Fault Position Research Articles

Study on sound transmission characteristics and positioning strategy of gas insulated transmission line shell

Gas insulated transmission line (GIL) is widely used for large-capacity power transmission in complex environment, and has the characteristics of long distance and totally enclosed structure. When the insulation fault occurs inside GIL, its metal shell structure makes it more difficult to monitor through optical, electrical and other physical quantities. Considering the rapidity and accuracy of positioning, the propagation of sound waves along the GIL sheath is a commonly used method in GIL on-site PD testing and running state online monitoring for fault positioning. This paper establishes a high-pressure GIL acoustic propagation simulation model based on pipe acoustics theory, analyzes the frequency dispersion and mode distribution of acoustic waves along the GIL shell, determines an appropriate fault location strategy based on the propagation velocity and attenuation of the selected acoustic wave mode, and carries out experiments to verify it. The results of the research show that the low order bending wave F(1,1) propagated along the GIL shell has good positioning characteristics, and the propagation velocity conforms to the dispersion curve distribution. By taking into account the attenuation and delay of the acoustic wave passing through epoxy insulators or expansion joints in the fault localization strategy, the localization accuracy can be improved by 60%. And this positioning strategy was verified to be effective in the GIL insulation fault localization test conducted in the field.

Precise Fault Location in Active Distribution Systems Using Unsynchronized Source Measurements

This article presents a phase-domain based fault location algorithm for unbalanced power distribution systems with distributed generation. Unsynchronized voltage and current measurements, taken from the sources prior and during the fault, are utilized to calculate the equivalent source impedances and the incremental current quantities required. The latter are substituted into the fault location equations, which are solved to determine the fault resistance(s), the synchronization angles, and the possible fault positions. Multiple possible fault position estimations are eliminated by applying an index-based methodology to find the exact fault position. Extensive simulations are performed for a benchmark distribution system with conventional and inverter-interfaced generation units, considering all types of common short-circuit faults, several fault resistance magnitudes, varying load levels, different distributed generation (DG) mixture, and the impact of line segment length. The results show that fault distance is accurately estimated by the proposed algorithm.

Tunnel Geohazard Evaluation Using Improved Seismic Time-Reversal Mirror

Tunnel geohazard evaluation method is an important method for evaluating the geo-hazard during tunnel construction. The seismic method has become the most widely used approach for understanding the geological conditions ahead of the tunnel face. Limited by the small aperture in the tunnel and the little offset of the observation system, migration methods for imaging geological structures are mainly based on Ray theory without using the dynamic information of reflected waves, resulting in less accurate imaging results. To improve the detection accuracy, the time reversal mirror method was studied and improved for better imaging geological conditions ahead of the tunnel face. Specifically, for the positioning error caused by the traditional time reversal mirror method (based on constant velocity), the parameter of variable velocity was added and optimized for the calculation process. By calculating each velocity value in different propagation paths, the reflected waves can focus on the scattering point with a more accurate location. Based on several typical adverse geology numerical simulations proved that the improved time reverse mirror method can get more accurate imaging results than the traditional method, achieving the position and imaging of fault, fractured zone, etc. Then the improved method has been applied in a water supply project and successfully predicted the distribution of adverse geologies ahead of the tunnel face, which further verified the applicability and effectiveness of the improved time reversal mirror method. This paper provides reference and guidance for similar water diversion projects and tunnel engineering geological detection.

Subsurface Analysis Using Microtremor and Resistivity to Determine Soil Vulnerability and Discovery of New Local Fault

