Wszystkie pola: Cichoń, A. - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Selecting Mother Wavelet for Wavelet Analysis of On-Load Tap Changer Acoustic Emission
Autorzy:: Cichoń, A.
Berger, P.
Wotzka, D.
Powiązania:: https://bibliotekanauki.pl/articles/1401875.pdf
Data publikacji:: 2015-09
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 43.40.-r
43.58.Wc
Opis:: Wavelet transformation is one of the most popular tools for acoustic signal analysis. It provides good resolution both in time and frequency domains as well as wide choice of mother wavelets - this makes wavelet transformation a choice when flexible approach is required. However, selecting parameters of analysis can be difficult, especially regarding mother wavelet as different mother wavelets have various properties regarding number of vanishing moments and symmetry. This paper presents studies to determine the possibility of on-load tap changer wear detection by applying wavelet transformation. In research, different mother wavelets were selected and their usefulness was examined. Signals to be analyzed were obtained during on-load tap changer operation in different mechanical conditions - simulating devices wear in service. All measurements were performed on model very similar to real industrial on-load tap changer. Tests were conducted in controlled laboratory environment, reducing most of the possible disruptions.
Źródło:: Acta Physica Polonica A; 2015, 128, 3; 310-314
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: Modeling of Acoustic Emission Signals Generated in On Load Tap Changer
Autorzy:: Cichoń, A.
Borucki, S.
Wotzka, D.
Powiązania:: https://bibliotekanauki.pl/articles/1199209.pdf
Data publikacji:: 2014-06
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 43.40.-r
43.40.Vn
43.58.Wc
Opis:: The paper deals with mathematical modeling of acoustic emission signals which are generated in on load tap changers. In power engineering area acoustic emission method is commonly used for diagnosis purposes. Authors in their research works apply it for detection of defects occurring in on load tap changers, which are important elements of power transformers. The acoustic emission method is based on measurements performed by use of wideband piezoelectric transducers that are mounted on transformer tank surface. The registered signal is then analyzed in the time, frequency, and time-frequency domains or is evaluated with computer expert systems for diagnosis purposes. Depending on indicators device technical condition can be determined. The contribution given by the authors in this paper is proposal of a mathematical model, which describes envelope of the measured acoustic emission signal.
Źródło:: Acta Physica Polonica A; 2014, 125, 6; 1396-1399
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Zastosowanie uczenia nadzorowanego do klasyfikacji defektów PPZ na podstawie sygnałów EA
Application of supervised learning for classification of OLTC defects on the basis of AE signals
Autorzy:: Wotzka, D.
Cichoń, A.
Manowski, P.
Powiązania:: https://bibliotekanauki.pl/articles/376716.pdf
Data publikacji:: 2018
Wydawca:: Politechnika Poznańska. Wydawnictwo Politechniki Poznańskiej
Tematy:: analiza sygnałów EA
podobciążeniowe przełączniki zaczepów
PPZ
klasyfikacja uszkodzeń PPZ
uczenie nadzorowane
Opis:: Tematyka artykułu dotyczy rozpoznawania defektów podobciążeniowych przełączników zaczepów (PPZ) z wykorzystaniem uczenia nadzorowanego. PPZ to specjalistyczne urządzenie będące częścią transformatora elektroenergetycznego, które pozwala na skokową zmianę przekładni a tym samym napięcia na zaciskach tego transformatora. Jako metodę diagnostyczną zastosowano metodę emisji akustycznej (EA), której zaletą jest możliwość stosowania podczas normalnej pracy transformatora bez konieczności jego wyłączania. Sygnały EA pozyskane z badań laboratoryjnych, w których symulowano cztery rodzaje defektów - typowych uszkodzeń PPZ, poddano wstępnej analizie z wykorzystaniem filtrów cyfrowych i transformaty Hilberta, a następnie poddano procesowi klasyfikacji. W artykule zawarto przykładowe przebiegi czasowe sygnałów EA oraz wyniki wstępnych badań dotyczących klasyfikacji defektów PPZ z wykorzystaniem siedmiu metod wraz z oceną ich skuteczności.
The subject of the article concerns recognition of defects of on load tap changers (OLTC) with the use of supervised learning. OLTC is a specialized device that is part of a power transformer, which allows for a step change of the gear and thus the voltage at the terminals of this transformer. The acoustic emission (AE) method was applied as diagnostic method. The advantage of this method lies in the possibility of its application during normal operation of the device without having to turn it off. EA signals were obtained from laboratory tests in which four types of defects - typical OLTC damages, were simulated. The gathered signals were pre-analyzed using digital filters and Hilbert transforms, and then subjected to the classification process. The article contains examples of EA signal waveforms and the results of preliminary research on the classification of OLTC defects with the use of seven methods together with an assessment of their effectiveness.
Źródło:: Poznan University of Technology Academic Journals. Electrical Engineering; 2018, 93; 335-344
1897-0737
Pojawia się w:: Poznan University of Technology Academic Journals. Electrical Engineering
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: Modeling and Experimental Verification of Ultrasound Transmission in Electro Insulation Oil
Autorzy:: Wotzka, D.
Cichoń, A.
Boczar, T.
Powiązania:: https://bibliotekanauki.pl/articles/177158.pdf
Data publikacji:: 2012
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:: ultrasound transmission
numerical simulations
electro-insulation oil
Opis:: A verification study of ultrasound transmission numerical simulation results with experiment results is presented in this paper. The work considers a model of a transformer tank which is filled with electro insulating oil. In the experiment, performed under laboratory conditions, an ultrasound wave is generated by a piezoelectric transducer that is fixed in the centre of the tank and measured by another transducer mounted inside the tank at three distances: 10, 20 and 30 cm from the sound source. The transducer is able to measure and generate acoustic waves in the ultrasound frequency band up to 1 MHz. The simulation considers numerical calculation of acoustic pressure distribution inside the tank in which acoustic source emits waves with frequency equal to 100 kHz. Verification analysis has confirmed consistency of the numerically calculated values with the measurement results.
Źródło:: Archives of Acoustics; 2012, 37, 1; 19-22
0137-5075
Pojawia się w:: Archives of Acoustics
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 5.

Tytuł:: Characteristics of Acoustic Emission Signals Generated by the Contacts of the Selector
Autorzy:: Cichoń, A.
Borucki, S.
Wotzka, D.
Szmajda, M.
Powiązania:: https://bibliotekanauki.pl/articles/1417945.pdf
Data publikacji:: 2012-11
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 52.80.-s
43.28.Js
Opis:: An important part of electric power transformer is the on load tap changer which enables for voltage regulation in the network. Due to high level of failure frequency of these devices it is necessary 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 acoustic emission method for on load tap changer diagnosis. Results of scientifically-research works aiming to characterize the acoustic emission signals generated by a separated selector are presented in the paper. Measurements have been performed in a setup with a model of on load tap changer type VEL-110-27 from ELIN. Acoustic emission signals generated by the selector have been analyzed in detail. Analysis of the time-frequency components of signals generated by on load tap changer has been carried out with the short time Fourier transform and continuous wavelet transform. Based on the comparison outcome of acoustic emission signals generated by the power changer and by the selector two measuring paths endowed with wide band contact transducers have been proposed for the practical application.
Źródło:: Acta Physica Polonica A; 2012, 122, 5; 804-807
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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