Search results for "Fault"

Electrical Safety Analysis in the Presence of Resonant Grounding Neutral

2019

The resonant grounding is one of the possible methods of the system neutral grounding for the medium voltage distribution. IEEE standards do define this grounding configuration, but important advantages and drawbacks of the resonant grounding might not be fully known, due to its rather uncommon application in North America. On the other hand, resonant grounding in Europe is imposed by the increased requirements for power quality, especially for medium-voltage (MV) industrial users, imposed to electric utilities by regulatory authorities, with the purpose to protect the interests of users and consumers. Level of the continuity of the service, magnitude and phase of ground-fault currents, mag…

Spatial source phase : A new feature for identifying spatial differences based on complex-valued resting-state fMRI data

2019

Spatial source phase, the phase information of spatial maps extracted from functional magnetic resonance imaging (fMRI) data by data‐driven methods such as independent component analysis (ICA), has rarely been studied. While the observed phase has been shown to convey unique brain information, the role of spatial source phase in representing the intrinsic activity of the brain is yet not clear. This study explores the spatial source phase for identifying spatial differences between patients with schizophrenia (SZs) and healthy controls (HCs) using complex‐valued resting‐state fMRI data from 82 individuals. ICA is first applied to preprocess fMRI data, and post‐ICA phase de‐ambiguity and den…

Time domain symmetry parameters analysis for series arc fault detection

2022

This paper presents a feasibility study of exploiting the symmetry of some parameters for series arc fault detection in electrical circuits. The considered parameters are defined in the time domain and they are based on the current signal derivative and the evaluation of cross-correlation between subsequent observation windows. The analysis is carried out for AC systems, starting from an experimental characterization, which has been carried out in accordance with the Standard UL 1699 requirements for "unwanted tripping tests"and "operation inhibition tests"of arc fault circuit interrupters (AFCIs). The results obtained in different load conditions show that the proposed parameters can be us…

Performance Improvement of Grid-Integrated Doubly Fed Induction Generator under Asymmetrical and Symmetrical Faults

2023

The doubly fed induction generator (DFIG)-based wind energy conversion system (WECS) suffers from voltage and frequency fluctuations due to the stochastic nature of wind speed as well as nonlinear loads. Moreover, the high penetration of wind energy into the power grid is a challenge for its smooth operation. Hence, symmetrical faults are most intense, inflicting the stator winding to low voltage, disturbing the low-voltage ride-through (LVRT) functionality of a DFIG. The vector control strategy with proportional–integral (PI) controllers was used to control rotor-side converter (RSC) and grid-side converter (GSC) parameters. During a symmetrical fault, however, a series grid-side converter…

Condotta di singoli organi e condotta dell’apparato statale in tema di colpa nell’illecito internazionale

1988

In questo scritto si dimostra che l'elemento della colpa nell'illecito internazionale (inteso come "colpevolezza") è difficilmente compatibile con la struttura complessa dell'organizzazione dello Stato contemporaneo. La dimostrazione è essenzialmente condotta con riferimento alla giurisprudenza della Corte di giustizia delle comunità europee in tema di violazione dei trattati o di regolamenti da parte degli Stati. Viene altresì sottolineato che un tale risultato è in linea con l'evanescenza delle cause di invalidità dei trattati concernenti la volontà di singoli organi partecipanti al processo di stipulazione. The idea is advanced that state fault - understood as an essential precondition f…

Integreating geological and seismological data in point process models for seismical analysis

2017

Nowadays in the seismic and geological fields, large and complex data sets are available. This information is a valuable source that can be used for improving the seismic hazard assessment of a given region. In particular, the integration of geologic variables into point process models to study seismic pattern is an open research field that has not been fully explored. In this work, we present several open-access datasets (the catalogue of the earthquakes, geological information such as faults, plate boundary and the presence of volcanoes) that are properly treated to describe the seismicity of events occurred in Greece between 2005 and 2014. We use these datasets to fit an advanced spatial…

Plio-Pleistocene strike-slip deformation in NE Sicily: the example of the area between Capo Calavà and Capo Tindari

2005

The Peloritani Mts. in Northeastern Sicily are part of the Sicilian orogenic belt interposed between the Tyrrhenian basin and the Ionian Basin. In the Tyrrhenian basin crustal thinning has been active since the late Miocene, whereas wedge accretion (External Calabrian Arc) has occurred in the Ionian basin, due to the north-westward subduction of the Ionian Plate below the Calabrian-Peloritani Arc. Strike-slip tectonics in NE Sicily occurred during Plio-Pleistocene times. Faulting caused a non-uniform uplift rate of the Plio-Pleistocene deposits, which are elevated up to 500 m above sea level. The structural pattern is mainly represented by NW-SE and N-S/NNE-SSW trending transcurrent faults …

Extensional deformations during Neogene chain building in Sicily

2010

ABSTRACT In the Madonie-Nebrodi Mts (Northern Sicily belt) both Mesozoic carbonate platform/basin-derived deformed successions and Neogene foredeep deposits outcrop. Thrust sheets piled-up southwards in thin-skin piggy-back sequence. The chain building process began during the Oligo-Miocene. The syntectonic deposits involved in the compressional tectonics give evidence that syn-sedimentary extensional faults developed during fold nucleation and amplification. Syn-sedimentary extensional faults affect the foredeep strata at different stratigraphic levels, which are bounded by unconformities. Normal faults and bedding show constant cut-off relationships and are progressively tilted youngwards…

Gear classification and fault detection using a diffusion map framework

2013

Gear classification and fault detection using a diffusion map framework

2015

This article proposes a system health monitoring approach that detects abnormal behavior of machines. Diffusion map is used to reduce the dimensionality of training data, which facilitates the classification of newly arriving measurements. The new measurements are handled with Nyström extension. The method is trained and tested with real gear monitoring data from several windmill parks. A machine health index is proposed, showing that data recordings can be classified as working or failing using dimensionality reduction and warning levels in the low dimensional space. The proposed approach can be used with any system that produces high-dimensional measurement data. peerReviewed