Analiza utjecajnih čimbenika na kvalitetu čeličnih limova za jezgre transformatora

professional thesis

• Title (english): Analysis of the influence factors on the quality of transformer core steels
• Author: Dario Trbušić
• Mentor: Tomislav Filetin (mentor)
• Committee member: Zlatko Maljković (predsjednik povjerenstva)
• Committee member: Tomislav Filetin (član povjerenstva)
• Committee member: Žarko Janić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Electrical Engineering and Computing; (Department of Electric Machines, Drives and Automation); Zagreb
• Defense date and country: 2015-02-03, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Electrical Engineering; Power Engineering

Abstract

Jezgra je bitan dio transformatora, generatora, motora i ostale električne opreme. Magnetski tok jezgre i napon se koriste za pokretanje motora, proizvodnju električne energije i pretvara se u transformatoru. Magnetski materijali se koriste kao sastavni dijelovi električnih proizvoda, koji imaju osnovni zadatak da usmjereno vode magnetski tok i time omogućuju elektromagnetske pretvorbe na kojima se zasniva funkcija tih proizvoda. Orijentirani magnetski lim uglavnom se koristi kao magnetski aktivni materijal u jezgri električnih transformatora, s obzirom na visoku magnetsku propusnost i njegove niske "gubitke jezgre" (gubitak snage u obliku topline koja se pojavljuje zbog pojave rasipanja koja djeluje u materijalu tijekom procesa magnetiziranja). Trenutno najprivlačnije i pristupačne tehnologije za proizvodnju orijentiranog magnetskog lima temeljene su na "acquired inhibition" strategiji. Potencijali za smanjenje gubitaka su povezani sa sve tri komponente gubitaka (anomalijski gubici, gubici vrtložnih struja i gubici histereze) i to su: tanji magnetski lim (bez destabilizacije sekundarne rekristalizacije); izglađena površina lima (prilagodba između čelika i izolacijskog sloja); oštrija tekstura s poboljšanom strukturom zrna (generiranje mikro zrna, kontrola oblika zrna); poboljšanje prevlaka s povećanim naprezanjem i optimizacija laserskog zarezivanja površine lima. Jedan od instrumenata kontrole i osiguranja kvalitete magnetskog lima kod proizvođača transformatora, koji dolazi izvana i ulazi u proizvodni proces jesu „Tehničko-dobavni uvjeti“. Tehničko-dobavnim uvjetima definiraju se magnetska svojstva, geometrijske karakteristike, tehnološke karakteristike, tolerance, ispitne procedure, uvjeti isporuke i način pakiranja magnetskog lima u konačno žarenom stanju. Tipično se za trostupne „Step-lap” jezgre faktor kvarenja lima distributivnih transformatora kreće oko 20 %, a za jezgre energetskih transformatora oko 10 %. U svrhu smanjivanja gubitaka i buke, broj limova u slogu treba biti što manji, a broj koraka što veći. Zbog produktivnosti je broj limova u slogu najčešće 2-3, a broj slogova u ciklusu 3 - 7.

Abstract (english)

The core is an essential part of transformers, generators, motors and other electrical equipment. Magnetic flux core and voltage are used to start the engine, the production of electricity and turns into a transformer. Magnetic materials are used as components of electrical products, which have the primary task of directed conduct magnetic flux and thereby enable electromagnetic conversion underlying the function of these products. Grain oriented electrical steel is mainly used as the active material in the magnetic cores of electric transformers, due to the high magnetic permeability and the low "core loss" (loss of power in the form of heat that occurs due to scattering phenomena acting on the material during the process of magnetization). Currently, the most attractive and affordable technologies for the production of Grain oriented electrical steel are based on "acquired inhibition" strategy. The potential to reduce losses associated with all three losses (anomalous losses, eddy current losses and hysteresis losses) and following are: thin magnetic sheet (without destabilizing secondary recrystallization), a smooth surface sheet (adaptation between the steel and the insulation layer), sharper textures with improved grain structure (generating micro grains, control of particle shape), improving coating with increased stress and optimization of laser treatment of sheet surface. One of the instruments of control and quality assurance of the Grain oriented electrical steel from the manufacturer of transformers, which comes from the outside and enters the production process are "the Technical Co-supply conditions. The technical delivery conditions defined magnetic properties, geometric characteristics, technological characteristics, tolerances, test procedures, conditions of delivery and packaging method of the magnetic sheet in the final annealed condition. Typically for three-leg "Step-lap" cores, Building factor of distribution transformers is around 20%, and for the core of power transformers around 10%. In order to reduce losses and noise, the number of sheets in the layer should be as small as possible, a number of steps as much as possible. Because productivity is the number of sheets in the layer usually 2-3, and the number of layers in a cycle 3 - 7th.

• Keywords: jezgra transformatora; magnetski materijal; orijentirani magnetski lim; proizvodne tehnologije; gubici magnetskog lima; tehničko - dobavni uvjeti; faktor kvarenja lima
• Keywords (english): core of transformers; magnetic material; Grain oriented electrical steel; production technology; the losses of the Grain oriented electrical steel; technical - supply conditions; building factor
• Language: croatian
• URN:NBN: urn:nbn:hr:168:016515
• 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: 2022-11-03 08:57:20