Proračun zagrijavanja dalekovodnog užeta tijekom promjene strujnog opterećenja

undergraduate thesis

• Title (english): Calculation of overhead line conductor heat-up during load change
• Author: Tin Gužvinec
• Mentor: Davor Grgić (mentor)
• Committee member: Davor Grgić (predsjednik povjerenstva)
• Committee member: Siniša Šadek (član povjerenstva)
• Committee member: Štefica Vlahović (član povjerenstva)
• Granter: University of Zagreb; Faculty of Electrical Engineering and Computing; Zagreb
• Defense date and country: 2017-07-10, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Electrical Engineering

Abstract

U uvodu je dan osvrt na stanje današnje prijenosne mreže u smislu reluktantnosti društva da gradi nove dalekovodne trase uz istovremeni izostanak namjere da potrošnju električne energije smanji. Opisani su načini da se tome problemu doskoči, te je objašnjena logika iza DLM-a (Dynamic Line Monitoring). Odabrana je metoda indirektnog mjerenja temperature vodiča preko provjesa kao potencijalno moguća. Uz pomoć IEEE 738 standarda opisana je termodinamička ravnoteža koja vlada prilikom toka električne energije kroz dalekovodno uže. Napravljen je program koji na temelju stanja užeta i okolice užeta proračunava struju ili temperaturu u stacionarnom stanju ili tranzijent temperature prilikom nagle promjene opterećenja voda. U CIGRE-ovoj brošuri broj 324 dana je poveznica između proračuna temperature i provjesa. Na temelju nje napravljeno je nekoliko verzija programa. Koja će se verzija koristit ovisi o tome je li raspon ravan ili kosi, te modelira li se dalekovodno uže parabolom ili lančanicom. Na kraju su se pomoću programa koji je nastao kombinacijom iznad opisanih programa proračunale i grafički prikazale ovisnosti provjesa dalekovodnog užeta pri raznim strujnim opterećenjima.

Abstract (english)

A comment was given in the introduction concerning the state of contemporary transmission grids in the sense that the society is very reluctant to build new overhead lines while showing no intention to decrease the consumption of energy. Ways and means to overcome this paradox have been revised and the logic behind DLR has been described. Indirect measurement of temperature by measuring sag has been dubbed plausible and it is precisely this method that is to be analyzed and modeled. Using IEEE 738 standard, thermodynamic equilibrium governing the temperature of the conductor during the flow of electrical energy through the conductor has been explained. Based on this mathematical model a computer program in C has been written. It has the ability to calculate steady state temperature if the steady state current is known, as well as transient change of temperature. Overhead line is situated in space and modeled as a catenary. Change of temperature results as a change of length, tension and ultimately sag. This relationship has been described in CIGRE-s brochure 324. By implementing the described methods three versions of a fortran90 computer program have been written. The reason behind three versions is a superior computer resource management. In the end a skewed span has been exposed to three different currents and a plot was made vividly visualizing the shape of different catenaries.
Key words: current rating, maximum temperature, high voltage line sag and tension calculation

• Keywords: dozvoljeno strujno opterećenje; maksimalna temperatura; proračun provjesa i naprezanja dalekovodnog užeta
• Keywords (english): current rating; maximum temperature; high voltage line sag and tension calculation
• Language: croatian
• URN:NBN: urn:nbn:hr:168:833979
• Study programme: Title: Electrical Engineering and Information Technology; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka elektrotehnike i informacijske tehnologije (sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka elektrotehnike i informacijske tehnologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Closed access
• Created on: 2019-03-13 20:45:12