Microtremor and geoelectrical resistivity surveys have been conducted in areas where the April 10, 2021, earthquake of 6.1 Mw caused the most damage. Wirotaman Village, Malang Regency, was one of the regions with the most extensive damage. This study aims to investigate the seismic vulnerability and subsurface conditions that result in severe damage at the research location. This study's Horizontal to Vertical Spectral Ratio Analysis (HVSR) curve was derived from the recorded microtremor signal in the frequency domain. The frequency parameter and amplification factor obtained from the curve are used to determine the seismic vulnerability index. In addition, a geoelectrical resistivity study with a dipole-dipole configuration was conducted at the site with the most extensive damage. The results of this study show the correlation between the results of the HVSR curve analysis and geoelectrical resistivity in determining the seismic vulnerability of an area. The results indicated that the high seismic vulnerability index value ranged from Kg= 12.0 to 18.0, with the most severe damage concentrated in the Southwest at SA 05 and SA 06. Based on the results of the geoelectrical survey, information was obtained that several points of damage to buildings at SA 05 (red circle) were on the same line, where this condition was associated with the possibility of new faults at that location. This microtremor and geoelectric resistivity investigation reveals thick sedimentary deposits with a high seismic vulnerability index and low resistivity. This study's findings can be utilized as a guide for micro zonation studies in research areas. This research contributes to the surrounding community in the form of disaster mitigation, where construction must avoid local fault positions that have been found to reduce the level of damage when natural geological disasters occur. Doi: 10.28991/CEJ-2023-09-09-014 Full Text: PDF

Analysis of the Bending Fatigue Failure of Helical Idler Gear System Considering Different Fault Positions

Analysis of the Bending Fatigue Failure of Helical Idler Gear System Considering Different Fault Positions

Identification of Permeable Structures and Heat Source in the Geothermal Working Area of Galunggung Volcano and the Heat Source Connectivity to the Karaha-Cakrabuana Area Using Gravity Data

Galunggung volcano area is a geothermal concession area that adjacent with Karaha-Cakrabuana concession area with a distance around 1 km. Indonesian Government planning to build power plant in 2025 so additional research needed to support the plan. Gravity survey could help in identifying permeable structure (fault) as well as heat source to a certain depth. The results of data processing showed the presence of faults seen on the FHD, SVD, and ABL residual maps, while for heat sources it was shown from the closed contour patterns on the ABL, residual, and regional maps. Derivative analysis in strengthens the position and type of fault from the match between the maximum FHD value and zero SVD value. From these results, identified the existence of three faults in the study area and were all identified as normal faults. 3D modelling gave a picture of density contrast in research area. From the section profile that pass through Galunggung and Telaga Bodas crater, heat source was interpreted as density with value 2.8 – 3.0 gr/cm3 and marked by orange to red color that coincide below Galunggung crater and continoued to Talaga Bodas crater at depths below -3000 masl. This indicate that both concession area was connected.

A novel fault location method based on traveling wave for multi-branch distribution network

In this paper, a novel fault location method is proposed for multi-branch distribution network based on traveling wave. The improved complete ensemble empirical mode decomposition with adaptive noise (ICEEMDAN) and Teager energy operator (TEO) is used to detect the arrival time of traveling waves. Firstly, according to the signal processing ability of the ICEEMDAN method, the ICEEMDAN method is used to decompose the sampled signals when the fault occurs, and extract the high-frequency component of the sampled signals. Then, the TEO is used to extract the abrupt characteristics of high-frequency modal components. And the first maximum mutation point of the signal is regarded as the initial fault traveling wave signal. In addition, considering the transmission characteristic of fault traveling wave signal in multi-branch lines of distribution network, the difference value characteristic of branches is defined. And the recognition principle and the fault location method of multi-branch lines are established to realize the accurate location of distribution network line faults. Simulation results show that the proposed ICEEMDAN-TEO method can effectively detect the fault traveling wave signals, and has a better detection performance than CEEMDAN-TEO and HHT methods. The proposed fault location method can effectively locate fault positions and reduce location errors.© 2017 Elsevier Inc. All rights reserved.

Estimation of Position and Shorted Turns Percentage of an Inter-Turn Short Circuit in Interior Permanent Magnet Synchronous Machines Based on a Current Observer and Stationary Reference Frame Tracking

This paper presents a method to detect and diagnose an inter-turn short circuit in interior permanent magnet synchronous machines. The proposed method detects the inter-turn short circuit fault using a current observer to estimate a disturbance related to the fault, defined as a fault index current. The fault index current estimates in the rotor reference frame have information about the location and the percentage of shorted turns. A novel stationary frame tracking technique is proposed to simultaneously determine the fault index current in the stationary frame and the fault position. Look-up tables are implemented to correlate the stationary frame fault index current magnitude to the percentage of shorted turns, providing an estimate of the percentage of shorted turns. Simulation and experimental results are shown throughout the paper to analyze and validate the proposed technique.

