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Wyszukujesz frazę "frequency support" wg kryterium: Temat


Wyświetlanie 1-4 z 4
Tytuł:
Modelling of synchronous generators for the analysis of frequency transients above 1 Hz/s
Autorzy:
Assenkamp, Alf
Powiązania:
https://bibliotekanauki.pl/articles/2135729.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
control system
distributed energy systems
frequency support
generator model
RoCoF
synchronous generators
synchronous machines
Opis:
Large synchronous generators are of high importance for the stability of power systems. They generate the frequency of the system and stabilize it in case of severe grid faults like trips of large in-feeders or loads. In distributed energy systems, in-feed via inverters will replace this generation in large parts. Modern inverters are capable of supporting grid frequency during severe faults by different means on the one hand. On the other hand, higher Rates of Change of Frequency (RoCoF) after incidents need to be accustomed by future systems. To be able to analyse the RoCoF withstand capability of synchronous or induction generators, suitable models need to be developed. Especially the control and excitation system model need enhancements compared to models proposed in standards like IEEE Std 421.5. This paper elaborates on the necessary modelling depth and validates the approach with example results.
Źródło:
Archives of Electrical Engineering; 2022, 71, 3; 687--700
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Music Performers Classification by Using Multifractal Features : A Case Study
Autorzy:
Reljin, N.
Pokrajac, D.
Powiązania:
https://bibliotekanauki.pl/articles/177266.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
music classification
multifractal analysis
support vector machines
cross-validation
mel-frequency cepstral coefficients
Opis:
In this paper, we investigated the possibility to classify different performers playing the same melodies at the same manner being subjectively quite similar and very difficult to distinguish even for musically skilled persons. For resolving this problem we propose the use of multifractal (MF) analysis, which is proven as an efficient method for describing and quantifying complex natural structures, phenomena or signals. We found experimentally that parameters associated to some characteristic points within the MF spectrum can be used as music descriptors, thus permitting accurate discrimination of music performers. Our approach is tested on the dataset containing the same songs performed by music group ABBA and by actors in the movie Mamma Mia. As a classifier we used the support vector machines and the classification performance was evaluated by using the four-fold cross-validation. The results of proposed method were compared with those obtained using mel-frequency cepstral coefficients (MFCCs) as descriptors. For the considered two-class problem, the overall accuracy and F-measure higher than 98% are obtained with the MF descriptors, which was considerably better than by using the MFCC descriptors when the best results were less than 77%.
Źródło:
Archives of Acoustics; 2017, 42, 2; 223-233
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Specific emitter identification using geometric features of frequency drift curve
Autorzy:
Zhao, Y.
Wui, L.
Zhang, J.
Li, Y.
Powiązania:
https://bibliotekanauki.pl/articles/200575.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
specific emitter identification
geometric features
frequency drift
adaptive fractional spectrogram
support vector machine
emiter
cechy geometryczne
dryf częstotliwości
spektrogram
Opis:
Specific emitter identification (SEI) is a technique for recognizing different emitters of the same type which have the same modulation parameters. Using only the classic modulation parameters for recognition, one cannot distinguish different emitters of a same type. To solve the problem, new features urgently need to be developed for recognition. This paper focuses on the common phenomenon of frequency drift, defines geometric features of frequency drift curve and, finally, proposes a practical algorithm of specific emitter identification using the geometric features. The proposed algorithm consists of three processes: instantaneous frequency estimation based on the adaptive fractional spectrogram, feature extraction of frequency drift curve based on geometric methods for describing a curve and recognition process based on support vector machine. Simulation results show that the identification rate is generally more than 98% above –5 dB of signal to noise ratio (SNR), and real data experiment verifies the practical performance of the proposed algorithm.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2018, 66, 1; 99-108
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Protection against high-frequency radiation of aviation electronic support systems used in air transport
Autorzy:
Dzunda, M.
Cekanova, D.
Cobirka, L.
Zak, P.
Dzurovcin, P.
Powiązania:
https://bibliotekanauki.pl/articles/116582.pdf
Data publikacji:
2018
Wydawca:
Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
Tematy:
air transport
aviation electronic support systems
high-frequency radiation
radiation
electromagnetic radiation
arport radars
air electronic safety technology
radar electric field
Opis:
The aim of the article is to analyze the impact of electromagnetic radiation of aviation electronic support systems on environmental segments and a human organism. We were looking for effects of electromagnetic radiation on inhabitants and environment in the vicinity of airport radars. We accomplished measuring and found out the level of radiation harmfulness of electromagnetic radiation sources. In the conclusion we suggest to eliminate the negative impact of electromagnetic radiation on the human organism. At the same time we present the ways how workers, performing their jobs in the vicinity of strong electromagnetic radiation source, can protect themselves in compliance with legislative of the Slovak Republic. We have proposed some possibilities of protection for workers who work close to a strong source of electromagnetic radiation.
Źródło:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2018, 12, 1; 183-186
2083-6473
2083-6481
Pojawia się w:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-4 z 4

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