01

    研究了在永磁同步电机矢量控制系统之下,电流传感器的故障诊断及容错控制。针对目前双电流传感器的矢量控制系统中可能出现的软故障,提出一种基于定子坐标变换的故障诊断及容错方法,通过控制器输出的电流值与实际反馈的电流值相比较,来判断故障类型并选择相应的容错方案。仿真结果表明:该方法能准确判断出一相或两相电流传感器故障,并选择相应的实际电流计算值来完成电流闭环控制,具有较高的可行性。%A technique for fault detection and isolation to make the traditional vector control of PMSM system drive fault tolerant against one or two phase current sensor soft failure were presented. Comparison between the output current value and the feedback value, the proposed current axes transformation were expected to determine the fault type and select the appropriate fault tolerance scheme. The simulation results showed that the control system could accurately judge the one or two phase current sensor faulty and select the corresponding current calculation value to complete the current closed-loop control, with a high feasibility.

  14. Research of Water Pump Fault Diagnosis System Based on Wavelet Transform and TMS320F2812%基于小波变换和TMS320F2812的水泵故障诊断系统研究

    Institute of Scientific and Technical Information of China (English)

    卢艳宏; 冯源

    2012-01-01

    For water pumps and uther rotating machinery, the running status of water pump equipment can be more comprehensive judged through the acquisition and analysis of water pump vibration signal. So the collection of vibration signal is the key part of equipment status monitoring and fault diagnosis. The water pump fault diagnosis system is designed in the paper based on wavelet transform and DSP, and the system can realise acquisition of the water pump vibration signal. In order to improve ratio of the vibration signal to noise, and get relatively pure vibration signal, the vibration signal which is collected is eliminated noise by the wavelet diagnosis technology. We do research on water pump fault diagnosis which exemplified by the water pump unit normal operation, overheating winding, imbalance, serious lopsided, pedestal looseness and so on, and fault set parametersamax smax , Tamax , Tsmax and amin , smir , Tamin , Tsmm arc 1. 1500, 0. 1600, 46.9787, 446. 5000 and 0. 9000, 0.0700, 40.9825, 410. 6000 respectively . The experimental results show that the system can effectively find the fault, distinguish fault type and identify degreeof fault, a kind of effective method is provided for water pump unit fault diagnosis, and has the certain instruction significance for other similar mechanical fault diagnosis.%对于水泵等旋转机械来说,通过采集水泵振动信号并进行分析,能够较全面地判断出水泵设备运行状态,因此,振动信号的采集就成为设备状态监测与故障诊断的关键部分;设计了一套基于小波变换和DSP的水泵故障诊断系统,该系统可以实现对水泵振动信号的实时采集;为了提高振动信号的信噪比,得到较为纯净的振动信号,采用小波消噪的技术对采集的振动信号进行消噪处理;并且以水泵机组正常运行和发生绕组过热、轻度不平衡、严重不平衡、支座松动等故障为例进行诊断实验,并且故障集参数am(s)x·smax

  15. 相关向量机及其在变压器故障诊断中的应用%Relevance vector machine and its application in transformer fault diagnosis

    Institute of Scientific and Technical Information of China (English)

    尹金良; 朱永利; 俞国勤

    2012-01-01

    分析并用典型数据分类算例验证相关向量机(RVM)在分类性能方面优于支持向量机(SVM),在此基础上以标准化的变压器主要特征气体含量为输入量,采用二叉树的分类方法建立基于RVM的变压器故障诊断模型.实例分析表明,同基于SVM的故障诊断方法相比,该方法可以取得与其相当甚至更优的故障诊断正确率,相关向量个数明显少于支持向量个数,诊断速度显著提高.%Analysis and typical data classification examples validate the classification performance of RVM (Relevance Vector Machine) is better than that of SVM (Support Vector Machine). A transformer fault diagnosis method based on RVM is put forward, which takes the normalized contents of transformer feature gases as inputs and adopts the binary tree classification means. Experimental results show that, compared with the fault diagnosis method based on SVM,it gets comparable or better diagnostic accuracy with less vector amount and faster diagnosis speed.

  16. 变压器励磁涌流和内部故障识别新判据%A New Criterion for Identification of Transformer Inrush Current and Internal Fault

    Institute of Scientific and Technical Information of China (English)

    李艺文

    2011-01-01

    Aiming at the identification of inrush current and internal fault, which is the key issue of transformer differential protection, and adopting the ampitudes and attenuation factors of the fundamental wave and second harmonic in the original signal with Prony algorithm, a new criterion based on Id2/Id1 and a2l a1 is established in this paper. When the inrush current occurs, Id2 /Id1 = 0.617 > 0.15 , a2 /a1 = 1.67 2. This result is obtained through analysis on the simulation data of transformer inrush current and internal fault from calculations with PSCAD / EMTDC software. The proposed criterion can significantly improve the sensitivity for identification of the inrush current and internal fault.%针对励磁涌流和内部故障识别这个变压器差动保护关键问题,利用Prony算法求取原信号中基波和二次谐波的幅值和衰减因数,建立了一种新判据:二次谐波与基波幅值之比(Id2/Id1)及衰减系数之比(a2/a1).当励磁涌流时,Id2/Id1>0.15,a2/a12.这一结果是通过分析基于PSCAD/EMTDC建立的变压器发生励磁涌流和内部故障时的仿真图得到的.所建议的识别励磁涌流和内部故障的新判据具有高的灵敏度.

  17. Fault diagnosis

    Science.gov (United States)

    Abbott, Kathy

    1990-01-01

    The objective of the research in this area of fault management is to develop and implement a decision aiding concept for diagnosing faults, especially faults which are difficult for pilots to identify, and to develop methods for presenting the diagnosis information to the flight crew in a timely and comprehensible manner. The requirements for the diagnosis concept were identified by interviewing pilots, analyzing actual incident and accident cases, and examining psychology literature on how humans perform diagnosis. The diagnosis decision aiding concept developed based on those requirements takes abnormal sensor readings as input, as identified by a fault monitor. Based on these abnormal sensor readings, the diagnosis concept identifies the cause or source of the fault and all components affected by the fault. This concept was implemented for diagnosis of aircraft propulsion and hydraulic subsystems in a computer program called Draphys (Diagnostic Reasoning About Physical Systems). Draphys is unique in two important ways. First, it uses models of both functional and physical relationships in the subsystems. Using both models enables the diagnostic reasoning to identify the fault propagation as the faulted system continues to operate, and to diagnose physical damage. Draphys also reasons about behavior of the faulted system over time, to eliminate possibilities as more information becomes available, and to update the system status as more components are affected by the fault. The crew interface research is examining display issues associated with presenting diagnosis information to the flight crew. One study examined issues for presenting system status information. One lesson learned from that study was that pilots found fault situations to be more complex if they involved multiple subsystems. Another was pilots could identify the faulted systems more quickly if the system status was presented in pictorial or text format. Another study is currently under way to

  18. Improved DFIG Capability during Asymmetrical Grid Faults

    DEFF Research Database (Denmark)

    Zhou, Dao; Blaabjerg, Frede

    2015-01-01

    , the capability of a 2 MW DFIG to ride through asymmetrical grid faults can be estimated at the existing design of the power electronics converter. Finally, a control scheme aimed to improve the DFIG capability is proposed and the simulation results validate its feasibility.......In the wind power application, different asymmetrical types of the grid fault can be categorized after the Y/d transformer, and the positive and negative components of a single-phase fault, phase-to-phase fault, and two-phase fault can be summarized. Due to the newly introduced negative and even...

  19. The Intersection between the Gloria Transform Fault and the Tore-Madeira Rise in the NE Atlantic: New Tectonic Insights from Analog Modeling Results

    Science.gov (United States)

    Rosas, F. M.; Tomas, R.; Duarte, J. C.; Schellart, W. P.; Terrinha, P.

    2014-12-01

    The intersection between the Gloria Fault (GF) and the Tore-Madeira rise (TMR) in NE Atlantic marks a transition from a discrete to a diffuse nature along a critical segment of the Eurasia/Africa plate boundary. To the West of such intersection, approximately since the Azores triple junction, this plate boundary is mostly characterized by a set of closely aligned and continuous strike-slip faults that make up the narrow active dextral transcurrent system of the GF (with high magnitude M>7 historical earthquakes). While intersecting the TMR the closely E-W trending trace of the GF system is slightly deflected (changing to WNW-ESE), and splays into several fault branches that often coincide with aligned (TMR related?) active volcanic plugs. The segment of the plate boundary between the TMR and the Gorringe Bank (further to the East) corresponds to a more complex (less discrete) tectonic configuration, within which the tectonic connection between the Gloria Fault and another major dextral transcurrent system (the so called SWIM system) occurs. This SWIM fault system has been described to extend even further to the East (almost until the Straits of Gibraltar) across the Gulf of Cadiz domain. In this domain the relative movement between the Eurasian and the African plates is thought to be accommodated through a diffuse manner, involving large scale strain partition between a dextral transcurrent fault-system (the SWIM system), and a set of active west-directed én-échelon major thrusts extending to the North along the SW Iberian margin. We present new analog modeling results, in which we employed different experimental settings to address (namely) the following main questions (as a first step to gain new insight on the tectonic evolution of the TRM-GF critical intersection area): Could the observed morphotectonic configuration of such intersection be simply caused by a bathymetric anomaly determined by a postulated thickened oceanic crust, or is it more compatible with

  20. A new method of identifying inrush and internal faults of power transformer based on H-S transform%基于双曲S变换的变压器励磁涌流和内部故障识别新方法

    Institute of Scientific and Technical Information of China (English)

    焦尚彬; 黄璜; 赵黎明; 张青

    2011-01-01

    A new method to identify inrush and internal fault of transformer based on hyperbolic S-transform (HST) is discussed. This paper uses the S transform (ST) which has excellent characteristics of time-frequency skills and time-frequency resolution and adopts the Hyperbolic window function. The signals of inrush current and fault current are transformed to phase space by using HST to extract the feature > the time-frequency contours are obtained. It is found that the time-frequency contours in case of inrush are different from that in case of internal faults. By calculating the energy after H-S transform and the ratio of energy level 1-9 and level 1 we found that ratio 6 is the threshold between inrush and fault current. The simulation result and dynamic test show that H-S transform can reflect the signal's time-frequency localization clearly, can identify inrush current, and it has strong capability in noise reduction, and is easy to separate signal from noise in ST domain.%提出了一种基于双曲S变换识别励磁涌流和变压器内部故障的新方法.利用S变换具有优秀时频呈现能力和时频分辨率的特点,采用双曲窗函数,把励磁涌流和故障电流信号变换到相空间进行特征提取,从经过变换以后得到的时频等值线图可以发现二者具有明显不同的特征.通过计算H-S变换后的能量以及1-9层能量与1层能量的比值,发现比值6是区别励磁涌流和故障电流的阈值.仿真分析结果和动模试验均表明:H-S变换可以更清楚地反映信号的时频局部化特性,能准确识别励磁涌流;并且具有较好的抗干扰能力,在变换域易于信号和噪声的分离.

  1. 基于小波变换的变压器励磁涌流和内部故障电流的识别研究%Research of Magnetizing Inrush Current and Internal Fault Current Identification Basedon Wavelet Transform in Transformer Protection

    Institute of Scientific and Technical Information of China (English)

    王俊俊; 曹龙汉; 姜昆

    2015-01-01

    在变压器差动保护中,励磁涌流的准确识别是保护可靠动作的保证,也是变压器保护的难点之一。提出一种准确可靠的基于小波变换的变压器励磁涌流和内部故障电流识别新方法。采用Matlab/Simulink建立模型进行仿真,得到了励磁涌流与内部故障电流的波形图,利用db2小波进行4尺度小波变换,将高频分量在第4尺度上的2个初始峰值比作为励磁涌流和内部故障电流识别的判据。大量实验表明,此判据能有效识别变压器差动保护中的励磁涌流和故障电流。%In differential protection of transformer, the accurate identification of magnetizing inrush current is a guarantee of reliable action, which also is difficult point in the protection of transformer. This paper proposes a new accurate and reliable method of transformer magnetizing inrush current and internal fault current based on wavelet transform. We get the oscillograms of magnetizing inrush current and internal fault current by Matlab/Simulink modeling simulation, in which we make use of the db2 4-scale wavelet transform and treat the 4th dimension of two initial peak values as the identify basis of magnetizing inrush current and internal fault current in high frequency components. Experiments show that this criterion can effectively recognize the magnetizing inrush current and internal fault current in differential protection of transformer.

  2. Irrelevance of Reliability Coefficients to Accountability Systems: Statistical Disconnect in Kane-Staiger

    Directory of Open Access Journals (Sweden)

    David Rogosa

    2005-04-01

    Full Text Available The body of this report consists of a fairly thorough effort to discredit the empirical assertions and methodological prescriptions of Kane and Staiger (KS. The four main sections of content that follow this (lengthy Preamble are:Section 1 Accuracy Of Group SummariesExact results are obtained for the accuracy of grade-level scores (forn=68 which are then compared with the reliability-style calculationsreported in KS for North Carolina data. Also, accuracy properties ofCalifornia API school-level scores are presented, and to compare with KS assertions, the reliability coefficients for these scores are calculated. KS find high volatility even when accuracy is very good, and KS find extreme absence of volatility even when accuracy is moderate to poor.Section 2 Accuracy of ImprovementPrecision of improvement is contrasted with KS-style reliability ofimprovement. Analytic and empirical examples for accuracy of improvement reinforce the basic message: reliability is not precision. Most importantly, precision, which is what matters, can be low, and reliability still be high. And vice versa. Also, school-level California API data display no relation between amount of improvement and uncertainty in the scores (Figures 2.1-2.3, refuting a key KS assertion about school size.Section 3 Persistence of Change.The KS correlation of consecutive changes--and thus the KS estimate of"proportion of variance in changes due to nonpersistent factors"--isshown to be a function of the reliability of the difference score. KSdeterminations of persistence of change are shown to be without valuein accountability systems. Common-sense definitions of consistency ofimprovement and empirical demonstrations using artificial data arepresented.Section 4 California Academic Performance Index Award ProgramsDiscussion of appropriate methods for describing the properties of Award Programs (e.g., determinations of false positive and false negatives are contrasted with the incorrect

  3. Kane-Mele Hubbard model on a zigzag ribbon: Stability of the topological edge states and quantum phase transitions

    Science.gov (United States)

    Chung, Chung-Hou; Lee, Der-Hau; Chao, Sung-Po

    2014-07-01

    We study the quantum phases and phase transitions of the Kane-Mele Hubbard (KMH) model on a zigzag ribbon of honeycomb lattice at a finite size via the weak-coupling renormalization group (RG) approach. In the noninteracting limit, the Kane-Mele (KM) model is known to support topological edge states where electrons show helical property with orientations of the spin and momentum being locked. The effective interedge hopping terms are generated due to finite-size effect. In the presence of an on-site Coulomb (Hubbard) interaction and the interedge hoppings, special focus is put on the stability of the topological edge states (TI phase) in the KMH model against (i) the charge and spin gaped (II) phase, (ii) the charge gaped but spin gapless (IC) phase, and (iii) the spin gaped but charge gapless (CI) phase depending on the number (even/odd) of the zigzag ribbons, doping level (electron filling factor) and the ratio of the Coulomb interaction to the interedge tunneling. We discuss different phase diagrams for even and odd numbers of zigzag ribbons. We find the TI-CI, II-IC, and II-CI quantum phase transitions are of the Kosterlitz-Thouless (KT) type. By computing various correlation functions, we further analyze the nature and leading instabilities of these phases. The relevance of our results for graphene is discussed.

  4. 气体色谱分析在变压器故障判断中的应用%The Applying of Gas Chromatography Analysis in Transformer Fault Diagnosis

    Institute of Scientific and Technical Information of China (English)

    黄仰凯

    2013-01-01

      运用气体色谱分析法对一起变压器内部绕组引线短路事故进行试验分析,结合变压器抽芯检查,验证采用气体色谱分析法判断变压器内部故障性质的准确性,提出气体色谱分析在变压器故障判断中的重要性,工程施工中必须重视大型变压器投运前后变压器油的气体色谱分析试验。%The paper analyzes transformer winding short-circuit using gas chromatography analysis. It has proved the reliability of gas chromatography analysis with transformer core pulling. And offers the importance of gas chromatography analysis in transformer fault diagnosis. In engineering construction , we must attach great importance to gas chromatography analysis of transformer-oil in the beginning of runing and the end.

  5. 珠江口盆地惠州凹陷北部边界断裂复合联接和转换%Complex Linkage and Transformation of Boundary Faults of Northern Huizhou Sag in Pearl River Mouth Basin

    Institute of Scientific and Technical Information of China (English)

    田巍; 何敏; 杨亚娟; 刘海伦; 袁勋; 吴森; 朱定伟; 梅廉夫

    2015-01-01

    study.The results show that the northern boun-ding faults of northern Huizhou sag have an offset geometry in Early Eocene,characterized by along-strike and transverse two-way linkage.The along-strike linkage is a composite connection-transformation of “soft and hard”linkage,forming a relay ramp and transverse folds which restrict the structural evolution within Huizhou sag and the migration of its depocenters and sequences.The transverse linkage means the multiple-stage linkage of the transfer faults in relay ramp,including three stages, namely,isolated normal faulting,synthetic overlapping and hard linkage,which control the migration and distribution of depo-sitional system within the relay ramp.This paper presents a unique case of spatial evolution,complex linkage and transforma-tion model of boundary faults in a rift basin,which can facilitate further studies on the response relationship among the bounda-ry fault,sedimentary sequence,sag evolution and regional dynamics mechanism.

  6. 鹰潭变电站变压器有载分接开关故障诊断研究%Study on Fault Diagnosis of Transformer On-load Tap Changer Based on Vibration signal

    Institute of Scientific and Technical Information of China (English)

    吴昊; 徐红英

    2015-01-01

    提出了一种基于小波-高低频包络谱能量提取振动信号特征并进行有载分接开关故障诊断的新方法。首先应用小波变换对振动信号进行降噪处理,然后与希尔伯特变换结合,提取振动信号的低频和高频包络,最后对包络信号进行谱分析和能量特征提取。通过实验证明,此方法可以有效地判别分接开关的状态类型,为变压器有载分接开关的状态监测与故障诊断提供了一种新的研究。%In this paper, a new method based on wavelet-envelop spectrum energy for vibration signals characteristics and making fault diagnosis of transformer on-load tap changers is presented. Firstly, the vibration signals are de-noising by wavelet analysis method. Then the envelope of low frequency and high frequency signals are extracted by wavelet analysis combined with Hilbert transformation. Lastly, the spectral analysis and energy characteristics extracted for envelope signals are completed. Through the analyzing result of the testing signal, the conclusion can be obtained this method is can effectively determine the status of the OLTC, as a new study in the fault diagnosis of the transformer on-load tap changer.

  7. Transformer Oil Dissolved Gas Research and Fault Diagnosis%变压器油中溶解气体研究和故障判断

    Institute of Scientific and Technical Information of China (English)

    贺天宇

    2014-01-01

    The transformer system failure or abnormal, transformer oil decomposition change more obvious. With transformer oil dissolved gas as the research object, and as a basis to judge a transformer failure, in order to protect the reliability of transformer operation.%变压器系统发生故障或出现异常时,变压器油液的分解变化更为明显。以变压器油液中的溶解气体为研究对象,并以此作为变压器发生故障的判断依据,从而保障变压器运行的可靠性。

  8. The Museum of Irish Industry, Robert Kane and Education for All in the Dublin of the 1850s and 1860s

    Science.gov (United States)

    Cullen, Clara

    2009-01-01

    The Museum of Irish Industry in Dublin, in its short existence (1845-1867) facilitated the access of ordinary people to popular scientific education, became a "cause celebre" and was defended by popular protest when the government recommended its abolition in 1862. Its Director, Sir Robert Kane (1809-1890) was not only an advocate of…

  9. MANIFESTATION OF FAULT ZONES IN GEOPHYSICAL FIELDS

    Directory of Open Access Journals (Sweden)

    A. A. Spivak

    2015-09-01

    Full Text Available Geophysical fields influenced by tectonics faults were observed, and instrumental observation results are analysed in the article. It is shown that fault zones are characterized by geophysical fields that are more variable than those in midmost segments of crustal blocks, more intense responses to weak external impacts such as lunar and solar tides and atmospheric pressure variations, and intensive relaxation. Transformation of energy between geophysical fields varying in origin takes place mainly in the fault zones.

  10. 基于故障分量的牵引变压器和应涌流识别方法%An algorith m based on the fault component to identify traction transformer sympathetic inrush

    Institute of Scientific and Technical Information of China (English)

    谭明; 罗建; 余高旺; 祝海明

    2012-01-01

    Sympathetic inrush may cause mal-operation of traction transformer differential protection, so it is necessary to study the method of identifying sympathetic inrush. The emergence mechanism of sympathetic inrush is analyzed firstly, and then it is pointed out that the long time effect of non-periodic components of sympathetic inrush causes current transformer locally saturated and produces the differential current by changing the preach variable characteristics of current transformer, which leads to the mal-operation of differential protection. There is time difference between differential current and the non-periodic fluctuation of excitation voltage fault component caused by initial inrush. Then, combined with the characteristics which are mentioned above, an algorithm of identifying the sympathetic inrush based on the time differential method of fault component is put forward. Lastly, a dynamic model test is made in the case of the traction transformer's common V/V connection model. The algorithm is easy to realize and the dynamic model test verifies its validity and practicability.%和应涌流可能引起牵引变压器差动保护误动,因此有必要对和应涌流的识别方法进行研究.首先对和应涌流的产生机理进行深入剖析,指出和应涌流中的非周期分量长时间的作用导致电流互感器(Current Transformer,CT)局部暂态饱和引起其两侧的传变特性发生变化产生差流而导致误动.然后,结合变压器的起始涌流引起励磁电压故障分量出现非周期波动与差流出现时刻之间存在一定的时间差的特点,提出基于故障分量的时差法来识别和应涌流的方法.最后以牵引变压器中常见的V/V接线方式为例,通过动模实验对所提出的算法进行仿真验证.该算法原理简单且易于实现,仿真结果表明了算法的有效性和实用性.

  11. 负荷端变压器和接地过渡阻抗对短路故障仿真的影响%Influence of load-side transformers and grounding impedance on short-circuit fault simulation

    Institute of Scientific and Technical Information of China (English)

    夏成军; 黄冬燕; 代文良; 邱桂华

    2011-01-01

    Combining with C-phase short-circuit fault case of a regional power grid and taking advantage of electrical wiring diagram and action sequence of protection device in this fault, this paper firstly models PSCAD/EMTDC to calculate the error between simulation outputs and the actual system response, and then analyzes the main error sources. To determine whether and how the simplified model will impact on the simulation results, component models on zero sequence current path and their parameters are adjusted to reduce the error and make the simulation result more realistic from two aspects of load-side transformers and grounding resistance, providing reference basis to increase the validity of short-circuit fault simulation based on PSCAD/EMTDC and to guide scientific modeling.%在结合某地区电网C相短路故障实例,根据电网电气接线图及该事故中继电保护装置的动作时序在PSCAD/EMTDC中初步建立仿真模型,计算仿真值与现场实测数据的误差,并分析主要误差来源.围绕建模过程中对模型的简化处理是否会对仿真结果造成影响以及影响的程度如何这一问题,着重从负荷端变压器和接地过渡阻抗两个角度出发,通过修正零序电流通路上的元件模型及其参数,减小了误差,使仿真结果逼近实测值,为进一步研究影响仿真准确度的因素打下基础.

  12. 油色谱分析在变压器状态监测中的应用研究%Application of Oil Chromatographic Analysis to Transformer Fault Diagnosis

    Institute of Scientific and Technical Information of China (English)

    李晨

    2012-01-01

      电力变压器发生潜在性故障时,绝缘油会分解产生烃类气体,采用油色谱法分析这些烃类气体,可诊断出电压器中存在的潜伏性故障信息,保证设备可靠运行;首先分析了油色谱分析的原理,然后设计了变压器油色谱在线监测系统,最后测试表明利用油色谱技术对变压器故障进行分析诊断的有效性和正确性。%  Hydrocarbon gas will be generated by the decomposition of the Insulating oil when there is a potential failure in pow⁃er transformers,the potential failure is diagnosed by using Oil Chromatographic Analysis to Hydrocarbon gas,firstly,this paper analyses the principle of Oil chromatographic,and it designs the on-line transformer oil chromatography monitoring system,in the end, the experiment shows the Validity and correctness of using the use of oil chromatographic techniques to Diagnosis the Transformer Fault.

  13. Fault diagnosis of radar filter based on wavelet transform and neural network%基于小波变换和神经网络的雷达滤波器故障诊断

    Institute of Scientific and Technical Information of China (English)

    王翔文; 李志华

    2016-01-01

    由于模拟电路的非线性、容差性及元器件参数的连续可变性等特点的存在,传统的模拟电路故障诊断手段在实际运用中已经很难得到令人满意的结果。本文将小波变换与神经网络结合,对特征提取进行优化,以雷达滤波电路为研究对象,在考虑容差性的情况下对电路进行故障诊断,体现出小波神经网络在诊断正确性及时效性上所具有的优势。%With the consideration of actual analog circuit has some characteristics, such as nonlinear-ity, tolerance and the continuous variability of parameters on component, it is difficult to achieve expected results for traditional technology of analog circuit fault diagnosis in particular engineering. In this paper, wavelet transform and neural network are combined to optimization the feature extraction. Taking into account the tolerance, we researched fault diagnosis of radar filter. The result shows that wavelet neural network method reflects its adventages from both diagnosis correctness and timeliness.

  14. Contemporary fault mechanics in southern Alaska

    Science.gov (United States)

    Kalbas, James L.; Freed, Andrew M.; Ridgway, Kenneth D.

    Thin-shell finite-element models, constrained by a limited set of geologic slip rates, provide a tool for evaluating the organization of contemporary faulting in southeastern Alaska. The primary structural features considered in our analysis are the Denali, Duke River, Totschunda, Fairweather, Queen Charlotte, and Transition faults. The combination of fault configurations and rheological properties that best explains observed geologic slip rates predicts that the Fairweather and Totschunda faults are joined by an inferred southeast-trending strike-slip fault that crosses the St. Elias Mountains. From a regional perspective, this structure, which our models suggest slips at a rate of ˜8 mm/a, transfers shear from the Queen Charlotte fault in southeastern Alaska and British Columbia northward to the Denali fault in central Alaska. This result supports previous hypotheses that the Fairweather-Totschunda connecting fault constitutes a newly established northward extension of the Queen Charlotte-Fairweather transform system and helps accommodate right-lateral motion (˜49 mm/a) of the Pacific plate and Yakutat microplate relative to stable North America. Model results also imply that the Transition fault separating the Yakutat microplate from the Pacific plate is favorably oriented to accommodate significant thrusting (23 mm/a). Rapid dip-slip displacement on the Transition fault does not, however, draw shear off of the Queen Charlotte-Fairweather transform fault system. Our new modeling results suggest that the Totschunda fault, the proposed Fairweather-Totschunda connecting fault, and the Fairweather fault may represent the youngest stage of southwestward migration of the active strike-slip deformation front in the long-term evolution of this convergent margin.

  15. There Transformer Fault-oriented Security Research Technology Transfer Capacity Load%有载调容变压器故障导向安全技术研究

    Institute of Scientific and Technical Information of China (English)

    罗伟彬; 范伟波

    2014-01-01

    In view of the current load capacity of transformer operation tone lack of adequate security measures, will users of electrical equipment and electrical safety threat, and product applications, adversely affect the promotion of practical problems were the fault-oriented security technology research, specifically from security, advanced, practical point of view are discussed.%针对目前有载调容变压器运行中缺乏足够的安全保护措施,会对用户用电设备和用电安全造成威胁,并对产品的应用、推广产生不良影响的现实问题,进行了故障导向安全技术的研究,具体从安全性、先进性、实用性角度进行了探讨。

  16. 采用改进人工鱼群优化粗糙集算法的变压器故障诊断%Transformer Fault Diagnosis Using Improved Artificial Fish Swarm with Rough Set Algorithm

    Institute of Scientific and Technical Information of China (English)

    陈小青; 刘觉民; 黄英伟; 付波

    2012-01-01

    传统的人工智能方法对变压器大量的不完备故障信息不能有效地分析,或在故障数据的离散化过程中由于区间分割不当而无法正确诊断故障甚至误诊。为此,提出了一种基于改进人工鱼群优化粗糙集的变压器故障诊断方法。该方法首先将变压器溶解气体分析(DGA)的值作为条件属性,将故障类型作为决策属性,建立故障决策表,利用鱼群的聚群寻优行为对决策表中的连续属性数据进行离散化;然后采用粗糙集理论对离散化后的决策表进行约简,建立故障诊断规则决策表,大大简化了决策表属性约简的难度,使诊断变得更加简便。最后通过实例验证表明:该方法能够有效地对样本进行离散和约简,与传统方法相比,提高了故障诊断的正确率。%Facing a large number of incomplete fault data, the traditional artificial intelligence methods cannot effectively and timely analyze or accurately diagnosed because of the ill-conditioned problem caused by inefficient discretization approaches. We presented a method based on rough set theory integrated with improved artificial fish swarm algorithm {AFSA} for fault diagnosis of transformer. Firstly, the values of dissolved gas analysis {DGA) in oil were taken as conditional attributes and the type faults were taken as decision attributes. Various relations between fault and symptom were connected, and decision table was established. Then, the improved artificial fish swarm algorithm was used to discrete continuous attribute, and the rough set theory was used to reduce the decision table. Finally, the simplified decision rules were got, which greatly simplified the difficulty of diagnosis. The experimental results indicate that the method increases the diagnosis accuracy compared with the traditional algorithm.

  17. GENERAL FAULT ADMITTANCE METHOD LINETO- LINE-TO-LINE UNSYMMETRICAL FAULT

    Directory of Open Access Journals (Sweden)

    J. D. SAKALA

    2015-09-01

    Full Text Available Line-to-line-to-line unsymmetrical faults either involving or not involving ground are in the classical fault analysis approach difficult to analyse. This is because the classical solution requires use of the knowledge of connection of symmetrical component sequence networks for various common faults. In this approach, the phase fault constraints are converted into symmetrical sequence constraints and the sequence networks connected in a way that satisfies the constraints. The symmetrical component constraints for an unsymmetrical three-phase fault not involving ground do not lend themselves easy to the connection of the sequence networks. The exception is that, because the phase currents at the fault summate to zero, the zero sequence current is zero and therefore the zero sequence network is not connected. The connection of the positive and negative sequence networks is difficult to deduce when the fault is unsymmetrical. A classical solution is therefore difficult to find. In contrast, a solution by the general method of fault admittance matrix does not require prior knowledge of how the sequence networks are connected. It is therefore more versatile than the classical methods. The paper presents a procedure for solving a three-phase unsymmetrical fault, with different fault impedances, hence fault admittances in each phase. A computer program based on the general fault admittance method is developed and used to analyse an unsymmetrical three-phase fault on a simple power system with a delta-earthed-star connected transformer.

  18. Analysis of Distribution Transformer DC Resistance Fault Test and Prevention Measures%配电变压器直流电阻故障测试分析与防范措施

    Institute of Scientific and Technical Information of China (English)

    王观友

    2015-01-01

    配电变压器在电力系统中占据极其重要的地位,一旦烧坏或发生故障必然会影响工农业生产和人们的正常生活。可以通过对配电变压器直流电阻故障测试的方式,分析其变化情况,来判断配电变压器是否完好。此外,还可通过比较分析故障状况下的直流电阻值判定实际故障原因,及时排除和修复故障,恢复正常供电,提高供电可靠性。文章以某供电局的一台配变烧损后进行直流电阻测试为例,从测试数据分析,寻找故障原因并提出相应的防范措施,以供参考。%Distribution transformer plays a very important position in power system,once it burns out or fail will defi-nitely affect industrial and agricultural production and people's lives.You can use the distribution transformer DC resistance fault testing method,and analysis of changes,to determine whether the distribution transformers in good condition.In ad-dition,through comparative analysis of DC resistance value under fault conditions to found the actual cause of the failure,e-liminate and repair the failure,to improve the reliability of the power supply.In this article,taking DC resistance testing of a burned out distribution transformation in some power supply bureau as an example,from the test data analysis,find the failure reasons and propose appropriate measures for reference.