A First Approach on the Impact of Distributed Generation and Fault Impedance on Studies on domain of frequency of Voltage Sags

An analysis of the distributed generation (DG) and fault impedance on studies of voltage sags caused by system faults is presented on domain of frequency. The simulation of 62 case studies of phase-to-ground faults on 13.8, 69, 138 and 230 kV transmission lines were performed and the voltage of a 380 V sensitive industrial busbar client was monitored. These lines are part of the electrical system of the city of Goiania, Brazil. For each case study, different fault positions and impedance fault were simulated by considering different DG levels connected to the consumer busbar. Long-term simulation scenarios were obtained by the Monte Carlo method and analyzed based on their cumulative distribution functions and probability density curves of voltage sags. This is one major contribution of this work.

Application of bayesian network based on fault tree in fault diagnosis of Radio Altimeter System

The radio altimeter system is an important part of the aircraft navigation system, the system failure will directly affect flight safety. Therefore, to ensure the safe flight of the aircraft, a fault diagnosis method based on fault trees and Bayesian networks was proposed in this paper. Firstly, starting from the system composition and working principle, taking the typical failure of the system ‘loss of radio altitude displays’ as an example, the fault trees were set up to comprehensively analyze the cause of the fault. On this basis, the built-in fault tree models were used to build the Bayesian network model, and to determine the maximum possible paths and key nodes of the fault through reverse reasoning to achieve the fault positioning. The outcomes demonstrate the excellent accuracy and dependability of the proposed method.

Fault Location of Distribution Network Based on Back Propagation Neural Network Optimization Algorithm

Research on fault diagnosis and positioning of the distribution network (DN) has always been an important research direction related to power supply safety performance. The back propagation neural network (BPNN) is a commonly used intelligent algorithm for fault location research in the DN. To improve the accuracy of dual fault diagnosis in the DN, this study optimizes BPNN by combining the genetic algorithm (GA) and cloud theory. The two types of BPNN before and after optimization are used for single fault and dual fault diagnosis of the DN, respectively. The experimental results show that the optimized BPNN has certain effectiveness and stability. The optimized BPNN requires 25.65 ms of runtime and 365 simulation steps. And in diagnosis and positioning of dual faults, the optimized BPNN exhibits a higher fault diagnosis rate, with an accuracy of 89%. In comparison to ROC curves, the optimized BPNN has a larger area under the curve and its curve is smoother. The results confirm that the optimized BPNN has high efficiency and accuracy.

An analysis of the spatial distribution of geophysical filds in the source region of the 2013 Ilin-Tas (Aby) earthquake

This article analyzes the powerful Ilin-Tas earthquake that occurred in the Chersky Range system in the territory of the Republic of Sakha (Yakutia) in 2013. The mountain system of the Chersky Range system is confied to the Chersky seismotectonic zone, which is part of the Arctic-Asian seismic belt separating the Eurasian and North American lithospheric plates in Northeast Asia. The earthquake magnitude at the epicenter was 9.0. Geophysical filds were used as a material to clarify the structural-tectonic features of the study area and their relationship with seismicity. Involving the data on spatial distribution of anomalies of magnetic and gravity filds made it possible to detail the parameters of the position of the Ilin-Tas fault, where the epicentre of the Ilin-Tas earthquake originated. This fault traces between the Indigirka and Kolyma rivers along the border of the junction of the Moma Range with the Indigiro-Zyryansk depression, and is traced by gradient transition zones from negative to positive values of ΔTa and Δg. The main seismic shock is confied to thickening of Δg isoanomalies, forming a gravitational step, within which gravity values decrease from south to north. The epicentral fild of this earthquake with aftershocks captures the western slope of the Andrey-Tas Range (northwestern flnk of the Moma Range). A qualitative analysis of the geophysical filds in the epicentral region of the earthquake is carried out. Materials of instrumental and macroseismic data, focal mechanism and seismotectonic setting of the focal zone are given in the article. The data obtained as a result of studying the Ilin-Tas earthquake consequences allows to reveal local seismic activity in details and specify seismodanger degree of north-east Yakutia.

