Otkrivanje kvarova rotora kaveznoga asinkronoga motora analizom magnetskoga polja u zračnom rasporu

doctoral thesis

• Title (english): Rotor faults detection in squirrel-cage induction motor based on magnetic field analysis in air-gap
• Author: Stjepan Tvorić; MBZ: 337780
• Mentor: Željko Štih (mentor)
• Mentor: Stjepan Car (komentor)
• Committee member: Željko Štih (član povjerenstva)
• Committee member: Stjepan Car (član povjerenstva)
• Granter: University of Zagreb; Faculty of Electrical Engineering and Computing; (Department of Electrical Engineering Fundamentals and Measurements); Zagreb
• Defense date and country: 2019, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Electrical Engineering; Electromechanical Engineering
• Universal decimal classification (UDC): 621.3 - Electrical engineering

Abstract

Otkrivanje kvarova s ciljem sprečavanja štetnih posljedica za tehnološki proces kod električnih strojeva je od iznimne važnosti. U radu je istraženo točno otkrivanje i prepoznavanje kvarova rotora kaveznoga asinkronog motora: prekid jednog ili više štapova, prekid prstena te pojava statičkog ekscentriciteta. Prikazana je raspodjela kvarova prema glavnim komponentama, uzroci i priroda nastajanja kvara te različite metode detekcije. Odabrana je metodologija otkrivanja kvarova analizom magnetskog polja u zračnom rasporu temeljena na naponu induciranom u mjernim svicima ugrađenima na zub statora i razmaknutima za polni korak. Izrađen je numerički 2D model temeljen na metodi konačnih elemenata. Proračunima je dokazano da je pomoću induciranog napona u mjernim svicima moguće, s visokom razinom osjetljivosti, otkriti i prepoznati pojedini kvar. Dokazano je da svaki kvar ima svoju prirodu ponašanja koja se manifestira u razlici induciranih napona dvaju svitaka ili u samom induciranom naponu svitka. Rezultati proračuna verificirani su mjerenjima u laboratoriju na motoru dorađenom za simuliranje kvarova. Razvijen je algoritam koji temeljem vrijednosti induciranog napona u četiri mjerna svitka otkriva i međusobno prepoznaje pojedinu vrstu kvara rotora. Izvorni znanstveni doprinosi: - analiza utjecaja oštećenja kaveza i statičkog ekscentriciteta asinkronog motora na inducirane napone u mjernim svicima, - određivanje optimalnog rasporeda i položaja mjernih svitaka za određivanje kvarova, - algoritam za prepoznavanje kvarova temeljem izmjerenih induciranih napona u mjernim svicima.

Abstract (english)

The induction motors are one of the most common types of electrical machines, and they play a key role in various industrial plants and process. Because of the importance in the process, these machines must achieve reliable and safe operation. To ensure this, all key machines contain some types of protection and monitoring. The main goal is an early machine fault detection and the possibility to recognize the type and nature of a fault. The cause of induction machines faults lies in electrical and mechanical conditions together with operational environment. As a part of this dissertation, a method based on the magnetic field measurement in the air gap using the measuring coils embedded in the machine is presented. This methodology is used for reliable and unambiguous detection of squirrel-cage rotor faults: broken rotor bar, broken rotor ring, and static eccentricity. Within this dissertation, the issues regarding the rotor faults detection are discussed. Also, the corresponding algorithm for the rotor faults recognition has been designed. The aim of the thesis is a contribution to the early and reliable fault detection of electrical rotating machines based on the magnetic field analysis in the air gap. Original scientific contribution: - Impact analysis of the squirrel-cage damages and static eccentricity of the induction motor on the induced voltages in measuring coils, - Determination of the optimal layout and position of the measuring coils for fault detection, - Fault detection algorithm based on the measured induced voltages in the measuring coils.

• Keywords: asinkroni motor; kavezni rotor; prekid štapa; prekid prstena; statički ekscentricitet; mjerni svitak; inducirani napon; magnetska indukcija; polni korak; algoritam
• Keywords (english): induction motor; squirrel-cage rotor; broken rotor bar; broken rotor ring; static eccentricity; measuring coil; induced voltage; magnetic induction; pole pitch; algorithm
• Language: croatian
• URN:NBN: urn:nbn:hr:168:643924
• Study programme: Title: Electrical Engineering and Computing; Study programme type: university; Study level: postgraduate; Academic / professional title: Doktor znanosti elektrotehnike i računarstva (Doktor znanosti elektrotehnike i računarstva)
• Type of resource: Text
• Extent: 203 str. ; 30 cm
• File origin: Born digital
• Access conditions: Open access
• Created on: 2020-01-20 10:20:16