  19. An Improved Wavelet Network with Application to the Fault Diagnosis of Oil-immersed Transformer%改进小波网络在油浸式变压器故障诊断中的应用

    Institute of Scientific and Technical Information of China (English)

    方健; 彭辉; 李自品; 舒乃秋

    2011-01-01

    小波网络是近年来神经网络研究中的一个新分支,是结合小波变换理论与神经网络的思想构造的一种新的神经网络模型.笔者构造的前馈小波神经网络是将小波分析与BP神经网络融合,以Gauss小波及其伸缩平移系作为隐含层小波基函数并且对小波神经网络做了一些改进.选择了300组油中溶解气体含量作为前馈小波神经网络训练及故障识别的样本,并对仿真结果进行分析.实验结果显示:文中构造的小波神经网络适合变压器故障诊断,其性能优于改良IEC法,传统BP神经网络法和基于主成分分析法的BP神经网络.该方法已经运用在实际的变压器故障诊断项目中.%This paper constructs a feed-forward wavelet network by combining the wavelet analysis with BP neural network. The wavelet network takes Gauss wavelet and its telescopic translation system as the hidden layer of the wavelet basic function, and the wavelet neural network is improved. 300 measured content data of dissolved gas in oil are selected as the samples for training the feed-forward wavelet network and faults recognition, and the simulation results are compared and analyzed. Experimental results demonstrate that the proposed improved wavelet network adapts to transformer fault diagnosis with better performance than the IEC, BPNN and the BP neural network based on principal component analysis. This method has been used in the actual transformer fault diagnosis project.

  20. Analysis and Treatment of Moist Insulation Fault in 110kV Oil-Immersed Power Transformer%110kV油浸式电力变压器绝缘受潮故障原因分析及处理

    Institute of Scientific and Technical Information of China (English)

    罗军川

    2012-01-01

    The reason of a moist insulation fault in 110kV oil-immersed power transformer is analyzed. The drying treatment of the transformer is discussed.%对一起110kV油浸式电力变压器绝缘受潮故障的原因进行了分析,并叙述了变压器干燥处理过程。

  1. Facies composition and scaling relationships of extensional faults in carbonates

    Science.gov (United States)

    Bastesen, Eivind; Braathen, Alvar

    2010-05-01

    :1000. In general the complete dataset shows a positive correlation between thickness (T) of fault cores and the displacement (D) on faults. For increasing displacement relationships, the D/T relationship is not constant. The D/T relationship is generally higher for small faults than for larger faults, which implies that comparisons between small and large fault with respect to this parameter should be handled with care. Fault envelope composition, as reflected by the relative proportions of different fault facies in the core, varies with displacement. In small scale faults (0-1 m displacement), secondary calcite layers and fault gouge dominate, whereas shale dominated fault rocks (shale smear) and carbonate dominated fault rocks (breccias) constitute minor components. Shale dominated fault rocks are restricted to shale-rich protoliths, and fault breccias to break-down of lenses formed near fault jogs. In medium scale faults (1-10m), fault rocks form the dominating facies, whereas the amount of secondary calcite layers decreases due to transformation into breccias. Further, in shale rich carbonates the fault cores consist of composite facies associations. In major faults (10-300 m displacement) fault rock layers and lenses dominate the fault cores. A common observation in large scale faults is a distinct layering of different fault rocks, shale smearing of major shale layers and massive secondary calcite layers along slip surfaces. Fault core heterogeneity in carbonates is ascribed to the distribution of fault facies, such as fault rocks, secondary calcite layers and shale smear. In a broader sense, facies distribution and thickness are controlled by displacement, protolith and tectonic environment. The heterogeneous properties and the varied distribution observed in this study may be valuable in forecasting fault seal characteristics of carbonate reservoirs.

  2. Temperature profiles from expendable bathythermograph (XBT) casts from the USS KANE in the Mediterranean Sea in support of the Integrated Global Ocean Services System (IGOSS) from 02 August 1975 to 05 September 1975 (NODC Accession 7500936)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — XBT data were collected from the USS KANE in support of the Integrated Global Ocean Services System (IGOSS). Data were collected by the US Navy; Naval Oceanographic...

  3. Temperature profiles from expendable bathythermograph (XBT) casts from the KANE in the North Atlantic Ocean in support of the Integrated Global Ocean Services System (IGOSS) from 03 May 1977 to 23 May 1977 (NODC Accession 7700644)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — XBT data were collected from the KANE in support of the Integrated Global Ocean Services System (IGOSS). Data were collected by the US Navy; Naval Oceanographic...

  4. Temperature profiles from expendable bathythermograph (XBT) casts from the USS KANE in the North Atlantic Ocean in support of the Integrated Global Ocean Services System (IGOSS) project from 23 April 1976 to 07 May 1976 (NODC Accession 7601121)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — XBT data were collected from the USS KANE in support of the Integrated Global Ocean Services System (IGOSS) project. Data were collected by the US Navy; Naval...

  5. Temperature profiles from expendable bathythermograph (XBT) casts from the KANE in the Mediterranean Sea in support of the Integrated Global Ocean Services System (IGOSS) from 13 October 1976 to 10 November 1976 (NODC Accession 7700096)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — XBT data were collected from the KANE in support of the Integrated Global Ocean Services System (IGOSS). Data were collected by the US Navy; Naval Oceanographic...

  6. Temperature profiles from expendable bathythermograph (XBT) casts from the USS KANE in the Norwegian Sea in support of the Integrated Global Ocean Services System (IGOSS) project from 22 May 1975 to 17 June 1975 (NODC Accession 7500790)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — XBT data were collected from the USS KANE in support of the Integrated Global Ocean Services System (IGOSS) project. Data were collected by the US Navy; Naval...

  7. Improved wavelet analysis for induction motors mixed-fault diagnosis

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hanlei; ZHOU Jiemin; LI Gang

    2007-01-01

    Eccentricity is one of the frequent faults of induction motors,and it may cause rub between the rotor and the stator.Early detection of significant rub from pure eccentricity can prolong the lifespan of induction motors.This paper is devoted to such mixed-fault diagnosis:eccentricity plus rub fault.The continuous wavelet transform(CWT)is employed to analyze vibration signals obtained from the motor body.An improved continuous wavelet trartsform was proposed to alleviate the frequency aliasing.Experimental results show that the proposed method can effectively distinguish two types of faults,single-fault of eccentricity and mixed-fault of eccentricity plus rub.

  8. An Aspect-Oriented Approach to Assessing Fault Tolerance

    Science.gov (United States)

    2014-10-01

    misconfiguration, and so forth. The Hadoop File System [8] includes a fault injection framework built using AspectJ similar to that which we describe in...this paper. The main differences between our framework and Hadoop fault injectors is that the Hadoop fault injector only supports probabilistic...Transformation and Net-Centric Systems Conference, Orlando, Florida, April 2009. [8] “ Hadoop fault injection, http://hadoop.apache.org/hdfs/docs/r0.21.0

  9. 基于灰色理论的电力变压器故障预测%Predication of Power Transformer Faults Based on Gray Theory

    Institute of Scientific and Technical Information of China (English)

    郝宁波; 廖海斌

    2011-01-01

    文章提出了一种基于综合灰色模型的电力变压器油中溶解气体浓度预测的方法,进而预测电力变压器的故障.首先对非等间隔时间序列进行等间隔处理,然后对序列进行级比检验,对于级比检验不合格的序列进行弱化处理,使用GM(1,1)得到预测序列,检验预测序列精度,对精度未满足要求的序列使用残差 GM(1,1)进行残差修正,通过预测某超高压公司电力变压器的油中溶解气体的历史数据,证明了该预测模型具有较强的实用性.%This paper presents a method based on a synthesis gray model to predict the power transformer oil dissolved gas concentrations, then predict the failure of power transformer. First, do equal-space processing to the non-equal-space time series, then carries on level compare examination to the sequence, carries on attenuated processing regarding to the unqualified sequence, after qualified we use GM(l, 1) to obtain the forecast sequence, then exam the forecast sequence's precision, to the sequence that not satisfied the request to the precision, we use residual GM(1,1) to revise residual. Through the forecast of a ultrahigh voltage company's power transformer's oil dissolved gas's historical data, we find this forecast model has strong usability.

  10. Machine Fault Signature Analysis

    Directory of Open Access Journals (Sweden)

    Pratesh Jayaswal

    2008-01-01

    Full Text Available The objective of this paper is to present recent developments in the field of machine fault signature analysis with particular regard to vibration analysis. The different types of faults that can be identified from the vibration signature analysis are, for example, gear fault, rolling contact bearing fault, journal bearing fault, flexible coupling faults, and electrical machine fault. It is not the intention of the authors to attempt to provide a detailed coverage of all the faults while detailed consideration is given to the subject of the rolling element bearing fault signature analysis.

  11. 纵横交叉算法与模糊聚类相结合的变压器故障诊断%Fault diagnosis method of transformer based on crisscross optimization algorithm and fuzzy clustering

    Institute of Scientific and Technical Information of China (English)

    孟安波; 卢海明; 郭壮志

    2016-01-01

    Optimized the FCM clustering by the proposed CSO ( CSO-FCM) is introduced to diagnose the fault of transformer in order to conquer the shortages of FCM clustering.The combination of dissolved gas analysis and FCM clustering is effective on improving the accuracy rate of power transformer fault diagnosis, but the result of FCM cluste-ring is unstable and easy getting stuck in a local optimum.The CSO algorithm includes horizon cross as well as verti-cal cross, whose combining can enhance the global convergent ability while the introduction of competitive mechanism drives the potential solutions approximate the global optima in an accelerating fashion without sacrificing the conver-gence speed.This novel method effectively compensates the demerits of single intelligent algorithm, which not only has the ability to dispose the unstable information of fuzzy theory, also has an advantage of global convergence of CSO. Simulation and case analysis indicate that, compared with the traditional FCM clustering, the CSO-FCM clustering can obtain high performance clustering center and effectively raise the accuracy and diagnosis speed of power transformer fault diagnosis.%针对FCM(模糊C-均值聚类)在变压器故障诊断中的不足,提出采用纵横交叉算法优化FCM ( CSO-FCM)聚类来进行故障诊断。溶解气体分析与FCM相结合,能有效提高变压器故障诊断的准确率,但FCM存在聚类结果不稳定和容易陷入局部最优等问题。而纵横交叉算法是一种基于种群的随机搜索算法,在算法中首次提出了维局部最优概念和纵横交叉双搜索思想。实验证明,相比其它主流群智能优化算法,CSO算法在解决维数灾问题和收敛精度问题方面取得了较大突破,能有效克服局部最优的问题。新诊断模型有效弥补了单一诊断法的不足,拥有全局收敛性强和处理模糊信息的能力。实例分析表明,该方法与传统FCM相比,能获得

  12. 大型走滑断裂对青藏高原地体构架的改造%The transformation of the terrain structures of the Tibet Plateau through large-scale strike-slip faults

    Institute of Scientific and Technical Information of China (English)

    许志琴; 李海兵; 唐哲民; 戚学祥; 李化启; 蔡志慧

    2011-01-01

    show an early ductile strike-slip shearing in the deep crust, followed by the transformation of ductile to ductile/brittle to brittle deformations during uplift process. However, in northern Tibet, it is shown as the reactivation of old strike-slip shear zones or suture zones such as the Altyn Tagh, Karakax shear zones and the East Kunlun suture zone, as well as the occurrence of the new brittle fault ( e. G. The Haiyuan fault). In this paper, we will explain the characteristics of large-scale strike-slip faults formed during different geological periods and their roles on terrain amalgamation and collision orogeny within the Tibetan plateau, including " strike-slip" type folded orogeny, " transpression" type orogeny, "compression" type basin and range system, as well as relative displacement and lateral extrusion of terrains.

  13. The Energetics of Gravity Driven Faulting

    Science.gov (United States)

    Barrows, L.

    2007-12-01

    Faulting can result from either of two different mechanisms. These involve fundamentally different energetics. In displacement-bounded faulting, locked-in elastic strain energy is transformed into seismic waves plus work done in the fault zone. Elastic rebound is an example of displacement-bounded faulting. In force-driven faulting, the forces that create the stress on the fault supply work or energy to the faulting process. Half of this energy is transformed into seismic waves plus work done in the fault zone and half goes into an increase in locked-in elastic strain. In displacement-bounded faulting the locked-in elastic strain drives slip on the fault. In force-driven faulting it stops slip on the fault. Tectonic stress is reasonably attributed to gravity acting on topography and the Earth's lateral density variations. This includes the thermal convection that ultimately drives plate tectonics. The gravity collapse seismic mechanism assumes the fault fails and slips in direct response to the gravitational tectonic stress. Gravity collapse is an example of force-driven faulting. In the simplest case, energy that is released from the gravitational potential of the topography and internal stress-causing density variations is equally split between the seismic waves plus work done in the fault zone and the increase in locked-in elastic strain. The release of gravitational potential energy requires a change in the Earth's density distribution. Gravitational body forces are solely dependent on density so a change in the density distribution requires a change in the body forces. This implies the existence of volumetric body-force displacements. The volumetric body-force displacements are in addition to displacements generated by slip on the fault. They must exist if gravity participates in the energetics of the faulting process. From the perspective of gravitational tectonics, the gravity collapse mechanism is direct and simple. The related mechanics are a little more

  14. Online fault location on crossbonded AC cables in underground transmission systems

    DEFF Research Database (Denmark)

    F. Jensen, Christian; Bak, Claus Leth; Gudmundsdottir, Unnur Stella

    2014-01-01

    system are identified. The fault locator system uses the Wavelet Transform both to create reliable triggers in the units and to estimate the fault location based on time domain signals obtained in the substations by two fault locator units. Field measurements of faults artificially created on a section...

  15. Seismic imaging of deep low-velocity zone beneath the Dead Sea basin and transform fault: Implications for strain localization and crustal rigidity

    Science.gov (United States)

    ten Brink, U.S.; Al-Zoubi, A. S.; Flores, C.H.; Rotstein, Y.; Qabbani, I.; Harder, S.H.; Keller, Gordon R.

    2006-01-01

    New seismic observations from the Dead Sea basin (DSB), a large pull-apart basin along the Dead Sea transform (DST) plate boundary, show a low velocity zone extending to a depth of 18 km under the basin. The lower crust and Moho are not perturbed. These observations are incompatible with the current view of mid-crustal strength at low temperatures and with support of the basin's negative load by a rigid elastic plate. Strain softening in the middle crust is invoked to explain the isostatic compensation and the rapid subsidence of the basin during the Pleistocene. Whether the deformation is influenced by the presence of fluids and by a long history of seismic activity on the DST, and what the exact softening mechanism is, remain open questions. The uplift surrounding the DST also appears to be an upper crustal phenomenon but its relationship to a mid-crustal strength minimum is less clear. The shear deformation associated with the transform plate boundary motion appears, on the other hand, to cut throughout the entire crust. Copyright 2006 by the American Geophysical Union.

  16. Melt-rock interactions and fabric development of peridotites from North Pond in the Kane area, Mid-Atlantic Ridge: Implications of microstructural and petrological analyses of peridotite samples from IODP Hole U1382A

    Science.gov (United States)

    Harigane, Yumiko; Abe, Natsue; Michibayashi, Katsuyoshi; Kimura, Jun-Ichi; Chang, Qing

    2016-06-01

    North Pond is an isolated sedimentary pond on the western flank of the Kane area along the Mid-Atlantic Ridge. Drill-hole U1382A of IODP Expedition 336 recovered peridotite and gabbro samples from a sedimentary breccia layer in the pond, from which we collected six fresh peridotite samples. The peridotite samples came from the southern slope of the North Pond where an oceanic core complex is currently exposed. The samples were classified as spinel harzburgite, plagioclase-bearing harzburgite, and a vein-bearing peridotite that contains tiny gabbroic veins. No obvious macroscopic shear deformation related to the formation of a detachment fault was observed. The spinel harzburgite with a protogranular texture was classified as refractory peridotite. The degree of partial melting of the spinel harzburgite is estimated to be ˜17%, and melt depletion would have occurred at high temperatures in the uppermost mantle beneath the spreading axis. The progressive melt-rock interactions between the depleted spinel harzburgite and the percolating melts of Normal-Mid Ocean Ridge Basalt (N-MORB) produced the plagioclase-bearing harzburgite and the vein-bearing peridotite at relatively low temperatures. This implies that the subsequent refertilization occurred in an extinct spreading segment of the North Pond after spreading at the axis. Olivine fabrics in the spinel and plagioclase-bearing harzburgites are of types AG, A, and D, suggesting the remnants of a mantle flow regime beneath the spreading axis. The initial olivine fabrics appear to have been preserved despite the later melt-rock interactions. The peridotite samples noted above preserve evidence of mantle flow and melt-rock interactions beneath a spreading ridge that formed at ˜8 Ma.

  17. Determination of the Density of Energy States in a Quantizing Magnetic Field for Model Kane

    Directory of Open Access Journals (Sweden)

    G. Gulyamov

    2016-01-01

    Full Text Available For nonparabolic dispersion law determined by the density of the energy states in a quantizing magnetic field, the dependence of the density of energy states on temperature in quantizing magnetic fields is studied with the nonquadratic dispersion law. Experimental results obtained for PbTe were analyzed using the suggested model. The continuous spectrum of the energy density of states at low temperature is transformed into discrete Landau levels.

  18. 抽水蓄能机组背靠背启动中跳闸技术改造方案%Transformation on the Fault Trip during Back-to-back Starting of Pumped-storage Power Station

    Institute of Scientific and Technical Information of China (English)

    常永亮; 张兵海; 王勇; 何忠华

    2011-01-01

    针对抽水蓄能机组在背靠背拖动过程中若发生电气或机械故障跳闸,当跳开拖动机组和被拖动机组的灭磁开关的时间差过大时,会在启动回路中产生很大的短路电流,引起继电保护误动作,严重时会损毁启动回路的电气设备,提出一种抽水蓄能机组背靠背跳闸技术改造方案,通过在机组保护系统中添加“跳相邻机组单元”接点,与“跳本机组”接点同时动作,达到同时跳开拖动和被拖动机组灭磁开关的目的.技术改造后的试验证明了方案的正确性和有效性.%When the trip is occurred during the back-to-back starting of pumped-storage units as electrical or mechanical faults and there is a larger time difference between the field breaking switches, the large short -circuit current will be generated in the starting circuits and leads to the malfunction of relay protection, even to damage the electrical equipments of starting circuit in a severe condition. A trip transformation was presented for the back-to-back starting of pumped-storage units, in which, the contact of "Breaking adjacent unit" was added in protection system and will be simultaneously operated with the contact of "Breaking local unit" to meet the requirements on breaking the units on the same time. The tests show that the transformation program is effective.

  19. An Evidential Reasoning Approach to Transformer Fault Diagnosis%基于证据推理的电力变压器故障诊断策略

    Institute of Scientific and Technical Information of China (English)

    董明; 严璋; 杨莉; M.D.Judd

    2006-01-01

    Methods used to assess the insulation status of power transformers before they deteriorate to a critical state include dissolved gas analysis (DGA), partial discharge (PD)detection and transfer function techniques, etc. All of these approaches require experience in order to correctly interpret the observations. Artificial Intelligence (AI) is increasingly used to improve interpretation of the individual data sets. However, a satisfactory diagnosis may not be obtained if only one technique is used. For example, the exact location of PD cannot be predicted if only DGA is performed. However, using diverse methods may result in different diagnosis solutions, a problem that is addressed through the introduction of a fuzzy information infusion model. An inference scheme is proposed that yields consistent conclusions and manages the inherent uncertainty in the various methods. With the aid of information fusion, a framework is established that allows different diagnostic tools to be combined in a systematic way. The application of information fusion technique for insulation diagnostics of transformer is effective by means of examples.%在变压器绝缘劣化之前,可以进行油中溶解气体分析、局部放电检测、传递函数测量等试验方法对其状态进行评估.所有这些试验现象需要很多实际经验才能正确解释.因此人工智能技术逐渐被应用于提高单一试验数据的分析中.但是,仅使用一种方法,可能难以得到满意的诊断结果,如油中溶解气体分析是不能准确对局部放电进行定位.然而,应用不同的方法可能产生各异的诊断结果,因此文中引入模糊信息融合系统来解决此问题,提出了产生一致性结论和处理不同方法中不确定性的证据推理策略.并在信息融合的帮助下,建立了有机组合多种诊断方法系统框架.通过实例证明,基于信息融合的变压器绝缘故障诊断方法是有效的.

  20. A "Kane's Dynamics" Model for the Active Rack Isolation System Part Two: Nonlinear Model Development, Verification, and Simplification

    Science.gov (United States)

    Beech, G. S.; Hampton, R. D.; Rupert, J. K.

    2004-01-01

    Many microgravity space-science experiments require vibratory acceleration levels that are unachievable without active isolation. The Boeing Corporation's active rack isolation system (ARIS) employs a novel combination of magnetic actuation and mechanical linkages to address these isolation requirements on the International Space Station. Effective model-based vibration isolation requires: (1) An isolation device, (2) an adequate dynamic; i.e., mathematical, model of that isolator, and (3) a suitable, corresponding controller. This Technical Memorandum documents the validation of that high-fidelity dynamic model of ARIS. The verification of this dynamics model was achieved by utilizing two commercial off-the-shelf (COTS) software tools: Deneb's ENVISION(registered trademark), and Online Dynamics Autolev(trademark). ENVISION is a robotics software package developed for the automotive industry that employs three-dimensional computer-aided design models to facilitate both forward and inverse kinematics analyses. Autolev is a DOS-based interpreter designed, in general, to solve vector-based mathematical problems and specifically to solve dynamics problems using Kane's method. The simplification of this model was achieved using the small-angle theorem for the joint angle of the ARIS actuators. This simplification has a profound effect on the overall complexity of the closed-form solution while yielding a closed-form solution easily employed using COTS control hardware.

  1. Gauge-theoretic invariants for topological insulators: A bridge between Berry, Wess-Zumino, and Fu-Kane-Mele

    CERN Document Server

    Monaco, Domenico

    2016-01-01

    We establish a connection between two recently-proposed approaches to the understanding of the geometric origin of the Fu-Kane-Mele invariant $\\mathrm{FKM} \\in \\mathbb{Z}_2$, arising in the context of 2-dimensional time-reversal symmetric topological insulators. On the one hand, the $\\mathbb{Z}_2$ invariant can be formulated in terms of the Berry connection and the Berry curvature of the Bloch bundle of occupied states over the Brillouin torus. On the other, using techniques from the theory of bundle gerbes it is possible to provide an expression for $\\mathrm{FKM}$ containing the square root of the Wess-Zumino amplitude for a certain $U(N)$-valued field over the Brillouin torus. We link the two formulas by showing directly the equality between the above mentioned Wess-Zumino amplitude and the Berry phase, as well as between their square roots. An essential tool of independent interest is an equivariant version of the adjoint Polyakov-Wiegmann formula for fields $\\mathbb{T}^2 \\to U(N)$, of which we provide a p...

  2. Gauge-theoretic invariants for topological insulators: a bridge between Berry, Wess-Zumino, and Fu-Kane-Mele

    Science.gov (United States)

    Monaco, Domenico; Tauber, Clément

    2017-02-01

    We establish a connection between two recently proposed approaches to the understanding of the geometric origin of the Fu-Kane-Mele invariant FKMin Z_2 , arising in the context of two-dimensional time-reversal symmetric topological insulators. On the one hand, the Z_2 invariant can be formulated in terms of the Berry connection and the Berry curvature of the Bloch bundle of occupied states over the Brillouin torus. On the other, using techniques from the theory of bundle gerbes, it is possible to provide an expression for FKM containing the square root of the Wess-Zumino amplitude for a certain U(N)-valued field over the Brillouin torus. We link the two formulas by showing directly the equality between the above-mentioned Wess-Zumino amplitude and the Berry phase, as well as between their square roots. An essential tool of independent interest is an equivariant version of the adjoint Polyakov-Wiegmann formula for fields T^2 → U(N) , of which we provide a proof employing only basic homotopy theory and circumventing the language of bundle gerbes.

  3. Fault current limiters using superconductors

    Science.gov (United States)

    Norris, W. T.; Power, A.

    Fault current limiters on power systems are to reduce damage by heating and electromechanical forces, to alleviate duty on switchgear used to clear the fault, and to mitigate disturbance to unfaulted parts of the system. A basic scheme involves a super-resistor which is a superconductor being driven to high resistance when fault current flows either when current is high during a cycle of a.c. or, if the temperature of the superconductive material rises, for the full cycle. Current may be commuted from superconductor to an impedance in parallel, thus reducing the energy dispersed at low temperature and saving refrigeration. In a super-shorted transformer the ambient temperature primary carries the power system current; the superconductive secondary goes to a resistive condition when excessive currents flow in the primary. A super-transformer has the advantage of not needing current leads from high temperature to low temperature; it behaves as a parallel super-resistor and inductor. The supertransductor with a superconductive d.c. bias winding is large and has small effect on the rate of fall of current at current zero; it does little to alleviate duty on switchgear but does reduce heating and electromechanical forces. It is fully active after a fault has been cleared. Other schemes depend on rapid recooling of the superconductor to achieve this.

  4. Application of fault current limiters

    Energy Technology Data Exchange (ETDEWEB)

    Neumann, A.

    2007-11-30

    This report presents the results of a study commissioned by the Department for Business, Enterprise and Industry (BERR; formerly the Department of Trade and Industry) into the application of fault current limiters in the UK. The study reviewed the current state of fault current limiter (FCL) technology and regulatory position in relation to all types of current limiters. It identified significant research and development work with respect to medium voltage FCLs and a move to high voltage. Appropriate FCL technologies being developed include: solid state breakers; superconducting FCLs (including superconducting transformers); magnetic FCLs; and active network controllers. Commercialisation of these products depends on successful field tests and experience, plus material development in the case of high temperature superconducting FCL technologies. The report describes FCL techniques, the current state of FCL technologies, practical applications and future outlook for FCL technologies, distribution fault level analysis and an outline methodology for assessing the materiality of the fault level problem. A roadmap is presented that provides an 'action agenda' to advance the fault level issues associated with low carbon networks.

  5. Fault Line Selection Method Considering Grounding Fault Angle for Distribution Network

    Institute of Scientific and Technical Information of China (English)

    Li Si-bo; Zhao Yu-lin; Li Ji-chang; Sui Tao

    2015-01-01

    In the distribution network system with its neutral point grounding via arc suppression coil, when single-phase grounding fault occurred near zero-crossing point of the phase voltage, the inaccuracy of the line selection always existed in existing methods. According to the characteristics that transient current was different between the fault feeder and other faultless feeders, wavelet transformation was performed on data of the transient current within a power frequency cycle after the fault occurred. Based on different fault angles, wavelet energy in corresponding frequency band was chosen to compare. The result was that wavelet energy in fault feeder was the largest of all, and it was larger than sum of those in other faultless feeders, when the bus broke down, the disparity between each wavelet energy was not significant. Fault line could be selected out by the criterion above. The results of MATLAB/simulink simulation experiment indicated that this method had anti-interference capacity and was feasible.

  6. FAULT IDENTIFICATION IN HETEROGENEOUS NETWORKS USING TIME SERIES ANALYSIS

    Institute of Scientific and Technical Information of China (English)

    孙钦东; 张德运; 孙朝晖

    2004-01-01

    Fault management is crucial to provide quality of service grantees for the future networks, and fault identification is an essential part of it. A novel fault identification algorithm is proposed in this paper, which focuses on the anomaly detection of network traffic. Since the fault identification has been achieved using statistical information in management information base, the algorithm is compatible with the existing simple network management protocol framework. The network traffic time series is verified to be non-stationary. By fitting the adaptive autoregressive model, the series is transformed into a multidimensional vector. The training samples and identifiers are acquired from the network simulation. A k-nearest neighbor classifier identifies the system faults after being trained. The experiment results are consistent with the given fault scenarios, which prove the accuracy of the algorithm. The identification errors are discussed to illustrate that the novel fault identification algorithm is adaptive in the fault scenarios with network traffic change.

  7. East-west faults due to planetary contraction

    CERN Document Server

    Beuthe, Mikael

    2010-01-01

    Contraction, expansion and despinning have been common in the past evolution of Solar System bodies. These processes deform the lithosphere until it breaks along faults. The type and orientation of faults are usually determined under the assumption of a constant lithospheric thickness, but lithospheric thinning can occur at the equator or at the poles due either to latitudinal variation in solar insolation or to localized tidal dissipation. Using thin elastic shells with variable thickness, I show that the equatorial thinning of the lithosphere transforms the homogeneous and isotropic fault pattern caused by contraction/expansion into a pattern of faults striking east-west, preferably formed in the equatorial region. By contrast, lithospheric thickness variations only weakly affect the despinning faulting pattern consisting of equatorial strike-slip faults and polar normal faults. If contraction is added to despinning, the despinning pattern first shifts to thrust faults striking north-south and then to thrus...

  8. Fault Location Based on Synchronized Measurements: A Comprehensive Survey

    Directory of Open Access Journals (Sweden)

    A. H. Al-Mohammed

    2014-01-01

    Full Text Available This paper presents a comprehensive survey on transmission and distribution fault location algorithms that utilize synchronized measurements. Algorithms based on two-end synchronized measurements and fault location algorithms on three-terminal and multiterminal lines are reviewed. Series capacitors equipped with metal oxide varistors (MOVs, when set on a transmission line, create certain problems for line fault locators and, therefore, fault location on series-compensated lines is discussed. The paper reports the work carried out on adaptive fault location algorithms aiming at achieving better fault location accuracy. Work associated with fault location on power system networks, although limited, is also summarized. Additionally, the nonstandard high-frequency-related fault location techniques based on wavelet transform are discussed. Finally, the paper highlights the area for future research.

  9. Saturating time-delay transformer for overcurrent protection

    Science.gov (United States)

    Praeg, Walter F.

    1977-01-01

    Electrical loads connected to d-c supplies are protected from damage by overcurrent in the case of a load fault by connecting in series with the load a saturating transformer that detects a load fault and limits the fault current to a safe level for a period long enough to correct the fault or else disconnect the power supply.

  10. Saturating time-delay transformer for overcurrent protection. [Patent application

    Science.gov (United States)

    Praeg, W.F.

    1975-12-18

    Electrical loads connected to dc supplies are protected from damage by overcurrent in the case of a load fault by connecting in series with the load a saturating transformer that detects a load fault and limits the fault current to a safe level for a period long enough to correct the fault or else disconnect the power supply.

  11. “A horror so deep only ritual can contain it”: The art of dying in the theatre of Sarah Kane

    Directory of Open Access Journals (Sweden)

    Sara Soncini

    2010-10-01

    Full Text Available Death is an overarching presence in Sarah Kane's dramatic universe, peopled by characters charging towards death, and usually encountering it in scenes of Grand Guignol excess and grotesque violence. Death is ambivalently presented as the only escape from the nightmare of living and, at the same time, as that which makes living a nightmare; as the moment of "complete sanity and humanity" in which "everything suddenly connects", and as the ultimate, irrevocable and unredeemable act of self-annihilation. Following Kane's turn towards a more poetic form of drama, in her last two plays this discourse of death is handed over to the words nameless characters or unidentified voices who are likewise engaged in a long, painful quest for selfhood pivoting on the awareness of mortality and the simultaneous dread of and longing for death it engenders. This essay focuses on the ritual quality of the death scenes and/or narratives that crowd Kane's drama. Throughout her work, dying is never an easy, straightforward business, but rather a long, complicated, and at times frustrating mise en scène which also entails rehearsing a repertory of traditional rituals and, once their shortcomings become apparent, devising and testing new ones. The amount of theatricality involved in the art of dying is foregrounded through a web of intertextual references to other literary and/or dramatic sources; this dialogue ties in with a self-reflexive probing of the theatre's ability to provide a ritual that will be capable of "contain[ing] the horror" by supplying a formal framework to express, embody and experience death collectively.

  12. Large seismic faults in the Hellenic arc

    Directory of Open Access Journals (Sweden)

    B. S. Papazachos

    1996-06-01

    Full Text Available Using information concerning reliable fault plane solutions, spatial distribution of strong earthquakes (Ms³ 6.0 as well as sea bottom and coastal topography, properties of the seismic faults (orientation, dimension, type of faulting were determined in seven shallow (h < 40 km seismogenic regions along the convex part of thc Hellenic arc (Hellenic trench and in four seismogenic regions of intermediate depth earthquakes (h = 40-100 km along the concave part of this arc. Except for the northwesternmost part of the Hellenic trench, where the strike-slip Cephalonia transform fault dominates, all other faults along this trench are low angle thrust faults. III thc western part of the trench (Zante-west Crete faults strike NW-SE and dip NE, while in its eastern part (east Crete-Rhodos faults strike WNW-ESE and dip NNE. Such system of faulting can be attributed to an overthrust of the Aegean lithosphere on the eastern Mediterranean lithosphere. The longest of these faults (L = 300 km is that which produced the largest known shallow earthquake in the Mediterranean area (21 July 365, Ms = 8.3 which is located near the southwestern coast of Crete. The second longest such fault (L = l 70 km is that which produced a large earthquake (December 1303, Ms = 8.0 in the easternmost part of the trench (east of Rhodos island. Both earthquakes were associated with gigantic tsunamis which caused extensive damage in the coast of many Eastern Mediterranean countries. Seismic faults of the intermediate depth earthquakes in the shallow part of the Benioff zone (h = 40- 100 km are of strike-slip type, with a thrust component. The orientations of these faults vary along the concave part of the arc in accordance with a subduction of remnants of all old lithospheric slab from the convex side (Mediterranean to the concave side (Aegean of thc Hellenic arc. The longest of these faults (L = 220 km is that which produced the largest known intermediate depth earthquake in the

  13. Fault Tolerant Feedback Control

    DEFF Research Database (Denmark)

    Stoustrup, Jakob; Niemann, H.

