Model tropolno oklopljenog plinom izoliranog rasklopnog postrojenja za proračune vrlo brzih prijelaznih prenapona

scientific master's theses

• Author: Sandra Hutter
• Mentor: Ante Marušić (mentor)
• Committee member: Ante Marušić (predsjednik povjerenstva)
• Committee member: Ivo Uglešić (član povjerenstva)
• Committee member: Franc Jakl (član povjerenstva)
• Granter: University of Zagreb; Faculty of Electrical Engineering and Computing; 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

U prvom poglavlju su opisani problemi koji se javljaju kod pogona plinom SF6 izoliranih postrojenja. Dane su statistike o učestalosti i uzrocima najčešćih kvarova, pouzdanosti i raspoloživosti, očekivanom životnom vijeku, itd. U radu su prikazana različite izvedbe optimiranih i hibridnih postrojenja. Modularne izvedbe omogućuju veliku fleksibilnost kod izgradnje novih ili nadogradnje starih postrojenja. Glavne prednosti su u raznolikosti ponuđenih rješenja, efikasnosti, robustnosti, minimalnoj potrebi za održavanjem, niskim troškovima pogona, dugom životnom vijeku, te pouzdanom i sigurnom pogonu. Razvijeni su modeli različitih dijelova tropolno oklopljenog postrojenja i primjenjeni su kod kompjuterskih simulacija unutarnjih i vanjskih vrlo brzih prenapona. Modelirane su slijedeće komponente: tropolno i jednopolno oklopljene sabirnice, rastavljači i prekidači, zemljospojnici, strujni i naponski transformatori, energetski transformatori, provodni izolatori, kabelski priključci, oklop postrojenja, uzemljivačke trake i glavni uzemljivač. Na ovaj način su modelirana dva postrojenja: postojeće 123 kV tropolno oklopljeno postrojenje i modificirani tip postrojenja iste naponske razine, koje je u fazi projekta. Provedeni su proračuni unutarnjih VFTO i prijelaznih porasta potencijala oklopa prilikom uklopa i isklopa rastavljača pomoću programa za proračun prijelaznih elektromagnetskih pojava - EMTP. Objašnjen je i način rješavanja diferencijalnih jednadžbi mreže pomoću programa EMTP. Također su izračunati i preneseni prenaponi u sekundarnim krugovima. Dobiveni računski rezultati uspoređeni su sa izmjerenim vanjskim tranzijentima na prelasku energetskih kabela u postrojenje u vremenskoj i frekvencijskoj domeni.

Abstract (english)

In the first chapter are described problems that can occur during operation of the gas insulated switchgear. Statistics on the failure frequency and main failure causes, reliability and availability, life expectancy, etc, were given. In the thesis are described different solutions of optimized and hybrid substations. Modular design enables a great flexibility if erecting new or upgrading an old substation. Their main advantages are: variety of offered solutions, efficiency, robustness, minimum maintenance, low operating costs, long operating life, and safe and reliable operation. Models for different parts of the three-phase encapsulated switchgear were developed and applied in computer simulations for calculation of inner and outer very fast transient overvoltages. Following components were modeled: three-phase and one-phase encapsulated bus bars, disconnectors and circuit breakers, earth switches, power transformers, gas to air bushings, GIS/cable junctions, GIS enclosure, ground straps and earthing grid. In this way are modeled two substations: an existing 123 kV three-phase encapsulated switchgear and a modified type of the switchgear with the same nominal voltage, that is currently in the design phase. Computer simulations of the inner VFTO and transient enclosure voltage rise during disconnector switching operations were conducted with the electromagnetic transient program - EMTP. Method of solutions of the differential equations for an network with EMTP program is also explained. Transmitted voltages in the secondary circuits were calculated, as well. Obtained calculation results were compared with the measured outer transients on the GIS/cable junction in time and frequency domain.

• Keywords: Plinom izolirana postrojenja; vrlo brzi prijelazni prenaponi; tranzijentni porast potencijala oklopa.
• Keywords (english): Gas Insulated Switchgear; Very Fast Transient Overvoltages; Transient Enclosure Voltage Rise
• Language: croatian
• URN:NBN: urn:nbn:hr:168:259715
• 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)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Closed access
• Created on: 2019-03-25 08:54:31