Analiza načina uzemljenja zvjezdišta sinkronog generatora

scientific master's theses

• Title (english): Synchronous generator grounding principles analysis
• Author: Ivan Višić
• Mentor: Ante Marušić (mentor)
• Committee member: Sejid Tešnjak (predsjednik povjerenstva)
• Committee member: Ante Marušić (član povjerenstva)
• Committee member: Ivan Sarajčev (član povjerenstva)
• Committee member: Tomislav Tomiša (član povjerenstva)
• Granter: University of Zagreb; Faculty of Electrical Engineering and Computing; (Department of Energy and Power Systems); Zagreb
• Defense date and country: 2003, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Electrical Engineering; Power Engineering
• Universal decimal classification (UDC): 621.3 - Electrical engineering

Abstract

Zemljospoj statorskog namota najčešći je kvar sinkronog generatora i uzrok oštećenja statorskog namota generatora. Osim toga direktni je uzrok i međufaznih kvarova na generatoru. Svrha uzemljavanja zvjezdišta generatora preko određene impedancije je ograničenje štete na mjestu kvara, ograničenje prijelaznih prenapona i osiguranje osjetljive detekcije zemljospojeva na statorskom namotu generatora. U radu je nakon općih teorijskih razmatranja dan pregled metoda uzemljenja generatora i odgovarajućih shema štićenja. Detaljnija analiza napravljena je za visokoomsko i rezonantno uzemljenje generatora u blok spoju. Teorijska razmatranja provjerena su na praktičnom primjeru generatora iz elektroenergetskog sustava Hrvatske. Rezultati analize pokazuju da rezonantno uzemljenje ima niz prednosti u odnosu na visokoomsko uzemljenje. Šteta na mjestu kvara znatno je manja, dok je osjetljivost detekcije zemnih spojeva na bilo kojem mjestu u namotu generatora povećana kod rezonantnog uzemljenja. Kod rezonantnog uzemljenja naponi preneseni iz mreže veći su nego kod visokoomskog uzemljenja generatora, no ispravnim odabirom konstante prigušnice K mogu se svesti na normalne iznose.

Abstract (english)

Ground fault in stator windings is the most frequent fault in the synchronous generator and direct cause of phase-to-phase faults. The objective of grounding a synchronous generator system through the impedance is minimizing damage at the point of the fault, limiting transient overvoltages and providing sensitive detection of ground faults in generator system. A summary of generator protection schemes and generator grounding methods is given after general theoretical analysis. More detailed analysis has been done for high resistance and resonant grounding methods on unit-connected generators and applied on practical example from Croatian Power System. The results outlines the advantages of resonant grounding over high resistance grounding. The damage at the point of the fault is greatly reduced and the sensitivity of the detection for localized deterioration of insulation at any location in generator system is increased. Impressed overvoltages on generator system from transmission system will be higher in magnitude with resonant grounding than with resistor grounding but it can be controlled within acceptable limits by the proper selection of coil constant of the reactor.

• Keywords: Generator; Visokoomsko uzemljenje; Rezonantno uzemljenje; Neutralizator zemnog spoja; Zemljospoj; Zemljospojna zaštita
• Keywords (english): Generator; High resistance grounding; Resonant grounding; Ground fault neutralizer; Ground fault; Graund fault protection
• Language: croatian
• URN:NBN: urn:nbn:hr:168:193139
• 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:8080/cgi-bin/koha/catalogue/detail.pl?biblionumber=29115
• Type of resource: Text
• Extent: 77 str. ; 30 cm
• File origin: Born digital
• Access conditions: Closed access
• Created on: 2019-07-08 08:58:33