Automatizirana obrada rezultata pokusa zagrijavanja transformatora

professional thesis

• Title (english): Automatic processing of transformer heat-run test results
• Author: Vedran Gojević
• Mentor: Zlatko Maljković (mentor)
• Committee member: Ivo Uglešić (predsjednik povjerenstva)
• Committee member: Zlatko Maljković (član povjerenstva)
• Committee member: Zvonimir Valković (član povjerenstva)
• Granter: University of Zagreb; Faculty of Electrical Engineering and Computing; (Department of Energy and Power Systems); Zagreb
• Defense date and country: 2010-05-27, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Electrical Engineering; Power Engineering

Abstract

Stanje izolacijskog sustava transformatora u direktnoj je vezi s njegovom pouzdanošću. Može se reći da mu pogonska sigurnost nije ugrožena sve dok je njegova izolacija u dobrom stanju. Kod transformatora najčešće se koristi kombinacija uljno-papirne izolacije. Povišene temperature pri pogonskom terećenju pospješuju razgradnju, a time i ubrzano starenje izolacijskog sustava, te direktno utječu na skraćenje očekivane životne dobi transformatora. Pokusom zagrijavanja transformatora simulira se termički najteža pogonska situacija, utvrđuju najviša zagrijanja ulja i namota, te se na taj način dokazuje da je rashladni sustav transformatora dobro dimenzioniran. U radu je dan pregled dozvoljenih graničnih vrijednosti zagrijanja za različite tipove transformatora. Također dan je pregled ispitnih metoda koje se mogu koristiti za provođenje pokusa zagrijanja. Detaljno je opisan pokus zagrijavanja metodom 'kratkog spoja' koja je zbog svoje praktičnosti i najčešće upotrebljavana metoda. Dana je i preporuka o korištenju dodatnih ispitnih metoda koje je korisno primjeniti uz pokus zagrijavanja. Pokus zagrijavanja definiran je standardom IEC 60076-2 ( 1993-04 ), a u fazi pripreme je novi. Za sad je izdan 'first draft' novog standarda IEC 14/563/CD ( 2007-08 ), pa je napravljena i usporedba trenutno važećeg standarda sa novim. Pokus zagrijavanja je dugotrajan pokus tijekom kojeg se prikupi velika količina mjerenih podataka. Da bi se odredile tražene vrijednosti zagrijanja dobivene podatke treba obraditi. Sama obrada je opsežna i kompleksna. Zato je opisana i programska podrška sa detaljnom matematičkom obradom. Sam program za obradu podataka napisan je u programskom paketu Excel. Excel je kompatibilan sa podacima dobivenim iz mjernih instrumenata, što omogućava jednostavan unos i brzu obradu velike količine ulaznih podataka. Omogućava i brzu obradu međurezultata tijekom samog pokusa zagrijavanja zbog potrebe za što ranijom procjenom konačnih vrijednosti.

Abstract (english)

Transformer reliability is in direct connection with condition of transformer insulation system. In other words, operation safety of transformer in not affected as long as transformer insulation is in good condition. The most common insulation system used in transformer is oil-celulose system. Higher temperatures during service load accelerate degradation of insulation and directly influence on reduction of transformer life-time expectancy. Temperature rise test simulates the most severe service load situation regarding thermal condition of tranformer, determines maximum oil and winding temperatures and as a result can be used as functional test and also proof-test of good dimensioning of transformer cooling system. This paper gives an overview of testing methods that can be used for performance of temperature rise test. Paper gives detail description of heat run test done by 'short circuit' method, which is proven to be the most practical and therefore most commonly used method. Also, a recommendation is given on applying of additional testing methods along with temperature rise test. Temperature rise test is defined by standard IEC 60076-2 ( 1993-04 ), and new standard is being prepared. By now, only 'first draft' of new standard IEC 14/563/CD ( 2007-08 ) is published, and also a comparison of old and new standard is given. Heat run test is long-run test during which a great amount of measuring data is collected. To determine the required heating values, measured data must be processed. Processing itself is a thorough, long-lasting and complex process. For that reason a programming support with detail mathematical model is also given. Data processing program itself is written using Excel program package, following the presumption that Excel is a program package majority of users is familiar with. Also, Excel is compatible with data taken by measurement instruments, making input simple and allowing quick processing of great numbers of input data. It also allows quick processing of semi-results during the temperature rise test, which is a result of need for evaluation of final results as early as possible.

• Keywords: pokus zagrijavanja; metoda 'kratkog spoja'; ulje; namot; hlađenje; zagrijanje; temperatura; transformator; gubici; najtoplija točka namota; najtoplije ulje
• Keywords (english): heat run test; 'short circuit' method; oil; winding; cooling; temperature rise; temperature; transformer; losses; winding hot spot; top oil
• Language: croatian
• URN:NBN: urn:nbn:hr:168:669390
• Study programme: Title: Postgraduate specialist Study in Transformers; Study programme type: university; Study level: postgraduate specialist; Academic / professional title: sveučilišni/a specijalist/specijalistica transformatora (sveučilišni/a specijalist/specijalistica transformatora)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Closed access
• Created on: 2022-10-21 09:49:33