An important part of electric power transformer is the on load tap changer (OLTC) which enables for voltage regulation in the network. Due to high level of failure frequency of these devices it is necessarily to look ...
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ISBN:
(纸本)9781627485609
An important part of electric power transformer is the on load tap changer (OLTC) which enables for voltage regulation in the network. Due to high level of failure frequency of these devices it is necessarily to look for new diagnostic methods which enable for theirs technical state estimation under transformer normal operating condition. Presently at the Electric Power institute at Opole University of Technology there are works in progress aspiring to determine the application possibility of the AE method for OLTC diagnosis. Results of scientifically-research works aiming to characterize the acoustic emission (AE) signals generated by OLTC constructed from a separated selector and a power switch are presented in the paper. AE signals generated during the whole OLTC joining cycle are presented. Within the signal four characteristic acoustic structures have been enhanced which regard to succeeding stages of the joining process. AE signals generated by the selector and by the power switch have been analyzed in detail. Analysis of the timefrequency components of signals generated by OLTC has been carried out with the short time Fourier transform (STFT) and continuous wavelet transform (CWT).
In this paper, the robust stability and stabilization problems are investigated for a class of uncertain discrete-time T-S fuzzy descriptor system with time-delay. In terms of strict linear matrix inequality and witho...
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The equation for the recovered spectrum is derived in spatially modulated interferometric imagers, which takes into account the pixel photosensor width. The results show that the effect of the pixel photosensor width ...
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Solving linear systems of equations is ubiquitous in all areas of science and engineering. With rapidly growing data sets, such a task can be intractable for classical computers, as the best known classical algorithms...
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Solving linear systems of equations is ubiquitous in all areas of science and engineering. With rapidly growing data sets, such a task can be intractable for classical computers, as the best known classical algorithms require a time proportional to the number of variables N. A recently proposed quantum algorithm shows that quantum computers could solve linear systems in a time scale of order log (N), giving an exponential speedup over classical computers. Here we realize the simplest instance of this algorithm, solving 2×2 linear equations for various input vectors on a quantum computer. We use four quantum bits and four controlled logic gates to implement every subroutine required, demonstrating the working principle of this algorithm.
Identification of machine condition is crucial to reduce machine downtime and scrap parts in the manufacturing industries. In this paper, we propose a novel methodology to identify life stage and estimate machine wear...
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The impedance matching and the optimization of power from a circular piezoelectric energy harvester with a central-attached mass are studied. A finite element model is constructed to analyze the electrical equivalent ...
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Forecasting of machine outages have been actively pursued in the manufacturing industries to ensure that maintenance is carried out only when required. In this paper, we propose a precognitive maintenance framework ba...
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ISBN:
(纸本)9780889869523
Forecasting of machine outages have been actively pursued in the manufacturing industries to ensure that maintenance is carried out only when required. In this paper, we propose a precognitive maintenance framework based on mixed time- and condition-based models to predict both machine degradation stage and wear. The decision-making framework is based on stage classification using Support Vector Machines (SVMs) and time-based AutoRegressive Moving Average with exogenous inputs (ARMAX) models, and the effectiveness of our proposed methodology is verified with mathematical rigour and simulation studies.
In this contribution we present a method to estimate structured high order ARX models. By this we mean that the estimated model, despite its high order is close to a low order model. This is achieved by adding two ter...
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This paper presented an equivalent circuit simulation model of the cantilevered piezoelectric bimorph energy harvester for predicting the electrical power output of the energy harvester. The alternating voltage in the...
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