Relejna zaštita srednjenaponskih motora

scientific master's theses

• Title (english): Relay protection of medium voltage motors
• Author: Krunoslav Flajšek
• Mentor: Ante Marušić (mentor)
• Committee member: Zlatko Maljković (predsjednik povjerenstva)
• Committee member: Ante Marušić (član povjerenstva)
• Committee member: Srđan Žutobradić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Electrical Engineering and Computing; (Department of Energy and Power Systems); Zagreb
• Defense date and country: 2011-03-04, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Electrical Engineering
• Universal decimal classification (UDC): 621.3 - Electrical engineering

Abstract

Zbog velikog broja tipova motora, različite veličine i različite primjene, zaštita električnih motora standardizirana je u znatno manjoj mjeri od zaštite drugih strojeva i drugih dijelova elektroenergetskih postrojenja. Prilikom projektiranja veličinu i cijenu sustava relejne zaštite potrebno je uskladiti s potencijalnim opasnostima i mogućim kvarovima, kako bi se postigla maksimalna pogonska raspoloživost i sigurnost uz prihvatljivu cijenu. Analizom podataka prikupljenih istraživanjem pokazano je da se više od 80% kvarova može izbjeći korištenjem točne i efektivne relejne zaštite. Budući da suvremeni uređaji relejne zaštite nude više zaštitnih funkcija, a s porastom broja funkcija raste cijena samih uređaja, dane su preporuke za izbor opsega funkcija zaštite. Velik dio navedenih funkcija koje se koriste u zaštiti sinkronih i asinkronih motora detaljno je opisan u radu te razrađen kroz rješenja koja su implementirana u današnjim uređajima zaštite. Uz detaljan opis dani su i prijedlozi podešenja za različite primjene. Budući da je najveći dio kvarova u motoru direktno ili indirektno povezan s porastom temperature, a upravo je funkcija termičke zaštita primjenom numeričkih uređaja doživjela najveći napredak, u posljednjem poglavlju opisan je algoritam termičke zaštite s modelom prvog reda. Usporedbom termičkog i nadstrujnog modela prikazane su prednosti termičkog modela.

Abstract (english)

Due to the many motor types, different sizes and applications, relay protection of electrical motors is less standardized than protection of other machines and other electrical facilities. During designing, size and cost of protection system should be adjusted with potential hazards and faults, to achieve maximal availability and security with acceptable price. Analysis of collected survey data shows that more than 80% of faults can be avoided using precise and effective relay protection. Since contemporary relay protection devices offer more protection functions, increase of number of protection functions cause increase of device price, there are given recommendations for choose of function scope. Majority of the given functions that are used in synchronous and induction motor protection, is described in details and elaborated through solutions implemented in nowadays protection devices. A detailed description is given with proposed setting for different applications. Since majority of faults in motor dealing directly or indirectly with temperature rise, and thermal protection function with application of numerical devices has experienced largest progress, in the last chapter the first order thermal model algorithm is described. Advantages of thermal model are shown through comparison of thermal and overcurrent model.

• Keywords: relejna zaštita; srednjenaponski motor; numerička zaštita; termički model motora
• Keywords (english): relay protection; medium voltage motor; numerical protection; motor thermal model
• Language: croatian
• URN:NBN: urn:nbn:hr:168:224662
• Study programme: Title: Postgraduate master programme in electrical engineering; Study programme type: university; Study level: postgraduate; Academic / professional title: Magistar znanosti elektrotehnike (Magistar znanosti elektrotehnike)
• Catalog URL: http://lib.fer.hr/cgi-bin/koha/opac-detail.pl?biblionumber=34422
• Type of resource: Text
• Extent: 115 str ; 30 cm
• File origin: Born digital
• Access conditions: Closed access
• Created on: 2020-08-24 07:50:14