Probabilistic Tsunami Hazard Analysis for Vancouver Island Coast Using Stochastic Rupture Models for the Cascadia Subduction Earthquakes

Tsunami hazard analysis is an essential step for designing buildings and infrastructure and for safeguarding people and assets in coastal areas. Coastal communities on Vancouver Island are under threat from the Cascadia megathrust earthquakes and tsunamis. Due to the deterministic nature of current megathrust earthquake scenarios, probabilistic tsunami hazard analysis has not been conducted for the coast of Vancouver Island. To address this research gap, this study presents a new probabilistic tsunami hazard model for Vancouver Island from the Cascadia megathrust subduction events. To account for uncertainties of the possible rupture scenarios more comprehensively, time-dependent earthquake occurrence modeling and stochastic rupture modeling are integrated. The time-dependent earthquake model can capture a multi-modal distribution of inter-arrival time data on the Cascadia megathrust events. On the other hand, the stochastic rupture model can consider variable fault geometry, position, and earthquake slip distribution within the subduction zone. The results indicate that the consideration of different inter-arrival time distributions can result in noticeable differences in terms of site-specific tsunami hazard curves and uniform tsunami hazard curves at different return period levels. At present, the use of the one-component renewal model tends to overestimate the tsunami hazard values compared to the three-component Gaussian mixture model. With the increase in the elapsed time since the last event and the duration of tsunami hazard assessment, the differences tend to be smaller. Inspecting the regional variability of the tsunami hazards, specific segments of the Vancouver Island coast are likely to experience higher tsunami hazards due to the directed tsunami waves from the main subduction zone and due to the local underwater topography.

An accurate fault location method for distribution lines based on data fusion of outcomes from multiple algorithms

Accurate fault location technology for distribution lines is of great importance as it can shorten power outage time and enhance power supply reliability. Current and voltage transformer errors and line parameter errors will result in location error of the existing algorithms, which cannot meet the requirements of power supply reliability. To solve this problem, a data-fusion model based on multiple algorithms is proposed in this study, which makes full use of the location results of existing algorithms. First, the complementarity among the four selected algorithms is analyzed. Then the feasibility of improving fault location accuracy by constructing a data-fusion model is explained and the overall structure of the data-fusion model is determined. Finally, an artificial neural network with a strong fitting ability is used to complete the construction of the data-fusion model. The performance of the model is tested for different factors, such as fault positions, line parameters, fault resistances, and fault inception angles. The test cases based on PSCAD/EMTDC show that the constructed model has excellent generalization ability. Additionally, performance of the model is not affected by distributed generation and sampling rate. The proposed method does not use high-sampling devices and is cost-effective.

Thermal architecture of the Salmon River suture zone, Idaho, USA: Implications for the structural evolution of a ductile accretionary complex during arc-continent collision

Abstract Documenting the tectono-thermal evolution of the exhumed ductile portions of orogenic systems is critical for interpreting orogen dynamics. Here, we utilize Raman spectroscopy of carbonaceous material thermometry to quantify the thermal architecture of the Salmon River suture zone in west-central Idaho, USA, which records the Cretaceous collision of the Wallowa island arc terrane with North America. We integrate this thermal architecture with published structural interpretations, geochronology, and pressure-temperature-time histories to interpret the evolution of deformation during arc-continent collision in this portion of the North America Cordillera. Mean peak temperatures within four, ~1–3-km-thick, penetratively deformed thrust sheets in the western part of the suture zone decrease moving structurally downward from 652 ± 28 °C (Pollock Mountain thrust sheet), to 577 ± 30 °C (Rapid River thrust sheet), to 426 ± 32 °C (Morrison Ridge thrust sheet), to 358 ± 18 °C (Heavens Gate thrust sheet). These ductile thrust sheets are separated by 100–500-m-thick intervals of inverted temperatures that surround the mapped positions of thrust faults. We interpret the western part of the suture zone as a ductile accretionary complex that records the progressive underplating and top-to-the-west translation of ductile thrust sheets that were derived from the Wallowa terrane during ca. 144–105 Ma collision-related deformation. Accretion of ductile thrust sheets began at ~30–35 km depths and completed at depths of ~10–20 km. Rocks at all structural levels in the suture zone exhibit distributed ductile fabrics, but the inverted thermal gradients that surround the mapped positions of thrust faults suggest that the majority of top-to-the-west displacement was accommodated within 100–500-m-thick, high-strain, thrust-sense ductile shear zones.