    2001-01-01

    An architecture for fault tolerant feedback controllers based on the Youla parameterization is suggested. It is shown that the Youla parameterization will give a residual vector directly in connection with the fault diagnosis part of the fault tolerant feedback controller. It turns out...... that there is a separation be-tween the feedback controller and the fault tolerant part. The closed loop feedback properties are handled by the nominal feedback controller and the fault tolerant part is handled by the design of the Youla parameter. The design of the fault tolerant part will not affect the design...... of the nominal feedback con-troller....

  14. Phase Transformations and Earthquakes

    Science.gov (United States)

    Green, H. W.

    2011-12-01

    Phase transformations have been cited as responsible for, or at least involved in, "deep" earthquakes for many decades (although the concept of "deep" has varied). In 1945, PW Bridgman laid out in detail the string of events/conditions that would have to be achieved for a solid/solid transformation to lead to a faulting instability, although he expressed pessimism that the full set of requirements would be simultaneously achieved in nature. Raleigh and Paterson (1965) demonstrated faulting during dehydration of serpentine under stress and suggested dehydration embrittlement as the cause of intermediate depth earthquakes. Griggs and Baker (1969) produced a thermal runaway model of a shear zone under constant stress, culminating in melting, and proposed such a runaway as the origin of deep earthquakes. The discovery of Plate Tectonics in the late 1960s established the conditions (subduction) under which Bridgman's requirements for earthquake runaway in a polymorphic transformation could be possible in nature and Green and Burnley (1989) found that instability during the transformation of metastable olivine to spinel. Recent seismic correlation of intermediate-depth-earthquake hypocenters with predicted conditions of dehydration of antigorite serpentine and discovery of metastable olivine in 4 subduction zones, suggests strongly that dehydration embrittlement and transformation-induced faulting are the underlying mechanisms of intermediate and deep earthquakes, respectively. The results of recent high-speed friction experiments and analysis of natural fault zones suggest that it is likely that similar processes occur commonly during many shallow earthquakes after initiation by frictional failure.

  15. Analysis of the effects of asymmetric faults in three-phase superconducting inductive fault current limiters

    Science.gov (United States)

    Ferreira, R.; Pina, J. M.; Vilhena, N.; Arsénio, P.; Pronto, A. G.; Martins, J.

    2014-05-01

    Inductive fault current limiters of magnetic shielding type can be described in terms of the excursion in the plane defined by flux linked with primary and line current, and this methodology has been previously applied to single-phase devices. Practical applications, however, require three-phase limiters, which, for the sake of compactness, may be built by three legged cores, instead of three single phase units. This has the advantage of using well established methods of power transformers industry, but the performance of the devices depends on the type of fault, e.g. phase to ground or phase to phase. For instance, in a three legged core, a phase to ground fault affects healthy phases, and these are the most frequent faults in distribution grids, where such systems are envisaged. The effects of asymmetric faults are analysed in this paper, by means of measured excursions in the linked flux-current plane.

  16. Fault detection and isolation in systems with parametric faults

    DEFF Research Database (Denmark)

    Stoustrup, Jakob; Niemann, Hans Henrik

    1999-01-01

    The problem of fault detection and isolation of parametric faults is considered in this paper. A fault detection problem based on parametric faults are associated with internal parameter variations in the dynamical system. A fault detection and isolation method for parametric faults is formulated...

  17. Iowa Bedrock Faults

    Data.gov (United States)

    Iowa State University GIS Support and Research Facility — This fault coverage locates and identifies all currently known/interpreted fault zones in Iowa, that demonstrate offset of geologic units in exposure or subsurface...

  18. null Faults, null Images

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Through the study of faults and their effects, much can be learned about the size and recurrence intervals of earthquakes. Faults also teach us about crustal...

  19. Research on Power Cable Fault Location Based on Traveling Wave Method and Wavelet Transform%基于小波变换和行波法的电缆故障测距方法研究

    Institute of Scientific and Technical Information of China (English)

    于泽; 费明

    2011-01-01

    To find out the singularity of the high coefficients of fault signal, the method of searching modulus maxima is adopted and realized the precise rangefinder fault. Through the simulation platform of MATLAB, the power cable fault system simulation model is established and obtaind the cable faults fluctuations in the end. The relative error of different locations of the different faults simulation data is less than 4% , that shows that this method is feasible and accuracy.. At the same time a kind range finder formula is put forward and developed that doesn' t include wave velocity v. That makes the calculation of the fault distance to dispense the affect from wave velocity theoretically.%采用搜索模极大值的方法,进而实现故障的精确测距.通过MATLAB仿真平台,建立了电力电缆故障系统的仿真模型,得出电缆故障波形图.不同位置的不同故障的仿真数据相对误差均小于4%,验证了该方法的可行性和准确性.同时提出并推导一种不包含波速v的测距公式,使得在计算故障距离从理论上摆脱了波速对测距结果的影响.

  20. Formal Validation of Fault Management Design Solutions

    Science.gov (United States)

    Gibson, Corrina; Karban, Robert; Andolfato, Luigi; Day, John

    2013-01-01

    The work presented in this paper describes an approach used to develop SysML modeling patterns to express the behavior of fault protection, test the model's logic by performing fault injection simulations, and verify the fault protection system's logical design via model checking. A representative example, using a subset of the fault protection design for the Soil Moisture Active-Passive (SMAP) system, was modeled with SysML State Machines and JavaScript as Action Language. The SysML model captures interactions between relevant system components and system behavior abstractions (mode managers, error monitors, fault protection engine, and devices/switches). Development of a method to implement verifiable and lightweight executable fault protection models enables future missions to have access to larger fault test domains and verifiable design patterns. A tool-chain to transform the SysML model to jpf-Statechart compliant Java code and then verify the generated code via model checking was established. Conclusions and lessons learned from this work are also described, as well as potential avenues for further research and development.

  1. The mechanics of gravity-driven faulting

    Science.gov (United States)

    Barrows, L.; Barrows, V.

    2010-04-01

    Faulting can result from either of two different mechanisms. These involve fundamentally different energetics. In elastic rebound, locked-in elastic strain energy is transformed into the earthquake (seismic waves plus work done in the fault zone). In force-driven faulting, the forces that create the stress on the fault supply work or energy to the faulting process. Half of this energy is transformed into the earthquake and half goes into an increase in locked-in elastic strain. In elastic rebound the locked-in elastic strain drives slip on the fault. In force-driven faulting it stops slip on the fault. Tectonic stress is reasonably attributed to gravity acting on topography and the Earth's lateral density variations. This includes the thermal convection that ultimately drives plate tectonics. Mechanical analysis has shown the intensity of the gravitational tectonic stress that is associated with the regional topography and lateral density variations that actually exist is comparable with the stress drops that are commonly associated with tectonic earthquakes; both are in the range of tens of bar to several hundred bar. The gravity collapse seismic mechanism assumes the fault fails and slips in direct response to the gravitational tectonic stress. Gravity collapse is an example of force-driven faulting. In the simplest case, energy that is released from the gravitational potential of the stress-causing topography and lateral density variations is equally split between the earthquake and the increase in locked-in elastic strain. The release of gravitational potential energy requires a change in the Earth's density distribution. Gravitational body forces are solely dependent on density so a change in the density distribution requires a change in the body forces. This implies the existence of volumetric body-force displacements. The volumetric body-force displacements are in addition to displacements generated by slip on the fault. They must exist if gravity

  2. The mechanics of gravity-driven faulting

    Directory of Open Access Journals (Sweden)

    L. Barrows

    2010-04-01

    Full Text Available Faulting can result from either of two different mechanisms. These involve fundamentally different energetics. In elastic rebound, locked-in elastic strain energy is transformed into the earthquake (seismic waves plus work done in the fault zone. In force-driven faulting, the forces that create the stress on the fault supply work or energy to the faulting process. Half of this energy is transformed into the earthquake and half goes into an increase in locked-in elastic strain. In elastic rebound the locked-in elastic strain drives slip on the fault. In force-driven faulting it stops slip on the fault.

    Tectonic stress is reasonably attributed to gravity acting on topography and the Earth's lateral density variations. This includes the thermal convection that ultimately drives plate tectonics. Mechanical analysis has shown the intensity of the gravitational tectonic stress that is associated with the regional topography and lateral density variations that actually exist is comparable with the stress drops that are commonly associated with tectonic earthquakes; both are in the range of tens of bar to several hundred bar.

    The gravity collapse seismic mechanism assumes the fault fails and slips in direct response to the gravitational tectonic stress. Gravity collapse is an example of force-driven faulting. In the simplest case, energy that is released from the gravitational potential of the stress-causing topography and lateral density variations is equally split between the earthquake and the increase in locked-in elastic strain.

    The release of gravitational potential energy requires a change in the Earth's density distribution. Gravitational body forces are solely dependent on density so a change in the density distribution requires a change in the body forces. This implies the existence of volumetric body-force displacements. The volumetric body-force displacements are in addition to displacements generated by slip on

  3. Continental Transform Boundaries: Tectonic Evolution and Geohazards

    Directory of Open Access Journals (Sweden)

    Michael Steckler

    2012-04-01

    Full Text Available Continental transform boundaries cross heavily populated regions, and they are associated with destructive earthquakes,for example, the North Anatolian Fault (NAFacross Turkey, the Enriquillo-Plantain Garden fault in Haiti,the San Andreas Fault in California, and the El Pilar fault in Venezuela. Transform basins are important because they are typically associated with 3-D fault geometries controlling segmentation—thus, the size and timing of damaging earthquakes—and because sediments record both deformation and earthquakes. Even though transform basins have been extensively studied, their evolution remains controversial because we don’t understand the specifics about coupling of vertical and horizontal motions and about the basins’long-term kinematics. Seismic and tsunami hazard assessments require knowing architecture and kinematics of faultsas well as how the faults are segmented.

  4. Performance based fault diagnosis

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik

    2002-01-01

    Different aspects of fault detection and fault isolation in closed-loop systems are considered. It is shown that using the standard setup known from feedback control, it is possible to formulate fault diagnosis problems based on a performance index in this general standard setup. It is also shown...

  5. Fault tolerant computing systems

    CERN Document Server

    Randell, B

    1981-01-01

    Fault tolerance involves the provision of strategies for error detection, damage assessment, fault treatment and error recovery. A survey is given of the different sorts of strategies used in highly reliable computing systems, together with an outline of recent research on the problems of providing fault tolerance in parallel and distributed computing systems. (15 refs).

  6. Fault Tolerant Control Systems

    DEFF Research Database (Denmark)

    Bøgh, S. A.

    was to avoid a total close-down in case of the most likely faults. The second was a fault tolerant attitude control system for a micro satellite where the operation of the system is mission critical. The purpose was to avoid hazardous effects from faults and maintain operation if possible. A method...

  7. The electrical resistivity signature of a fault controlling gold mineralization and the implications for Mesozoic mineralization: a case study from the Jiaojia Fault, eastern China

    Science.gov (United States)

    Zhang, Kun; Lü, Qingtian; Yan, Jiayong; Hu, Hao; Fu, GuangMing

    2017-07-01

    We use 3D audio magnetotelluric method to the south segment of Jiaojia fault belt, and obtain the 3D electrical model of this area. Regional geophysical data were combined in an analysis of strata and major structural distribution in the study area, and included the southern segment of the Jiaojia fault zone transformed into two fault assemblages. Together with the previous studies of the ore-controlling action of the Jiaojia fault belt and deposit characteristics, the two faults are considered to be favorable metallogenic provinces, because some important features coupled with them, such as the subordinate fault intersection zone and several fault assemblages in one fault zone. It was also suggested the control action of later fault with reversed downthrows to the ore distribution. These studies have enabled us to predict the presence of two likely target regions of mineralization, and are prospecting breakthrough in the southern section of Jiaojia in the Shandong Peninsula, China.

  8. Information Based Fault Diagnosis

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik; Poulsen, Niels Kjølstad

    2008-01-01

    Fault detection and isolation, (FDI) of parametric faults in dynamic systems will be considered in this paper. An active fault diagnosis (AFD) approach is applied. The fault diagnosis will be investigated with respect to different information levels from the external inputs to the systems....... These inputs are disturbance inputs, reference inputs and auxilary inputs. The diagnosis of the system is derived by an evaluation of the signature from the inputs in the residual outputs. The changes of the signatures form the external inputs are used for detection and isolation of the parametric faults....

  9. Fault-Tree Compiler

    Science.gov (United States)

    Butler, Ricky W.; Boerschlein, David P.

    1993-01-01

    Fault-Tree Compiler (FTC) program, is software tool used to calculate probability of top event in fault tree. Gates of five different types allowed in fault tree: AND, OR, EXCLUSIVE OR, INVERT, and M OF N. High-level input language easy to understand and use. In addition, program supports hierarchical fault-tree definition feature, which simplifies tree-description process and reduces execution time. Set of programs created forming basis for reliability-analysis workstation: SURE, ASSIST, PAWS/STEM, and FTC fault-tree tool (LAR-14586). Written in PASCAL, ANSI-compliant C language, and FORTRAN 77. Other versions available upon request.

  10. Earthquake fault superhighways

    Science.gov (United States)

    Robinson, D. P.; Das, S.; Searle, M. P.

    2010-10-01

    Motivated by the observation that the rare earthquakes which propagated for significant distances at supershear speeds occurred on very long straight segments of faults, we examine every known major active strike-slip fault system on land worldwide and identify those with long (> 100 km) straight portions capable not only of sustained supershear rupture speeds but having the potential to reach compressional wave speeds over significant distances, and call them "fault superhighways". The criteria used for identifying these are discussed. These superhighways include portions of the 1000 km long Red River fault in China and Vietnam passing through Hanoi, the 1050 km long San Andreas fault in California passing close to Los Angeles, Santa Barbara and San Francisco, the 1100 km long Chaman fault system in Pakistan north of Karachi, the 700 km long Sagaing fault connecting the first and second cities of Burma, Rangoon and Mandalay, the 1600 km Great Sumatra fault, and the 1000 km Dead Sea fault. Of the 11 faults so classified, nine are in Asia and two in North America, with seven located near areas of very dense populations. Based on the current population distribution within 50 km of each fault superhighway, we find that more than 60 million people today have increased seismic hazards due to them.

  11. Analysis and Processing of a Multi-point Earthing Fault in the Magnetic Core of the Main Transformer at a 66kV Substation%一起66 kV变电站主变铁心多点接地故障的分析与处理

    Institute of Scientific and Technical Information of China (English)

    李钢; 戚革庆; 柳尚一; 潘超; 刘建国

    2016-01-01

    针对一起66 kV变电站主变铁心多点接地故障实例,详细阐述并分析了主变从投入系统到油色谱例行试验发现异常,再到跟踪监测、带电诊断性试验,最后停电检查、返厂吊罩定位故障点的全过程。通过这起主变故障原因的分析及处理,电网企业对厂家监造、设备运输、验收试验及在线监测等环节提出了更高的要求。%With regards to the multi-point earthing fault example of the magnetic core of the main transformer at a 66kV substation,this paper explains and analyzes the whole process from input of the main transformer into the system,detection of abnormal result of regular oil chromatograph test,tracking monitoring and live diagnostic test,up to inspection after power cut,and localization of fault point after hang cover transportation back to the factory.Through the analysis of the causes and the processing of the fault of the main transformer,the grid enterprise presents higher standards for manufacturer monitoring,equipment transportation,acceptance test and online monitoring.

  12. Analysis of energy leakage characteristics of dual-tree complex wavelet packet transform and its application on gear fault diagnosis%基于双树复小波包变换能量泄漏特性分析的齿轮故障诊断

    Institute of Scientific and Technical Information of China (English)

    胥永刚; 孟志鹏; 赵国亮; 付胜

    2014-01-01

    为有效利用双树复小波包变换提取齿轮故障特征信息,提出基于双树复小波包能量泄漏特性分析的故障诊断方法。首先根据高斯白噪声频率充满整个频带的特性,通过双树复小波包变换对高斯白噪声进行分解,利用频带能量泄漏的定量分析方法,验证了双树复小波包变换具有较低的频带能量泄漏特性;其次利用双树复小波包变换逐层分解信号,对每层分解所得分量求其FFT谱的峭度,得到基于双树复小波包变换的谱峭度图,根据图中峭度最大的原则,可以自动准确的选择信号分解最佳层数和最佳分量;最后将基于双树复小波包变换的谱峭度图的故障诊断方法应用于实际工程中,对齿轮故障振动信号进行分析,选择最佳分解层数和分量后利用希尔伯特包络解调,有效准确地提取了故障特征信息,验证了方法的可行性和有效性。该研究可为旋转机械设备中齿轮箱故障诊断的故障特征提取提供参考。%The gear is the key component of rotating machinery, so a fault in the gear will directly affect the condition of the whole machine’s operation. It was difficult to extract the fault feature information effectively from the vibration signals of a faulty gear. In the field of fault diagnosis, envelope demodulation was one of the most common signal processing methods. However, a filtering process was required before envelope demodulation. The parameters of a filter were determined by experience, and that has a great influence on the results of signal processing. The discrete wavelet packet transform has a larger energy leakage of frequency band, which obviously affected the results of the envelope demodulation. It is necessary to have a method with a lower energy leakage of the frequency band before envelope demodulation. The dual tree complex wavelet packet transform (DT-CWPT) was a new signal processing method that had many

  13. Fault locking and slip rate deficit of the Haiyuan-Liupanshan fault zone in the northeastern margin of the Tibetan Plateau

    Science.gov (United States)

    Li, Yanchuan; Shan, Xinjian; Qu, Chunyan; Wang, Zhenjie

    2016-12-01

    GPS-derived horizontal velocities, geologic fault slip rates and earthquake-derived fault slip vector azimuths are inverted simultaneously for fault coupling and slip rate deficit on the Haiyuan-Liupanshan fault in the northeastern margin of the Tibetan Plateau. Along the Haiyuan fault, the results show 3.2-6.2 mm/yr of left-lateral strike-slip, and the strike-slip transformed into thrusting deformation (2.8-3.5 mm/yr) along the Liupanshan fault. The results suggest full coupling down to ∼10 km along the Haiyuan fault. Significant portions from the Jinqianghe fault to the Maomaoshan fault, however, are locked to ∼23 km depth. The abrupt change in fault coupling coincides with the Tianzhu seismic gap. High slip rate deficit (3.0-4.5 mm/yr) and seismic moment accumulation rate are also interpreted along the seismic gap. The Liupanshan fault is locked to 15-20 km depth. A high seismic moment accumulation rate, low slip rate deficit (2.0-3.2 mm/yr) and scarcity of large seismic event over the last 1400 years may imply high strain accumulation on the fault. The results demonstrate that crustal deformation in the northeastern Tibetan Plateau is dominated by elastic block rotation. We also conclude that deformation due to fault coupling is limited along the near-field (less than 50 km with velocities less than 2 mm/yr) of the Haiyuan-Liupanshan fault.

  14. Metamorphism, argon depletion, heat flow and stress on the Alpine fault

    Science.gov (United States)

    Scholz, C. H.; Beavan, J.; Hanks, T. C.

    1978-01-01

    The Alpine fault of New Zealand is a major continental transform fault which was uplifted on its southeast side 4 to 11 km within the last 5 m.y. This uplift has exposed the Haast schists, which were metamorphosed from the adjacent Torlesse graywackes. The Haast schists increase in metamorphic grade from prehnite-pumpellyite facies 9-12 km from the fault through the chlorite and biotite zones of the greenschist facies to the garnet-oligoclase zone amphibolite facies within 4 km of the fault. These metamorphic zone boundaries are subparallel to the fault for 350 km along the strike. The K-Ar and Rb-Sr ages of the schists increase with distance from the fault: from 4 m.y. within 3 km of the fault to approximately 110 m.y. 20 km from the fault. Field relations show that the source of heat that produced the argon depletion aureole was the fault itself.

  15. Multisensor Fault Identification Scheme Based on Decentralized Sliding Mode Observers Applied to Reconfigurable Manipulators

    Directory of Open Access Journals (Sweden)

    Bo Zhao

    2013-01-01

    Full Text Available This paper concerns with a fault identification scheme in a class of nonlinear interconnected systems. The decentralized sliding mode observer is recruited for the investigation of position sensor fault or velocity sensor fault. First, a decentralized neural network controller is proposed for the system under fault-free state. The diffeomorphism theory is utilized to construct a nonlinear transformation for subsystem structure. A simple filter is implemented to convert the sensor fault into pseudo-actuator fault scenario. The decentralized sliding mode observer is then presented for multisensor fault identification of reconfigurable manipulators based on Lyapunov stable theory. Finally, two 2-DOF reconfigurable manipulators with different configurations are employed to verify the effectiveness of the proposed scheme in numerical simulation. The results demonstrate that one joint’s fault does not affect other joints and the sensor fault can be identified precisely by the proposed decentralized sliding mode observer.

  16. The formulation of dynamical contact problems with friction in the case of systems of rigid bodies and general discrete mechanical systems—Painlevé and Kane paradoxes revisited

    Science.gov (United States)

    Charles, Alexandre; Ballard, Patrick

    2016-08-01

    The dynamics of mechanical systems with a finite number of degrees of freedom (discrete mechanical systems) is governed by the Lagrange equation which is a second-order differential equation on a Riemannian manifold (the configuration manifold). The handling of perfect (frictionless) unilateral constraints in this framework (that of Lagrange's analytical dynamics) was undertaken by Schatzman and Moreau at the beginning of the 1980s. A mathematically sound and consistent evolution problem was obtained, paving the road for many subsequent theoretical investigations. In this general evolution problem, the only reaction force which is involved is a generalized reaction force, consistently with the virtual power philosophy of Lagrange. Surprisingly, such a general formulation was never derived in the case of frictional unilateral multibody dynamics. Instead, the paradigm of the Coulomb law applying to reaction forces in the real world is generally invoked. So far, this paradigm has only enabled to obtain a consistent evolution problem in only some very few specific examples and to suggest numerical algorithms to produce computational examples (numerical modeling). In particular, it is not clear what is the evolution problem underlying the computational examples. Moreover, some of the few specific cases in which this paradigm enables to write down a precise evolution problem are known to show paradoxes: the Painlevé paradox (indeterminacy) and the Kane paradox (increase in kinetic energy due to friction). In this paper, we follow Lagrange's philosophy and formulate the frictional unilateral multibody dynamics in terms of the generalized reaction force and not in terms of the real-world reaction force. A general evolution problem that governs the dynamics is obtained for the first time. We prove that all the solutions are dissipative; that is, this new formulation is free of Kane paradox. We also prove that some indeterminacy of the Painlevé paradox is fixed in this

  17. 双树复小波和局部投影算法在齿轮故障诊断中的应用%Application of gear fault diagnosis method based on dual-tree complex wavelet transform and local projective method

    Institute of Scientific and Technical Information of China (English)

    胥永刚; 赵国亮; 马朝永; 杨红玉

    2015-01-01

    齿轮故障振动信号往往表现为非线性非平稳特性,并且早期故障振动信号往往包含较强的背景噪声,不利于故障特征的提取。针对该问题,提出了基于双树复小波变换和局部投影算法的齿轮故障诊断方法。首先,对故障信号进行双树复小波变换,得到不同尺度下的小波系数和最后一层的尺度系数,并计算各层小波系数的模与相角。然后,选择模周期性较强的小波系数或尺度系数进行局部投影算法处理,得到周期性增强的系数的模,并选择合适的阈值进行软阈值处理。最后,利用处理后的系数进行双树复小波重构,从而提取出齿轮故障特征信号,进行希尔伯特包络解调分析便能准确地得到故障特征频率。仿真信号和工程应用表明,该方法能够有效地提取齿轮故障特征信息,提供了一种齿轮故障特征提取的新方法。%As gear fault vibration signal is always nonlinear and nonstationary and always with a strong background noise which result in difficulty of fault feature extraction ,a new method based on dual‐tree complex wavelet transform and local projective method is proposed .As a improved method of the conventional discrete wavelet transform (DWT ) ,dual‐tree complex wavelet transform has many advantages over DWT ,such as the improvement of frequency aliasing and oscillations of wavelet coeffi‐cients which is the key to the method proposed .Local projective method for nonlinear time series has a good ability of signal period strengthen and noise suppression ,which fits for wavelet coefficients denoising .Firstly ,the fault signal is decomposed by dual‐tree complex wavelet transform to obtain the coefficients of different layers .Secondly ,the nonlinear time series method is used to strengthen the periodicity of the coefficient whose amplitude is more periodic ,and then do soft‐threshold denoising . Finally ,the fault characteristic

  18. General Fault Admittance Method Solution of a Line-to-Line Fault

    Directory of Open Access Journals (Sweden)

    J.D. Sakala

    2013-12-01

    Full Text Available In the classical approach, line-to-line faults are usually analysed using a parallel connection of symmetrical component sequence networks. The sequence networks are solved separately, and then the positive and negative sequence networks are connected in parallel for a line-to-line fault, and solved to obtain the phase quantities. The solution proceeds by identifying the connection of the sequence networks at the fault point and then solving for the symmetrical component currents and voltages. These are then used to determine the symmetrical component voltages at the other busbars and hence the symmetrical component currents in the lines. The approach requires that the connection of the sequence networks be known for the common fault types. However, a solution by the general method of fault admittance matrix does not require prior knowledge of how the sequence networks are connected. This makes the general method more versatile than the classical methods. The paper presents a procedure for simulating a short circuit, which is a requirement for using the general fault admittance method. A simple power system containing a delta earthed star transformer is analysed for a line-to-line fault. The results obtained are as accurate as those obtained using the classical approaches.

  19. Design of the Fault Indicator Depending on the Non - Contact Current Transformer to Take Power%基于非接触式电流互感器取电的故障指示器设计

    Institute of Scientific and Technical Information of China (English)

    冯小明; 吴国平; 周献飞; 王艳松; 金锋; 郑佳明

    2014-01-01

    10kV配电网中电缆故障指示器无法采集电缆运行电流和故障电流,现场信号传输多用光纤等硬连接形式增加施工和维护工作量,且现场较少采集运行环境温度,电缆故障指示器无法正常运行。针对以上这种经常发生的情况,本文介绍了一种基于电流互感器取电,超级电容储电和具备遥测、遥信功能的故障指示器的设计方法。故障指示器从10kV电缆获取能量,以电池作备用电源,实时检测各相电流和温度指示故障。该设计方案现场施工维护量小、寿命长,对提高设备的便携性,降低设备成本和能耗,有一定的参考价值。%The cable fault indicator in the 10kV cable distribution network cannot collect cable - running current and fault current. The use of hard - wired forms such as the optical fiber to transmit on - site signals increases construction and maintenance work. The running ambient temperature is seldom collected on the site. And the cable fault indicator cannot work nomially. In view of the above situations,this paper introduces a method to design a remote fault indicator with the functions of telemetry and remote signaling,which depends on the current transfomier to take power and the super capacitor to store power. The fault indicator obtains energy from the 10kV cable,and with batteries as the backup power,detects the phase current and temperature indication fault in real time. This design has some practical values in that it contains several advantages such as little on - site construction and maintenance work,long service life,and great potentials to improve the portability of the equipment and to reduce the cost and energy consumption.

  20. Fault detection in rotor bearing systems using time frequency techniques

    Science.gov (United States)

    Chandra, N. Harish; Sekhar, A. S.

    2016-05-01

    Faults such as misalignment, rotor cracks and rotor to stator rub can exist collectively in rotor bearing systems. It is an important task for rotor dynamic personnel to monitor and detect faults in rotating machinery. In this paper, the rotor startup vibrations are utilized to solve the fault identification problem using time frequency techniques. Numerical simulations are performed through finite element analysis of the rotor bearing system with individual and collective combinations of faults as mentioned above. Three signal processing tools namely Short Time Fourier Transform (STFT), Continuous Wavelet Transform (CWT) and Hilbert Huang Transform (HHT) are compared to evaluate their detection performance. The effect of addition of Signal to Noise ratio (SNR) on three time frequency techniques is presented. The comparative study is focused towards detecting the least possible level of the fault induced and the computational time consumed. The computation time consumed by HHT is very less when compared to CWT based diagnosis. However, for noisy data CWT is more preferred over HHT. To identify fault characteristics using wavelets a procedure to adjust resolution of the mother wavelet is presented in detail. Experiments are conducted to obtain the run-up data of a rotor bearing setup for diagnosis of shaft misalignment and rotor stator rubbing faults.

  1. Global strike-slip faults: Bounds from plate tectonics

    Science.gov (United States)

    Gordon, R. G.; Argus, D. F.

    2006-12-01

    According to the tenets of plate tectonics, a transform fault is a strike-slip fault along which neither convergence nor divergence occurs. Analysis of global plate motion data indicates that the only true transform faults are the strike-slip faults that offset segments of mid-ocean ridges. Thus, many of Earth's major strike-slip fault systems are not true transform faults as they accommodate large components of oblique convergence or oblique divergence. This is particularly true for several important ocean-continent systems such as the San Andreas, the strike-slip systems bounding the northern and southern Caribbean plate, the Alpine fault system of New Zealand, the Anatolian fault system, and the Azores-Gibraltar-Alboran sea system. These strike-slip systems are commonly sites of large scale mountain building and basin formation. Here we examine the far-field constraints on the motions of the plates bounding several of these strike-slip systems using both conventional plate motion circuits and results from global positioning system and other space geodetic data. We pay particular attention to the San Andreas fault system in central and northern California, where the San Andreas system is part of the boundary between the Sierran microplate and the Pacific plate. Most of the fault system accommodates obliquely convergent motion, giving rise to the California Coast Range, but in the northern San Francisco Bay Area it is obliquely divergent, producing San Pablo Bay and a gap in the Coast Range that permits the Sierran watershed to drain to the Pacific through the Golden Gate.

  2. Investigation оf Microprocessor Differential Protection оf Power Reducing Transformer

    Directory of Open Access Journals (Sweden)

    F. A. Romaniuk

    2014-01-01

    Full Text Available The paper presents investigations on functioning of a differential protection of 110 kV reducing transformer  with internal faults using computer simulation. Internal single-, double-, double-phase-to- ground and three-phase faults including faults accompanied with saturation of current transformers have been considered in the paper.

  3. Faulted Ancient Aqueduct and Successive Displacements along the Dead Sea Fault in Syria

    Science.gov (United States)

    Sbeinat, R.; Meghraoui, M.; Gomez, F.; van der Woerd, J.; Layyous, I.; Al-Ghazzi, R.; Barazangi, M.

    2003-04-01

    We conducted a combined study in archeoseismology with detailed descriptions and mapping with a total station of a faulted ancient aqueduct, and in paleoseismology with a 15-m-long and 3.5-m-deep trench near the aqueduct and across the fault. Micro-topographic surveys and trenching show that the fault offsets left-laterally an ancient aqueduct which is repeatedly fractured and younger than BC 410. Projecting the aqueduct walls into the north-south striking DSF displays a total left-lateral displacement of 13.6 ±0.2 m between the two blocks of the faulted aqueduct. Moreover, the northern warped wall shows a deflection (with cracks and brecciated travertines below) that amount 4.3 m and can be considered as a minimum for the first left-lateral displacement. The aqueduct also displays at least two kinds of building stones suggesting rebuilding episodes. Using radiocarbon dating of faulted young alluvial deposits we document the occurrence of three large earthquakes in the past 2200 years (between BC 150 - AD 750, between AD 700 - 1030 and between AD 990 - 1210). The most recent faulting event may correspond to the well-documented large earthquake of AD 1170 for which we estimate Mw = 7.3 - 7.5. Our study provides the timing of late Holocene earthquakes and constrains the 6.9 ± 1.2 mm/yr. slip rate of the Dead Sea transform fault in northwestern Syria (the Missyaf fault segment). Reports of large earthquakes and their associated damage in the Middle East are frequently reported during the Greek, Hebrew, Assyrian, Roman, Byzantine and Islamic times. The ˜830 years of seismic quiescence along the Missyaf fault segment implies that a large earthquake is overdue and may result in a major catastrophe to the population centres of Syria and Lebanon.

  4. Numerical modeling of transformer inrush currents

    Science.gov (United States)

    Cardelli, E.; Faba, A.

    2014-02-01

    This paper presents an application of a vector hysteresis model to the prediction of the inrush current due the arbitrary initial excitation of a transformer after a fault. The approach proposed seems promising in order to predict the transient overshoot in current and the optimal time to close the circuit after the fault.

