Procjena rizika primjene elektromotornih pogona u prostorima ugroženim eksplozivnom atmosferom

doctoral thesis

• Title (english): Risk assessment of electrical drives application in hazardous areas
• Author: Ivica Gavranić
• Mentor: Drago Ban (mentor)
• Committee member: Vladimir Mikuličić (predsjednik povjerenstva)
• Committee member: Igor Zorić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Electrical Engineering and Computing; Zagreb
• Defense date and country: 2010-03-26, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Electrical Engineering
• Universal decimal classification (UDC): 621.3 - Electrical engineering

Abstract

Procjena rizika primjene elektromotornih pogona u prostorima ugroženim eksplozivnom atmosferom je istraživana teorijski i eksprimentalno.
Na temelju iskustva je procijenjeno da bi kvarovi, u kaveznom rotoru asinkronog motora, ovisno o intenzitetu, mogli biti efikasan uzročnik paljenja eksplozivne atmosfere. Asinkroni kavezni motor je odabran kao ključna elektrotehnička komponenta elektromotornog pogona smještenog u ugroženi prostor. Analizom suvremenih dijagnostičkih metoda za rano otkrivanje kvarova u rotoru kaveznog asinkronog motora je zaključeno da je s aspekta primjene u prostorima ugroženim eksplozivnom atmosferom najprikladnija metoda analize spektra statorske struje motora. Njenom primjenom se može otkriti kvar u kaveznom rotoru i njegov intenzitet. Provedbom kompliciranog eksperimenta na „Ex e II T3“ trofaznom asinkronom motoru snage 47 kW, 380 V, 50 Hz je dokazano da zbog prekida više štapova u rotoru uz istovremenu prisutnost plina acetilena nastaje eksplozija. Time je potvrđena osnovna teza da stvorena vruća površina u rotoru može u uvjetima istovremenosti s eksplozivnom atmosferom izazvati eksploziju. Istraživanjem su produbljene spoznaje o mogućnostima pojavljivanja uzročnika paljenja eksplozivne atmosfere, stvaranjem vrućih površina u rotoru motora zbog kvarova koji su skriveni i ne mogu se otkriti bez primjena suvremenih dijagnostičkih metoda.
Osmišljena je nova metoda procjene rizika primjene elektromotornih pogona u prostorima ugroženim eksplozivnom atmosferom te je uvedena poopćena kategorizacija rizika u četiri kvantitativno-kvalitativne razine: prihvatljiv, podnošljiv, neprihvatljiv i izravna opasnost.

Abstract (english)

In the Ph. D. thesis, the risk assessment of the application of electrical drives in areas at risk of explosive atmospheres has been researched teoretically and empirically. Based on experience, it has been assessed that faults in the rotor cage of the squirrel-cage induction motor, depending on the intensity of the fault, could generate an effective source of ignition of surrounding explosive atmospheres. The squirrel-cage induction motor has been selected as a key component in electrical drives installed in hazardous areas. By detailed study of modern diagnostic methods for early detection of faults in the rotor cage of the squirrel-cage induction motor, the spectrum analysis of the stator current has been found to be the most appropriate for application in areas at risk of explosive atmospheres. Using this method, the fault in the rotor cage can be detected and its intensity determined. Comprehensive tests performed on the ”Ex e II T3” squirrel-cage induction motor rated 47 kW, 380 V, 50 Hz, have verified that an occurrence of several broken bars in the rotor cage in an explosive atmosphere of acetylene will lead to an explosion. This approved the basic thesis that a hot surface generated by a fault on a rotor cage can initiate an explosion when it coincides with explosive atmosphere.
This research uncovered the possibilities of the existence of effective sources of ignition due to faults in the rotor cage of the squirrel-cage induction motor, which cannot be detected without the use of modern diagnostic methods. A new method for the risk assessment of the application of electrical drives in areas at risk of explosive atmospheres has been developed, with categorization in four quantitative-qualitative levels: acceptable, tolerable, unacceptable and direct danger.

• Keywords: eksplozivna atmosfera; elektromotorni pogon (EMP); procjena rizika; statistička analiza i vjerojatnost; kvar asinkronog kaveznog motora; uzročnik paljenja; dijagnostička ispitivanja; protueksplozijska zaštita
• Keywords (english): explosive atmosphere; electrical drive (ED); risk assessment; statistical analysis and probability; fault of squirrel-cage induction motor; source of ignition; technical diagnostics; explosion protection
• Language: croatian
• URN:NBN: urn:nbn:hr:168:763248
• Promotion: 2010
• Study programme: Title: Doctoral study programme "Electrical Engineering and Computing"; Study programme type: university; Study level: postgraduate; Academic / professional title: doktor/doktorica znanosti, po-dručje tehničkih znanosti (doktor/doktorica znanosti, po-dručje tehničkih znanosti)
• Type of resource: Text
• Extent: ii, 149 str. : graf. prikazi
• File origin: Born digital
• Access conditions: Open access
• Created on: 2024-03-18 13:17:37