Dynamics Modeling and Analysis of Rolling Bearings Variable Stiffness System with Local Faults

By analyzing the support of load-carrying rolling elements when the rolling elements fall into the fault position, the dynamics model of a rolling bearing variable stiffness system with local faults is proposed, considering the retention factor of the contact deformation. Then, this paper researches the change of effective contact stiffness, contact deformation, contact force, and the total effective stiffness of the rolling elements. The results show that the contact stiffness of the rolling elements abruptly decreases when the rolling elements fall into the fault position. The contact deformation and contact force of the load-carrying rolling elements in the load zone increase, rebalancing the external radial load while causing a sudden reduction in the total effective stiffness, resulting in the vibration of the system. When different rolling elements fall into the outer ring fault position, the change in total effective stiffness and the system response are equal in magnitude. Additionally, there is a significant outer race fault characteristic frequency accompanied by frequency multiplication in the fault characteristic spectrums. When different rolling elements fall into the inner race fault position, the total effective stiffness is modulated by the inner race rotation and varies dramatically, resulting in the amplitude of the system time domain vibration response also being modulated by the inner race rotation and varying dramatically. Additionally, there is a significant inner race rotational frequency accompanied by frequency multiplication, an inner race fault characteristic frequency accompanied by frequency multiplication, and a side frequency in the fault characteristic spectrums. The research can provide some reference for the effective diagnosis of the rolling bearing fault.

Anomalous position of Paleozoic faults of Western Donbas

Statement of the general problem. The oil and gas-bearing province of Eastern Ukraine is located in the Dnipro-Donetsk Basin (DDB). It covers the Paleozoic structural floor and is buried under younger sediments. The Paleozoic structural floor of the territory is represented as a long rift graben. The maximum thickness of the sedimentary cover in the graben is 15–17 km. According to geophysical data, the thickness of the earth's crust is 31–32 km under the axial part of the DDB and increases towards the sides. But according to the maximum thickness and facies characteristics of the Paleozoic deposits, the thickness of the Earth's crust below them could not exceed 20 km. The modern thickness is 1.5 times higher. Therefore, such a geological-geophysical model of the structure of the DDB is contradictory. Analysis of recent research and publications. The removal of the contradiction is possible due to the detection of a series of Hercynian thrusts with total amplitude of thrusts of the order of 50 km. Such thrusts began to be established on the northern and southern flanks of the DDB. Hercynian thrusts have a southwestern vergence. In the north, the Voronezh crystalline massif is pushed onto the DDB along the Noviy thrust with an amplitude of 9–10 km. In the south, the South Donbas melange zone is established, which pushes the folded Donbas onto the Ukrainian shield. On its continuation to the northwest is the southern side of the DDB - the so-called Southern monocline. The well-studied Pavlograd-Petropavlovsk coal mining district of Western Donbass with operating coal mines is located within its borders. An unsolved part of the overall problem. Numerous faults with relatively small amplitudes are established within the Paleozoic Southern Monocline. Together, they form a system of horsts and grabens with a north-western extension. But the bottom parts of the grabens are 1–3 km higher than the tops of the horsts. Such a geological situation is anomalous. This indicates the post-fault dislocation of the horst-graben system as a whole. The purpose of the article is identification of the causes of the anomalous structural position of the graben-horst system in the modern geological structure of the Southern Monocline and in the general model of the geological structure of Eastern Ukraine. Research materials and methods. Were involved more than 390 geological sections, constructed based on the data of more than 10,000 wells. Of them, 265 wells revealed the folds that are being analyzed. In addition, were used data of catagenetic transformations of the sedimentary section. Presentation of the main research material. The South Donbas mélange zone falls to the northeast and continues under the Southern Monocline. It is located in the upper block of this regional thrust structure and is in an allochthonous setting. According to geological data, the true amplitude of the thrust of Western Donbas on the Ukrainian shield is 15–20 km, and the vertical component of this amplitude exceeds 3 km. Such spatial parameters explain the abnormality of the structural position of the horsts and grabens of Western Donbass - their southwestern flanks were significantly raised relative to the northeastern flanks during thrusting. Scientific novelty. Therefore, in the modern geological structure, the Dnipro-Donetsk "basin" is not a rift, but a post-rift Hercynian folded region. It is formed by high-amplitude thrusts on the northern and southern flanks. The Hercynian fold region is buried under Mesozoic and Cenozoic sediments and is further complicated by Laramian and Attic fold-thrust dislocations of lesser intensity. Conclusions. The thrust model brings the geophysical parameters into the correspondence with the geological data and is confirmed by the actual material.

