Wyniki wyszukiwania - BazTech

1

Fast one-cycle frequency estimation of a single sinusoid in noise using downsampled linear prediction model

Duda Krzysztof, Zieliński Tomasz P.

Metrology and Measurement Systems

|

2021

|

Vol. 28, nr 4

661--672

EN

A new solution to the problem of frequency estimation of a single sinusoid embedded in the white Gaussian noise is presented. It exploits, approximately, only one signal cycle, and is based on the well-known 2nd order autoregressive difference equation into which a downsampling is introduced. The proposed method is a generalization of the linear prediction based Prony method for the case of a single undamped sinusoid. It is shown that, thanks to the proposed downsampling in the linear prediction signal model, the overall variance of the least squares solution of frequency estimation is decreased, when compared to the Prony method, and locally it is even close to the Cramér-Rao Lower Bound, which is a significant improvement. The frequency estimation variance of the proposed solution is comparable with, computationally more complex, the Matrix Pencil and the Steiglitz-McBride methods. It is shown that application of the proposed downsampling to the popular smart DFT frequency estimation method also significantly reduces the method variance and makes it even better than the least squares smart DFT. The noise immunity of the proposed solution is achieved simultaneously with the reduction of computational complexity at the cost of narrowing the range of measured frequencies, i.e. a sinusoidal signal must be sufficiently oversampled to apply the proposed downsampling in the autoregressive model. The case of 64 samples per period with downsampling up to 16, i.e. 1/4th of the cycle, is presented in detail, but other sampling scenarios, from 16 to 512 samples per period, are considered as well.

2

Monitoring of electric arc furnace supply voltage frequency using phasor analysis

Barczentewicz Szymon, Duda Krzysztof, Bień Andrzej

Przegląd Elektrotechniczny

|

2020

|

R. 96, nr 5

51--54

EN

This paper presents the results of measurement experiment conducted in the operating steel plant. Frequency analysis of measured signals revealed an interesting phenomenon, as it happened that after switching off the electric arc furnace, the frequency of the supplying voltage and current increased slightly instead of decreasing, as we would normally expect. This abnormal frequency behaviour was identified by phasor analysis and also confirmed by the DTFT (Discrete Time Fourier Transform) analysis, and the MatrixPencil analysis.

PL

Artykuł prezentuje wyniki eksperymentu wykonanego w hucie stali. Analiza częstotliwości ujawniła ciekawe zjawisko, w którym po wyłączeniu pieca łukowego częstotliwości napięcia i prądu w wewnętrznej części huty zmniejszyła się zamiast zwiększyć, jak można by się spodziewać. To nieoczekiwane zjawisko zostało zarejestrowane z pomocą PMU i potwierdzone przez transformację Fouriera dla sygnałów dyskretnych oraz analizę MatrixPencil.

3

The Use of PMU Data for Detecting and Monitoring Selected Electromagnetic Disturbances

Barczentewicz Szymon H., Bień Andrzej, Duda Krzysztof

International Journal of Electronics and Telecommunications

|

2020

|

Vol. 66, No. 4

775--780

EN

Power quality (PQ) monitoring is important for both the utilities and also the users of electric power. The most widespread measurement instrument used for PQ monitoring is the PQM (Power Quality Monitor) or PQA (Power Quality Analyzer). In this paper we propose the usage of PMU data for PQ parameters monitoring. We present a new methodology of PQ parameters monitoring and classification based on PMU data. The proposed methodology is tested with real measurements performed in distribution system using dedicated PMU system.

4

Monitorowanie częstotliwości pieca łukowego wykorzystujące technikę fazorową

Barczentewicz Szymon, Duda Krzysztof, Bień Andrzej

Zeszyty Naukowe Wydziału Elektrotechniki i Automatyki Politechniki Gdańskiej

|

2019

|

Nr 67

115--118

PL

Artykuł prezentuje wyniki eksperymentu wykonanego w hucie stali. System pomiarowy wykorzystany do przeprowadzenia pomiarów jest oparty na systemie czasu rzeczywistego z układem FPGA, który pozwala na wykonanie pomiarów sygnałów analogowych. Trzy fazy napięcia i prądu zostały zmierzone w trzech wybranych punktach sieci zasilającej. Analiza częstotliwości ujawniła ciekawe zjawisko, w którym po wyłączeniu pieca łukowego częstotliwości napięcia i prądu w wewnętrznej części huty zmniejszyła się zamiast zwiększyć, jak można by się spodziewać. To nieoczekiwane zjawisko zostało zarejestrowane z pomocą PMU i potwierdzone przez analizę MatrixPencil. Przeprowadzone pomiary potwierdziły zasadność monitorowania częstotliwości napięcia zasilania pieców łukowych za pomocą analizy fazora.

EN

This paper presents the results of measurement experiment conducted in the operating steel plant. The measurement system was built with real time system with FPGA module, capable of measuring analog signals. Three phase voltages and currents were acquired in three selected points of supplying power network. Frequency analysis of measured signals revealed an interesting phenomenon, as it happened that after switching off the electric arc furnace, the frequency of the supplying voltage and current increased slightly instead of decreasing, as we would normally expect. This abnormal frequency behavior was identified by phasor analysis and also confirmed by DTFT (Discrete Time Fourier Transform) analysis, and MatrixPencil analysis. Performed measurements proved phasor analysis to be a useful application for electric arc furnace frequency monitoring.