Based on literature review and measurements performed on electric power stations which considered adjusted acoustic pressure level, generated during operation of high power transformer units with integrated on load ta...
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The subject area regards realization of scientific research works considering technical condition estimation of electric power transformer cores based on vibroacoustic measurements performed during their normal operat...
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In this paper we present novel algorithmic solutions for several resource processing and data transfer multicriteria optimization problems. The results of most of the presented techniques are strategies which solve th...
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This paper shows how control techniques, such as PID or generalized predictive control, can improve the performance of TCP/IP networks when dealing with congestion. Drop tail, or more sophisticated AQM techniques such...
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The development area of web technologies has gained great popularity due to the power with which these new technologies can manage resources and due to developers or experts of various types who can build applications...
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The optimal stochastic approximation procedure (OSAP) is applied to the parameter identification problem of distributed parameter system (DPS) driven by random disturbances and observed through noisy measurements. Thi...
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The optimal stochastic approximation procedure (OSAP) is applied to the parameter identification problem of distributed parameter system (DPS) driven by random disturbances and observed through noisy measurements. This procedure is a stochastic approximation procedure (SAP) with an optimal gain sequence and an optimal transformation on the gradient of the objective function: these optimal values accelerate the convergence rate by minimizing the mean squared parameter estimation error, under the assumption that the density functions of the system and observation noises are known, or can be easily estimated. An example of parameter identification of a stochastic parabolic DPS is simulated on the digital computer. A comparison is made among the results of the optimal, the modified, the nominal first-order, and the nominal second-order SAP. It is shown that the OSAP gives higher accuracy and faster rate of convergence as compared to the nominal SAP
The subject matter of the paper refers to the improvement of the acoustic emission (AE) method used in diagnostics of insulation systems of electric power devices. During measurements of the AE pulses that are generat...
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ISBN:
(纸本)9781627485609
The subject matter of the paper refers to the improvement of the acoustic emission (AE) method used in diagnostics of insulation systems of electric power devices. During measurements of the AE pulses that are generated by partial discharges (PDs) in the insulation of electric power devices, there appear diverse kinds of interfering signals. These disturbances, occurring during measurements in laboratory as well as under industrial conditions, can be generated by sources placed inside the electric power device under study or/and by sources emitting in its surrounding. The sources mentioned can be physical phenomena of mechanical, electric or acoustic nature. If the disturbances appear at the same time during measurements as the AE pulses generated by PDs this can cause deformation of the gathered time-runs. This can have direct influence on the proper interpretation of the measurement results obtained by use of the AE method. Hence, the necessity of the influence estimation of the interfering signals on the by PDs generated AE pulses time-runs. The performed research works consider the following issues: The measurements and analysis of the acoustic disturbances generated by corona discharges in the overhead electric power transmission line.
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).
Timely pest detection and identification is critical as part of modern agriculture. Halyomorpha Halys is a prevalent pest with proven harmful impacts on numerous crops and agricultural regions. The paper proposes an e...
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