High-Frequency Ladder Network Synthesis of Transformer Winding for Its Mechanical Condition Assessment

Fault localization and severity evaluation of transformer winding is crucial for its mechanical condition assessment. Ladder network synthesis of winding entity based on its frequency response analysis (FRA) data is an elegant solution to this problem. This paper proposes a generic method for high-frequency (HF) ladder network synthesis of winding in different mechanical conditions for its fault diagnosis. The simplified HF network used in the synthesis process is firstly built. Afterwards, the synthesis algorithms with high precision and efficiency and the mathematical model for normal HF ladder network are elaborated. Further, the synthesis method for defective network is proposed to locate the winding fault positions and evaluate their severities. Finally, the network synthesis method is applied on a distribution transformer, with the fact that the obtained network components comply with all the constraints and the diagnostic results also match well with the actual mechanical conditions of winding, which verifies its feasibility and accuracy.

Preliminary Study on Automatic Detection of Hard Defects in Integrated Circuits Based on Thermal Laser Stimulation

Locating the fault position is a crucial part of the failure mechanism analysis of integrated circuits. This paper proposes a hard defect locating system based on Thermal Laser Stimulation (TLS) technology. The equation for laser-induced changes in the electrical parameters of semiconductor devices is a good guide to the hardware and software design of the hard defect locating system. The scanning mode of fast total scanning combined with slow point-to-point scanning can quickly locate abnormal areas. A modified median absolute difference (MAD) method is applied to the extraction of anomalous data. The system software can automatically and collaboratively control the 3D mobile station, laser, and signal acquisition unit. It also can intuitively display the distribution of abnormal points on the infrared image. Using a failure MRAM chip and a good one to conduct a comparative test, the abnormal points distributed on the infrared image of the chip indicate that the failure area is in the digital module or eFuse module of the chip, and the Emission Microscopy (EMMI) experiment also verifies the accuracy of the test system.

PETROCHEMICAL AND STRUCTURAL CHARACTERISTICS OF PORPHYRY COPPER MINERALIZATION IN THE ASTANEH ORE DEPOSIT, MIDDLE PART OF THE URUMIEH-DOKHTAR MAGMATIC ARC (IRAN)

Within the Urumieh-Dokhtar Magmatic Arc in the central part of Iran, the formation of which is associated with the Neotethys closure, there are many porphyry copper deposits and ore occurrences. One of them is the Astaneh porphyry copper ore deposit, located in the central part of the Saveh-Ardestan ore region southeast of Ardestan city. The purpose of this study is to investigate the petrochemical characteristics of rocks and to determine the relationship between the distribution of porphyry copper mineralization and tectonic position of faults within the study area. To achieve the goal, there were used the structural and geological data obtained in the fieldwork, as well as the results of mineralogical and geochemical analyses. The obtained results show that rocks of different composition of the Astaneh ore deposit (andesite, andesite-basalt, basalt, trachybasalt) were formed in the suprasubduction zone, and probably in the environment prior to the collision of the of continental plates. Paragenetic relationships and mineralogical analysis show that the evolution of mineralization of the Astaneh ore deposit can be divided into three stages: pre-ore, hypogene and supergene mineralization. Geochemical research based on the study of the content of the major chemical elements in the rocks of the region shows that igneous rocks belong to calc-alkaline basalts and geodynamically can be attributed to the products of magmatism of the ensial island arc. The results concluded that the main stages of the formation of a porphyry copper ore deposit in the study area attain maximum spatio-temporal similarity with the tectonomagmatic phases of the development of the Neotethys Ocean. In addition, the Southern Ardestan fault, running through the study area and intersecting the basement structures, forms wide permeable zones favorable for the formation of porphyry copper deposits therein.