  5. Numerical modeling of transformer inrush currents

    Energy Technology Data Exchange (ETDEWEB)

    Cardelli, E. [Department of Industrial Engineering, University of Perugia, I-06125 Perugia (Italy); Center for Electric and Magnetic Applied Research (Italy); Faba, A., E-mail: faba@unipg.it [Department of Industrial Engineering, University of Perugia, I-06125 Perugia (Italy); Center for Electric and Magnetic Applied Research (Italy)

    2014-02-15

    This paper presents an application of a vector hysteresis model to the prediction of the inrush current due the arbitrary initial excitation of a transformer after a fault. The approach proposed seems promising in order to predict the transient overshoot in current and the optimal time to close the circuit after the fault.

  6. Temperature profiles from expendable bathythermograph (XBT) casts from the USNS KANE and USNS WILKES in the North/South Atlantic Ocean and Indian Ocean in support of the Integrated Global Ocean Services System (IGOSS) project from 12 April 1977 to 31 May 1977 (NODC Accession 7700604)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — XBT data were collected from the USNS KANE and USNS WILKES in support of the Integrated Global Ocean Services System (IGOSS) project. Data were collected by the US...

  7. Research of Transformer Intelligent Evaluation and Diagnosis Method Based on DGA

    Directory of Open Access Journals (Sweden)

    Wang Feng

    2016-01-01

    Full Text Available Oil chromatography analysis is the foundation of transformer fault diagnosis, In this paper, based on knowledge base of the oil chromatographic analysis, an extended research combining the improved three ratio method, BP neural network, and case-based reasoning method for the transformer fault diagnosis was proposed, in the purpose of building a transformer Intelligent Evaluation Diagnosis model, to improve the accuracy of the transformer fault diagnosis, which is of a great significance for practice.

  8. Layered clustering multi-fault diagnosis for hydraulic piston pump

    Science.gov (United States)

    Du, Jun; Wang, Shaoping; Zhang, Haiyan

    2013-04-01

    Efficient diagnosis is very important for improving reliability and performance of aircraft hydraulic piston pump, and it is one of the key technologies in prognostic and health management system. In practice, due to harsh working environment and heavy working loads, multiple faults of an aircraft hydraulic pump may occur simultaneously after long time operations. However, most existing diagnosis methods can only distinguish pump faults that occur individually. Therefore, new method needs to be developed to realize effective diagnosis of simultaneous multiple faults on aircraft hydraulic pump. In this paper, a new method based on the layered clustering algorithm is proposed to diagnose multiple faults of an aircraft hydraulic pump that occur simultaneously. The intensive failure mechanism analyses of the five main types of faults are carried out, and based on these analyses the optimal combination and layout of diagnostic sensors is attained. The three layered diagnosis reasoning engine is designed according to the faults' risk priority number and the characteristics of different fault feature extraction methods. The most serious failures are first distinguished with the individual signal processing. To the desultory faults, i.e., swash plate eccentricity and incremental clearance increases between piston and slipper, the clustering diagnosis algorithm based on the statistical average relative power difference (ARPD) is proposed. By effectively enhancing the fault features of these two faults, the ARPDs calculated from vibration signals are employed to complete the hypothesis testing. The ARPDs of the different faults follow different probability distributions. Compared with the classical fast Fourier transform-based spectrum diagnosis method, the experimental results demonstrate that the proposed algorithm can diagnose the multiple faults, which occur synchronously, with higher precision and reliability.

  9. Rotor Faults Detection in Induction Motor by Wavelet Analysis

    Directory of Open Access Journals (Sweden)

    Neelam Mehala

    2009-12-01

    Full Text Available Motor current signature analysis has been successfully used for fault diagnosis in induction motors. However, this method does not always achieve good results when the speed or the load torque is not constant, because this cause variation on the motor slip and fast Fourier transform problems appear due to non-stationary signal. This paper experimentally describes the effects of rotor broken bar fault in the stator current of induction motor operating under non-constant load conditions. To achieve this, broken rotor bar fault is eplicated in a laboratory and its effect on the motor current has been studied. To diagnose the broken rotor bar fault, a new approach based on wavelet transform is applied by using ‘Labview 8.2 software’ of National Instrument (NI. The diagnosis procedure was performed by using the virtual instruments. The theoretical basis of proposed method is proved by laboratory tests.

  10. Fault-tolerant design

    CERN Document Server

    Dubrova, Elena

    2013-01-01

    This textbook serves as an introduction to fault-tolerance, intended for upper-division undergraduate students, graduate-level students and practicing engineers in need of an overview of the field.  Readers will develop skills in modeling and evaluating fault-tolerant architectures in terms of reliability, availability and safety.  They will gain a thorough understanding of fault tolerant computers, including both the theory of how to design and evaluate them and the practical knowledge of achieving fault-tolerance in electronic, communication and software systems.  Coverage includes fault-tolerance techniques through hardware, software, information and time redundancy.  The content is designed to be highly accessible, including numerous examples and exercises.  Solutions and powerpoint slides are available for instructors.   ·         Provides textbook coverage of the fundamental concepts of fault-tolerance; ·         Describes a variety of basic techniques for achieving fault-toleran...

  11. Active Fault Diagnosis in Sampled-data Systems

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik; Poulsen, Niels Kjølstad

    2015-01-01

    The focus in this paper is on active fault diagnosis (AFD) in closed-loop sampleddata systems. Applying the same AFD architecture as for continuous-time systems does not directly result in the same set of closed-loop matrix transfer functions. For continuous-time systems, the LFT (linear fractional...... transformation) structure in the connection between the parametric faults and the matrix transfer function (also known as the fault signature matrix) applied for AFD is not directly preserved for sampled-data system. As a consequence of this, the AFD methods cannot directly be applied for sampled-data systems....... Two methods are considered in this paper to handle the fault signature matrix for sampled-data systems such that standard AFD methods can be applied. The first method is based on a discretization of the system such that the LFT structure is preserved resulting in the same LFT structure in the fault...

  12. Fault Monitoring and Fault Recovery Control for Position Moored Tanker

    DEFF Research Database (Denmark)

    Fang, Shaoji; Blanke, Mogens

    2011-01-01

    This paper addresses fault tolerant control for position mooring of a shuttle tanker operating in the North Sea. A complete framework for fault diagnosis is presented but the loss of a sub-sea mooring line buoyancy element is given particular attention, since this fault could lead to mooring line....... Properties of detection and fault-tolerant control are demonstrated by high fidelity simulations....

  13. Fault tolerant control for uncertain systems with parametric faults

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik; Poulsen, Niels Kjølstad

    2006-01-01

    A fault tolerant control (FTC) architecture based on active fault diagnosis (AFD) and the YJBK (Youla, Jarb, Bongiorno and Kucera)parameterization is applied in this paper. Based on the FTC architecture, fault tolerant control of uncertain systems with slowly varying parametric faults...

  14. Fault isolability conditions for linear systems with additive faults

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik; Stoustrup, Jakob

    2006-01-01

    In this paper, we shall show that an unlimited number of additive single faults can be isolated under mild conditions if a general isolation scheme is applied. Multiple faults are also covered. The approach is algebraic and is based on a set representation of faults, where all faults within a set...

  15. Fault Analysis in Cryptography

    CERN Document Server

    Joye, Marc

    2012-01-01

    In the 1970s researchers noticed that radioactive particles produced by elements naturally present in packaging material could cause bits to flip in sensitive areas of electronic chips. Research into the effect of cosmic rays on semiconductors, an area of particular interest in the aerospace industry, led to methods of hardening electronic devices designed for harsh environments. Ultimately various mechanisms for fault creation and propagation were discovered, and in particular it was noted that many cryptographic algorithms succumb to so-called fault attacks. Preventing fault attacks without

  16. 基于Kane方法的双臂空间机器人动力学分析%Dynamics Analysis of a Dual-arm Space Robot Using Kane-Huston Method

    Institute of Scientific and Technical Information of China (English)

    殷志锋; 葛新锋

    2012-01-01

    Its dynamics analysis plays an intermediate part in its design and control, so it is important to understand its unique dynamics and control characteristics. The topology, kinematics and dynamics of a dual-arm space robot are systematically studied, and its dynamic model is established by using the Kane-Huston method and the screw theory was presented in this paper. The numerical example shows that, given the values of motion parameters, the transient motion of all parts of the space robot can be solved by using the dynamics model we established. Simulations results show that the dynamics model established with the Kane-Huston method and the screw theory is true to reality.%机器人的动力学分析作为机器人设计和控制的中间桥梁,其独特的动力学特性和控制特征非常重要。本文系统研究了双臂空间机器人系统的拓扑结构、运动学及动力学特征,并基于Kane-Huston方法和旋量理论建立了双臂空间机器人系统动力学模型。算例表明,对于给定的运动参数,采用所建立的模型,可以求出双臂空间机器人各组成部分的瞬时运动,反之亦然。仿真结果表明,本文中基于旋量理论的Kane-Huston方法建立的双臂空间机器人系统动力学模型是符合实际的。

  17. Robust Nonlinear Analytic Redundancy for Fault Detection and Isolation in Mobile Robot

    Institute of Scientific and Technical Information of China (English)

    Bibhrajit Halder; Nilanjan Sarkar

    2007-01-01

    A robust nonlinear analytical redundancy (RNLAR) technique is presented to detect and isolate actuator and sensor faults in a mobile robot. Both model-plant-mismatch (MPM) and process disturbance are considered during fault detection. The RNLAR is used to design primary residual vectors (PRV), which are highly sensitive to the faults and less sensitive to MPM and process disturbance, for sensor and actuator fault detection. The PRVs are then transformed into a set of structured residual vectors (SRV) for fault isolation. Experimental results on a Pioneer 3-DX mobile robot are presented to justify the effectiveness of the RNLAR scheme.

  18. Wavelet Based Fault Detection, Classification in Transmission System with TCSC Controllers

    Directory of Open Access Journals (Sweden)

    G.Satyanarayana,

    2015-08-01

    Full Text Available This paper presents simulation results of the application of distance relays for the protection of transmission systems employing flexible alternating current transmission controllers such as Thyristor Controlled Series Capacitor (TCSC. The complete digital simulation of TCSC within a transmission system is performed in the MATLAB/Simulink environment using the Power System Block set (PSB. This paper presents an efficient method based on wavelet transforms both fault detection and classification which is almost independent of fault impedance, fault location and fault inception angle of transmission line fault currents with FACTS controllers.

  19. Performance evaluation of transformer oil using uv-visible spectrophotometer

    Directory of Open Access Journals (Sweden)

    Radha Karthik

    2014-04-01

    Full Text Available To ensure reliable operation of Power transformer, condition monitoring of transformer becomes obligatory. In this paper, condition assessment of transformer oil under various working conditions is performed using UV-visible spectrophotometer. Test samples include both laboratorial prepared ones and those obtained from in service transformers.  An index table of spectral responses for various faults which predominantly occur in the transformer is developed. The index table will acts as a reference for spectral response of faulted transformer oil. In this paper, an attempt has been made to determine the quality of transformer oil using their spectral response characteristics.

  20. Fault Diagnosis for Electrical Distribution Systems using Structural Analysis

    DEFF Research Database (Denmark)

    Knüppel, Thyge; Blanke, Mogens; Østergaard, Jacob

    2014-01-01

    Fault-tolerance in electrical distribution relies on the ability to diagnose possible faults and determine which components or units cause a problem or are close to doing so. Faults include defects in instrumentation, power generation, transformation and transmission. The focus of this paper...... redundancies in large sets of equations only from the structure (topology) of the equations. A salient feature is automated generation of redundancy relations. The method is indeed feasible in electrical networks where circuit theory and network topology together formulate the constraints that define...

  1. Bevel Gearbox Fault Diagnosis using Vibration Measurements

    Directory of Open Access Journals (Sweden)

    Hartono Dennis

    2016-01-01

    Full Text Available The use of vibration measurementanalysis has been proven to be effective for gearbox fault diagnosis. However, the complexity of vibration signals observed from a gearbox makes it difficult to accurately detectfaults in the gearbox. This work is based on a comparative studyof several time-frequency signal processing methods that can be used to extract information from transient vibration signals containing useful diagnostic information. Experiments were performed on a bevel gearbox test rig using vibration measurements obtained from accelerometers. Initially, thediscrete wavelet transform was implementedfor vibration signal analysis to extract the frequency content of signal from the relevant frequency region. Several time-frequency signal processing methods werethen incorporated to extract the fault features of vibration signals and their diagnostic performances were compared. It was shown thatthe Short Time Fourier Transform (STFT could not offer a good time resolution to detect the periodicity of the faulty gear tooth due the difficulty in choosing an appropriate window length to capture the impulse signal. The Continuous Wavelet Transform (CWT, on the other hand, was suitable to detection of vibration transients generated by localized fault from a gearbox due to its multi-scale property. However, both methods still require a thorough visual inspection. In contrast, it was shown from the experiments that the diagnostic method using the Cepstrumanalysis could provide a direct indication of the faulty tooth without the need of a thorough visual inspection as required by CWT and STFT.

  2. Quaternary Fault Lines

    Data.gov (United States)

    Department of Homeland Security — This data set contains locations and information on faults and associated folds in the United States that are believed to be sources of M>6 earthquakes during the...

  3. Nearly frictionless faulting by unclamping in long-term interaction models

    Science.gov (United States)

    Parsons, T.

    2002-01-01

    In defiance of direct rock-friction observations, some transform faults appear to slide with little resistance. In this paper finite element models are used to show how strain energy is minimized by interacting faults that can cause long-term reduction in fault-normal stresses (unclamping). A model fault contained within a sheared elastic medium concentrates stress at its end points with increasing slip. If accommodating structures free up the ends, then the fault responds by rotating, lengthening, and unclamping. This concept is illustrated by a comparison between simple strike-slip faulting and a mid-ocean-ridge model with the same total transform length; calculations show that the more complex system unclapms the transforms and operates at lower energy. In another example, the overlapping San Andreas fault system in the San Francisco Bay region is modeled; this system is complicated by junctions and stepovers. A finite element model indicates that the normal stress along parts of the faults could be reduced to hydrostatic levels after ???60-100 k.y. of system-wide slip. If this process occurs in the earth, then parts of major transform fault zones could appear nearly frictionless.

  4. Construction of adaptive redundant multiwavelet packet and its application to compound faults detection of rotating machinery

    Institute of Scientific and Technical Information of China (English)

    CHEN JingLong; ZI YanYang; HE ZhengJia; WANG XiaoDong

    2012-01-01

    It is significant to detect the fault type and assess the fault level as early as possible for avoiding catastrophic accidents.Due to diversity and complexity,the compound faults detection of rotating machinery under non-stationary operation turns to be a challenging task.Multiwavelet with two or more base functions may match two or more features of compound faults,which may supply a possible solution to compound faults detection.However,the fixed basis functions of multiwavelet transform,which are not related with the vibration signal,may reduce the accuracy of compound faults detection.Moreover,the decomposition results of multiwavelet transform not being own time-invariant is harmful to extract the features of periodical impulses.Furthermore,multiwavelet transform only focuses on the multi-resolution analysis in the low frequency band,and may leave out the useful features of compound faults.To overcome these shortcomings,a novel method called adaptive redundant multiwavelet packet (ARMP) is proposed based on the two-scale similarity transforms.Besides,the relative energy ratio at the characteristic frequency of the concerned component is computed to select the sensitive frequency bands of multiwavelet packet coefficients.The proposed method was used to analyze the compound faults of rolling element beating.The results showed that the proposed method could enhance the ability of compound faults detection of rotating machinery.

  5. Modeling Technology in Traveling-Wave Fault Location

    Directory of Open Access Journals (Sweden)

    Tang Jinrui

    2013-06-01

    Full Text Available Theoretical research and equipment development of traveling-wave fault location seriously depend on digital simulation. Meanwhile, the fault-generated transient traveling wave must be transferred through transmission line, mutual inductor and secondary circuit before it is used. So this paper would maily analyze and summarize the modeling technology of transmission line and mutual inductor on the basis of the research achievement. Firstly several models of transmission line (multiple Π or T line model, Bergeron line model and frequency-dependent line model are compared in this paper with analysis of wave-front characteristics and characteristic frequency of traveling wave. Then modeling methods of current transformer, potential transformer, capacitive voltage transformer, special traveling-wave sensor and secondary cable are given. Finally, based on the difficult and latest research achievements, the future trend of modeling technology in traveling-wave fault location is prospected.  

  6. A New Algorithm of Online Stator Faults Diagnosis of Three-Phase Induction Motors Using Duty Ratios of Half-Period Frequencies According to Phase Angle Changes

    Directory of Open Access Journals (Sweden)

    Go YoungJin

    2016-01-01

    Full Text Available The causes of faults of induction motors are largely categorized into bearing fault, which causes a mechanical fault, and stator fault and rotor fault, which cause an electrical fault. A stator fault among these faults, which causes an electrical fault, occurs due to the breakdown of insulation, meaning the stator is directly connected with the power supply, and the direct connection is a direct cause of a major accident. For this reason, many studies are being performed to detect the faults. This paper explained the effects of a negative sequence on phase angle change by analyzing the effects of the existing negative sequence on the d-q transform of Park’s vector approach. This paper suggested a new algorithm that identifies the causes of stator faults with the use of the change in the duty ratio of the half-period frequency of the frequency when a phase angle change occurs at that moment.

  7. Multiple incipient sensor faults diagnosis with application to high-speed railway traction devices.

    Science.gov (United States)

    Wu, Yunkai; Jiang, Bin; Lu, Ningyun; Yang, Hao; Zhou, Yang

    2017-03-01

    This paper deals with the problem of incipient fault diagnosis for a class of Lipschitz nonlinear systems with sensor biases and explores further results of total measurable fault information residual (ToMFIR). Firstly, state and output transformations are introduced to transform the original system into two subsystems. The first subsystem is subject to system disturbances and free from sensor faults, while the second subsystem contains sensor faults but without any system disturbances. Sensor faults in the second subsystem are then formed as actuator faults by using a pseudo-actuator based approach. Since the effects of system disturbances on the residual are completely decoupled, multiple incipient sensor faults can be detected by constructing ToMFIR, and the fault detectability condition is then derived for discriminating the detectable incipient sensor faults. Further, a sliding-mode observers (SMOs) based fault isolation scheme is designed to guarantee accurate isolation of multiple sensor faults. Finally, simulation results conducted on a CRH2 high-speed railway traction device are given to demonstrate the effectiveness of the proposed approach.

  8. Active Fault Isolation in MIMO Systems

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik; Poulsen, Niels Kjølstad

    2014-01-01

    Active fault isolation of parametric faults in closed-loop MIMO system s are considered in this paper. The fault isolation consists of two steps. T he first step is group- wise fault isolation. Here, a group of faults is isolated from other pos sible faults in the system. The group-wise fault iso...

  9. Rough Faults, Distributed Weakening, and Off-Fault Deformation

    Science.gov (United States)

    Griffith, W. A.; Nielsen, S. B.; di Toro, G.; Smith, S. A.; Niemeijer, A. R.

    2009-12-01

    We report systematic spatial variations of fault rocks along non-planar strike-slip faults cross-cutting the Lake Edison Granodiorite, Sierra Nevada, California (Sierran Wavy Fault) and the Lobbia outcrops of the Adamello Batholith in the Italian Alps (Lobbia Wavy Fault). In the case of the Sierran fault, pseudotachylyte formed at contractional fault bends, where it is found as thin (1-2 mm) fault-parallel veins. Epidote and chlorite developed in the same seismic context as the pseudotachylyte and are especially abundant in extensional fault bends. We argue that the presence of fluids, as illustrated by this example, does not necessarily preclude the development of frictional melt. In the case of the Lobbia fault, pseudotachylyte is present in variable thickness along the length of the fault, but the pseudotachylyte veins thicken and pool in extensional bends. The Lobbia fault surface is self-affine, and we conduct a quantitative analysis of microcrack distribution, stress, and friction along the fault. Numerical modeling results show that opening in extensional bends and localized thermal weakening in contractional bends counteract resistance encountered by fault waviness, resulting in an overall weaker fault than suggested by the corresponding static friction coefficient. Models also predict stress redistribution around bends in the faults which mirror microcrack distributions, indicating significant elastic and anelastic strain energy is dissipated into the wall rocks due to non-planar fault geometry. Together these observations suggest that, along non-planar faults, damage and energy dissipation occurs along the entire fault during slip, rather than being confined to the region close to the crack tip as predicted by classical fracture mechanics.

  10. SS7E机车辅助变流器的工作原理及常见故障分析%Operation Principle of the Auxiliary Current Transformer of SS7E Electric Locomotives and Common Fault Analysis

    Institute of Scientific and Technical Information of China (English)

    卢亚东; 林立新

    2009-01-01

    该文简要介绍了SS7E机车辅助变流器的工作原理及常见故障分析,详细阐述了运用TGF11的工作原理、电路分析,论述了如何运用辅助变流器在SS7E机车上的运用,阐明了机车辅助变流器其原理的掌握和常见故障的处理方法.%This paper briefly introduced the SS7E locomotive assistance converter principle of work and the common fault analysis. Elabo-rated in detail utilizes TGF11 the principle of work, the circuit analysis, how elaborated has utilized the assistance converter on SS7E loco-motive utilization. It also describes locomotive assistance converter its principle grasping and the common breakdown processing method.

  11. Model Transformations? Transformation Models!

    NARCIS (Netherlands)

    Bézivin, J.; Büttner, F.; Gogolla, M.; Jouault, F.; Kurtev, I.; Lindow, A.

    2006-01-01

    Much of the current work on model transformations seems essentially operational and executable in nature. Executable descriptions are necessary from the point of view of implementation. But from a conceptual point of view, transformations can also be viewed as descriptive models by stating only the

  12. DWT based bearing fault detection in induction motor using noise cancellation

    Directory of Open Access Journals (Sweden)

    K.C. Deekshit Kompella

    2016-12-01

    Full Text Available This paper presents an approach to detect the bearing faults experienced by induction machine using motor current signature analysis (MCSA. At the incipient stage of bearing fault, the current signature analysis has shown poor performance due to domination of pre fault components in the stator current. Therefore, in this paper domination of pre fault components is suppressed using noise cancellation by Wiener filter. The spectral analysis is carried out using discrete wavelet transform (DWT. The fault severity is estimated by calculating fault indexing parameter of wavelet coefficients. It is further proposed that, the fault indexing parameter of power spectral density (PSD based wavelet coefficients gives better results. The proposed method is examined using simulation and experiment on 2.2 kW test bed.

  13. Apparent stress, fault maturity and seismic hazard for normal-fault earthquakes at subduction zones

    Science.gov (United States)

    Choy, G.L.; Kirby, S.H.

    2004-01-01

    The behavior of apparent stress for normal-fault earthquakes at subduction zones is derived by examining the apparent stress (?? a = ??Es/Mo, where E s is radiated energy and Mo is seismic moment) of all globally distributed shallow (depth, ?? 1 MPa) are also generally intraslab, but occur where the lithosphere has just begun subduction beneath the overriding plate. They usually occur in cold slabs near trenches where the direction of plate motion across the trench is oblique to the trench axis, or where there are local contortions or geometrical complexities of the plate boundary. Lower ??a (tectonic regime suggests that the level of ?? a is related to fault maturity. Lower stress drops are needed to rupture mature faults such as those found at plate interfaces that have been smoothed by large cumulative displacements (from hundreds to thousands of kilometres). In contrast, immature faults, such as those on which intraslab-normal-fault earthquakes generally occur, are found in cold and intact lithosphere in which total fault displacement has been much less (from hundreds of metres to a few kilometres). Also, faults on which high ??a oceanic strike-slip earthquakes occur are predominantly intraplate or at evolving ends of transforms. At subduction zones, earthquakes occurring on immature faults are likely to be more hazardous as they tend to generate higher amounts of radiated energy per unit of moment than earthquakes occurring on mature faults. We have identified earthquake pairs in which an interplate-thrust and an intraslab-normal earthquake occurred remarkably close in space and time. The intraslab-normal member of each pair radiated anomalously high amounts of energy compared to its thrust-fault counterpart. These intraslab earthquakes probably ruptured intact slab mantle and are dramatic examples in which Mc (an energy magnitude) is shown to be a far better estimate of the potential for earthquake damage than Mw. This discovery may help explain why loss of

  14. Fault Monitooring and Fault Recovery Control for Position Moored Tanker

    DEFF Research Database (Denmark)

    Fang, Shaoji; Blanke, Mogens

    2009-01-01

    This paper addresses fault tolerant control for position mooring of a shuttle tanker operating in the North Sea. A complete framework for fault diagnosis is presented but the loss of a sub-sea mooring line buoyancy element is given particular attention, since this fault could lead to line breakage...... algorithm is proposed to accommodate buoyancy element failure and keep the mooring system in a safe state. Detection properties and fault-tolerant control are demonstrated by high delity simulations...

  15. Discriminating Fault Rate and Persistency to Improve Fault Treatment

    OpenAIRE

    Bondavalli, Andrea; Chiaradonna, Silvano; Di Giandomenico,Felicita; Grandoni, Fabrizio

    1997-01-01

    In this paper the consolidate identification of faults, distinguished as transient or permanent/intermittent, is approached, through the definition of a fault identification mechanism, called a-count. The goal is to allow continued use of parts being hit by transient faults, which may lead to better overall system performance if proper handling is provided. Transient faults discrimination is especially important in all those dependability-qualified applications where replacing and repairing f...

  16. Study on Fault Current of DFIG during Slight Fault Condition

    OpenAIRE

    Xiangping Kong; Zhe Zhang; Xianggen Yin; Zhenxing Li

    2013-01-01

    In order to ensure the safety of DFIG when severe fault happens, crowbar protection is adopted. But during slight fault condition, the crowbar protection will not trip, and the DFIG is still excited by AC-DC-AC converter. In this condition, operation characteristics of the converter have large influence on the fault current characteristics of DFIG. By theoretical analysis and digital simulation, the fault current characteristics of DFIG during slight voltage dips are studied. And the influenc...

  17. Computer hardware fault administration

    Science.gov (United States)

    Archer, Charles J.; Megerian, Mark G.; Ratterman, Joseph D.; Smith, Brian E.

    2010-09-14

    Computer hardware fault administration carried out in a parallel computer, where the parallel computer includes a plurality of compute nodes. The compute nodes are coupled for data communications by at least two independent data communications networks, where each data communications network includes data communications links connected to the compute nodes. Typical embodiments carry out hardware fault administration by identifying a location of a defective link in the first data communications network of the parallel computer and routing communications data around the defective link through the second data communications network of the parallel computer.

  18. Fault Tolerant Computer Architecture

    CERN Document Server

    Sorin, Daniel

    2009-01-01

    For many years, most computer architects have pursued one primary goal: performance. Architects have translated the ever-increasing abundance of ever-faster transistors provided by Moore's law into remarkable increases in performance. Recently, however, the bounty provided by Moore's law has been accompanied by several challenges that have arisen as devices have become smaller, including a decrease in dependability due to physical faults. In this book, we focus on the dependability challenge and the fault tolerance solutions that architects are developing to overcome it. The two main purposes

  19. Fault tolerant linear actuator

    Science.gov (United States)

    Tesar, Delbert

    2004-09-14

    In varying embodiments, the fault tolerant linear actuator of the present invention is a new and improved linear actuator with fault tolerance and positional control that may incorporate velocity summing, force summing, or a combination of the two. In one embodiment, the invention offers a velocity summing arrangement with a differential gear between two prime movers driving a cage, which then drives a linear spindle screw transmission. Other embodiments feature two prime movers driving separate linear spindle screw transmissions, one internal and one external, in a totally concentric and compact integrated module.

  20. Research on Gear-broken Fault Diagnosis in a Tank Gearbox

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A fault diagnosis method of working position gear in a tank gearbox is put forward based on simulating the fault of working position gear in an actual tank, extracting the envelope of vibration signal by Hilbert transformation amplitude demodulation method, and zooming the low-frequency band to envelope signal.

  1. Using the EMD method to determine fault criterion for medium-low pressure gas regulators

    Science.gov (United States)

    Hao, Xuejun; Liu, Qiang; Yang, Guobin; Du, Yi

    2015-11-01

    By extracting the outlet pressure data of gas regulators, this paper uses the EMD toolbox of the MATLAB software, which can perform data decomposition and the Hilbert-Huang Transform to find the rules with fault data. Eventually, the medium-low pressure gas regulator fault criterion can be established.

  2. Fault tolerant control based on active fault diagnosis

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik

    2005-01-01

    An active fault diagnosis (AFD) method will be considered in this paper in connection with a Fault Tolerant Control (FTC) architecture based on the YJBK parameterization of all stabilizing controllers. The architecture consists of a fault diagnosis (FD) part and a controller reconfiguration (CR...

  3. Wind turbine fault detection and fault tolerant control

    DEFF Research Database (Denmark)

    Odgaard, Peter Fogh; Johnson, Kathryn

    2013-01-01

    In this updated edition of a previous wind turbine fault detection and fault tolerant control challenge, we present a more sophisticated wind turbine model and updated fault scenarios to enhance the realism of the challenge and therefore the value of the solutions. This paper describes the challe...

  4. Fuzzy Algorithm for Power Transformer Diagnostics

    Directory of Open Access Journals (Sweden)

    Nitin K. Dhote

    2013-01-01

    Full Text Available Dissolved gas analysis (DGA of transformer oil has been one of the most reliable techniques to detect the incipient faults. Many conventional DGA methods have been developed to interpret DGA results obtained from gas chromatography. Although these methods are widely used in the world, they sometimes fail to diagnose, especially when DGA results fall outside conventional methods codes or when more than one fault exist in the transformer. To overcome these limitations, the fuzzy inference system (FIS is proposed. Two hundred different cases are used to test the accuracy of various DGA methods in interpreting the transformer condition.

  5. On-line monitoring for the detection and prevention of faults in the power transformers; Monitoreo en linea para la deteccion y prevencion de fallas en transformadores de potencia

    Energy Technology Data Exchange (ETDEWEB)

    Lopez Tagle, Alfredo; Equihua Tapia, Hugo [Comision Federal de Electricidad (Mexico); Linan Garcia, Roberto; Pascacio de los Santos, Alberth; Nunez Dominguez, Arturo [Instituto de Investigaciones Electricas, Temixco, Morelos (Mexico)

    2000-07-01

    Power transformers are held to thermal, electrical and mechanical efforts, which degrade the isolation system oil/paper. So that to detect incipient degradations in transformers with more than 25 years of service installed in the transmission network of Commission Federal de Electricidad (CFE). The Instituto de Investigaciones Electricas (IIE), developed and installed six on-line Monitoring Systems for Power Transformers (SMLTP). The systems are installed at the substations Puebla II, banks AT-1 and AT-2, Malpaso II, bank, AT-1 and phase B of bank AT-1 of the electrical substation Villa de Garcia. [Spanish] Los transformadores de potencia estan sujetos a esfuerzos termicos, electricos y mecanicos, los cuales degradan el sistema de aislamiento aceite/papel. De modo que con el proposito de detectar degradaciones incipientes en transformadores con mas de 25 anos de servicio instalado en la red de transmision de la Comision Federal de Electricidad (CFE). El Instituto de Investigaciones Electricas (IIE), desarrollo e instalo seis Sistemas de Monitoreo en Linea para Transformadores de Potencia (SMLTP). Los sistemas se encuentran en las subestaciones Puebla II, bancos AT-1 y AT-2, Malpaso II, banco, AT-1 y fase B del banco AT-1 de la subestacion electrica Villa de Garcia.

  6. Improving Multiple Fault Diagnosability using Possible Conflicts

    Data.gov (United States)

    National Aeronautics and Space Administration — Multiple fault diagnosis is a difficult problem for dynamic systems. Due to fault masking, compensation, and relative time of fault occurrence, multiple faults can...

  7. Fault Management Assistant (FMA) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — S&K Aerospace (SKA) proposes to develop the Fault Management Assistant (FMA) to aid project managers and fault management engineers in developing better and more...

  8. ESR dating of fault rocks

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hee Kwon [Kangwon National Univ., Chuncheon (Korea, Republic of)

    2002-03-15

    Past movement on faults can be dated by measurement of the intensity of ESR signals in quartz. These signals are reset by local lattice deformation and local frictional heating on grain contacts at the time of fault movement. The ESR signals then trow back as a result of bombardment by ionizing radiation from surrounding rocks. The age is obtained from the ratio of the equivalent dose, needed to produce the observed signal, to the dose rate. Fine grains are more completely reset during faulting, and a plot of age vs grain size shows a plateau for grains below critical size : these grains are presumed to have been completely zeroed by the last fault activity. We carried out ESR dating of fault rocks collected from the Yangsan fault system. ESR dates from the this fault system range from 870 to 240 ka. Results of this research suggest that long-term cyclic fault activity continued into the pleistocene.

  9. Seismic fault zone trapped noise

    National Research Council Canada - National Science Library

    Hillers, G; Campillo, M; Ben‐Zion, Y; Roux, P

    2014-01-01

    Systematic velocity contrasts across and within fault zones can lead to head and trapped waves that provide direct information on structural units that are important for many aspects of earthquake and fault mechanics...

