Methods for calculations of high frequency transmitted over voltages through a power transformer

Jurišić, Bruno

prikaz prve stranice dokumenta Methods for calculations of high frequency transmitted over voltages through a power transformer

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doctoral thesis

Methods for calculations of high frequency transmitted over voltages through a power transformer

Zagreb: University of Zagreb, Faculty of Electrical Engineering and Computing, 2016. urn:nbn:hr:168:954411

Jurišić, Bruno

University of Zagreb
Faculty of Electrical Engineering and Computing
Department of Energy and Power Systems

Cite this document

APA 6th Edition

Jurišić, B. (2016). Methods for calculations of high frequency transmitted over voltages through a power transformer (Doctoral thesis). Retrieved from https://urn.nsk.hr/urn:nbn:hr:168:954411

MLA 8th Edition

Jurišić, Bruno. "Methods for calculations of high frequency transmitted over voltages through a power transformer." Doctoral thesis, University of Zagreb, Faculty of Electrical Engineering and Computing, 2016. https://urn.nsk.hr/urn:nbn:hr:168:954411

Chicago 17th Edition

Harvard

Jurišić, B. (2016). 'Methods for calculations of high frequency transmitted over voltages through a power transformer', Doctoral thesis, University of Zagreb, Faculty of Electrical Engineering and Computing, accessed 27 March 2023, https://urn.nsk.hr/urn:nbn:hr:168:954411

Vancouver

Jurišić B. Methods for calculations of high frequency transmitted over voltages through a power transformer [Doctoral thesis]. Zagreb: University of Zagreb, Faculty of Electrical Engineering and Computing; 2016 [cited 2023 March 27] Available at: https://urn.nsk.hr/urn:nbn:hr:168:954411

IEEE

B. Jurišić, "Methods for calculations of high frequency transmitted over voltages through a power transformer", Doctoral thesis, University of Zagreb, Faculty of Electrical Engineering and Computing, Zagreb, 2016. Available at: https://urn.nsk.hr/urn:nbn:hr:168:954411

Cite this item: https://urn.nsk.hr/urn:nbn:hr:168:954411

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Metadata

Title	Methods for calculations of high frequency transmitted over voltages through a power transformer
Title (croatian)	Metode proračuna prenesenih prenapona visokih frekvencija energetskoga transformatora
Author	Bruno Jurišić MBZ: -333386
Mentor	Ivo Uglešić (mentor)
Mentor	Francoise Paladian (komentor) strani drzavljanin: Nije dostupno
Committee member	Ivo Uglešić (član povjerenstva)
Granter	University of Zagreb Faculty of Electrical Engineering and Computing (Department of Energy and Power Systems) Zagreb
Defense date and country	2016, Croatia
Scientific / art field, discipline and subdiscipline	TECHNICAL SCIENCES Electrical Engineering Power Engineering
Universal decimal classification (UDC)	621.3 - Electrical engineering
Abstract	Traditional transformer models available in EMTP-like software packages are not capable of representing transformer behaviour at high frequencies which occur during fast transient. Moreover, the existing high frequency transformer models are often too complex or require confidential information on transformer geometry. In this Doctoral Thesis two models of a transformer compatible with EMTP-like software packages capable of representing the electromagnetic interaction between a transformer and an electric system, as well as voltage and current at the external nodes of the transformer, are established. These models are suitable for usage in insulation coordination studies, especially for power utilities’ engineers. The developed Black Box model is based on sweep frequency response analyser measurements of the transformer’s admittance matrix, while the developed Grey Box model is based on a finite elements method calculation, derived from limited knowledge of the internal lay-out of the transformer. Both models are prepared for use in an EMTP-like software packages using the rational approximation, passivity enforcement and state space equations. The models were validated using lightning impulse tests’ measurements and transformer’s frequency response field measurements. Furthermore, the developed models were tested on a real application, taking into account the randomness of lightning. Therefore, a procedure for the calculation of transmitted lightning overvoltages through a power transformer in EMTP-like software package, which takes into account the uncertainties of the lightning current parameters, is established. As one of the developed transformer models is based on a limited knowledge of the internal lay-out of the transformer, it is important to have tools helping the engineer to debate the most influential parameters. A sensitivity analysis using the Morris’ Method is conducted to detect the most influential parameters on the electromagnetic behaviour of power transformers, as well as to detect zero-influential ones.
Abstract (croatian)	Tradicionalni modeli transformatora dostupni u računalnim programima za proračun elektromagnetskih prijelaznih pojava (EMTP) nisu dostatni za simulaciju elektromagnetskog ponašanja transformatora pri prenaponima visokih frekvencija. S druge strane, modeli transformatora za prenapone visokih frekvencija su često složeni i zahtijevaju podatke o geometriji transformatora koji su industrijska tajna. U ovoj doktorskoj disertaciji opisana su dva razvijena modela transformatora za simulaciju elektromagnetskih interakcija između transformatora i ostatka elektroenergetske mreže te za proračun napona i struja na vanjskim stezaljkama transformatora, namijenjena upotrebi u EMTP računalnim alatima. Modeli su namijenjeni inženjerima koji rade u elektroprivredi te primjenjivi u studijama koordinacije izolacije. Razvijeni model crne kutije se temelji na mjerenju frekvencijskog odziva matrice admitancije transformatora dok se razvijeni model sive kutije temelji na proračunu elektromagnetskih polja primjenom metode konačnih elementa i ograničenog znanja o geometriji transformatora. Oba modela su prilagođena upotrebi u EMTP računalnim alatima na način da su modeli opisani pomoću matematičke metode racionalne aproksimacije te jednadžbe prostora stanja. Korištene racionalne funkcije za matematički opis modela zadovoljavaju uvjet pasivnosti. Usporedbom rezultata proračuna s mjerenjima vidljivo je da oba razvijena modela zadovoljavajuće predstavljaju transformator pri proračunu prenesenih prenapona tijekom ispitivanja udarnim impulsom te pri proračunu frekvencijskog odziva transformatora. Nadalje, razvijeni modeli su testirani pri realnom događaju kvara u elektroenergetskoj mreži, uzimajući u obzir nesigurnosti parametara struje munje. Za potrebe ove analize razvijena je procedura za proračun prenesenih prenapona transformatora uzrokovanih munjom u računalnom alatu za proračun elektromagnetskih prijelaznih pojava, koja uzima u obzir nesigurnosti parametara struje munje. Budući da je jedan od razvijenih modela transformatora temeljen na ograničenom znanju o geometriji transformatora, važno je napraviti alat koji će omogućiti inženjerima razumijevanje utjecaja pojedinih parametara na ponašanje modela. Analiza osjetljivosti je provedena na modelu transformatora sive kutije koristeći Morisovu metodu. Cilj takve analize bio je predvidjeti ključne, najutjecajnije parametre na elektromagnetsko ponašanje energetskog transformatora, kao i one koji imaju zanemariv utjecaj na ponašanje modela.
Keywords
Keywords (croatian)
Language	english
URN:NBN	urn:nbn:hr:168:954411
Study programme	Title: Electrical Engineering and Computing Study programme type: university Study level: postgraduate Academic / professional title: Doktor znanosti elektrotehnike i računarstva (Doktor znanosti elektrotehnike i računarstva)
Type of resource	Text
Extent	228 str. ; 30 cm.
File origin	Born digital
Access conditions	Closed access
Terms of use
Repository	FER Repository
Created on	2019-04-10 13:37:21