Modeli transformatora za proračun prenesenih prenapona visokih frekvencija

master's thesis

• Title (english): Transformer models for calculation of high frequency transmitted over-voltages
• Author: Luka Bučar
• Mentor: Ivo Uglešić (mentor)
• Committee member: Ivo Uglešić (predsjednik povjerenstva)
• Committee member: Ivica Pavić (član povjerenstva)
• Committee member: Boško Milešević (član povjerenstva)
• Granter: University of Zagreb; Faculty of Electrical Engineering and Computing; Zagreb
• Defense date and country: 2017-07-17, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Electrical Engineering

Abstract

Ovim radom razmotreni su utjecaji prenapona visokih frekvencija prouzrokovanih atmosferskim izbijanjima i operacijom vakuumskih rastavljača. U takvim uvjetima transformatorski RLCG parametri se ponašaju drugačije što navodi na potrebu prilagodbe modela za visokofrekvencijske uvjete. Zbog ograničenosti manjkom detalja o unutarnjoj geometriji transformatora modeliranje se provodi modelom „sive kutije“ koja se temelji na metodi konačnih elemenata. Cilj je takvim modelom odrediti raspodjelu napona u namotu. U Matlabu se postavljaju ulazni parametri geometrije transformatorskog prozora i broja segmenata. Zatim se u FEMM-u provodi crtanje geometrije, elektrostatski i magnetski proračun, te proračun R, L i C parametra. Nakon čega se ponovno u Matlabu vrši proračun G parametra i izračun matrica vodljivosti vanjskih i unutarnjih čvorišta. U EMTP-RV-u se računaju konačne jednadžbe stanja. Kako prvi dio rada pojašnjava teorijsku pozadinu i cilj takve simulacije, drugi dio rada usredotočen je na detalje simuliranog modela, dimenzije transformatorskog namota koja je dostupna i testne scenarije čiji rezultati se naposljetku uspoređuju CIGRE-nim rezultatima testiranog modela.

Abstract (english)

This document will explain the effects of high frequency overvoltages caused by atmospheric discharge and switching operations with vacuum circuit breaker. In such conditions transformer RLCG parameters behave differently, suggesting the need to adapt the model for high frequency conditions. Due to limited detail on transformer interior geometry, modeling is carried out using „grey box“ model based on finite element method. The goal is to determine the voltage distribution in the winding. The Matlab is used to set the input parameters of the geometry of the transformer window and the number of segments. Then, in FEMM, geometry was drawn, electrostatic and magnetic calculation, and calculation of R, L and C parameters are performed. After that, Matlab is used to calculate the G parameter and calculate the matrix of conductivity of the external and internal nodes. EMTP-RV calculates the finite equations of the state. As the first part of this paper clarified the theoretical background and purpose of such simulation, the second part of the paper focuses on the details of the simulated model, available transformer winding dimensions and the test scenarios whose results are ultimately compared to CIGRE results of the tested model.

• Keywords: Transformator; model „siva kutija“; visokofrekvencijski model; brze prijelazne pojave; atmosferski prenaponi; EMTP; metoda konačnih elemenata
• Keywords (english): Transformer; „grey box“ model; high frequency model; fast front transients; atmospheric discharge overvoltages; EMTP; finite element method
• Language: croatian
• URN:NBN: urn:nbn:hr:168:789498
• Study programme: Title: Electrical Engineering and Information Technology; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka elektrotehnike i informacijske tehnologije (magistar/magistra inženjer/inženjerka elektrotehnike i informacijske tehnologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Closed access
• Created on: 2019-03-13 19:24:05