  10. Fault Tolerant Control for Civil Structures Based on LMI Approach

    Directory of Open Access Journals (Sweden)

    Chunxu Qu

    2013-01-01

    Full Text Available The control system may lose the performance to suppress the structural vibration due to the faults in sensors or actuators. This paper designs the filter to perform the fault detection and isolation (FDI and then reforms the control strategy to achieve the fault tolerant control (FTC. The dynamic equation of the structure with active mass damper (AMD is first formulated. Then, an estimated system is built to transform the FDI filter design problem to the static gain optimization problem. The gain is designed to minimize the gap between the estimated system and the practical system, which can be calculated by linear matrix inequality (LMI approach. The FDI filter is finally used to isolate the sensor faults and reform the FTC strategy. The efficiency of FDI and FTC is validated by the numerical simulation of a three-story structure with AMD system with the consideration of sensor faults. The results show that the proposed FDI filter can detect the sensor faults and FTC controller can effectively tolerate the faults and suppress the structural vibration.

  11. Nonlinear sensor fault diagnosis using mixture of probabilistic PCA models

    Science.gov (United States)

    Sharifi, Reza; Langari, Reza

    2017-02-01

    This paper presents a methodology for sensor fault diagnosis in nonlinear systems using a Mixture of Probabilistic Principal Component Analysis (MPPCA) models. This methodology separates the measurement space into several locally linear regions, each of which is associated with a Probabilistic PCA (PPCA) model. Using the transformation associated with each PPCA model, a parity relation scheme is used to construct a residual vector. Bayesian analysis of the residuals forms the basis for detection and isolation of sensor faults across the entire range of operation of the system. The resulting method is demonstrated in its application to sensor fault diagnosis of a fully instrumented HVAC system. The results show accurate detection of sensor faults under the assumption that a single sensor is faulty.

  12. Stator Fault Detection in Induction Motors by Autoregressive Modeling

    Directory of Open Access Journals (Sweden)

    Francisco M. Garcia-Guevara

    2016-01-01

    Full Text Available This study introduces a novel methodology for early detection of stator short circuit faults in induction motors by using autoregressive (AR model. The proposed algorithm is based on instantaneous space phasor (ISP module of stator currents, which are mapped to α-β stator-fixed reference frame; then, the module is obtained, and the coefficients of the AR model for such module are estimated and evaluated by order selection criterion, which is used as fault signature. For comparative purposes, a spectral analysis of the ISP module by Discrete Fourier Transform (DFT is performed; a comparison of both methodologies is obtained. To demonstrate the suitability of the proposed methodology for detecting and quantifying incipient short circuit stator faults, an induction motor was altered to induce different-degree fault scenarios during experimentation.

  13. A New Fault Diagnosis Method of Rotating Machinery

    Directory of Open Access Journals (Sweden)

    Chih-Hao Chen

    2008-01-01

    Full Text Available This paper presents a new fault diagnosis procedure for rotating machinery using the wavelet packets-fractal technology and a radial basis function neural network. The faults of rotating machinery considered in this study include imbalance, misalignment, looseness and imbalance combined with misalignment conditions. When such faults occur, they usually induce non-stationary vibrations to the machine. After measuring the vibration signals, the wavelet packets transform is applied to these signals. The fractal dimension of each frequency bands is extracted and the box counting dimension is used to depict the failure characteristics of the vibration signals. The failure modes are then classified by a radial basis function neural network. An experimental study was performed to evaluate the proposed method and the results show that the method can effectively detect and recognize different kinds of faults of rotating machinery.

  14. The property of fault zone and fault activity of Shionohira Fault, Fukushima, Japan

    Science.gov (United States)

    Seshimo, K.; Aoki, K.; Tanaka, Y.; Niwa, M.; Kametaka, M.; Sakai, T.; Tanaka, Y.

    2015-12-01

    The April 11, 2011 Fukushima-ken Hamadori Earthquake (hereafter the 4.11 earthquake) formed co-seismic surface ruptures trending in the NNW-SSE direction in Iwaki City, Fukushima Prefecture, which were newly named as the Shionohira Fault by Ishiyama et al. (2011). This earthquake was characterized by a westward dipping normal slip faulting, with a maximum displacement of about 2 m (e.g., Kurosawa et al., 2012). To the south of the area, the same trending lineaments were recognized to exist even though no surface ruptures occurred by the earthquake. In an attempt to elucidate the differences of active and non-active segments of the fault, this report discusses the results of observation of fault outcrops along the Shionohira Fault as well as the Coulomb stress calculations. Only a few outcrops have basement rocks of both the hanging-wall and foot-wall of the fault plane. Three of these outcrops (Kyodo-gawa, Shionohira and Betto) were selected for investigation. In addition, a fault outcrop (Nameishi-minami) located about 300 m south of the southern tip of the surface ruptures was investigated. The authors carried out observations of outcrops, polished slabs and thin sections, and performed X-ray diffraction (XRD) to fault materials. As a result, the fault zones originating from schists were investigated at Kyodo-gawa and Betto. A thick fault gouge was cut by a fault plane of the 4.11 earthquake in each outcrop. The fault materials originating from schists were fault bounded with (possibly Neogene) weakly deformed sandstone at Shionohira. A thin fault gouge was found along the fault plane of 4.11 earthquake. A small-scale fault zone with thin fault gouge was observed in Nameishi-minami. According to XRD analysis, smectite was detected in the gouges from Kyodo-gawa, Shionohira and Betto, while not in the gouge from Nameishi-minami.

  15. Investigating fault coupling: Creep and microseismicity on the Hayward fault

    Science.gov (United States)

    Evans, E. L.; Loveless, J. P.; Meade, B. J.; Burgmann, R.

    2009-12-01

    We seek to quantify the relationship between interseismic slip activity and microseismicity along the Hayward fault in the eastern San Francisco Bay Area. During the interseismic regime the Hayward fault is known to exhibit variable degrees of locking both along strike and down-dip. Background microseismicity on and near the fault has been suggested to provide independent information about the rates of interseismic creep and the boundaries of creeping regions. In particular, repeating earthquakes within the fault zone have been suggested as a proxy for fault creep rates. To investigate this relationship, we invert GPS data for microplate rotations, fault slip rates, and fault coupling using a block model that spans western United States and includes the San Andreas, Hayward, Calaveras, Rogers Creek, and Green Valley faults in the greater Bay area. The tectonic context provided by the regional scale model ensures that the slip budget across Bay Area faults is consistent with large scale tectonic motions and kinematically connected to the central San Andreas fault. We image the spatial distribution of interseismic slip on a triangulated mesh of the Hayward fault and compare the distribution of interseismic fault coupling with the number of earthquakes and the moment rate of all on-fault seismicity. We quantitatively test the hypothesis that microseismicity might define the transitions between locked and creeping regions. The calculated correlations are tested against a null hypothesis that microseismicity is randomly distributed. We further extend this investigation to the step over region between the Hayward and Calaveras faults to illuminate the interactions between linking faults.

  16. Detection of inrush current in distribution transformer using wavelet transform

    Energy Technology Data Exchange (ETDEWEB)

    Sedighi, A.-R.; Haghifam, M.-R. [Tarbiat Modarres Univ., Dept. of Electrical Engineering, Tehran (Iran)

    2005-07-01

    Inrush currents in transformers are non-sinusoidal, high magnitude currents generated due to flux saturation in the core during energization. For protection purpose, in this paper an efficient method for detection of inrush current in distribution transformer based on wavelet transform is presented. Using this method inrush current can be discriminated from the other switching transients such as: load switching, capacitor switching and single phase to ground fault. Inrush current and other events for feature extraction and discrimination are simulated using Electro Magnetic Transient Program (EMTP). Results in all cases show the effectiveness of proposed procedure in identifying inrush current from other transients. (Author)

  17. Diversity vs. Difference: A Critical Analysis of Hybridity and Cultural Identity Crisis in the Novels of Cheikh Hamidou Kane and Chinua Achebe

    Directory of Open Access Journals (Sweden)

    Alassane Abdoulaye DIA

    2014-03-01

    Full Text Available Hybridity has been one of the most recurrent themes of the African fiction during and after the colonial period. It is one of the complex issues of postcolonial Africa as it was difficult for many Négritude writers, such as Léopold Sédar Senghor, Aimé Césaire, and Frantz Fanon, to find a common ground on what colonization bequeathed to Africa. Hence, Senghor (1977 came up with the oxymoron of “colonization as a necessary evil”. However, to evaluate the advantages and disadvantages of colonization to Africans, in terms of impact, one should go further than expected to approve or dismantle Senghor’s position. The issues of cultural hybridity and identity crisis are still topical in African literature. Also, in the context of globalization, it is relevant to study the post-independence situation of African societies as represented by their early prominent and visionary writers such as Chinua Achebe from Nigeria and Cheikh Hamidou Kane from Senegal. Therefore, hybridity becomes a concern, through which writers address the dilemma of the African. They portray the intellectual who is entrapped in two different cultures and becomes alienated. The corpus of this article showcases this phenomenon through the characters of Obi Okonkwo in No Longer at Ease (1960 and Samba Diallo in Ambiguous Adventure (1962. Through a critical analysis and a post-colonial perspective, the article focuses on identity crisis, alongside the contentious debate over cultural diversity versus cultural difference, which is highly reflected in the novels investigated in the paper.

  18. Fault-Mechanism Simulator

    Science.gov (United States)

    Guyton, J. W.

    1972-01-01

    An inexpensive, simple mechanical model of a fault can be produced to simulate the effects leading to an earthquake. This model has been used successfully with students from elementary to college levels and can be demonstrated to classes as large as thirty students. (DF)

  19. Heat reveals faults

    Energy Technology Data Exchange (ETDEWEB)

    Weinreich, Bernhard [Solarschmiede GmbH, Muenchen (Germany). Engineering Dept.

    2010-07-01

    Gremlins cannot hide from the all-revealing view of a thermographic camera, whereby it makes no difference whether it is a roof-mounted system or a megawatt-sized farm. Just as diverse are the range of faults that, with the growing level of expertise, can now be detected and differentiated with even greater detail. (orig.)

  20. Row fault detection system

    Science.gov (United States)

    Archer, Charles Jens; Pinnow, Kurt Walter; Ratterman, Joseph D.; Smith, Brian Edward

    2008-10-14

    An apparatus, program product and method checks for nodal faults in a row of nodes by causing each node in the row to concurrently communicate with its adjacent neighbor nodes in the row. The communications are analyzed to determine a presence of a faulty node or connection.

  1. Adaptive Fault Tolerance

    Science.gov (United States)

    1994-05-01

    center ( MOCl ) and one workstation processor (WS1) in the Adaptive Fault Tolerance 22 command center (CCE). The remaining data processing routines (GDI...78243-7063 NRAIR232 ATTN: DANIEL W. ATKINSON 9800 SAVAGE RD FT MEADE MD 20755-6000 TRUSTED INFORMATION SYSTEMS, INC. ATTN: WILLIAM C. BARKER 3060

  2. Fault-Mechanism Simulator

    Science.gov (United States)

    Guyton, J. W.

    1972-01-01

    An inexpensive, simple mechanical model of a fault can be produced to simulate the effects leading to an earthquake. This model has been used successfully with students from elementary to college levels and can be demonstrated to classes as large as thirty students. (DF)

  3. Fault-Related Sanctuaries

    Science.gov (United States)

    Piccardi, L.

    2001-12-01

    Beyond the study of historical surface faulting events, this work investigates the possibility, in specific cases, of identifying pre-historical events whose memory survives in myths and legends. The myths of many famous sacred places of the ancient world contain relevant telluric references: "sacred" earthquakes, openings to the Underworld and/or chthonic dragons. Given the strong correspondence with local geological evidence, these myths may be considered as describing natural phenomena. It has been possible in this way to shed light on the geologic origin of famous myths (Piccardi, 1999, 2000 and 2001). Interdisciplinary researches reveal that the origin of several ancient sanctuaries may be linked in particular to peculiar geological phenomena observed on local active faults (like ground shaking and coseismic surface ruptures, gas and flames emissions, strong underground rumours). In many of these sanctuaries the sacred area is laid directly above the active fault. In a few cases, faulting has affected also the archaeological relics, right through the main temple (e.g. Delphi, Cnidus, Hierapolis of Phrygia). As such, the arrangement of the cult site and content of relative myths suggest that specific points along the trace of active faults have been noticed in the past and worshiped as special `sacred' places, most likely interpreted as Hades' Doors. The mythological stratification of most of these sanctuaries dates back to prehistory, and points to a common derivation from the cult of the Mother Goddess (the Lady of the Doors), which was largely widespread since at least 25000 BC. The cult itself was later reconverted into various different divinities, while the `sacred doors' of the Great Goddess and/or the dragons (offspring of Mother Earth and generally regarded as Keepers of the Doors) persisted in more recent mythologies. Piccardi L., 1999: The "Footprints" of the Archangel: Evidence of Early-Medieval Surface Faulting at Monte Sant'Angelo (Gargano, Italy

  4. 基于自适应多尺度形态梯度变换的滚动轴承故障特征提取%Feature extraction for roller bearing fault diagnosis based on adaptive multi-scale morphological gradient transformation

    Institute of Scientific and Technical Information of China (English)

    李兵; 张培林; 刘东升; 米双山; 任国全

    2011-01-01

    Impulsive type signal is the characteristic response of a defected roller bearing. How to extract impulsive signal from a noised vibration signal becomes the key step for bearing fault diagnosis. A novel method named adaptive multi-scale morphological gradient ( AMMG) based on mathematical morphology was proposed for feature extraction of a roller bearing fault signal here. The AMMG technique had the advantage to depress noise and keep the detail of a signal. Compared with the envelope demodulation method and the morphological closed transformation one, simulation and test results demonstrated that the proposed AMMG technique can extract impulse signals more effectively from the original signals disturbed with strong background noise; moreover, the computation of AMMG is relatively simple and fast; it provides an effective way to extract features for fault diagnosis of roller bearings.%滚动轴承故障信号是一种典型的周期性冲击信号,如何从含有强噪声的振动信号中有效地提取出冲击特征信号是轴承故障诊断的关键.基于数学形态学理论,提出了一种自适应多尺度形态梯度变换(AMMG)方法,能够在有效抑制噪声的同时很好的保留信号的细节.仿真信号和实测轴承故障信号的分析结果表明,与常用的包络解调分析和近来提出的另一种基于数学形态学的形态闭变换方法相比较,自适应多尺度形态梯度变换具有更强的噪声抑制和脉冲提取能力,并且计算简单、快速,为滚动轴承故障特征提取提供了一种有效的方法.

  5. Improved Hilbert-Huang Transform and Its Applications to Rolling Bearing Fault Diagnosis%改进的希尔伯特-黄变换及其在滚动轴承故障诊断中的应用

    Institute of Scientific and Technical Information of China (English)

    郑近德; 程军圣

    2015-01-01

    希尔伯特黄变换(Hilbert-Huang transform, HHT)是一种优秀的时频分析方法,包含经验模态分解(Empirical mode decomposition, EMD)和希尔伯特变换(Hilbert transform, HT)两部分,通过EMD对信号进行分解,再对得到的内禀模态函数(Intrinsic mode function, IMF)进行HT解调。针对EMD存在的包络误差,模态混淆,端点效应以及HT易产生负频率等缺陷,提出一种改进的HHT方法(Improved HHT, IHHT),IHHT包括广义经验模态分解(Generalized EMD, GEMD)和改进的直接正交(Improved direct quadrature, IDQ)解调,GEMD通过定义多种均值曲线,从得到的多个IMF中选择最优分量,从而保证了每阶分量的优越性;再采用改进的经验调幅调频分解和 IDQ 方法对信号进行解调,提高了分解和解调的精确性、抑制了端点效应的产生。将提出的方法应用于滚动轴承故障诊断,分析结果表明IHHT是一种有效的信号处理方法。%Hilbert-Huang transform (HHT) is an excellent time-frequency analysis method, which contains empirical mode decomposition (EMD) and Hilbert transform (HT). A given signal is decomposed by EMD and then each of the obtained intrinsic mode functions (IMFs) is demodulated by HT. Aim to solve the problems of envelope errors, mode mixing and end effort of EMD method and negative frequency of HT, an improved HHT method (IHHT) is proposed, which contains generalized EMD (GEMD) and improved direct quadrature (IDQ) demodulation. By GEMD several different IMFs are obtained by defining different mean curves and in each rank the best IMF is selected. The improved empirical AM-FM decomposition and IDQ are used to demodulate the component. The proposed method improved the accuracy of decomposition and demodulation and restrained the end effort. IHHT is applied to rolling bearing experiment data and the analysis results indicate that IHHT is an effective signal processing method.

  6. Overcurrent protection of transformers. Part 2: Traditional and new fusing philosophies for small and large transformers

    Energy Technology Data Exchange (ETDEWEB)

    Cook, C. J.; Niemira, J. K.

    2003-07-01

    New and traditional fusing philosophies for protecting transformers are discussed. This second in a two-part paper covers selection criteria for a transformer-primary fuse to protect the transformer consistent with industry-accepted through-fault protection curves. Also covered are the principles of coordination as they relate to the proper selection of the primary-side fuse and power fuses and the principles underlying the protection of load-side conductors and cables. The critical nature of secondary fault protection on small three-phase transformers used on industrial, commercial, and institutional power systems, as well as small-to-medium size three-phase power transformers used in utility substations is emphasized, in view of the long lead time and expense involved in replacing these transformers. In contrast, no special protection recommendations are made for small-kVA overhead distribution transformers, since they are not considered likely to experience secondary faults, and the rare faults that do occur will not likely be detected and cleared by the primary fuse. Also of importance is the fact that these transformers are inexpensive and readily available. Overall, large fuse rating, used in combination with a tank-mounted surge arrester is recommended, because it can provide better transformer protection than the smaller fuse ratings traditionally employed. 4 refs., 2 tabs., 4 figs.

  7. Applying Parametric Fault Detection to a Mechanical System

    DEFF Research Database (Denmark)

    Felício, P.; Stoustrup, Jakob; Niemann, H.

    2002-01-01

    A way of doing parametric fault detection is described. It is based on the representation of parameter changes as linear fractional transformations (lfts). We describe a model with parametric uncertainty. Then a stabilizing controller is chosen and its robustness properties are studied via mu...

  8. A Hybrid Algorithm for Fault Locating in Looped Microgrids

    DEFF Research Database (Denmark)

    Beheshtaein, Siavash; Savaghebi, Mehdi; Quintero, Juan Carlos Vasquez

    2016-01-01

    occurs within them. Two criteria are defined in such a way to prevent injection of voltage harmonic by the other DGs. Finally, the fault is located in the reduced space of search by wavelet transform and optimized multiclass support vector machine (M-SVM). In the simulation results, the contribution...

  9. ACCELERATED SYNERGISM ALONG A FAULT: A POSSIBLE INDICATOR FOR AN IMPENDING MAJOR EARTHQUAKE

    Directory of Open Access Journals (Sweden)

    Ma Jin

    2015-09-01

    as both the expansion of strain release areas and rise of strain level of strain accumulation areas are accelerated. The synergism is accelerated when the quasi-static expansion transforms into quasi-dynamic expansion, with interaction between fault segments as its mechanism. The essence of such transformation is that the expansion mechanism has changed, i.e. expansion of isolated fault segments is replaced by linkage of the interacting segments when the fault enters the critical state of a potential earthquake. Based on the experimental results, coupled with data on the temporal-spatial evolution of earthquakes along the Laohushan-Maomaoshan fault, west of the Haiyuan fault zone in northwestern China, the synergism process of this fault before the 6 June 2000 M6.2 earthquake is analyzed. 

  10. Network Fault Diagnosis Using DSM

    Institute of Scientific and Technical Information of China (English)

    Jiang Hao; Yan Pu-liu; Chen Xiao; Wu Jing

    2004-01-01

    Difference similitude matrix (DSM) is effective in reducing information system with its higher reduction rate and higher validity. We use DSM method to analyze the fault data of computer networks and obtain the fault diagnosis rules. Through discretizing the relative value of fault data, we get the information system of the fault data. DSM method reduces the information system and gets the diagnosis rules. The simulation with the actual scenario shows that the fault diagnosis based on DSM can obtain few and effective rules.

  11. Closure of the Africa-Eurasia-North America plate motion circuit and tectonics of the Gloria fault

    Science.gov (United States)

    Argus, Donald F.; Gordon, Richard G.; Demets, Charles; Stein, Seth

    1989-01-01

    The current motions of the African, Eurasian, and North American plates are examined. The problems addressed include whether there is resolvable motion of a Spitsbergen microplate, the direction of motion between the African and North American plates, whether the Gloria fault is an active transform fault, and the implications of plate circuit closures for rates of intraplate deformation. Marine geophysical data and magnetic profiles are used to construct a model which predicts about 4 mm/yr slip across the Azores-Gibraltar Ridge, and west-northwest convergence near Gibraltar. The analyzed data are consistent with a rigid plate model with the Gloria fault being a transform fault.

  12. Kinematical and Structural Patterns of the Yingjing-Mabian-Yanjin Thrust Fault Zone,Southeast of the Qinghai-Xizang (Tibet) Plateau and Its Segmentation from Earthquakes

    Institute of Scientific and Technical Information of China (English)

    Zhang Shimin; Nie Gaohong; Liu Xudong; Ren Junjie; Su Gang

    2006-01-01

    Segmentation of the thrust fault zone is a basic problem for earthquake hazard evaluation. The Yingjing-Mabian-Yanjin thrust fault zone is an important seismic belt NW-trending in the southeast margin of the Qinghai-Xizang (Tibet) plateau. The longitudinal faults in the thrust zone are mainly of the thrust slipping type. The late Quaternary motion modes and displacement rates are quite different from north to south. Investigation on valleys across the fault shows that the transverse faults are mainly of dextral strike-slipping type with a bit dip displacement. Based on their connections with the longitudinal faults, three types of transverse faults are generalized, namely: the separate fault, the transform fault and the tear fault, and their functions in the segmentation of the thrust fault zone are compared. As the result, the Yingjing-Mabian-Yanjin thrust fault zone is divided into three segments, and earthquakes occurring in these three segments are compared. The tri-section of the Yingjing-Mabian-Yanjin thrust fault zone identified by transverse fault types reflects, on the one hand, the differences in slip rate, earthquake magnitude and pace from each segment, and the coherence of earthquake rupturing pace on the other hand. It demonstrates that the transverse faults control the segmentation to a certain degree, and each type of the transverse faults plays a different role.

  13. Cryptanalysis of Two Fault Countermeasure Schemes

    DEFF Research Database (Denmark)

    Banik, Subhadeep; Bogdanov, Andrey

    2015-01-01

    is meant for the protection of block ciphers like AES. The second countermeasure was proposed in IEEE-HOST 2015 and protects the Grain-128 stream cipher. The design divides the output function used in Grain-128 into two components. The first called the masking function, masks the input bits to the output......In this paper, we look at two fault countermeasure schemes proposed very recently in literature. The first proposed in ACISP 2015 constructs a transformation function using a cellular automata based linear diffusion, and a non-linear layer using a series of bent functions. This countermeasure...

  14. Fault Diagnosis for Rolling Bearing under Variable Conditions Based on Image Recognition

    Directory of Open Access Journals (Sweden)

    Bo Zhou

    2016-01-01

    Full Text Available Rolling bearing faults often lead to electromechanical system failure due to its high speed and complex working conditions. Recently, a large amount of fault diagnosis studies for rolling bearing based on vibration data has been reported. However, few studies have focused on fault diagnosis for rolling bearings under variable conditions. This paper proposes a fault diagnosis method based on image recognition for rolling bearings to realize fault classification under variable working conditions. The proposed method includes the following steps. First, the vibration signal data are transformed into a two-dimensional image based on recurrence plot (RP technique. Next, a popular feature extraction method which has been widely used in the image field, scale invariant feature transform (SIFT, is employed to extract fault features from the two-dimensional RP and subsequently generate a 128-dimensional feature vector. Third, due to the redundancy of the high-dimensional feature, kernel principal component analysis is utilized to reduce the feature dimensionality. Finally, a neural network classifier trained by probabilistic neural network is used to perform fault diagnosis. Verification experiment results demonstrate the effectiveness of the proposed fault diagnosis method for rolling bearings under variable conditions, thereby providing a promising approach to fault diagnosis for rolling bearings.

  15. Performance evaluation of transformer oil using uv-visible spectrophotometer

    OpenAIRE

    Karthik, Radha; National Engineering College; Raja, Thangaswamy Sree Renga; Anna University; Shunmugam, Sundaram Sudalai; National Engineering College

    2014-01-01

    To ensure reliable operation of Power transformer, condition monitoring of transformer becomes obligatory. In this paper, condition assessment of transformer oil under various working conditions is performed using UV-visible spectrophotometer. Test samples include both laboratorial prepared ones and those obtained from in service transformers.  An index table of spectral responses for various faults which predominantly occur in the transformer is developed. The index table will acts as a refe...

  16. Seismic Fault Preserving Diffusion

    CERN Document Server

    Lavialle, Olivier; Germain, Christian; Donias, Marc; Guillon, Sebastien; Keskes, Naamen; Berthoumieu, Yannick

    2007-01-01

    This paper focuses on the denoising and enhancing of 3-D reflection seismic data. We propose a pre-processing step based on a non linear diffusion filtering leading to a better detection of seismic faults. The non linear diffusion approaches are based on the definition of a partial differential equation that allows us to simplify the images without blurring relevant details or discontinuities. Computing the structure tensor which provides information on the local orientation of the geological layers, we propose to drive the diffusion along these layers using a new approach called SFPD (Seismic Fault Preserving Diffusion). In SFPD, the eigenvalues of the tensor are fixed according to a confidence measure that takes into account the regularity of the local seismic structure. Results on both synthesized and real 3-D blocks show the efficiency of the proposed approach.

  17. Seismic fault preserving diffusion

    Science.gov (United States)

    Lavialle, Olivier; Pop, Sorin; Germain, Christian; Donias, Marc; Guillon, Sebastien; Keskes, Naamen; Berthoumieu, Yannick

    2007-02-01

    This paper focuses on the denoising and enhancing of 3-D reflection seismic data. We propose a pre-processing step based on a non-linear diffusion filtering leading to a better detection of seismic faults. The non-linear diffusion approaches are based on the definition of a partial differential equation that allows us to simplify the images without blurring relevant details or discontinuities. Computing the structure tensor which provides information on the local orientation of the geological layers, we propose to drive the diffusion along these layers using a new approach called SFPD (Seismic Fault Preserving Diffusion). In SFPD, the eigenvalues of the tensor are fixed according to a confidence measure that takes into account the regularity of the local seismic structure. Results on both synthesized and real 3-D blocks show the efficiency of the proposed approach.

  18. Managing Fault Management Development

    Science.gov (United States)

    McDougal, John M.

    2010-01-01

    As the complexity of space missions grows, development of Fault Management (FM) capabilities is an increasingly common driver for significant cost overruns late in the development cycle. FM issues and the resulting cost overruns are rarely caused by a lack of technology, but rather by a lack of planning and emphasis by project management. A recent NASA FM Workshop brought together FM practitioners from a broad spectrum of institutions, mission types, and functional roles to identify the drivers underlying FM overruns and recommend solutions. They identified a number of areas in which increased program and project management focus can be used to control FM development cost growth. These include up-front planning for FM as a distinct engineering discipline; managing different, conflicting, and changing institutional goals and risk postures; ensuring the necessary resources for a disciplined, coordinated approach to end-to-end fault management engineering; and monitoring FM coordination across all mission systems.

  19. Fault Tree Handbook

    Science.gov (United States)

    1981-01-01

    to be Evaluated Manufacturer Location Seismic Susceptibility Flood Susceptibility Temperature Humidity Radiation Wear-out Susceptibility Test...For the category " Seismic Susceptibility," we might define several sensitivity levels ranging from no sensitivity to extreme sensitivity, and for more... Hanford Company, Richland, Wash- ington, ARH-ST-l 12, July 1975. 40. W.E. Vesely, "Analysis of Fault Trees by Kinetic Tree Theory," Idaho Nuclear

  20. Faults in Linux

    DEFF Research Database (Denmark)

    Palix, Nicolas Jean-Michel; Thomas, Gaël; Saha, Suman

    2011-01-01

    In 2001, Chou et al. published a study of faults found by applying a static analyzer to Linux versions 1.0 through 2.4.1. A major result of their work was that the drivers directory contained up to 7 times more of certain kinds of faults than other directories. This result inspired a number...... of development and research efforts on improving the reliability of driver code. Today Linux is used in a much wider range of environments, provides a much wider range of services, and has adopted a new development and release model. What has been the impact of these changes on code quality? Are drivers still...... a major problem? To answer these questions, we have transported the experiments of Chou et al. to Linux versions 2.6.0 to 2.6.33, released between late 2003 and early 2010. We find that Linux has more than doubled in size during this period, but that the number of faults per line of code has been...

  1. Mobilities and dislocation energies of planar faults in an ordered A3B (D019) structure

    Indian Academy of Sciences (India)

    A K Singh; R Sankarasubramanian; T K Nandy

    2013-08-01

    Present work describes the stability of possible planar faults of the A3B (D019) phase with an axial ratio less than the ideal. Mobilities and dislocation energies of various planar faults viz. antiphase boundaries (APBs), superlattice intrinsic stacking faults (SISFs) and complex stacking faults (CSFs) have been computed using complex fourth-order tensor transformations and hard sphere model. Displacements normal to the slip planes for various slip systems (vertical shift) have been used to calculate mobility of dislocations. The energy of the planar faults in Ti3Al intermetallic is calculated using some simplifying assumptions. Based on the mobility and energy, stability of planar faults has been explained. These results are compared with single crystal ordered Ti3Al alloy having D019 structure.

  2. Mechanism of water-inrush from fault induced by mining near the working face

    Institute of Scientific and Technical Information of China (English)

    WANG Lian-guo; WU Yu; MIAO Xie-xing; DONG Xu

    2007-01-01

    Adopted the fractal tree-like failure model, and established the renormalization group transform function of fractured fault, and investigated the mechanism of water-inrush from fault, and found out the critical probability of water-inrush from fault caused by fault fracture. The results indicate: when the failure rate P is less than the critical failure rate Pc=0.206 3, the failure of the system is just partial. When P is more than the critical failure rate Pc=0.206 3, the random distributed crannies concentrate to certain domain of attraction (such as the maximum shear stress face in the fault) gradually. The process will continue until the crannies run-through, forming conductivity channel, and cause water-inrush from fault.

  3. Structural character of Hosgri fault zone and adjacent areas in offshore central California

    Energy Technology Data Exchange (ETDEWEB)

    Crouch, J.K.; Bachman, S.B.

    1987-05-01

    The Hosgri fault zone extends from the east-west Transverse Ranges structures near Point Arguello northward for more than 150 km to the offshore area near San Simeon Point. The fault zone is seismically active and consists chiefly of a continuous series of eastside-up thrust and high-angle reverse faults. East of the fault zone, Miocene Monterey and volcanic rocks, along with underlying pre-Miocene strata, have been tightly folded as a result of low-angle imbricate thrust faulting during post-Miocene time. These highly deformed strata have been uplited and truncated along the inner shelf. Immediately west of the Hosgria fault zone, similar Monterey and older rocks, which are less folded, conformably underlie Pliocene and younger basinal strata at structural levels that are generally 1200 to 2000 m deeper than correlative strata east of the Hosgri fault zone. Following its discovery in 1971, the Hosgri fault zone was characterized by subsequent investigators as a northwest-trending fault that was part of the San Andreas system of strike-slip faults, with disagreements on the timing and amount of right-lateral offset along the fault zone. However, modern offshore seismic-reflection data, earthquake focal-mechanism studies, and recently available offshore well information suggest that the Hosgri fault zone is instead a major imbricate thrust zone. Detailed structural analyses along part of the Hosgri fault zone suggest that little, if any, strike-slip offset has occurred along this structural trend since its post-Miocene inception. Nevertheless, the Hosgri fault zone itself can be interpreted to be a product of the larger overall San Andreas transform system in that compression has developed because the San Andreas is not parallel to the Pacific-North American plate motion.

  4. Diagnosis Method for Analog Circuit Hard fault and Soft Fault

    Directory of Open Access Journals (Sweden)

    Baoru Han

    2013-09-01

    Full Text Available Because the traditional BP neural network slow convergence speed, easily falling in local minimum and the learning process will appear oscillation phenomena. This paper introduces a tolerance analog circuit hard fault and soft fault diagnosis method based on adaptive learning rate and the additional momentum algorithm BP neural network. Firstly, tolerance analog circuit is simulated by OrCAD / Pspice circuit simulation software, accurately extracts fault waveform data by matlab program automatically. Secondly, using the adaptive learning rate and momentum BP algorithm to train neural network, and then applies it to analog circuit hard fault and soft fault diagnosis. With shorter training time, high precision and global convergence effectively reduces the misjudgment, missing, it can improve the accuracy of fault diagnosis and fast.  

