Starenje transformatorske izolacije

undergraduate thesis

• Title (english): Ageing of transformer insulation
• Author: Tamara Fiolić
• Mentor: Domagoj Vrsaljko (mentor)
• Committee member: Domagoj Vrsaljko (predsjednik povjerenstva)
• Committee member: Zrinka Buhin Šturlić (član povjerenstva)
• Committee member: Vesna Ocelić Bulatović (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2017-09-19, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Basic Technical Sciences; Materials

Abstract

Transformatori se prema izvedbi dijele na uljne i suhe transformatore. U ovome radu opisani su uljni transformatori kod kojih su namoti međusobno i prema ostalim vodljivim dijelovima izolirani čvrstom izolacijom i uljem. Ulja koja se koriste kao izolacijske tekućine mogu biti esterska i mineralna ulja. Sintetsko estersko ulje je biorazgradljivo i ima veću toplinsku postojanost u usporedbi s mineralnim transformatorskim uljem, a mineralno ulje ima veću oksidacijsku stabilnost u usporedbi s esterskim uljem. Čvrsta izolacija transformatora je celulozni papir načinjen od visoko kvalitetnih pamučnih vlakana. Djelovanjem različitih čimbenika dolazi do degradacije celuloze te do oksidacije ulja pri čemu dolazi do starenja glavne izolacije uljnog transformatora i na temelju toga se provode ispitivanja pri kojima se utvrđuje starost izolacije prije nego li dođe do kvara transformatora. Ispitivanja vezana uz stanje izolacije provode se prema normama. Karakteristična ispitivanja transformatorskog ulja i papira su: kromatografska analiza plinova (DGA), fizikalno-kemijska ispitivanja ulja, ukupni sadržaj plinova u ulju, analiza sadržaja furana (HPLC), stupanj polimerizacije papira, prekidna čvrstoća papira i mjerenje sadržaja vlage u ulju i papiru. Osim karakterističnih ispitivanja transformatorskog ulja i papira, provode se i ispitivanja ulja i papira s ostalim izolacijskim materijalima, a neka od njih su: kiselost ulja, međupovršinska napetost između ulja i vode, faktor dielektričkih gubitaka i otpor ulja, nastajanje plinova iz gumenih materijala. Također, postoje metode ispitivanja izolacijskog sustava istosmjernim i izmjeničnim naponom, te mjerenjem temperature najtoplije točke namota.

Abstract (english)

The transformers can be divided into oil and dry transformers. In this paper are described oil transformers in which the windings are interconnected with other conductive parts by isolation and oil. The oils used as insulating liquids can be esters and mineral oils. Synthetic ester oils are biodegradable and have higher thermal stability compared to mineral transformer oils, and mineral oil has a higher oxidative stability compared to ester oil. Solid insulation of the transformer is cellulose paper made from high quality cotton fibers. By the action of various factors cellulose degradation and oil oxidation result in the aging of the main isolation of the oil transformer, and on this basis tests are carried out to determine the age of insulation before the transformer fails. Insulation-related tests are conducted according to standards. Characteristic tests of transformer oil and paper are: dissolved gas analysis (DGA), physico-chemical analysis of oil, total oil content in oil, high-performance liquid chromatography (HPLC), degree of polymerization of paper, tensile strength of paper and measurement of moisture content in oil and paper. In addition to the typical testing of transformer oil and paper, oil and paper testing with other insulating materials are also carried out, some of which are: oil acidity, surface tension between oil and water, dielectric loss factor and oil resistance, formation of rubber gases. Also, there are methods for testing the isolation system by DC and alternating voltage and by measuring the warmest temperature of the winding point.

• Keywords: transformator; estersko ulje; mineralno ulje; celulozni papir; izolacija transformatora
• Keywords (english): transformer; ester oil; mineral oil; cellulose paper; transformer insulation
• Language: croatian
• URN:NBN: urn:nbn:hr:149:752672
• Study programme: Title: Materials Science and Engineering - Undergraduate study; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka kemijskog inženjerstva (sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka kemijskog inženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2021-03-12 12:48:40