Dimenzioniranje izolacijskih sustava u SF6 plinom izoliranim postrojenjima

master's thesis

• Title (english): Dimensioning of isolating systems in SF6 gas insulated substations
• Author: Anja Baklaić
• Mentor: Željko Štih (mentor)
• Committee member: Željko Štih (predsjednik povjerenstva)
• Committee member: Sead Berberović (član povjerenstva)
• Committee member: Bojan Trkulja (član povjerenstva)
• Granter: University of Zagreb; Faculty of Electrical Engineering and Computing; Zagreb
• Defense date and country: 2014-07-02, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Electrical Engineering

Abstract

Električno polje se formira u izolaciji između električnih naboja smještenih na površini elektroda u kojoj djeluju električne sile. Elektrostatsko polje je definirano kao polje koje je uzrokovano mirnim nabojem na površini elektroda, i unutar kojeg nema slobodnog naboja u prostoru. U ovom radu računa se statičko električno polje u GIS prekidaču. Glavna značajka GIS postrojenja je potpuno oklapanje dijelova pod naponom metalnim plaštem gdje prethodno definirani SF_6 plin služi i kao izolaciono sredstvo i kao sredstvo za gašenje električnog luka. Sumporov heksafluorid (SF_6) je neotrovan, neagresivan, kemijski stabilan plin pri atmosferskom tlaku i temperaturi < 500⁰C, bez boje i mirisa. Ovaj plin ne postoji u prirodi, nego se dobiva direktnom sintezom fluora i tekućeg sumpora egzotermnom reakcijom u posebnim postrojenjima. osnovna svojstva koja su mu omogućila upotrebu i osigurala vodeće mjesto u prekidačima visokog napona jesu: velika gustoća, elektronegativnost, dobra toplinska vodljivost i mala vremenska konstanta luka. Pri proračunu statičkih električnih polja i dimenzioniranju izolacije potrebno je poznavati brojne pojave i utjecaje na napon preskoka/proboja u plinu kao što su: napon pojave korone, površinske nesavršenosti (hrapavost) elektroda, čestice prašine u plinu, kombinacija plina i izolatora od krutog materijala i prisutnost vlage. Proračuni polja se izvode u programu Maxwell. Maxwell je simulacijski program elektromagnetskog polja namijenjen za elektroinženjere zadužene za projektiranje i 3-D i 2-D analizu elektromagnetskih i elektromehaničkih uređaja.

Abstract (english)

The electric field is formed in the isolation between electric charges located on the surface of the electrode in which they operate electric power. Electrostatic field is defined as a field that is caused by peaceful charge on the surface of electrodes, and within which there is no free charge in the area . In this paper we calculated the static electric field in GIS. The main feature of the GIS facility is completely shielding parts energized metal mantle where previously defined SF_6 gas is used as the insulating agent and as a means of extinguishing the arc. Sulfur hexafluoride (SF_6) is non-toxic, non-aggressive, chemically stable gas at atmospheric pressure and temperatures < 500 ⁰ C, colorless and odorless . This gas does not exist in nature, but is obtained by direct synthesis of fluorine and sulfur exothermic reaction liquid in a plant. Basic properties that enabled him to use and secure a leading position in the high-voltage circuit breakers are: high density, electronegativity , good thermal conductivity and a small time constant arc. For calculations of the static electric field and the dimensioning of insulation is necessary to know the number of occurrence and effects of the flashover/breakdown voltage in a gas such as: the occurrence of voltage corona, surface imperfections (roughness) of electrodes, the dust particles in a gas, a combination of gas and solid material of the insulator, and the presence of moisture. Field calculations are performed in Maxwell. Maxwell is electromagnetic field simulation program designed for 3 - D and 2 - D analysis of electromagnetic and electromechanical devices .

• Keywords: Statičko električno polje; SF_6 plin; plinom izolirani prekidač; napon preskoka; napon proboja; Maxwell
• Keywords (english): Static electric field; SF_6 gas; gas-insulated switchgear; voltage flashover; voltage breakdown; Maxwell
• Language: croatian
• URN:NBN: urn:nbn:hr:168:417348
• Study programme: Title: Electrical Engineering and Information Technology; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka elektrotehnike i informacijske tehnologije (magistar/magistra inženjer/inženjerka elektrotehnike i informacijske tehnologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Closed access
• Created on: 2019-03-19 13:36:53