  5. ESR dating of fault rocks

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hee Kwon [Kangwon National Univ., Chuncheon (Korea, Republic of)

    2003-02-15

    Past movement on faults can be dated by measurement of the intensity of ESR signals in quartz. These signals are reset by local lattice deformation and local frictional heating on grain contacts at the time of fault movement. The ESR signals then grow back as a result of bombardment by ionizing radiation from surrounding rocks. The age is obtained from the ratio of the equivalent dose, needed to produce the observed signal, to the dose rate. Fine grains are more completely reset during faulting, and a plot of age vs. grain size shows a plateau for grains below critical size; these grains are presumed to have been completely zeroed by the last fault activity. We carried out ESR dating of fault rocks collected near the Gori nuclear reactor. Most of the ESR signals of fault rocks collected from the basement are saturated. This indicates that the last movement of the faults had occurred before the Quaternary period. However, ESR dates from the Oyong fault zone range from 370 to 310 ka. Results of this research suggest that long-term cyclic fault activity of the Oyong fault zone continued into the Pleistocene.

  6. Large earthquakes and creeping faults

    Science.gov (United States)

    Harris, Ruth A.

    2017-01-01

    Faults are ubiquitous throughout the Earth's crust. The majority are silent for decades to centuries, until they suddenly rupture and produce earthquakes. With a focus on shallow continental active-tectonic regions, this paper reviews a subset of faults that have a different behavior. These unusual faults slowly creep for long periods of time and produce many small earthquakes. The presence of fault creep and the related microseismicity helps illuminate faults that might not otherwise be located in fine detail, but there is also the question of how creeping faults contribute to seismic hazard. It appears that well-recorded creeping fault earthquakes of up to magnitude 6.6 that have occurred in shallow continental regions produce similar fault-surface rupture areas and similar peak ground shaking as their locked fault counterparts of the same earthquake magnitude. The behavior of much larger earthquakes on shallow creeping continental faults is less well known, because there is a dearth of comprehensive observations. Computational simulations provide an opportunity to fill the gaps in our understanding, particularly of the dynamic processes that occur during large earthquake rupture and arrest.

  7. Rolling Bearing Fault Detection Based on Complex Wavelet Transform and Singlar Value Ratio Spectrum%基于复小波和奇异值比谱的轴承故障检测方法

    Institute of Scientific and Technical Information of China (English)

    侯者非; 杨杰; 张雪

    2011-01-01

    A novel signal processing algorithm was proposed here for vibration signal analysis in condition monitoring and health diagnosis of rolling bearings.Such technique required an envelope being extracted from the vibration signal with complex Morlet wavelet transform (MWT).The principal periodic component in the envelope was subsequently detected, enhanced and reconstructed automatically with sweep frequency method based on finding the peak value of singular value ratio (SVR) spectrum.Such signal processing approach was experimentally evaluated by using vibration signals measured on rolling element bearings that contained localized structural defects with proved validity and efficiency.%提出一种基于包络分析和奇异值比谱的滚动轴承振动故障监测和诊断方法.首先利用具有解析带通特性的复Morlet小波来获得信号的包络,然后采用扫频方式检测奇异值比谱最大峰值自动提取、增强、重构包络信号中的主周期分量,提取到轴承故障特征.该方法已成功地应用到了对滚动轴承故障检测实验,验证了该方法的有效性、可行性.

  8. One New Scheme to Discriminate Inrush Current from Internal Fault of Power Transformer Based on EMD Decomposition%基于EMD分解的变压器励磁涌流鉴别

    Institute of Scientific and Technical Information of China (English)

    罗伟强; 边铁

    2009-01-01

    针对励磁涌流波形畸变严重且会出现尖顶波,而故障电流基本保持基频正弦波特征的特点,提出了一种利用HHT(Hilbert-Huang Transform)的EMD(Empirical Mode Decomposition)分解来识别变压器励磁涌流的新方法.该方法利用EMD将数据分解成有限个IMF(Intrinsic Mode Function),定义并计算各个IMF在X轴上的投影面积Sc、Simf的比重系数Kc及其最大值Kmax.在比较励磁涌流和故障电流Kmax不同特点的基础上,提出了一种变压器保护新方案.理论分析及动模实验结果表明,该方法能够正确区分励磁涌流及故障电流,其判断时间约20ms;方法实现方便,不受非周期分量等影响.

  9. Imaging of subsurface faults using refraction migration with fault flooding

    Science.gov (United States)

    Metwally, Ahmed; Hanafy, Sherif; Guo, Bowen; Kosmicki, Maximillian

    2017-08-01

    We propose a novel method for imaging shallow faults by migration of transmitted refraction arrivals. The assumption is that there is a significant velocity contrast across the fault boundary that is underlain by a refracting interface. This procedure, denoted as refraction migration with fault flooding, largely overcomes the difficulty in imaging shallow faults with seismic surveys. Numerical results successfully validate this method on three synthetic examples and two field-data sets. The first field-data set is next to the Gulf of Aqaba and the second example is from a seismic profile recorded in Arizona. The faults detected by refraction migration in the Gulf of Aqaba data were in agreement with those indicated in a P-velocity tomogram. However, a new fault is detected at the end of the migration image that is not clearly seen in the traveltime tomogram. This result is similar to that for the Arizona data where the refraction image showed faults consistent with those seen in the P-velocity tomogram, except that it also detected an antithetic fault at the end of the line. This fault cannot be clearly seen in the traveltime tomogram due to the limited ray coverage.

  10. Imaging of Subsurface Faults using Refraction Migration with Fault Flooding

    KAUST Repository

    Metwally, Ahmed

    2017-05-31

    We propose a novel method for imaging shallow faults by migration of transmitted refraction arrivals. The assumption is that there is a significant velocity contrast across the fault boundary that is underlain by a refracting interface. This procedure, denoted as refraction migration with fault flooding, largely overcomes the difficulty in imaging shallow faults with seismic surveys. Numerical results successfully validate this method on three synthetic examples and two field-data sets. The first field-data set is next to the Gulf of Aqaba and the second example is from a seismic profile recorded in Arizona. The faults detected by refraction migration in the Gulf of Aqaba data were in agreement with those indicated in a P-velocity tomogram. However, a new fault is detected at the end of the migration image that is not clearly seen in the traveltime tomogram. This result is similar to that for the Arizona data where the refraction image showed faults consistent with those seen in the P-velocity tomogram, except it also detected an antithetic fault at the end of the line. This fault cannot be clearly seen in the traveltime tomogram due to the limited ray coverage.

  11. Simultaneous-Fault Diagnosis of Gas Turbine Generator Systems Using a Pairwise-Coupled Probabilistic Classifier

    Directory of Open Access Journals (Sweden)

    Zhixin Yang

    2013-01-01

    Full Text Available A reliable fault diagnostic system for gas turbine generator system (GTGS, which is complicated and inherent with many types of component faults, is essential to avoid the interruption of electricity supply. However, the GTGS diagnosis faces challenges in terms of the existence of simultaneous-fault diagnosis and high cost in acquiring the exponentially increased simultaneous-fault vibration signals for constructing the diagnostic system. This research proposes a new diagnostic framework combining feature extraction, pairwise-coupled probabilistic classifier, and decision threshold optimization. The feature extraction module adopts wavelet packet transform and time-domain statistical features to extract vibration signal features. Kernel principal component analysis is then applied to further reduce the redundant features. The features of single faults in a simultaneous-fault pattern are extracted and then detected using a probabilistic classifier, namely, pairwise-coupled relevance vector machine, which is trained with single-fault patterns only. Therefore, the training dataset of simultaneous-fault patterns is unnecessary. To optimize the decision threshold, this research proposes to use grid search method which can ensure a global solution as compared with traditional computational intelligence techniques. Experimental results show that the proposed framework performs well for both single-fault and simultaneous-fault diagnosis and is superior to the frameworks without feature extraction and pairwise coupling.

  12. Application of neural networks for identification of faults in a 3D seismic survey offshore Tunisia

    Science.gov (United States)

    Mastouri, Raja; Marchant, Robin; Marillier, François; Jaboyedoff, Michel; Bouaziz, Samir

    2013-04-01

    The Kerkennah High area (offshore Tunisia) is dominated by series of horst and grabens resulting from multiple tectonic events and multiphase stress (extension, compression, translation). In order to decipher this complex structural history from a 3D seismic survey, a neural network is applied to extract a fault-cube from the amplitude data (which does not image faults directly). The neural network transforms seismic attributes into a new 3D data cube in which faults are highlighted. This technique comprises the following steps. First, we compute several seismic attributes (dip-steering similarity, curvature, frequency, ridge and fault enhancement filters…) that enhance different aspects of the seismic data related to faulting. In a second step, a number of points in the seismic data are selected as representative of either faults or areas devoid of faults. These points are tested by the artificial neural network to determine the range in which the different attributes are representative of faults or not. Based on this learning phase, the neural network is then applied to the entire 3D seismic cube to produce a fault-cube that contains only faults which contrast and continuity have been enhance.

  13. Transient analyses using symmetrical component calculus in three-phase resistive and transformer-type SFCLs

    Science.gov (United States)

    Cho, Y. S.; Choi, H. S.; Jung, B. I.

    2010-11-01

    A transformer-type superconducting fault current limiter (SFCL) can control fault current by adjusting a turn's ratio of the primary and secondary windings. In addition, by inserting a neutral line into the secondary winding, the power burden of the superconducting elements can be evenly distributed. We compared the operating and transient characteristics of the three-phase resistive and transformer-type SFCLs in the balanced and unbalanced faults that occur in power systems. In transformer-type SFCLs, where the primary and secondary windings of each phase were connected to one iron core, flux was induced to each winding of the normal phases by the fault current of the fault phase, thus causing simultaneous quench between superconducting elements. In the three-phase power systems, however, when faults occurred in more than two phases, the flux from fault current of the fault phase affected the other normal phase, thus decreasing the reduction ratio of fault current. We confirmed, however, that the fault current was reduced by 70% relative to cases without SFCLs. The results of the analysis of the transient characteristics of the three-phase transformer-type SFCL through the symmetrical component calculus showed that in the case of triple line-to-ground fault, a difference between positive and negative phase currents was large enough to cause an increase in the phase angle (δ) between the generator creating the power and the motor acting as a load. Thus, we expect that the transient stability deteriorates.

  14. Mechanical stratigraphy and normal faulting

    Science.gov (United States)

    Ferrill, David A.; Morris, Alan P.; McGinnis, Ronald N.; Smart, Kevin J.; Wigginton, Sarah S.; Hill, Nicola J.

    2017-01-01

    Mechanical stratigraphy encompasses the mechanical properties, thicknesses, and interface properties of rock units. Although mechanical stratigraphy often relates directly to lithostratigraphy, lithologic description alone does not adequately describe mechanical behavior. Analyses of normal faults with displacements of millimeters to 10's of kilometers in mechanically layered rocks reveal that mechanical stratigraphy influences nucleation, failure mode, fault geometry, displacement gradient, displacement distribution, fault core and damage zone characteristics, and fault zone deformation processes. The relationship between normal faulting and mechanical stratigraphy can be used either to predict structural style using knowledge of mechanical stratigraphy, or conversely to interpret mechanical stratigraphy based on characterization of the structural style. This review paper explores a range of mechanical stratigraphic controls on normal faulting illustrated by natural and modeled examples.

  15. Fault Tolerant Wind Farm Control

    DEFF Research Database (Denmark)

    Odgaard, Peter Fogh; Stoustrup, Jakob

    2013-01-01

    with best at a wind turbine control level. However, some faults are better dealt with at the wind farm control level, if the wind turbine is located in a wind farm. In this paper a benchmark model for fault detection and isolation, and fault tolerant control of wind turbines implemented at the wind farm...... control level is presented. The benchmark model includes a small wind farm of nine wind turbines, based on simple models of the wind turbines as well as the wind and interactions between wind turbines in the wind farm. The model includes wind and power references scenarios as well as three relevant fault...... scenarios. This benchmark model is used in an international competition dealing with Wind Farm fault detection and isolation and fault tolerant control....

  16. Handling Software Faults with Redundancy

    Science.gov (United States)

    Carzaniga, Antonio; Gorla, Alessandra; Pezzè, Mauro

    Software engineering methods can increase the dependability of software systems, and yet some faults escape even the most rigorous and methodical development process. Therefore, to guarantee high levels of reliability in the presence of faults, software systems must be designed to reduce the impact of the failures caused by such faults, for example by deploying techniques to detect and compensate for erroneous runtime conditions. In this chapter, we focus on software techniques to handle software faults, and we survey several such techniques developed in the area of fault tolerance and more recently in the area of autonomic computing. Since practically all techniques exploit some form of redundancy, we consider the impact of redundancy on the software architecture, and we propose a taxonomy centered on the nature and use of redundancy in software systems. The primary utility of this taxonomy is to classify and compare techniques to handle software faults.

  17. USING MUTATION IN FAULT LOCALIZATION

    Directory of Open Access Journals (Sweden)

    Chenglong Sun

    2016-05-01

    Full Text Available Fault localization is time-consuming and difficult, which makes it the bottleneck of the debugging progress. To help facilitate this task, there exist many fault localization techniques that help narrow down the region of the suspicious code in a program. Better accuracy in fault localization is achieved from heavy computation cost. Fault localization techniques that can effectively locate faults also manifest slow response rate. In this paper, we promote the use of pre-computing to distribute the time-intensive computations to the idle period of coding phase, in order to speed up such techniques and achieve both low-cost and high accuracy. We raise the research problems of finding suitable techniques that can be pre-computed and adapt it to the pre-computing paradigm in a continuous integration environment. Further, we use an existing fault localization technique to demonstrate our research exploration, and shows visions and challenges of the related methodologies.

  18. Abrupt strike-slip fault to subduction transition: The Alpine Fault-Puysegur Trench connection, New Zealand

    Science.gov (United States)

    Lebrun, Jean-FréDéRic; Lamarche, Geoffroy; Collot, Jean-Yves; Delteil, Jean

    2000-08-01

    Swath bathymetry and other geophysical data collected over the Fiordland Margin, southwest of New Zealand are used to investigate the mechanism of transform-subduction transition between the Alpine Fault and the Puysegur Trench, two segments of the Pacific-Australian plate boundary. In this region the Cenozoic Southeast Tasman Basin, which obliquely underthrusts Fiordland at the Puysegur Trench, is separated from the Cretaceous Tasman Basin by the Resolution Ridge System, a major lithospheric discontinuity of the downgoing plate. Interpretation of seafloor morphology shows that the Alpine Fault extends offshore along the Fiordland coast and splits into West and East Branches. The West Branch cuts obliquely across the margin and connects sharply to the Puysegur subduction front at the northeastern tip of the Resolution Ridge System. Earthquake and seismic reflection data indicate that the West Branch is genetically controlled by downgoing plate structures associated with the Resolution Ridge System. Hence the West Branch is interpreted as the surface trace of the plate boundary segment extending between the Alpine Fault and the Puysegur Trench. We conclude that the development of the strike-slip segment of the plate boundary and its sharp transition to the Puysegur subduction are controlled by inherited structures of the Australian plate. Furthermore, according to geophysical data presented here, a tearing of the downgoing plate can be interpreted beneath the West Branch. A review of geophysical data along the region of the Alpine Fault-Hikurangi Trough, northeast New Zealand, shows a progressive transform-subduction transition that is accommodated by motion partitioning between the subduction interface and strike-slip faults. This transition is accounted for by an interplate coupling that progressively increases toward the Alpine Fault in relation with a gradual thickening of the downgoing crust. The comparison between the Fiordland and the Hikurangi strike

  19. Final Technical Report: PV Fault Detection Tool.

    Energy Technology Data Exchange (ETDEWEB)

    King, Bruce Hardison [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Jones, Christian Birk [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-12-01

    The PV Fault Detection Tool project plans to demonstrate that the FDT can (a) detect catastrophic and degradation faults and (b) identify the type of fault. This will be accomplished by collecting fault signatures using different instruments and integrating this information to establish a logical controller for detecting, diagnosing and classifying each fault.

  20. Seismological Studies for Tensile Faults

    Directory of Open Access Journals (Sweden)

    Gwo-Bin Ou

    2008-01-01

    Full Text Available A shear slip fault, an equivalence of a double couple source, has often been assumed to be a kinematic source model in ground motion simulation. Estimation of seismic moment based on the shear slip model indicates the size of an earthquake. However, if the dislocation of the hanging wall relative to the footwall includes not only a shear slip tangent to the fault plane but also expansion and compression normal to the fault plane, the radiating seismic waves will feature differences from those out of the shear slip fault. Taking account of the effects resulting from expansion and compression to a fault plane, we can resolve the tension and pressure axes as well as the fault plane solution more exactly from ground motions than previously, and can evaluate how far a fault zone opens or contracts during a developing rupture. In addition to a tensile angle and Poisson¡¦s ratio for the medium, a tensile fault with five degrees of freedom has been extended from the shear slip fault with only three degrees of freedom, strike, dip, and slip.

  1. Fault-Tree Compiler Program

    Science.gov (United States)

    Butler, Ricky W.; Martensen, Anna L.

    1992-01-01

    FTC, Fault-Tree Compiler program, is reliability-analysis software tool used to calculate probability of top event of fault tree. Five different types of gates allowed in fault tree: AND, OR, EXCLUSIVE OR, INVERT, and M OF N. High-level input language of FTC easy to understand and use. Program supports hierarchical fault-tree-definition feature simplifying process of description of tree and reduces execution time. Solution technique implemented in FORTRAN, and user interface in Pascal. Written to run on DEC VAX computer operating under VMS operating system.

  2. Causes of automotive turbocharger faults

    Directory of Open Access Journals (Sweden)

    Jan FILIPCZYK

    2013-01-01

    Full Text Available This paper presents the results of examinations of turbocharger damages. The analysis of the causes of faults in 100 engines with turbochargers of cars, buses and trucks has been carried out. The incidence and structure of turbocharged engine faults has been compared to the causes of faults of naturally aspirated engines. The cause of damage, the possibility of early detection, the time between overhaul and the impact on engine operation for each case of fault was carried out as well. The results of examinations allowed to determine the most common causes of damages and how to prevent them.

  3. An Overview of Transmission Line Protection by Artificial Neural Network: Fault Detection, Fault Classification, Fault Location, and Fault Direction Discrimination

    Directory of Open Access Journals (Sweden)

    Anamika Yadav

    2014-01-01

    Full Text Available Contemporary power systems are associated with serious issues of faults on high voltage transmission lines. Instant isolation of fault is necessary to maintain the system stability. Protective relay utilizes current and voltage signals to detect, classify, and locate the fault in transmission line. A trip signal will be sent by the relay to a circuit breaker with the purpose of disconnecting the faulted line from the rest of the system in case of a disturbance for maintaining the stability of the remaining healthy system. This paper focuses on the studies of fault detection, fault classification, fault location, fault phase selection, and fault direction discrimination by using artificial neural networks approach. Artificial neural networks are valuable for power system applications as they can be trained with offline data. Efforts have been made in this study to incorporate and review approximately all important techniques and philosophies of transmission line protection reported in the literature till June 2014. This comprehensive and exhaustive survey will reduce the difficulty of new researchers to evaluate different ANN based techniques with a set of references of all concerned contributions.

  4. A Digital Ground Distance Relaying Algorithm to Reduce the Effect of Fault Resistance during Single Phase to Ground and Simultaneous Faults

    Directory of Open Access Journals (Sweden)

    Mohammad Razaz

    2015-03-01

    Full Text Available This paper provides an algorithm of fault resistance compensation for digital ground distance relay considering the voltage and current transformer effects. Performance of the conventional ground distance relaying manner is adversely affected by different ground faults and also typical type, called a simultaneous open conductor and ground fault. The proposed scheme by using local-end data only, has shown satisfactory performances under wide variations in fault location, with different values of fault resistance and having positive and negative of power transfer angle. The presented method which has been carried out on the IEEE 14 bus benchmark is executed in PSCAD/EMTDC and MATLAB software, and the results show the accurate performance of mentioned configuration.

  5. Effective crustal permeability controls fault evolution: An integrated structural, mineralogical and isotopic study in granitic gneiss, Monte Rosa, northern Italy

    Science.gov (United States)

    Lawther, Susan E. M.; Dempster, Tim J.; Shipton, Zoe K.; Boyce, Adrian J.

    2016-10-01

    Two dextral faults within granitic gneiss in the Monte Rosa nappe, northern Italy reveal key differences in their evolution controlled by evolving permeability and water/rock reactions. The comparison reveals that identical host rock lithologies develop radically different mineralogies within the fault zones, resulting in fundamentally different deformation histories. Oxygen and hydrogen isotope analyses coupled to microstructural characterisation show that infiltration of meteoric water occurred into both fault zones. The smaller Virgin Fault shows evidence of periodic closed system behaviour, which promoted the growth of hydrothermal K-feldspar, whilst the more open system behaviour of the adjacent Ciao Ciao Fault generated a weaker muscovite-rich fault core, which promoted a step change in fault evolution. Effective crustal permeability is a vital control on fault evolution and, coupled to the temperature (i.e. depth) at which key mineral transformations occur, is probably a more significant factor than host rock strength in controlling fault development. The study suggests that whether a fault in granitic basement grows into a large structure may be largely controlled by the initial hydrological properties of the host rocks. Small faults exposed at the surface may therefore be evolutionary "dead-ends" that typically do not represent the early stages in the development of larger faults.

  6. Integrated design of fault reconstruction and fault-tolerant control against actuator faults using learning observers

    Science.gov (United States)

    Jia, Qingxian; Chen, Wen; Zhang, Yingchun; Li, Huayi

    2016-12-01

    This paper addresses the problem of integrated fault reconstruction and fault-tolerant control in linear systems subject to actuator faults via learning observers (LOs). A reconfigurable fault-tolerant controller is designed based on the constructed LO to compensate for the influence of actuator faults by stabilising the closed-loop system. An integrated design of the proposed LO and the fault-tolerant controller is explored such that their performance can be simultaneously considered and their coupling problem can be effectively solved. In addition, such an integrated design is formulated in terms of linear matrix inequalities (LMIs) that can be conveniently solved in a unified framework using LMI optimisation technique. At last, simulation studies on a micro-satellite attitude control system are provided to verify the effectiveness of the proposed approach.

  7. Fault Diagnosis and Fault Handling for Autonomous Aircraft

    DEFF Research Database (Denmark)

    Hansen, Søren

    Unmanned Aerial vehicles (UAVs) or drones are used increasingly for missions where piloted aircraft are unsuitable. The unmanned aircraft has a number of advantages with respect to size, weight and manoeuvrability that makes it possible for them to solve tasks that an aircraft previously has been...... that the fault is discovered in time such that appropriate actions can be taken. That could either be the aircraft controlling computer taking the fault into account or a human operator that intervenes. Detection of faults that occur during flight is exactly the subject of this thesis. Safety towards faults...... to another type of aircraft with different parameters. Amongst the main findings of this research project is a method to handle faults on the UAV’s pitot tube, which measures the aircraft speed. A set of software redundancies based on GPS velocity information and engine thrust are used to detect abnormal...

  8. Study on Fault Current of DFIG during Slight Fault Condition

    Directory of Open Access Journals (Sweden)

    Xiangping Kong

    2013-04-01

    Full Text Available In order to ensure the safety of DFIG when severe fault happens, crowbar protection is adopted. But during slight fault condition, the crowbar protection will not trip, and the DFIG is still excited by AC-DC-AC converter. In this condition, operation characteristics of the converter have large influence on the fault current characteristics of DFIG. By theoretical analysis and digital simulation, the fault current characteristics of DFIG during slight voltage dips are studied. And the influence of controller parameters of converter on the fault current characteristics is analyzed emphatically. It builds a basis for the construction of relay protection which is suitable for the power gird with accession of DFIG.

  9. Homogeneous Earthquake Faulting, Stress and Fault Strength on Kilometer Scales

    Science.gov (United States)

    Hardebeck, J. L.

    2006-12-01

    I investigate small-scale fault structure using three new high-quality focal mechanism datasets of small (MLoma Prieta earthquake. I quantify the degree of mechanism variability on a range of length scales, by comparing the hypocentral distance between every pair of events and the angular difference between their focal mechanisms. I explore the implications of focal mechanism variability for the heterogeneity or homogeneity of stress and fault strength on various length scales. Focal mechanisms are very similar, often identical to within the 1σ uncertainty of ~25°, on small length scales of effect of uncertainty in earthquake locations and focal mechanisms on the apparent mechanism variability. The result that fault geometry, stress and fault strength are generally homogeneous on ~10 km length scales is encouraging for understanding earthquake physics. It may be possible to measure these parameters with enough precision to be useful in studying and modeling large earthquakes and the behavior of major faults.

  10. Fault Management Design Strategies

    Science.gov (United States)

    Day, John C.; Johnson, Stephen B.

    2014-01-01

    Development of dependable systems relies on the ability of the system to determine and respond to off-nominal system behavior. Specification and development of these fault management capabilities must be done in a structured and principled manner to improve our understanding of these systems, and to make significant gains in dependability (safety, reliability and availability). Prior work has described a fundamental taxonomy and theory of System Health Management (SHM), and of its operational subset, Fault Management (FM). This conceptual foundation provides a basis to develop framework to design and implement FM design strategies that protect mission objectives and account for system design limitations. Selection of an SHM strategy has implications for the functions required to perform the strategy, and it places constraints on the set of possible design solutions. The framework developed in this paper provides a rigorous and principled approach to classifying SHM strategies, as well as methods for determination and implementation of SHM strategies. An illustrative example is used to describe the application of the framework and the resulting benefits to system and FM design and dependability.

  11. Fault Management Design Strategies

    Science.gov (United States)

    Day, John C.; Johnson, Stephen B.

    2014-01-01

    Development of dependable systems relies on the ability of the system to determine and respond to off-nominal system behavior. Specification and development of these fault management capabilities must be done in a structured and principled manner to improve our understanding of these systems, and to make significant gains in dependability (safety, reliability and availability). Prior work has described a fundamental taxonomy and theory of System Health Management (SHM), and of its operational subset, Fault Management (FM). This conceptual foundation provides a basis to develop framework to design and implement FM design strategies that protect mission objectives and account for system design limitations. Selection of an SHM strategy has implications for the functions required to perform the strategy, and it places constraints on the set of possible design solutions. The framework developed in this paper provides a rigorous and principled approach to classifying SHM strategies, as well as methods for determination and implementation of SHM strategies. An illustrative example is used to describe the application of the framework and the resulting benefits to system and FM design and dependability.

  12. Similarity measure application to fault detection of flight system

    Institute of Scientific and Technical Information of China (English)

    KIM J H; LEE S H; WANG Hong-mei

    2009-01-01

    Fault detection technique is introduced with similarity measure. The characteristics of conventional similarity measure based on fuzzy number are discussed. With the help of distance measure, similarity measure is constructed explicitly. The designed distance-based similarity measure is applicable to general fuzzy membership functions including non-convex fuzzy membership function, whereas fuzzy number-based similarity measure has limitation to calculate the similarity of general fuzzy membership functions. The applicability of the proposed similarity measure to general fuzzy membership structures is proven by identifying the definition. To decide fault detection of flight system, the experimental data (pitching moment coefficients and lift coefficients) are transformed into fuzzy membership functions. Distance-based similarity measure is applied to the obtained fuzzy membership functions, and similarity computation and analysis are obtained with the fault and normal operation coefficients.

  13. Accelerometer having integral fault null

    Science.gov (United States)

    Bozeman, Richard J., Jr. (Inventor)

    1995-01-01

    An improved accelerometer is introduced. It comprises a transducer responsive to vibration in machinery which produces an electrical signal related to the magnitude and frequency of the vibration; and a decoding circuit responsive to the transducer signal which produces a first fault signal to produce a second fault signal in which ground shift effects are nullified.

  14. Hard Fault Analysis of Trivium

    CERN Document Server

    Yupu, Hu; Yiwei, Zhang

    2009-01-01

    Fault analysis is a powerful attack to stream ciphers. Up to now, the major idea of fault analysis is to simplify the cipher system by injecting some soft faults. We call it soft fault analysis. As a hardware-oriented stream cipher, Trivium is weak under soft fault analysis. In this paper we consider another type of fault analysis of stream cipher, which is to simplify the cipher system by injecting some hard faults. We call it hard fault analysis. We present the following results about such attack to Trivium. In Case 1 with the probability not smaller than 0.2396, the attacker can obtain 69 bits of 80-bits-key. In Case 2 with the probability not smaller than 0.2291, the attacker can obtain all of 80-bits-key. In Case 3 with the probability not smaller than 0.2291, the attacker can partially solve the key. In Case 4 with non-neglectable probability, the attacker can obtain a simplified cipher, with smaller number of state bits and slower non-linearization procedure. In Case 5 with non-neglectable probability,...

  15. Multifractal entropy based adaptive multiwavelet construction and its application for mechanical compound-fault diagnosis

    Science.gov (United States)

    He, Shuilong; Chen, Jinglong; Zhou, Zitong; Zi, Yanyang; Wang, Yanxue; Wang, Xiaodong

    2016-08-01

    Compound-fault diagnosis of mechanical equipment is still challenging at present because of its complexity, multiplicity and non-stationarity. In this work, an adaptive redundant multiwavelet packet (ARMP) method is proposed for the compound-fault diagnosis. Multiwavelet transform has two or more base functions and many excellent properties, making it suitable for detecting all the features of compound-fault simultaneously. However, on the other hand, the fixed basis function used in multiwavelet transform may decrease the accuracy of fault extraction; what's more, the multi-resolution analysis of multiwavelet transform in low frequency band may also leave out the useful features. Thus, the minimum sum of normalized multifractal entropy is adopted as the optimization criteria for the proposed ARMP method, while the relative energy ratio of the characteristic frequency is utilized as an effective way in automatically selecting the sensitive frequency bands. Then, The ARMP technique combined with Hilbert transform demodulation analysis is then applied to detect the compound-fault of bevel gearbox and planetary gearbox. The results verify that the proposed method can effectively identify and detect the compound-fault of mechanical equipment.

  16. Fault Diagnosis of Power Systems Using Intelligent Systems

    Science.gov (United States)

    Momoh, James A.; Oliver, Walter E. , Jr.

    1996-01-01

    The power system operator's need for a reliable power delivery system calls for a real-time or near-real-time Al-based fault diagnosis tool. Such a tool will allow NASA ground controllers to re-establish a normal or near-normal degraded operating state of the EPS (a DC power system) for Space Station Alpha by isolating the faulted branches and loads of the system. And after isolation, re-energizing those branches and loads that have been found not to have any faults in them. A proposed solution involves using the Fault Diagnosis Intelligent System (FDIS) to perform near-real time fault diagnosis of Alpha's EPS by downloading power transient telemetry at fault-time from onboard data loggers. The FDIS uses an ANN clustering algorithm augmented with a wavelet transform feature extractor. This combination enables this system to perform pattern recognition of the power transient signatures to diagnose the fault type and its location down to the orbital replaceable unit. FDIS has been tested using a simulation of the LeRC Testbed Space Station Freedom configuration including the topology from the DDCU's to the electrical loads attached to the TPDU's. FDIS will work in conjunction with the Power Management Load Scheduler to determine what the state of the system was at the time of the fault condition. This information is used to activate the appropriate diagnostic section, and to refine if necessary the solution obtained. In the latter case, if the FDIS reports back that it is equally likely that the faulty device as 'start tracker #1' and 'time generation unit,' then based on a priori knowledge of the system's state, the refined solution would be 'star tracker #1' located in cabinet ITAS2. It is concluded from the present studies that artificial intelligence diagnostic abilities are improved with the addition of the wavelet transform, and that when such a system such as FDIS is coupled to the Power Management Load Scheduler, a faulty device can be located and isolated

  17. Fault tolerant control for switched linear systems

    CERN Document Server

    Du, Dongsheng; Shi, Peng

    2015-01-01

    This book presents up-to-date research and novel methodologies on fault diagnosis and fault tolerant control for switched linear systems. It provides a unified yet neat framework of filtering, fault detection, fault diagnosis and fault tolerant control of switched systems. It can therefore serve as a useful textbook for senior and/or graduate students who are interested in knowing the state-of-the-art of filtering, fault detection, fault diagnosis and fault tolerant control areas, as well as recent advances in switched linear systems.  

  18. Fault isolatability conditions for linear systems

    DEFF Research Database (Denmark)

    Stoustrup, Jakob; Niemann, Henrik

    2006-01-01

    In this paper, we shall show that an unlimited number of additive single faults can be isolated under mild conditions if a general isolation scheme is applied. Multiple faults are also covered. The approach is algebraic and is based on a set representation of faults, where all faults within a set...... the faults have occurred. The last step is a fault isolation (FI) of the faults occurring in a specific fault set, i.e. equivalent with the standard FI step. A simple example demonstrates how to turn the algebraic necessary and sufficient conditions into explicit algorithms for designing filter banks, which...

