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Wyszukujesz frazę "harmonic signal" wg kryterium: Temat


Wyświetlanie 1-8 z 8
Tytuł:
Prony’s method with reduced sampling - numerical aspects
Autorzy:
Zygarlicki, J.
Mroczka, J.
Powiązania:
https://bibliotekanauki.pl/articles/220676.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
signal analysis
harmonic analysis
signal processing
power quality
Opis:
This paper presents a new modification of the least-squares Prony’s method with reduced sampling, which allows for a significant reduction in the number of the analysed signal samples collected per unit time. The specific combination of non-uniform sampling with Prony’s method enables sampling of the analysed signals at virtually any average frequency, regardless of the Nyquist frequency, maintaining high accuracy in parameter estimation of sinusoidal signal components. This property allows using the method in measuring devices, such as for electric power quality testing equipped with low power signal processors, which in turn contributes to reducing complexity of these devices. This paper presents research on a method for selecting a sampling frequency and an analysis window length for the presented method, which provide maximum estimation accuracy for Prony’s model component parameters. This paper presents simulation tests performed in terms of the proposed method application for analysis of harmonics and interharmonics in electric power signals. Furthermore, the paper provides sensitivity analysis of the method, in terms of common interferences occurring in the actual measurement systems.
Źródło:
Metrology and Measurement Systems; 2014, 21, 3; 521-534
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Non-contact harmonic detection of ferromagnetic material defects based on SQGSR and OPLTF
Autorzy:
Zhao, Yizhen
Wang, Xinhua
Chen, Yingchun
Ju, Haiyang
Shuai, Yi
Powiązania:
https://bibliotekanauki.pl/articles/1848986.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
harmonic detection
ferromagnetic materials defects
focusing vector array
signal extraction algorithm
Opis:
In order to find the defects in ferromagnetic materials, a non-contact harmonic detection method is proposed. According to the principle of frequency modulated carrier wave, a tunnel magneto resistance harmonic focusing vector array detector was designed which radiates lower and higher frequency electromagnetic waves through the coil array to the detection targets. We use bistable stochastic resonance to enhance the energy of collected weak target signal and apply quantum computation and a Sobol low deviation sequence to improve genetic algorithm performance. Then we use the orthogonal phase-locked loop to eliminate the intrinsic background excitation field and tensor calculations to fuse the vector array signal. The finite element model of array detector and the magnetic dipole harmonic numerical model were also established. The simulation results show that the target signal can be identified effectively, its focusing performance is improved by 2 times, and the average signal-to-noise ratio is improved by 9.6 times after the algorithm processing. For the experiments, we take Q235 steel pipeline as the object to realize the recognition of three defects. Compared with the traditional methods, the proposed method is more effective for ferromagnetic materials defects detection.
Źródło:
Metrology and Measurement Systems; 2021, 28, 1; 55-72
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On the statistical analysis of the harmonic signal autocorrelation function
Autorzy:
Sienkowski, Sergiusz
Krajewski, Mariusz
Powiązania:
https://bibliotekanauki.pl/articles/2055177.pdf
Data publikacji:
2021
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
harmonic signal
autocorrelation function
mean squared error
sygnał harmoniczny
funkcja autokorelacji
błąd średniokwadratowy
Opis:
The article presents new tools for investigating the statistical properties of the harmonic signal autocorrelation function (ACF). These tools enable identification of the ACF estimator errors in measurements in which the triggering of the measurements is non-synchronized. This is important because in many measurement situations the initial phase of the measured signal is random. The developed tools enable testing the ACF estimator of a harmonic signal in the presence of Gaussian noise. These are the formulas on the basis of which the statistical properties of the estimator can be determined, including the bias, the variance and the mean squared error (MSE). For comparison, the article also presents the ACF statistical analysis tools used in the conditions of synchronized measurement triggering, known from the literature. Operation of the new tools is verified by simulation and experimental studies. The conducted research shows that differences between the MSE results obtained with the use of the developed formulas and those attained from simulations and experimental tests are not greater than 1 dB.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2021, 31, 4; 729--744
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On the use of multi-harmonic least-squares fitting for THD estimation in power quality analysis
Autorzy:
Ramos, P. M.
Janeiro, F. M.
Radil, T.
