Poboljšanje zaštite elektroenergetskog sustava primjenom Rogowskijevog strujnog mjernog pretvornika

scientific master's theses

• Title (english): Improvement of power system protection by application of Rogowski coil current sensor
• Author: Siniša Jergović
• Mentor: Ante Marušić (mentor)
• Committee member: Ivica Pavić (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: 2011-04-29, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Electrical Engineering
• Universal decimal classification (UDC): 621.3 - Electrical engineering

Abstract

U radu su istražene mogućnosti poboljšanja zaštite elektroenergetskog sustava primjenom Rogowskijevih svitaka umjesto strujnih transformatora. Provedena je neposredna usporedba značajki Rogowskijevog svitka i strujnog transformatora, s naglaskom na njihov učinak na rad relejne zaštite. Detaljno su analizirane prilike u strujnom transformatoru i vladanje u uvjetima povećane primarne struje i posebno tijekom prijelaznih pojava u mreži. Simulacijom različitih pogonskih uvjeta kvalitativno je prikazan utjecaj različitih čimbenika na zasićenje magnetske jezgre strujnog transformatora, te na izobličenje sekundarne struje i točnost mjerenja. Također su opisane osnovne značajke numeričkih releja, uzrok osjetljivosti releja na izobličenu ulaznu struju, kao i njen utjecaj na rad relejne zaštite. Nadalje, opisan je princip rada Rogowskijevog svitka, problematika mjerenja malih struja, karakteristike i izvedbe Rogowskijevog mjernog pretvornika te sučelje sa relejem. U pretposljednjem poglavlju izvršena je usporedba značajki strujnog transformatora i Rogowskijevog mjernog pretvornika s naglaskom na značajke bitne za rad relejne zaštite. Na kraju su opisane izvedbe zaštite s Rogowskijevim svitkom, te su navedene mogućnosti poboljšanja naspram zaštita koje koriste konvencionalne strujne transformatore. Radi potvrde provedenih razmatranja izvršena je ugradnja Rogowskijevih svitaka u postrojenje, te simulirano više kvarova prilikom kojih su provedena mjerenja i praćen rad zaštite.

Abstract (english)

This paper explores the possibility of improving the protection of power systems by the application of Rogowski coils in place of current transformers. The comparison was made between the features of the Rogowski coil against that of a current transformer, with an emphasis on how this impacts on the operation of relay protection. A detailed analysis was carried out into the conditions that existed in the current transformer and its behavior in relationship to the increase in primary current with emphasis during transients in the network. By simulating different operating conditions it seeks to qualitatively demonstrate the impact of various factors which, result in the saturation of the magnetic core of a current transformer, together with the associated secondary current distortion and accuracy. It also describes the basic features of numerical relays, the factors affecting distortion of the input current shape and the impact of this on the operation of relay protection. Furthermore, it describes the principles of the operation of a Rogowski coil. The problems associated with the measurement of small currents, together with the characteristics and performance of the Rogowski coils and their interface with the relay. In the penultimate chapter a comparison is made between the features of the current transformer and the Rogowski coil current sensor, with emphasis on the impact of these features on relay protection. The paper concludes with a description of how the Rogowski coil can be integrated into a power system and the opportunity it presents to improve relay protection, in comparison to that of a conventional current transformer. It describes the results of a trial which was carried out in which a Rogowski coil was integrated into an existing power system. Tests were conducted to simulate multiple failures for which current measurements were made and for which the operation of the relay was monitored.

• Keywords: strujni transformator; zasićenje; relejna zaštita; Rogowskijev svitak
• Keywords (english): current transformer; saturation; protection relay; Rogowski coil
• Language: croatian
• URN:NBN: urn:nbn:hr:168:974336
• 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=35438
• Type of resource: Text
• Extent: 146 str ; 30 cm
• File origin: Born digital
• Access conditions: Closed access
• Created on: 2020-08-24 07:56:33