  19. Fault Current Characteristics of the DFIG under Asymmetrical Fault Conditions

    Directory of Open Access Journals (Sweden)

    Fan Xiao

    2015-09-01

    Full Text Available During non-severe fault conditions, crowbar protection is not activated and the rotor windings of a doubly-fed induction generator (DFIG are excited by the AC/DC/AC converter. Meanwhile, under asymmetrical fault conditions, the electrical variables oscillate at twice the grid frequency in synchronous dq frame. In the engineering practice, notch filters are usually used to extract the positive and negative sequence components. In these cases, the dynamic response of a rotor-side converter (RSC and the notch filters have a large influence on the fault current characteristics of the DFIG. In this paper, the influence of the notch filters on the proportional integral (PI parameters is discussed and the simplified calculation models of the rotor current are established. Then, the dynamic performance of the stator flux linkage under asymmetrical fault conditions is also analyzed. Based on this, the fault characteristics of the stator current under asymmetrical fault conditions are studied and the corresponding analytical expressions of the stator fault current are obtained. Finally, digital simulation results validate the analytical results. The research results are helpful to meet the requirements of a practical short-circuit calculation and the construction of a relaying protection system for the power grid with penetration of DFIGs.

  20. Precambrian crustal evolution and Cretaceous–Palaeogene faulting in West Greenland: Faults and fractures in central West Greenland: onshore expression of continental break-up and sea-floor spreading in the Labrador – Baffin Bay Sea

    Directory of Open Access Journals (Sweden)

    Chalmers, James A.

    2006-12-01

    Full Text Available The complex Ungava fault zone lies in the Davis Strait and separates failed spreading centres in the Labrador Sea and Baffin Bay. This study focuses on coastal exposures east of the fault-bound Sisimiut basin, where the onshore expressions of these fault systems and the influence of pre-existing basement are examined. Regional lineament studies identify five main systems: N–S, NNE–SSW, ENE–WSW, ESE–WNW and NNW–SSE. Field studies reveal that strike-slip movements predominate, and are consistent with a ~NNE–SSW-oriented sinistral wrench system. Extensional faults trending N–S and ENE–WSW (basement-parallel, and compressional faults trending E–W, were also identified. The relative ages of these fault systems have been interpreted using cross-cutting relationships and by correlation with previously identified structures. A two-phase model for fault development fits the development of both the onshore fault systems observed in this study and regional tectonic structures offshore. The conclusions from this study show that the fault patterns and sense of movement on faults onshore reflect the stress fields that govern the opening of the Labrador Sea – Davis Strait – Baffin Bay seaway, and that the wrench couple on the Ungava transform system played a dominant role in the development of the onshore fault patterns

  1. Node Grouping in System-Level Fault Diagnosis

    Institute of Scientific and Technical Information of China (English)

    ZHANG Dafang; XIE Gaogang; MIN Yinghua

    2001-01-01

    With the popularization of network applications and multiprocessor systems,dependability of systems has drawn considerable attention. This paper presents a new technique of node grouping for system-level fault diagnosis to simplify the complexity of large system diagnosis. The technique transforms a complicated system to a group network, where each group may consist of many nodes that are either fault-free or faulty. It is proven that the transformation leads to a unique group network to ease system diagnosis. Then it studies systematically one-step t-faults diagnosis problem based on node grouping by means of the concept of independent point sets and gives a simple sufficient and necessary condition. The paper presents a diagnosis procedure for t-diagnosable systems. Furthermore, an efficient probabilistic diagnosis algorithm for practical applications is proposed based on the belief that most of the nodes in a system are fault-free. The result of software simulation shows that the probabilistic diagnosis provides high probability of correct diagnosis and low diagnosis cost, and is suitable for systems of any kind of topology.

  2. Absolute age determination of quaternary faults

    Energy Technology Data Exchange (ETDEWEB)

    Cheong, Chang Sik; Lee, Seok Hoon; Choi, Man Sik [Korea Basic Science Institute, Seoul (Korea, Republic of)] (and others)

    2000-03-15

    To constrain the age of neotectonic fault movement, Rb-Sr, K-Ar, U-series disequilibrium, C-14 and Be-10 methods were applied to the fault gouges, fracture infillings and sediments from the Malbang, Ipsil, Wonwonsa faults faults in the Ulsan fault zone, Yangsan fault in the Yeongdeog area and southeastern coastal area. Rb-Sr and K-Ar data imply that the fault movement of the Ulan fault zone initiated at around 30 Ma and preliminary dating result for the Yang san fault is around 70 Ma in the Yeongdeog area. K-Ar and U-series disequilibrium dating results for fracture infillings in the Ipsil fault are consistent with reported ESR ages. Radiocarbon ages of quaternary sediments from the Jeongjari area are discordant with stratigraphic sequence. Carbon isotope data indicate a difference of sedimentry environment for those samples. Be-10 dating results for the Suryum fault area are consistent with reported OSL results.

  3. Multi fault detection of the roller bearing using the wavelet transformand principal component analysis

    Directory of Open Access Journals (Sweden)

    Jaafar Khalaf Ali, Qusai Talib Abdulwahab, Sajjad Nayyef Abdul kareem

    2016-01-01

    Full Text Available Vibration monitoring and analysis techniques are the key features of successful predictive and proactive maintenance programs. In this work, advanced vibration analysis techniques like Wavelet transform, Principle Component Analysis (PCA and Squared Prediction Error (SPE have been used to detect the faults in bearing. Discrete Wavelet Transforms (DWT decomposes signal to high and low frequencies. PCA is employed to extract important feature and reduce dimension. SPE is used to detect the bearing faults. The experimental data is collected from SpectraQuest's Machine Fault Simulator (MFS-4 apparatus. In this study, four rollers were bearing defects (ball defect, outer race defect, inner race defect and combined defect for 1" and 3/4" bearing. From the results, the suggestion techniques can be used to detect multi-faults in the bearings. The results show that the best wavelet function is Coiflets4 in this method.

  4. Soft computing applications in high impedance fault detection in distribution systems

    Energy Technology Data Exchange (ETDEWEB)

    Sedighi, A.-R.; Haghifam, M.-R. [Department of Electrical Engineering, Tarbiat Modarres University, P.O. Box 14115-111, Tehran (Iran); Malik, O.P. [Department of Electrical and Computer Engineering, University of Calgary, Calgary, Alberta (Canada T2N 1N4)

    2005-09-15

    Two methods, one based on genetic algorithm (GA) and one based on neural networks (NN), are proposed for high impedance fault (HIF) detection in distribution systems. These methods are used to discriminate HIFs from isolator leakage current (ILC) and transients such as capacitor switching, load switching (high/low voltage), ground fault, inrush current and no load line switching. Wavelet transform is used for the decomposition of signals and feature extraction in both methods. In one method, GA is used for feature vector reduction and Bayes for classification. In the other method, principal component analysis (PCA) is applied for feature vector reduction and NN for classification. HIF and ILC data was acquired by experimental tests and the data for other faults was obtained by simulating a real network using EMTP. Results show that either of the proposed procedures can be used to identify HIF from other events efficiently. (author) [Bayes classifier; High impedance fault; Genetic algorithm; Neural network; Principal component analysis; Wavelet transform].

  5. Weak Fault Feature Extraction of Rolling Bearings Based on an Improved Kurtogram.

    Science.gov (United States)

    Chen, Xianglong; Feng, Fuzhou; Zhang, Bingzhi

    2016-09-13

    Kurtograms have been verified to be an efficient tool in bearing fault detection and diagnosis because of their superiority in extracting transient features. However, the short-time Fourier Transform is insufficient in time-frequency analysis and kurtosis is deficient in detecting cyclic transients. Those factors weaken the performance of the original kurtogram in extracting weak fault features. Correlated Kurtosis (CK) is then designed, as a more effective solution, in detecting cyclic transients. Redundant Second Generation Wavelet Packet Transform (RSGWPT) is deemed to be effective in capturing more detailed local time-frequency description of the signal, and restricting the frequency aliasing components of the analysis results. The authors in this manuscript, combining the CK with the RSGWPT, propose an improved kurtogram to extract weak fault features from bearing vibration signals. The analysis of simulation signals and real application cases demonstrate that the proposed method is relatively more accurate and effective in extracting weak fault features.

  6. Weak Fault Feature Extraction of Rolling Bearings Based on an Improved Kurtogram

    Directory of Open Access Journals (Sweden)

    Xianglong Chen

    2016-09-01

    Full Text Available Kurtograms have been verified to be an efficient tool in bearing fault detection and diagnosis because of their superiority in extracting transient features. However, the short-time Fourier Transform is insufficient in time-frequency analysis and kurtosis is deficient in detecting cyclic transients. Those factors weaken the performance of the original kurtogram in extracting weak fault features. Correlated Kurtosis (CK is then designed, as a more effective solution, in detecting cyclic transients. Redundant Second Generation Wavelet Packet Transform (RSGWPT is deemed to be effective in capturing more detailed local time-frequency description of the signal, and restricting the frequency aliasing components of the analysis results. The authors in this manuscript, combining the CK with the RSGWPT, propose an improved kurtogram to extract weak fault features from bearing vibration signals. The analysis of simulation signals and real application cases demonstrate that the proposed method is relatively more accurate and effective in extracting weak fault features.

  7. Based on the Wavelet Function of Power Network Fault Location

    Directory of Open Access Journals (Sweden)

    Fan YU

    2013-04-01

    Full Text Available In order to improve the measurement accuracy, in the traditional measuring method based on, by avoiding wave speed influence on fault location of transmission line method, and compares it with the combination of wavelet transform. This article selects dBN wavelet and three B spline wavelet contrast, compared them with new methods, through the Xi'an City Power Supply Bureau of the actual fault data validation. The results show that, with3 B spline wavelet and the new method combined with the location results are closer to the actual distance, its accuracy is higher than that of db3wavelet transform and a new method derived from the results, the error is far less than the db3 wavelet function, location is satisfactory.

  8. The Rolling Bearing Fault Feature Extraction Based on the LMD and Envelope Demodulation

    Directory of Open Access Journals (Sweden)

    Jun Ma

    2015-01-01

    Full Text Available Since the working process of rolling bearings is a complex and nonstationary dynamic process, the common time and frequency characteristics of vibration signals are submerged in the noise. Thus, it is the key of fault diagnosis to extract the fault feature from vibration signal. Therefore, a fault feature extraction method for the rolling bearing based on the local mean decomposition (LMD and envelope demodulation is proposed. Firstly, decompose the original vibration signal by LMD to get a series of production functions (PFs. Then dispose the envelope demodulation analysis on PF component. Finally, perform Fourier Transform on the demodulation signals and judge failure condition according to the dominant frequency of the spectrum. The results show that the proposed method can correctly extract the fault characteristics to diagnose faults.

  9. Bearing fault detection based on hybrid ensemble detector and empirical mode decomposition

    Science.gov (United States)

    Georgoulas, George; Loutas, Theodore; Stylios, Chrysostomos D.; Kostopoulos, Vassilis

    2013-12-01

    Aiming at more efficient fault diagnosis, this research work presents an integrated anomaly detection approach for seeded bearing faults. Vibration signals from normal bearings and bearings with three different fault locations, as well as different fault sizes and loading conditions are examined. The Empirical Mode Decomposition and the Hilbert Huang transform are employed for the extraction of a compact feature set. Then, a hybrid ensemble detector is trained using data coming only from the normal bearings and it is successfully applied for the detection of any deviation from the normal condition. The results prove the potential use of the proposed scheme as a first stage of an alarm signalling system for the detection of bearing faults irrespective of their loading condition.

  10. Application of fractal theory in detecting low current faults of power distribution system in coal mines

    Institute of Scientific and Technical Information of China (English)

    LIU Jian-hua; LIANG Rui; WANG Chong-lin; FAN Di-peng

    2009-01-01

    Single-phase low current grounding faults areoften seen in power distribution system of coal mines. These faults are difficult to reliably identify. We propose a new method of single-phase ground fault protection based upon a discernible matrix of the fractal dimension associated with line currents. The method builds on existing selective protection methods. Faulted feeders are distinguished using differences in the zero-sequence transient current fractal dimension. The current signals were first processed through a fast Fourier transform and then the characteristics of a faulted line were identified using a discernible matrix. The method of calculation is illustrated. The results show that the method involves simple calculations, is easy to do and is highly accurate. It is, therefore, suitable for distribution networks having different neutral grounding modes.

  11. A Novel Approach for Eccentricity Fault Detection in Squirrel Cage Induction Motors

    Directory of Open Access Journals (Sweden)

    Mehdi Ahmadi

    2013-01-01

    Full Text Available In this paper, static eccentricity fault detection in induction motors is studied. Two dimensional finite element method (2D-FEM is used for faultless and eccentric condition modeling in induction motors. Also current and speed signals are compared in two experimental and simulation cases for model validating. For fault detection, fast Fourier transform is used at first. In this method, high order harmonics with small amplitude can alarms the fault occurrence. For this reason, the fault detection process is difficult.To overcome these drawbacks, it is suggested that two test coils contrive around the air-gap. So, any changes in air-gap can be detected easily. Moreover this test coils are used in open circuit case. So, these test coils do not effect on motor dynamics. Also, the results show that modulated voltage can be alarm the fault occurrence, type and percent well.

  12. Design of parametric fault detection systems:An H-infinity optimization approach

    Institute of Scientific and Technical Information of China (English)

    Maiying ZHONG; Chuanfeng MA; Steven X.DING

    2005-01-01

    Problems related to the design of observer-based parametric fault detection (PFD) systems are studied.The core of our study is to first describe the faults occurring in system actuators,sensors and components in the form of additive parameter deviations,then to transform the PFD problems into a similar additive fault setup,based on which an optimal observer-based optimization fault detection approach is proposed.A constructive solution optimal in the sense of minimizing a certain performance index is developed.The main results consist of defining parametric fault detectability,formulating a PFD optimization problem and its solution.A numerical example to demonstrate the effectiveness of the proposed approach is provided.

  13. Analysis of experimental result and fault diagnosis for aeroengine rotating shaft

    Science.gov (United States)

    Zhao, Baoqun; Wang, Yuanyang

    2008-10-01

    To increase the accuracy of applying traditional fault diagnosis method to aeroengine vibrant faults, a novel approach based on wavelet neural network is proposed. The effective signal features are acquired by wavelet transform with multi-resolution analysis. These feature vectors then are applied to the neural network for training and testing. The synthesized method of recursive orthogonal least squares algorithm is used to fulfill the network structure and parameter initialization. By means of choosing enough practical samples to verify the proposed network performance, the information representing the faults is inputted into the trained network. According to the output result the fault pattern can be determined. The simulation results and actual applications show that the method can effectively diagnose and analyze the vibrant fault patterns of aeroengine and the diagnosis result is correct.

  14. Improved transformer protection using probabilistic neural network ...

    African Journals Online (AJOL)

    user

    This article presents a novel technique to distinguish between magnetizing inrush current ... the advanced Digital Signal Processing (DSP) techniques and Artificial Intelligence (AI) ... left some unsolved problems, including those of local minima and slow ...... A solution to the dilemma inrush/fault in transformer differential.

  15. A fuzzy-based approach for open-transistor fault diagnosis in voltage-source inverter induction motor drives

    Science.gov (United States)

    Zhang, Jianghan; Luo, Hui; Zhao, Jin; Wu, Feng

    2015-02-01

    This paper develops a novel method for the detection and isolation of open-transistor faults in voltage-source inverters feeding induction motors. Based on analyzing the load currents trajectories after Concordia transformation, six diagnostic signals each of which indicates a certain switch are extracted and a fuzzy rule base is designed to perform fuzzy reasoning in order to detect and isolate 21 fault modes including single- and double-transistor faults. In addition, the fuzzy rules are rearranged and each of them is set to a reasonable value representing the fault modes. The simulation and experiment are carried out to demonstrate the effectiveness of the proposed fuzzy approach.

  16. Deep Fault Drilling Project—Alpine Fault, New Zealand

    Directory of Open Access Journals (Sweden)

    Rupert Sutherland

    2009-09-01

    Full Text Available The Alpine Fault, South Island, New Zealand, constitutes a globally significant natural laboratory for research into how active plate-bounding continental faults work and, in particular, how rocks exposed at the surface today relate to deep-seated processes of tectonic deformation, seismogenesis, and mineralization. The along-strike homogeneity of the hanging wall, rapid rate of dextral-reverse slip on an inclined fault plane, and relatively shallow depths to mechanical and chemical transitions make the Alpine Fault and the broader South Island plate boundary an important international site for multi-disciplinary research and a realistic target for an ambitious long-term program of scientific drilling investigations.

  17. Reduction of Faults in Software Testing by Fault Domination"

    Institute of Scientific and Technical Information of China (English)

    XU Shiyi

    2007-01-01

    Although mutation testing is one of the practical ways of enhancing test effectiveness in software testing, it could be sometimes infeasible in practical work for a large scale software so that the mutation testing becomes time-consuming and even in prohibited time. Therefore, the number of faults assumed to exist in the software under test should be reduced so as to be able to confine the time complexity of test within a reasonable period of time. This paper utilizes the concept of fault dominance and equivalence, which has long been employed in hardware testing, for revealing a novel way of reducing the number of faults assumed to hide in software systems. Once the number of faults assumed in software is decreased sharply, the effectiveness of mutation testing will be greatly enhanced and become a feasible way of software testing. Examples and experimental results are presented to illustrate the effectiveness and the helpfulness of the technology proposed in the paper.

  18. Uniform analysis of fault trees through model transformations

    NARCIS (Netherlands)

    Ruijters, Enno Jozef Johannes; Schivo, Stefano; Stoelinga, Mariëlle Ida Antoinette; Rensink, Arend

    2017-01-01

    As the critical systems we rely on every day, such as nuclear power plants and airplanes, become ever more complex, the need to rigorously verify the safety and dependability of these systems is becoming very clear. Furthermore, deliberate attacks have become a prominent cause of concern for safety

  19. Influence of Superconductor Fault Current Limiter on Transformers Lifetime

    Directory of Open Access Journals (Sweden)

    2012-07-01

    Full Text Available In this article the impact of the superconducting current limiter and reducing the incidenceof stress single phase short circuit has been analyzed with this method and conventionalmethod of current limiting resistance has been compared. For this purpose a saturated corehigh temperature superconducting current limiter model considered and its effects on networkperformance in different modes has been studied. PSCAD software for simulating thenetwork is used.

  20. Online fault location on AC cables in underground transmission systems using screen currents

    DEFF Research Database (Denmark)

    Jensen, Christian Flytkjær; Nanayakkara, O.M.K.K; Rajapakse, Athula

    This paper studies online travelling wave methods for fault location on a crossbonded cable system using screen currents. During the construction of the electrical connection to the 400 MW off shore wind farm Anholt, it was possible to perform measurements on a 38.4 km crossbonded cable system...... coils if the screen currents contain the necessary information for accurate fault location. In this paper, this is examined by analysis of field measurements and through a study of simulations. The wavelet transform and visual inspection methods are used and the accuracy is compared. Field measurements...... and simulations are compared for testing the reliability of using simulations for studying fault location methods....

  1. Expert System Detects Power-Distribution Faults

    Science.gov (United States)

    Walters, Jerry L.; Quinn, Todd M.

    1994-01-01

    Autonomous Power Expert (APEX) computer program is prototype expert-system program detecting faults in electrical-power-distribution system. Assists human operators in diagnosing faults and deciding what adjustments or repairs needed for immediate recovery from faults or for maintenance to correct initially nonthreatening conditions that could develop into faults. Written in Lisp.

  2. Fault Detection for Diesel Engine Actuator

    DEFF Research Database (Denmark)

    Blanke, M.; Bøgh, S.A.; Jørgensen, R.B.

    1994-01-01

    Feedback control systems are vulnerable to faults in control loop sensors and actuators, because feedback actions may cause abrupt responses and process damage when faults occur.......Feedback control systems are vulnerable to faults in control loop sensors and actuators, because feedback actions may cause abrupt responses and process damage when faults occur....

  3. Active fault diagnosis by temporary destabilization

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik; Stoustrup, Jakob

    2006-01-01

    An active fault diagnosis method for parametric or multiplicative faults is proposed. The method periodically adds a term to the controller that for a short period of time renders the system unstable if a fault has occurred, which facilitates rapid fault detection. An illustrative example is given....

  4. From fault classification to fault tolerance for multi-agent systems

    CERN Document Server

    Potiron, Katia; Taillibert, Patrick

    2013-01-01

    Faults are a concern for Multi-Agent Systems (MAS) designers, especially if the MAS are built for industrial or military use because there must be some guarantee of dependability. Some fault classification exists for classical systems, and is used to define faults. When dependability is at stake, such fault classification may be used from the beginning of the system's conception to define fault classes and specify which types of faults are expected. Thus, one may want to use fault classification for MAS; however, From Fault Classification to Fault Tolerance for Multi-Agent Systems argues that

  5. Wavelet Entropy-Based Traction Inverter Open Switch Fault Diagnosis in High-Speed Railways

    Directory of Open Access Journals (Sweden)

    Keting Hu

    2016-03-01

    Full Text Available In this paper, a diagnosis plan is proposed to settle the detection and isolation problem of open switch faults in high-speed railway traction system traction inverters. Five entropy forms are discussed and compared with the traditional fault detection methods, namely, discrete wavelet transform and discrete wavelet packet transform. The traditional fault detection methods cannot efficiently detect the open switch faults in traction inverters because of the low resolution or the sudden change of the current. The performances of Wavelet Packet Energy Shannon Entropy (WPESE, Wavelet Packet Energy Tsallis Entropy (WPETE with different non-extensive parameters, Wavelet Packet Energy Shannon Entropy with a specific sub-band (WPESE3,6, Empirical Mode Decomposition Shannon Entropy (EMDESE, and Empirical Mode Decomposition Tsallis Entropy (EMDETE with non-extensive parameters in detecting the open switch fault are evaluated by the evaluation parameter. Comparison experiments are carried out to select the best entropy form for the traction inverter open switch fault detection. In addition, the DC component is adopted to isolate the failure Isolated Gate Bipolar Transistor (IGBT. The simulation experiments show that the proposed plan can diagnose single and simultaneous open switch faults correctly and timely.

  6. Comparison of Dissolved Gases in Mineral and Vegetable Insulating Oils under Typical Electrical and Thermal Faults

    Directory of Open Access Journals (Sweden)

    Chenmeng Xiang

    2016-04-01

    Full Text Available Dissolved gas analysis (DGA is attracting greater and greater interest from researchers as a fault diagnostic tool for power transformers filled with vegetable insulating oils. This paper presents experimental results of dissolved gases in insulating oils under typical electrical and thermal faults in transformers. The tests covered three types of insulating oils, including two types of vegetable oil, which are camellia insulating oil, Envirotemp FR3, and a type of mineral insulating oil, to simulate thermal faults in oils from 90 °C to 800 °C and electrical faults including breakdown and partial discharges in oils. The experimental results reveal that the content and proportion of dissolved gases in different types of insulating oils under the same fault condition are different, especially under thermal faults due to the obvious differences of their chemical compositions. Four different classic diagnosis methods were applied: ratio method, graphic method, and Duval’s triangle and Duval’s pentagon method. These confirmed that the diagnosis methods developed for mineral oil were not fully appropriate for diagnosis of electrical and thermal faults in vegetable insulating oils and needs some modification. Therefore, some modification aiming at different types of vegetable oils based on Duval Triangle 3 were proposed in this paper and obtained a good diagnostic result. Furthermore, gas formation mechanisms of different types of vegetable insulating oils under thermal stress are interpreted by means of unimolecular pyrolysis simulation and reaction enthalpies calculation.

  7. Ductilizing Bulk Metallic Glass Composite by Tailoring Stacking Fault Energy

    Science.gov (United States)

    Wu, Y.; Zhou, D. Q.; Song, W. L.; Wang, H.; Zhang, Z. Y.; Ma, D.; Wang, X. L.; Lu, Z. P.

    2012-12-01

    Martensitic transformation was successfully introduced to bulk metallic glasses as the reinforcement micromechanism. In this Letter, it was found that the twinning property of the reinforcing crystals can be dramatically improved by reducing the stacking fault energy through microalloying, which effectively alters the electron charge density redistribution on the slipping plane. The enhanced twinning propensity promotes the martensitic transformation of the reinforcing austenite and, consequently, improves plastic stability and the macroscopic tensile ductility. In addition, a general rule to identify effective microalloying elements based on their electronegativity and atomic size was proposed.

  8. Influence of Ordovician carbonate reservoir beds in Tarim Basin by faulting

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The quality of the Ordovician carbonate reservoir beds in the Tarim Basin is closely related to the development of secondary pores,fractures and cavities. Karstification is important in improving the properties of reservoir beds,and karstification related to unconformity has caught wide attention. Compared with the recent research on the unconformity karst reservoir bed improvement,this paper shows a new way of carbonate reservoir bed transformation. Based on field survey,core and slices observation,transformation of Ordovician carbonate reservoir beds by faulting can be classified into three types: (1) Secondary faults and fracturs generated by faulting improved carbonate reservoir bed properties,which were named the Lunnan or Tazhong82 model; (2) upflow of deep geothermal fluids caused by faulting,with some components metasomatizing with carbonate and forming some secon-dary deposit,such as fluorite. It can improve carbonate reservoir bed properties obviously and is named the Tazhong 82 model; and (3) the faulting extending up to the surface increased the depth of supergene karstification and the thickness of reservoir bed. It is named the Hetianhe model. Trans-formation effect of carbonate reservoir beds by faulting was very significant,mainly distributed on the slopes or on the edge or plunging end of the uplift.

  9. The fault-tree compiler

    Science.gov (United States)

    Martensen, Anna L.; Butler, Ricky W.

    1987-01-01

    The Fault Tree Compiler Program is a new reliability tool used to predict the top event probability for a fault tree. Five different gate types are allowed in the fault tree: AND, OR, EXCLUSIVE OR, INVERT, and M OF N gates. The high level input language is easy to understand and use when describing the system tree. In addition, the use of the hierarchical fault tree capability can simplify the tree description and decrease program execution time. The current solution technique provides an answer precise (within the limits of double precision floating point arithmetic) to the five digits in the answer. The user may vary one failure rate or failure probability over a range of values and plot the results for sensitivity analyses. The solution technique is implemented in FORTRAN; the remaining program code is implemented in Pascal. The program is written to run on a Digital Corporation VAX with the VMS operation system.

  10. Cell boundary fault detection system

    Science.gov (United States)

    Archer, Charles Jens; Pinnow, Kurt Walter; Ratterman, Joseph D.; Smith, Brian Edward

    2009-05-05

    A method determines a nodal fault along the boundary, or face, of a computing cell. Nodes on adjacent cell boundaries communicate with each other, and the communications are analyzed to determine if a node or connection is faulty.

  11. Fault Tolerant External Memory Algorithms

    DEFF Research Database (Denmark)

    Jørgensen, Allan Grønlund; Brodal, Gerth Stølting; Mølhave, Thomas

    2009-01-01

    Algorithms dealing with massive data sets are usually designed for I/O-efficiency, often captured by the I/O model by Aggarwal and Vitter. Another aspect of dealing with massive data is how to deal with memory faults, e.g. captured by the adversary based faulty memory RAM by Finocchi and Italiano....... However, current fault tolerant algorithms do not scale beyond the internal memory. In this paper we investigate for the first time the connection between I/O-efficiency in the I/O model and fault tolerance in the faulty memory RAM, and we assume that both memory and disk are unreliable. We show a lower...... bound on the number of I/Os required for any deterministic dictionary that is resilient to memory faults. We design a static and a dynamic deterministic dictionary with optimal query performance as well as an optimal sorting algorithm and an optimal priority queue. Finally, we consider scenarios where...

  12. Diagnosis and fault-tolerant control

    CERN Document Server

    Blanke, Mogens; Lunze, Jan; Staroswiecki, Marcel

    2016-01-01

    Fault-tolerant control aims at a gradual shutdown response in automated systems when faults occur. It satisfies the industrial demand for enhanced availability and safety, in contrast to traditional reactions to faults, which bring about sudden shutdowns and loss of availability. The book presents effective model-based analysis and design methods for fault diagnosis and fault-tolerant control. Architectural and structural models are used to analyse the propagation of the fault through the process, to test the fault detectability and to find the redundancies in the process that can be used to ensure fault tolerance. It also introduces design methods suitable for diagnostic systems and fault-tolerant controllers for continuous processes that are described by analytical models of discrete-event systems represented by automata. The book is suitable for engineering students, engineers in industry and researchers who wish to get an overview of the variety of approaches to process diagnosis and fault-tolerant contro...

  13. An architecture for fault tolerant controllers

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik; Stoustrup, Jakob

    2005-01-01

    degradation in the sense of guaranteed degraded performance. A number of fault diagnosis problems, fault tolerant control problems, and feedback control with fault rejection problems are formulated/considered, mainly from a fault modeling point of view. The method is illustrated on a servo example including......A general architecture for fault tolerant control is proposed. The architecture is based on the (primary) YJBK parameterization of all stabilizing compensators and uses the dual YJBK parameterization to quantify the performance of the fault tolerant system. The approach suggested can be applied...... for additive faults, parametric faults, and for system structural changes. The modeling for each of these fault classes is described. The method allows to design for passive as well as for active fault handling. Also, the related design method can be fitted either to guarantee stability or to achieve graceful...

  14. Static Decoupling in fault detection

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik

    1998-01-01

    An algebraic approach is given for a design of a static residual weighting factor in connection with fault detection. A complete parameterization is given of the weighting factor which will minimize a given performance index......An algebraic approach is given for a design of a static residual weighting factor in connection with fault detection. A complete parameterization is given of the weighting factor which will minimize a given performance index...

  15. Fault-tolerant rotary actuator

    Science.gov (United States)

    Tesar, Delbert

    2006-10-17

    A fault-tolerant actuator module, in a single containment shell, containing two actuator subsystems that are either asymmetrically or symmetrically laid out is provided. Fault tolerance in the actuators of the present invention is achieved by the employment of dual sets of equal resources. Dual resources are integrated into single modules, with each having the external appearance and functionality of a single set of resources.

  16. Recognition of Active Faults and Stress Field

    Science.gov (United States)

    Azuma, T.

    2012-12-01

    Around the plate-boundary region, the directions of maximum and minimum stress related to the plate motion is one of the key for the recognition of active faults. For example, it is typical idea that there are many N-S trading reverse faults, NE-SW and NW-SE trending strike slip faults and less normal faults (only near volcanoes) in Japan, where the compressional stress with E-W direction is dominant caused by the motion of the subduction of the Pacific Plate beneath the North American Plate. After the 2011 Tohoku earthquake (Mj 9.0), however, many earthquakes with the mechanism of the normal fault type occurred in the coastal region of the northern-east Japan. On 11th April 2011, the Fukushima Hamadori Earthquake (Mj 7.0) occurred accompanying surface faults along two faults, the Idosawa fault and the Yunotake fault, that recognized as active faults by the Research Group for Active Fault of Japan (1980, 1991). It impacted on active fault study by the reason of not only the appearance of two traces of significant surface faults with maximum displacement up to 2.1 m, but also the reactivation of the normal faults under the E-W compressional stress field. When we identify the active faults, it is one of the key whether the direction of slip on the fault consists with the stress field in that area or not. And there is a technique to recognized whether the fault is active or not by using the data of the direction of stress in the field and the geometry of the fault plane. Though it is useful for the fault in the rock without overlain Quaternary deposits, we should care that the active faults may react caused by the temporal stress condition after the generation of large earthquakes.

  17. Normal fault earthquakes or graviquakes

    Science.gov (United States)

    Doglioni, C.; Carminati, E.; Petricca, P.; Riguzzi, F.