Powiązania:
https://bibliotekanauki.pl/articles/220641.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
harmonic analysis
power quality
signal reconstruction
spectral analysis
harmonic distortion
Opis:
The quality of the supplied power by electricity utilities is regulated and of concern to the end user. Power quality disturbances include interruptions, sags, swells, transients and harmonic distortion. The instruments used to measure these disturbances have to satisfy minimum requirements set by international standards. In this paper, an analysis of multi-harmonic least-squares fitting algorithms applied to total harmonic distortion (THD) estimation is presented. The results from the different least-squares algorithms are compared with the results from the discrete Fourier transform (DFT) algorithm. The algorithms are assessed in the different testing states required by the standards.
Źródło:
Metrology and Measurement Systems; 2012, 19, 2; 295-306
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fast estimation of the non-stationary amplitude of a harmonically distorted signal using a Kalman filter
Autorzy:
Kovač, U.
Košir, A.
Powiązania:
https://bibliotekanauki.pl/articles/220868.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
amplitude estimation
harmonic signal
harmonic distortion
Kalman filter
Opis:
In this paper we introduce a self-tuning Kalman filter for fast time-domain amplitude estimation of noisy harmonic signals with non-stationary amplitude and harmonic distortion, which is the problem of a contactvoltage measurement to which we apply the proposed method. The research method is based on the self-tuning of the Kalman filter's dropping-off behavior. The optimal performance (in terms of accuracy and fast response) is achieved by detecting the jump of the amplitude based on statistical tests of the innovation vector of the Kalman filter and reacting to this jump by adjusting the values of the covariance matrix of the state vector. The method's optimal configuration of the parameters was chosen using a statistical power analysis. Experimental results show that the proposed method outperforms competing methods in terms of speed and accuracy of the jump detection and amplitude estimation.
Źródło:
Metrology and Measurement Systems; 2013, 20, 1; 27-42
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Operation of voltage transformer in grids with distorted signals
Autorzy:
Kasprzak, A.
Orlikowski, M.
Brodecki, D.
Powiązania:
https://bibliotekanauki.pl/articles/200071.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
voltage transformer
distorted signal
higher harmonic
accuracy
error
Opis:
Non-sinusoidal currents and voltages caused by nonlinear loads appear in power grids more and more frequently. Determination of the voltage transformer accuracy in such conditions makes a problem. Firstly, due to lack of definition of errors for distorted signals and secondly, typical measurement bridges do not accept higher harmonics. In the paper, the new definition of transformation error for distorted voltages has been proposed and some measurement results have been presented.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2011, 59, 4; 551-554
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Orthogonal Harmonic Signals of the Generalized Class
Autorzy:
Balashov, Vitaliy
Oreshkov, Vasyl
Barba, Iryna
Iegupova, Olena
Powiązania:
https://bibliotekanauki.pl/articles/1839479.pdf
Data publikacji:
2021
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
Fourier transformation
OFDM
orthogonal harmonic signals
orthogonality interval
signal envelope
Opis:
Telecommunications transmission technologies with OFDM rely on orthogonal harmonic signal (OHS) systems. The criteria applicable to synthesizing OHS systems of the generalized class, including both classical signals and signals whose duration exceeds the orthogonality interval, have been considered. The problems of minimizing the effective width of the spectrum of the generalized class OHS have been solved. Estimates of the efficiency of the generalized class OHS have been given.
Źródło:
Journal of Telecommunications and Information Technology; 2021, 1; 64-70
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Orthogonal Harmonic Signals of the Generalized Class
Autorzy:
Balashov, Vitaliy
Oreshkov, Vasyl
Barba, Iryna
Iegupova, Olena
Powiązania:
https://bibliotekanauki.pl/articles/1839469.pdf
Data publikacji:
2021
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
Fourier transformation
OFDM
orthogonal harmonic signals
orthogonality interval
signal envelope
Opis:
Telecommunications transmission technologies with OFDM rely on orthogonal harmonic signal (OHS) systems. The criteria applicable to synthesizing OHS systems of the generalized class, including both classical signals and signals whose duration exceeds the orthogonality interval, have been considered. The problems of minimizing the effective width of the spectrum of the generalized class OHS have been solved. Estimates of the efficiency of the generalized class OHS have been given.
Źródło:
Journal of Telecommunications and Information Technology; 2021, 1; 64-70
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-8 z 8

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