Wyniki wyszukiwania - BazTech

1

Detection and classification of short-circuit faults on a transmission line using current signal

Coban Melih, Tezcan Suleyman S.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2021

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Vol. 69, nr 4

art. no. e137630

EN

This study offers two Support Vector Machine (SVM) models for fault detection and fault classification, respectively. Different short circuit events were generated using a 154 kV transmission line modeled in MATLAB/Simulink software. Discrete Wavelet Transform (DWT) is performed to the measured single terminal current signals before fault detection stage. Three level wavelet energies obtained for each of three-phase currents were used as input features for the detector. After fault detection, half cycle (10 ms) of three-phase current signals was recorded by 20 kHz sampling rate. The recorded currents signals were used as input parameters for the multi class SVM classifier. The results of the validation tests have demonstrated that a quite reliable, fault detection and classification system can be developed using SVM. Generated faults were used to training and testing of the SVM classifiers. SVM based classification and detection model was fully implemented in MATLAB software. These models were comprehensively tested under different conditions. The effects of the fault impedance, fault inception angle, mother wavelet, and fault location were investigated. Finally, simulation results verify that the offered study can be used for fault detection and classification on the transmission line.

2

Applying machine translation methods in the problem of automatic text correction

Jarmosz Wojciech

Annals of Computer Science and Information Systems

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2021

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Vol. 26

227--228

EN

This document describes the problem of automatic text corrections. The author presents a classification of errors, a process of correcting texts and a proof of concept as a containerized version of machine translation system - MSuedin.

3

Communication assisted fuzzy based adaptive protective relaying scheme for microgrid

Chaitanya B. K., Soni A. K., Yadav A.

Journal of Power Technologies

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2018

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Vol. 98, nr 1

57--69

EN

This study proposes a communication assisted fuzzy based adaptive protective relaying scheme for fault detection, fault classification and faulty phase identification of microgrid along with a solution to isolate the microgrid from the utility grid by disconnecting the static-switch. Any fault in the utility grid causes the microgrid to be isolated from the utility grid whereas if there is a fault in the microgrid it continues to operate with the utility grid. An adaptive fuzzy inference system has been developed using a separate fuzzy rule base for the two modes of operation of microgrid, i.e. islanded mode or grid connected mode. The Central Grid Status Communication System (CGSCU) is considered which monitors the status of PCC and sends a command signal to the relays so that the relay settings are updated with new rules for any transition in the mode of the microgrid. The fundamental phasor amplitude and zero sequence component of current signals are used as input features, fault detection, fault classification and faulty phase identification. A standard microgrid model IEC 61850-7-420 was simulated using MATLAB/SIMULINK. The proposed method is tested for all types of faults by varying fault parameters and also for dynamic situations such as connection/disconnection of DGs and loads. The test results substantiate the effectiveness of the method.

4

Computer system for casting defects classification based on Polish, French and Czech specifications

Adrian A., Durak J., Mrzygłód B., Kluska-Nawarecka S., Miłkowska K., Wilk-Kołodziejczyk D.

Archives of Foundry Engineering

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2009

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Vol. 9, iss. 3

5-8

EN

Many foundries existing in Poland make casts for local and external market. It is necessary to adopt a quality control to client's requirements. The main problem in the quality control of casting products is to detect and to classify properly defects. Polish defect classification is base nod the Polish Norm. In other countries (Czech Republic and France for example), other systems exist for classification, they are based on the different criteria and groups of defects. In other word the classification of casting defects is country-specific. Translation of defects names and their descriptions introduce additional level of difficulties. The authors propose multi-context system for finding equivalents of casting defects from one classification system to another, using original languages for each classification.

5

Miary dokładności parametrów zewnętrznych czwórnika typu X o zmiennych rezystancjach. Cz. 2, Miary parametrów mostka 4R jako czwórnika przy zasilaniu napięciowym i dowolnym

Warsza Z. L.

Elektronika : konstrukcje, technologie, zastosowania

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2006

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Vol. 47, nr 3

49-53

PL

Wyznaczono miary dokładności napięcia wyjściowego i transmitancji napięciowej nieobciążonego czwórnika X w postaci mostka 4R o zasilaniu napięciowym w funkcji wartości bezwzględnych i względnych rezystancji wewnętrznych i ich miar. Omówiono przypadek ogólny niezależnych przyrostów tych rezystancji oraz kilka przypadków szczególnych pomiarów jednoparametrowych. Podano wzory względnych błędów bieżących i granicznych oraz standardowych miar losowych transmitancji napięciowej mostka 4R. Omówiono też miary rezystancji wejściowych na zaciskach mostka dla obu rodzajów jego zasilania. Przedstawiono wzory uogólnione i oryginalną pośrednią metodykę wyznaczania miar dokładności parametrów roboczych czwórnika przy dowolnych rezystancjach źródła i obciążenia.

EN

Scheme of the 4R bridge as twoport X of variable arm resistances and of voltage supply is presented. Formulas of its basic terminal parameters and of their errors as functions of its open circuit impedance parameters and their errors are given. Errors of the bridge supplied by voltage source are considered in details, i.e. errors of the voltage transmittance of open--circuit output, input and output resistances of this bridge and errors of their increments are described and discussed in details including some particular cases. Accuracy measures of voltage to voltage transmittances of the output circuit open-bridge are given. Formulas of errors of input and output resistances of both kind of twoport X supply are given. Method of obtaining accuracy of working terminal parameters of arbitrary supplied and loaded bridge as twoport, based on its open circuit terminal parameters is also presented. In the summary are compared relative accuracy measures of current to voltage and voltage to voltage transmittances of twoport X.