    2015-01-01

    Earthquakes are dissipation of energy throughout elastic waves. Canonically is the elastic energy accumulated during the interseismic period. However, in crustal extensional settings, gravity is the main energy source for hangingwall fault collapsing. Gravitational potential is about 100 times larger than the observed magnitude, far more than enough to explain the earthquake. Therefore, normal faults have a different mechanism of energy accumulation and dissipation (graviquakes) with respect to other tectonic settings (strike-slip and contractional), where elastic energy allows motion even against gravity. The bigger the involved volume, the larger is their magnitude. The steeper the normal fault, the larger is the vertical displacement and the larger is the seismic energy released. Normal faults activate preferentially at about 60° but they can be shallower in low friction rocks. In low static friction rocks, the fault may partly creep dissipating gravitational energy without releasing great amount of seismic energy. The maximum volume involved by graviquakes is smaller than the other tectonic settings, being the activated fault at most about three times the hypocentre depth, explaining their higher b-value and the lower magnitude of the largest recorded events. Having different phenomenology, graviquakes show peculiar precursors. PMID:26169163

  18. RECENT GEODYNAMICS OF FAULT ZONES: FAULTING IN REAL TIME SCALE

    Directory of Open Access Journals (Sweden)

    Yu. O. Kuzmin

    2015-09-01

    Full Text Available Recent deformation processes taking place in real time are analyzed on the basis of data on fault zones which were collected by long-term detailed geodetic survey studies with application of field methods and satellite monitoring.A new category of recent crustal movements is described and termed as parametrically induced tectonic strain in fault zones. It is shown that in the fault zones located in seismically active and aseismic regions, super intensive displacements of the crust (5 to 7 cm per year, i.e. (5 to 7·10–5 per year occur due to very small external impacts of natural or technogenic / industrial origin.The spatial discreteness of anomalous deformation processes is established along the strike of the regional Rechitsky fault in the Pripyat basin. It is concluded that recent anomalous activity of the fault zones needs to be taken into account in defining regional regularities of geodynamic processes on the basis of real-time measurements.The paper presents results of analyses of data collected by long-term (20 to 50 years geodetic surveys in highly seismically active regions of Kopetdag, Kamchatka and California. It is evidenced by instrumental geodetic measurements of recent vertical and horizontal displacements in fault zones that deformations are ‘paradoxically’ deviating from the inherited movements of the past geological periods.In terms of the recent geodynamics, the ‘paradoxes’ of high and low strain velocities are related to a reliable empirical fact of the presence of extremely high local velocities of deformations in the fault zones (about 10–5 per year and above, which take place at the background of slow regional deformations which velocities are lower by the order of 2 to 3. Very low average annual velocities of horizontal deformation are recorded in the seismic regions of Kopetdag and Kamchatka and in the San Andreas fault zone; they amount to only 3 to 5 amplitudes of the earth tidal deformations per year.A ‘fault

  19. Mantle phase changes and deep-earthquake faulting in subducting lithosphere.

    Science.gov (United States)

    Kirby, S H; Durham, W B; Stern, L A

    1991-04-12

    Inclined zones of earthquakes are the primary expression of lithosphere subduction. A distinct deep population of subduction-zone earthquakes occurs at depths of 350 to 690 kilometers. At those depths ordinary brittle fracture and frictional sliding, the faulting processes of shallow earthquakes, are not expected. A fresh understanding of these deep earthquakes comes from developments in several areas of experimental and theoretical geophysics, including the discovery and characterization of transformational faulting, a shear instability connected with localized phase transformations under nonhydrostatic stress. These developments support the hypothesis that deep earthquakes represent transformational faulting in a wedge of olivine-rich peridotite that is likely to persist metastably in coldest plate interiors to depths as great as 690 km. Predictions based on this deep structure of mantle phase changes are consistent with the global depth distribution of deep earthquakes, the maximum depths of earthquakes in individual subductions zones, and key source characteristics of deep events.

  20. VIBRATION ANALYSIS FOR DETECTION AND LOCALIZATION THE FAULTS OF ROTATING MACHINERY USING WAVELET TECHINIQUES

    Directory of Open Access Journals (Sweden)

    MIHAIL PRICOP

    2016-06-01

    Full Text Available Vulnerable and critical mechanical systems are bearings and drive belts. Signal analysis of vibration highlights the changes in root mean square, the frequency spectrum (frequencies and amplitudes in the time- frequency (Short Time Fourier Transform and Wavelet Transform, are the most used method for faults diagnosis and location of rotating machinery. This article presents the results of an experimental study applied on a di agnostic platform of rotating machinery through three Wavelet methods: (Discrete Wavelet Transform -DWT, Continuous Wavelet Transform -CWT, Wavelet Packet Transform -WPT with different mother wavelet. Wavelet Transform is used to decompose the original sig nal into sub -frequency band signals in order to obtain multiple data series at different resolutions and to identify faults appearing in the complex rotation systems. This paper investigates the use of different mother wavelet functions for drive belts and bearing fault diagnosis. The results demonstrate the possibility of using different mother wavelets in rotary systems diagnosis detecting and locating in this way the faults in bearings and drive belts.

  1. Map restoration of an early Pliocene horizon along the Hosgri-Purisima-Lompoc fault system, central California margin

    Energy Technology Data Exchange (ETDEWEB)

    Sorlien, C.C.; Kamerling, M.J. (Univ. of California, Santa Barbara, CA (United States)); Mayerson, D. (Minerals Management Service, Camarillo, CA (United States))

    1996-01-01

    The Hosgri fault is the southern part of the San Gregorio-Sur-San Simeon-Hosgri fault system, an important element of the Neogene California transform system. The Hosgri fault proper (top 1-2 km) is located in the hanging-wall of a 10 to 20 km wide zone of mostly E-dipping faults, the Hosgri-Purisima-Lompoc fault system. These faults have undergone Miocene extension, and have been reactivated by post-Miocene contraction or transpression. This wider fault system is truncated against or merges with the E-striking faults in northwestern Santa Barbara Channel. From this starting point of zero displacement, right-lateral displacement on a N- S fault can not be more than the sum of N-S shortening east of it, the N-S extension west of it, and the right-lateral slip fed into it by other faults. We are using a 3-D map restoration technique to quantify the displacements along this fault system. Depth-contoured folded surfaces are flattened using the software UNFOLD, and the restored surfaces are fit back together across faults using an interactive graphic program. Displacements are calculated by comparing the restored surface to the present state with respect to a relatively-fixed block. Our mapping of the early Pliocene top Sisquoc horizon indicates that broad, gentle folds characterize the Point Arguello oil field. Folds located between Point Arguello and Point Sal, are characterized by abrupt changes in amplitude, symmetry, and vergence along strike. The folded surface is unfaulted over wide areas, despite dips up to 45[degrees]. These folds are the result of basin inversion along former rift border faults. Folds are amplified where the basin fill is transpressed against NW-striking restraining bends in a regional NNW-striking system of right-reverse-oblique faults.

  2. Map restoration of an early Pliocene horizon along the Hosgri-Purisima-Lompoc fault system, central California margin

    Energy Technology Data Exchange (ETDEWEB)

    Sorlien, C.C.; Kamerling, M.J. [Univ. of California, Santa Barbara, CA (United States); Mayerson, D. [Minerals Management Service, Camarillo, CA (United States)

    1996-12-31

    The Hosgri fault is the southern part of the San Gregorio-Sur-San Simeon-Hosgri fault system, an important element of the Neogene California transform system. The Hosgri fault proper (top 1-2 km) is located in the hanging-wall of a 10 to 20 km wide zone of mostly E-dipping faults, the Hosgri-Purisima-Lompoc fault system. These faults have undergone Miocene extension, and have been reactivated by post-Miocene contraction or transpression. This wider fault system is truncated against or merges with the E-striking faults in northwestern Santa Barbara Channel. From this starting point of zero displacement, right-lateral displacement on a N- S fault can not be more than the sum of N-S shortening east of it, the N-S extension west of it, and the right-lateral slip fed into it by other faults. We are using a 3-D map restoration technique to quantify the displacements along this fault system. Depth-contoured folded surfaces are flattened using the software UNFOLD, and the restored surfaces are fit back together across faults using an interactive graphic program. Displacements are calculated by comparing the restored surface to the present state with respect to a relatively-fixed block. Our mapping of the early Pliocene top Sisquoc horizon indicates that broad, gentle folds characterize the Point Arguello oil field. Folds located between Point Arguello and Point Sal, are characterized by abrupt changes in amplitude, symmetry, and vergence along strike. The folded surface is unfaulted over wide areas, despite dips up to 45{degrees}. These folds are the result of basin inversion along former rift border faults. Folds are amplified where the basin fill is transpressed against NW-striking restraining bends in a regional NNW-striking system of right-reverse-oblique faults.

  3. A Correlation Based Method for Discriminating Inrush Current from Short Circuit Current Using Wavelet Transform in Power Transformer Differential Protection

    Directory of Open Access Journals (Sweden)

    M. Rasoulpoor

    2013-09-01

    Full Text Available This paper presents a new approach for power transformer differential protection. The Wavelet Transform is applied to discriminate between inrush currents and internal fault currents in power transformers. Discrete wavelet transform decomposes the current signal into sub-bands that give more information about the properties of the signals in different frequency bands. Also, this transform is used to investigate the energy distribution of the signal on the different time and frequency scales. Recognition method is based on the correlation factors between energy percentage vectors of the Wavelet coefficients. Discrete Wavelet transform is used for decomposing the current signals to different frequency coefficients. After that, by constituting the energy percentage vectors of wavelet transform coefficients and calculating the correlation factors between these vectors, it is possible to form a recognition criterion to distinguish between inrush and internal fault current in the proposed method. The proposed algorithm is tested for several conditions by simulated inrush and internal fault currents. Simulation of current signals is performed using electromagnetic transient program PSCAD/EMTDC software that is a powerful program for the investigation of transient signals. Simulation results show that the proposed scheme accurately identifies inrush and fault currents in the distance of the power transformer protection in less than quarter of power frequency cycle. Also, beside the sensitivity and high reliability, the proposed method has low computation content and unlike the common methods does not require to determine the threshold for each new power system.

  4. Fault creep and strain partitioning in Trinidad-Tobago: Geodetic measurements, models, and origin of creep

    Science.gov (United States)

    Geirsson, Halldór; Weber, John; La Femina, Peter; Latchman, Joan L.; Robertson, Richard; Higgins, Machel; Miller, Keith; Churches, Chris; Shaw, Kenton

    2017-04-01

    We studied active faults in Trinidad and Tobago in the Caribbean-South American (CA-SA) transform plate boundary zone using episodic GPS (eGPS) data from 19 sites and continuous GPS (cGPS) data from 8 sites, then modeling these data using a series of simple screw dislocation models. Our best-fit model for interseismic fault slip requires: 12-15 mm/yr of right-lateral movement and very shallow locking (0.2 ± 0.2 km; essentially creep) across the Central Range Fault (CRF); 3.4 +0.3/-0.2 mm/yr across the Soldado Fault in south Trinidad, and 3.5 +0.3/-0.2 mm/yr of dextral shear on fault(s) between Trinidad and Tobago. The upper-crustal faults in Trinidad show very little seismicity (1954-current from local network) and do not appear to have generated significant historic earthquakes. However, paleoseismic studies indicate that the CRF ruptured between 2710 and 500 yr. B.P. and thus it was recently capable of storing elastic strain. Together, these data suggest spatial and/or temporal fault segmentation on the CRF. The CRF marks a physical boundary between rocks associated with thermogenically generated petroleum and overpressured fluids in south and central Trinidad, from rocks containing only biogenic gas to the north, and a long string of active mud volcanoes align with the trace of the Soldado Fault along Trinidad's south coast. Fluid (oil and gas) overpressure may thus cause the CRF fault creep that we observe and the lack of seismicity, as an alternative or addition to weak mineral phases on the fault.

  5. Detection and Quantization of Bearing Fault in Direct Drive Wind Turbine via Comparative Analysis

    Directory of Open Access Journals (Sweden)

    Wei Teng

    2016-01-01

    Full Text Available Bearing fault is usually buried by intensive noise because of the low speed and heavy load in direct drive wind turbine (DDWT. Furthermore, varying wind speed and alternating loads make it difficult to quantize bearing fault feature that indicates the degree of deterioration. This paper presents the application of multiscale enveloping spectrogram (MuSEnS and cepstrum to detect and quantize bearing fault in DDWT. MuSEnS can manifest fault modulation information adaptively based on the capacity of complex wavelet transform, which enables the weak bearing fault in DDWT to be detected. Cepstrum can calculate the average interval of periodic components in frequency domain and is suitable for quantizing bearing fault feature under varying operation conditions due to the logarithm weight on the power spectrum. Through comparing a faulty DDWT with a normal one, the bearing fault feature is evidenced and the quantization index is calculated, which show a good application prospect for condition monitoring and fault diagnosis in real DDWT.

  6. Along-Fault Deformation Partitioning of NW Haiti:Implication on Fluid Transfer

    Science.gov (United States)

    Ellouz, N.; Hamon, Y.; Deschamps, R.; Schmitz, J.; Battani, A.; Leroy, S. D.; Monplaisir, R.; Ruffine, L.

    2014-12-01

    The area of Western Haiti located in between two major fault systems, the Enriquillo-Plantain Garden Fault (EPGF) and Ciabao-Oriente Septentrional fault system has been surveyed during the 2012 and 2013 Haiti-SIS cruises. From seismic interpretation and mapping the two bordering transform faults systems, EPGF (to the South) and Oriente-Septentrional (to the North), we document the deformation partitioning and the fault segmentation at different scales. A common tectonic evolution has been registered in S. Eastern Cuba and Western Hispaniola (Haiti area), up to early Miocene times. From the effective Hispaniola-Cuba separation at Oligocene/Miocene transition times, left lateral strike-slip motion was registered along large crustal faults cross-cutting different domains versus time. Rooted on these crustal/lithospheric discontinuties tectonic stress is also released on secondary fault systems where both deep and basin, even meteoric fluids may migrate. Sedimentation processes and sequence deposition have been also analyzed both offshore and onshore in the same area showing the strong tectonic-sedimentation processes interaction. A tentative calendar of this deformation, coupled with Present-Day evaluation of the draining areas along Septentrional fault, Transhaitian Ranges and Gonave Bay will be presented on regional seismic profiles and cross-sections.

  7. An Effective Fault Feature Extraction Method for Gas Turbine Generator System Diagnosis

    Directory of Open Access Journals (Sweden)

    Jian-Hua Zhong

    2016-01-01

    Full Text Available Fault diagnosis is very important to maintain the operation of a gas turbine generator system (GTGS in power plants, where any abnormal situations will interrupt the electricity supply. The fault diagnosis of the GTGS faces the main challenge that the acquired data, vibration or sound signals, contain a great deal of redundant information which extends the fault identification time and degrades the diagnostic accuracy. To improve the diagnostic performance in the GTGS, an effective fault feature extraction framework is proposed to solve the problem of the signal disorder and redundant information in the acquired signal. The proposed framework combines feature extraction with a general machine learning method, support vector machine (SVM, to implement an intelligent fault diagnosis. The feature extraction method adopts wavelet packet transform and time-domain statistical features to extract the features of faults from the vibration signal. To further reduce the redundant information in extracted features, kernel principal component analysis is applied in this study. Experimental results indicate that the proposed feature extracted technique is an effective method to extract the useful features of faults, resulting in improvement of the performance of fault diagnosis for the GTGS.

  8. Active Fault Research (1996); Katsudanso kenkyu (1996)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-03-25

    This is a general collection of papers dealing with the research of active faults. In Japan, since very heavy damage was produced by the Hyogoken-Nambu earthquake of January, 1955, discussion of active faults has promptly grown very active. In relation to the said earthquake, detailed maps of earthquake faults that emerged in the same, trench investigations of the Awajishima surface fault rupture related to the same, and the circumstances of the southern and northern ends of the Nojima earthquake fault are reported. Discussion is made about the re-examination of precaution faults and the possibility of the presence of C-class active faults, dealing with the entirety of Japan. Itemized discussion covers the fossil liquefaction observed on the campus of Hokkaido University, fault outcrop at the geological boundary west of Hanamaki and at the western edge of the Kitakami lowland, morphology at the Median Tectonic Line active fault system Iyo fault, fault outcrop discovered at the Iwakuni active fault system Otake fault, and the Kokura Higashi fault and the topography surrounding it (northern part of Kyushu) are introduced. Furthermore, there are reports on the F1 fault and neotectonics in the Tan-Lu fracture zone in the Linyi area, Shandong Province, eastern part of China.

  9. Managerial adjustment and its limits: sequential fault in comparative perspective

    Directory of Open Access Journals (Sweden)

    Flávio da Cunha Rezende

    2008-01-01

    Full Text Available This article focuses on explanations for sequential faults in administrative reform. It deals with the limits of managerial adjustment in an approach that attempts to connect theory and empirical data, articulating three levels of analysis. The first level presents comparative evidence of sequential fault within reforms in national governments through a set of indicators geared toward understanding changes in the role of the state. In light of analyses of a representative set of comparative studies on reform implementation, the second analytical level proceeds to identify four typical mechanisms that are present in explanations on managerial adjustment faults. In this way, we seek to configure an explanatory matrix for theories on sequential fault. Next we discuss the experience of management reform in the Brazilian context, conferring special attention on one of the mechanisms that creates fault: the control dilemma. The major hypotheses that guide our article are that reforms lead to sequential fault and that there are at least four causal mechanisms that produce reforms: a transactions costs involved in producing reforms; b performance legacy; c predominance of fiscal adjustment and d the control dilemma. These mechanisms act separately or in concert, and act to decrease chances for a transformation of State managerial patterns. Major evidence that is analyzed in these articles lend consistency to the general argument that reforms have failed in their attempts to reduce public expenses, alter patterns of resource allocation, reduce the labor force and change the role of the State. Our major conclusion is that reforms fail sequentially and managerial adjustment displays considerable limitations, particularly those of a political nature.

  10. Evolution of the Rodgers Creek–Maacama right-lateral fault system and associated basins east of the northward-migrating Mendocino Triple Junction, northern California

    Science.gov (United States)

    McLaughlin, Robert J.; Sarna-Wojcicki, Andrei M.; Wagner, David L.; Fleck, Robert J.; Langenheim, V.E.; Jachens, Robert C.; Clahan, Kevin; Allen, James R.

    2012-01-01

    The Rodgers Creek–Maacama fault system in the northern California Coast Ranges (United States) takes up substantial right-lateral motion within the wide transform boundary between the Pacific and North American plates, over a slab window that has opened northward beneath the Coast Ranges. The fault system evolved in several right steps and splays preceded and accompanied by extension, volcanism, and strike-slip basin development. Fault and basin geometries have changed with time, in places with younger basins and faults overprinting older structures. Along-strike and successional changes in fault and basin geometry at the southern end of the fault system probably are adjustments to frequent fault zone reorganizations in response to Mendocino Triple Junction migration and northward transit of a major releasing bend in the northern San Andreas fault. The earliest Rodgers Creek fault zone displacement is interpreted to have occurred ca. 7 Ma along extensional basin-forming faults that splayed northwest from a west-northwest proto-Hayward fault zone, opening a transtensional basin west of Santa Rosa. After ca. 5 Ma, the early transtensional basin was compressed and extensional faults were reactivated as thrusts that uplifted the northeast side of the basin. After ca. 2.78 Ma, the Rodgers Creek fault zone again splayed from the earlier extensional and thrust faults to steeper dipping faults with more north-northwest orientations. In conjunction with the changes in orientation and slip mode, the Rodgers Creek fault zone dextral slip rate increased from ∼2–4 mm/yr 7–3 Ma, to 5–8 mm/yr after 3 Ma. The Maacama fault zone is shown from several data sets to have initiated ca. 3.2 Ma and has slipped right-laterally at ∼5–8 mm/yr since its initiation. The initial Maacama fault zone splayed northeastward from the south end of the Rodgers Creek fault zone, accompanied by the opening of several strike-slip basins, some of which were later uplifted and compressed

  11. Fault geometry and earthquake mechanics

    Directory of Open Access Journals (Sweden)

    D. J. Andrews

    1994-06-01

    Full Text Available Earthquake mechanics may be determined by the geometry of a fault system. Slip on a fractal branching fault surface can explain: 1 regeneration of stress irregularities in an earthquake; 2 the concentration of stress drop in an earthquake into asperities; 3 starting and stopping of earthquake slip at fault junctions, and 4 self-similar scaling of earthquakes. Slip at fault junctions provides a natural realization of barrier and asperity models without appealing to variations of fault strength. Fault systems are observed to have a branching fractal structure, and slip may occur at many fault junctions in an earthquake. Consider the mechanics of slip at one fault junction. In order to avoid a stress singularity of order 1/r, an intersection of faults must be a triple junction and the Burgers vectors on the three fault segments at the junction must sum to zero. In other words, to lowest order the deformation consists of rigid block displacement, which ensures that the local stress due to the dislocations is zero. The elastic dislocation solution, however, ignores the fact that the configuration of the blocks changes at the scale of the displacement. A volume change occurs at the junction; either a void opens or intense local deformation is required to avoid material overlap. The volume change is proportional to the product of the slip increment and the total slip since the formation of the junction. Energy absorbed at the junction, equal to confining pressure times the volume change, is not large enongh to prevent slip at a new junction. The ratio of energy absorbed at a new junction to elastic energy released in an earthquake is no larger than P/µ where P is confining pressure and µ is the shear modulus. At a depth of 10 km this dimensionless ratio has th value P/µ= 0.01. As slip accumulates at a fault junction in a number of earthquakes, the fault segments are displaced such that they no longer meet at a single point. For this reason the

  12. Fault Management Guiding Principles

    Science.gov (United States)

    Newhouse, Marilyn E.; Friberg, Kenneth H.; Fesq, Lorraine; Barley, Bryan

    2011-01-01

    Regardless of the mission type: deep space or low Earth orbit, robotic or human spaceflight, Fault Management (FM) is a critical aspect of NASA space missions. As the complexity of space missions grows, the complexity of supporting FM systems increase in turn. Data on recent NASA missions show that development of FM capabilities is a common driver for significant cost overruns late in the project development cycle. Efforts to understand the drivers behind these cost overruns, spearheaded by NASA's Science Mission Directorate (SMD), indicate that they are primarily caused by the growing complexity of FM systems and the lack of maturity of FM as an engineering discipline. NASA can and does develop FM systems that effectively protect mission functionality and assets. The cost growth results from a lack of FM planning and emphasis by project management, as well the maturity of FM as an engineering discipline, which lags behind the maturity of other engineering disciplines. As a step towards controlling the cost growth associated with FM development, SMD has commissioned a multi-institution team to develop a practitioner's handbook representing best practices for the end-to-end processes involved in engineering FM systems. While currently concentrating primarily on FM for science missions, the expectation is that this handbook will grow into a NASA-wide handbook, serving as a companion to the NASA Systems Engineering Handbook. This paper presents a snapshot of the principles that have been identified to guide FM development from cradle to grave. The principles range from considerations for integrating FM into the project and SE organizational structure, the relationship between FM designs and mission risk, and the use of the various tools of FM (e.g., redundancy) to meet the FM goal of protecting mission functionality and assets.

  13. Fault Management Guiding Principles

    Science.gov (United States)

    Newhouse, Marilyn E.; Friberg, Kenneth H.; Fesq, Lorraine; Barley, Bryan

    2011-01-01

    Regardless of the mission type: deep space or low Earth orbit, robotic or human spaceflight, Fault Management (FM) is a critical aspect of NASA space missions. As the complexity of space missions grows, the complexity of supporting FM systems increase in turn. Data on recent NASA missions show that development of FM capabilities is a common driver for significant cost overruns late in the project development cycle. Efforts to understand the drivers behind these cost overruns, spearheaded by NASA's Science Mission Directorate (SMD), indicate that they are primarily caused by the growing complexity of FM systems and the lack of maturity of FM as an engineering discipline. NASA can and does develop FM systems that effectively protect mission functionality and assets. The cost growth results from a lack of FM planning and emphasis by project management, as well the maturity of FM as an engineering discipline, which lags behind the maturity of other engineering disciplines. As a step towards controlling the cost growth associated with FM development, SMD has commissioned a multi-institution team to develop a practitioner's handbook representing best practices for the end-to-end processes involved in engineering FM systems. While currently concentrating primarily on FM for science missions, the expectation is that this handbook will grow into a NASA-wide handbook, serving as a companion to the NASA Systems Engineering Handbook. This paper presents a snapshot of the principles that have been identified to guide FM development from cradle to grave. The principles range from considerations for integrating FM into the project and SE organizational structure, the relationship between FM designs and mission risk, and the use of the various tools of FM (e.g., redundancy) to meet the FM goal of protecting mission functionality and assets.

  14. Mechanical anisotropy and the common occurrence of misoriented faults

    Science.gov (United States)

    Bistacchi, A.; Massironi, M.; Menegon, L.; Bolognesi, F.; Donghi, V.

    2011-12-01

    classified as relatively weak faults, and all characterized by slip along phyllosilicate-rich mylonitic foliations. Anisotropic Slip Tendency analysis demonstrates that the activation of a mechanically weak misoriented phyllosilicate-rich foliation must be considered not only possible, but even more probable than the development of new Andersonian conjugate sets of strong faults. In other words, the activation of a weak foliation reduces differential stresses to a level that does not allow the development of "optimally oriented" (in the Andersonian sense) faults/fractures. This quantitative modelling result is confirmed by the field observation that, where faulting develops along a phyllosilicate-rich foliation, almost no classical Andersonian faults can be found. Finally, we will speculate on how the large scale tectonic evolution of orogenic belts, continental rifts, and some large scale continental transform margins results in the extensive formation, in the ductile/metamorphic layer of the crust, of phyllosilicate-rich mylonitic belts (mis)oriented in such a way as to be commonly activated as described above, once they are exhumed in the brittle/frictional layer. This mechanism is likely to influence the large-scale mechanics of the brittle crust.

  15. Fault Diagnosis for Rotating Machinery: A Method based on Image Processing.

    Science.gov (United States)

    Lu, Chen; Wang, Yang; Ragulskis, Minvydas; Cheng, Yujie

    2016-01-01

    Rotating machinery is one of the most typical types of mechanical equipment and plays a significant role in industrial applications. Condition monitoring and fault diagnosis of rotating machinery has gained wide attention for its significance in preventing catastrophic accident and guaranteeing sufficient maintenance. With the development of science and technology, fault diagnosis methods based on multi-disciplines are becoming the focus in the field of fault diagnosis of rotating machinery. This paper presents a multi-discipline method based on image-processing for fault diagnosis of rotating machinery. Different from traditional analysis method in one-dimensional space, this study employs computing method in the field of image processing to realize automatic feature extraction and fault diagnosis in a two-dimensional space. The proposed method mainly includes the following steps. First, the vibration signal is transformed into a bi-spectrum contour map utilizing bi-spectrum technology, which provides a basis for the following image-based feature extraction. Then, an emerging approach in the field of image processing for feature extraction, speeded-up robust features, is employed to automatically exact fault features from the transformed bi-spectrum contour map and finally form a high-dimensional feature vector. To reduce the dimensionality of the feature vector, thus highlighting main fault features and reducing subsequent computing resources, t-Distributed Stochastic Neighbor Embedding is adopt to reduce the dimensionality of the feature vector. At last, probabilistic neural network is introduced for fault identification. Two typical rotating machinery, axial piston hydraulic pump and self-priming centrifugal pumps, are selected to demonstrate the effectiveness of the proposed method. Results show that the proposed method based on image-processing achieves a high accuracy, thus providing a highly effective means to fault diagnosis for rotating machinery.

  16. Fault Diagnosis for Rotating Machinery: A Method based on Image Processing

    Science.gov (United States)

    Lu, Chen; Wang, Yang; Ragulskis, Minvydas; Cheng, Yujie

    2016-01-01

    Rotating machinery is one of the most typical types of mechanical equipment and plays a significant role in industrial applications. Condition monitoring and fault diagnosis of rotating machinery has gained wide attention for its significance in preventing catastrophic accident and guaranteeing sufficient maintenance. With the development of science and technology, fault diagnosis methods based on multi-disciplines are becoming the focus in the field of fault diagnosis of rotating machinery. This paper presents a multi-discipline method based on image-processing for fault diagnosis of rotating machinery. Different from traditional analysis method in one-dimensional space, this study employs computing method in the field of image processing to realize automatic feature extraction and fault diagnosis in a two-dimensional space. The proposed method mainly includes the following steps. First, the vibration signal is transformed into a bi-spectrum contour map utilizing bi-spectrum technology, which provides a basis for the following image-based feature extraction. Then, an emerging approach in the field of image processing for feature extraction, speeded-up robust features, is employed to automatically exact fault features from the transformed bi-spectrum contour map and finally form a high-dimensional feature vector. To reduce the dimensionality of the feature vector, thus highlighting main fault features and reducing subsequent computing resources, t-Distributed Stochastic Neighbor Embedding is adopt to reduce the dimensionality of the feature vector. At last, probabilistic neural network is introduced for fault identification. Two typical rotating machinery, axial piston hydraulic pump and self-priming centrifugal pumps, are selected to demonstrate the effectiveness of the proposed method. Results show that the proposed method based on image-processing achieves a high accuracy, thus providing a highly effective means to fault diagnosis for rotating machinery. PMID

  17. Fault estimation - A standard problem approach

    DEFF Research Database (Denmark)

    Stoustrup, J.; Niemann, Hans Henrik

    2002-01-01

    This paper presents a range of optimization based approaches to fault diagnosis. A variety of fault diagnosis problems are reformulated in the so-called standard problem set-up introduced in the literature on robust control. Once the standard problem formulations are given, the fault diagnosis pr...... problems can be solved by standard optimization techniques. The proposed methods include (1) fault diagnosis (fault estimation, (FE)) for systems with model uncertainties; FE for systems with parametric faults, and FE for a class of nonlinear systems. Copyright......This paper presents a range of optimization based approaches to fault diagnosis. A variety of fault diagnosis problems are reformulated in the so-called standard problem set-up introduced in the literature on robust control. Once the standard problem formulations are given, the fault diagnosis...

  18. Fault detection and isolation for complex system

    Science.gov (United States)

    Jing, Chan Shi; Bayuaji, Luhur; Samad, R.; Mustafa, M.; Abdullah, N. R. H.; Zain, Z. M.; Pebrianti, Dwi

    2017-07-01

    Fault Detection and Isolation (FDI) is a method to monitor, identify, and pinpoint the type and location of system fault in a complex multiple input multiple output (MIMO) non-linear system. A two wheel robot is used as a complex system in this study. The aim of the research is to construct and design a Fault Detection and Isolation algorithm. The proposed method for the fault identification is using hybrid technique that combines Kalman filter and Artificial Neural Network (ANN). The Kalman filter is able to recognize the data from the sensors of the system and indicate the fault of the system in the sensor reading. Error prediction is based on the fault magnitude and the time occurrence of fault. Additionally, Artificial Neural Network (ANN) is another algorithm used to determine the type of fault and isolate the fault in the system.

  19. Age determination and development of experimental methods for quaternary fault and formation

    Energy Technology Data Exchange (ETDEWEB)

    Cheong, Chang Sik; Kim, Jeong Min; Lee, S. H.; Han, J. H.; Shin, H. S.; Cheong, Y. J. [Korea Basic Science Institute, Daejeon (Korea, Republic of); Lee, H. S. [Pukyong National Univ., Busan (Korea, Republic of); Hong, D. G. [Kangwon National Univ., Gangneung (Korea, Republic of)

    2006-02-15

    Correlation of palaeo-shoreline elevations indicates that the MQt{sub 4} terrace in Suryum site has formed during MIS 5e, which is supported by stratigraphically concordant OSL ages for NQt{sub 3} terrace sediments in Yonghan area. Sedimentological features of the trench site of the Eupcheon fault suggest multiple fault movements during the Late Quaternary. All of these observations imply that uplift rate in the middle part of the coast has been much larger than that in the northern part during 125 ka {approx} 80 ka, requiring the revision of conventional view that the Korean peninsula is tectonically very stable. The ESR data suggest that the Ilkwang fault zone has been formed by the initial surface fault activity at 2-3 Ma and reactivated at least 4 times at 1.2-1.3 Ma, 1 Ma, 0.6 Ma and 0.5 Ma, with part of adjacent NNE and NE trending faults. The Eupcheon fault has been reactivated along the boundary between fault breccia originated from Cretaceous sedimentary rocks and Tertiary lithic tuff at around 2 Ma, 1.3 Ma, and 1 Ma. It has been reactivation again along the boundary between Cretaceous sandstone and fault breccia at 0.8 Ma, and between fault breccia and Tertiary lithic tuff at 0.6 Ma. During the late Quaternary after MIS 5e, the Eupcheon fault reactivated along the boundary between fault gouges, cutting Quaternary marine terrace deposits. The ESR data for the Eupcheon fault, however, should be carefully reexamined because it is probable that the samples contain clay components of weathering, not cataclastic origin. A weathering profile developed in the Suryum site was disturbed by tectonic movement that appears to be a simple one-time reverse faulting event based on field observations. A comparative analysis of the mineralogy, micromorphology, and chemistry of the weathering profile and fault gouge, however, reveals that both the microfissures in the deformed weathering profile and larger void spaces along the fault plane were filled with multi

  20. A new phase comparison pilot protection based on wavelet transform

    Institute of Scientific and Technical Information of China (English)

    YANG Ying; TAI Neng-ling; YU Wei-yong

    2006-01-01

    Current phase comparison based pilot protection had been generally utilized as primary protection of the transmission lines in China from the 1950's to the 1980's. Conventional phase comparison pilot protection has a long phase comparison time, which results in a longer fault-clearing time. This paper proposes a new current phase comparison. pilot protection scheme that is based on non-power frequency fault current component.The phase of the fourth harmonic current of each end of the protected line has been abstracted by utilizing complex wavelet transformation and then compared in order to determine whether the inner fault occurs or not. This way can greatly decrease fault-clearing time and improve performances of this pilot protection when fault occurs under the heavy-load current and asymmetrical operation conditions. Many EMTP simulations have verified theproposed scheme's correctness and effectiveness.