Thesis (MScIng)--University of Stellenbosch, 2008. / ENGLISH ABSTRACT: The behaviour of induction motors at a petrochemical plant under transient conditions was
investigated with the view to improve plant immunity to voltage fluctuations. The benefits of
using a phase-variable induction motor model rather than the simpler d-q models usually
employed are investigated.
A simplified model of the plant electrical distribution system was derived. Phase variable and
d-q induction motor models were implemented as well as a synchronous generator model.
Practical considerations precluded the use of commercial software for the simulation of
transient conditions and a basic simulation program was developed using Matlab to evaluate
the behaviour of the dynamic machine models and distribution system.
It was established that the configuration of the installed re-acceleration system can be
optimised to reduce the possibility of plant outages as a result of voltage fluctuations. It was
found that the use of more detailed induction machine models provide valuable insight into
system behaviour and is justified if accurate motor parameters are available or can be
estimated. The simplified plant model yielded useful results and enabled the identification of
incorrect system data. The investigation showed that Matlab is suitable for the rapid
development of a basic transient simulation program that can be used to study the behaviour
of different interconnected dynamic machine models. / AFRIKAANSE OPSOMMING: Die gedrag van induksiemotors in 'n petrochemiese aanleg onder oorgangstoestande is
ondersoek ten einde die immuniteit van die aanleg vir spanningsfluktuasies te verbeter. Die
voordele van die gebruik van 'n fase-veranderlike induksiemotor model eerder as die
eenvoudiger d-q modelle wat normaalweg gebruik word is ondersoek.
'n Vereenvoudigde model van die aanleg se elektriese distribusiestelsel is afgelei. Faseveranderlike
en d-q induksiemotor modelle is geimplementeer sowel as 'n sinkroongenerator
model. Praktiese oorwegings het die gebruik van kommersiële programmatuur vir die
simulasie van oorgangstoestande verhoed en 'n basiese program is in Matlab ontwikkel om
die gedrag dinamiese masjienmodelle en die distribusiestelsel te evalueer.
Daar is vasgestel dat die konfigurasie van die geinstalleerde herversnellerstelsel geoptimeer
kan word om die moontlikheid van aanleg onderbrekings as gevolg van spanningsfluktuasies
te verminder. Daar is gevind dat die gebruik van meer gedetaileerde induksiemasjien modelle
waardevolle insig in die gedrag van die stelsel lewer en geregverdig is indien akkurate
motorparameters beskikbaar is of afgeskat kan word. Die vereenvoudigde model van die
aanleg het bruikbare resultate gelewer en die het die identifikasie van foutiewe stelseldata
moontlik gemaak. Die ondersoek het getoon dat Matlab geskik is vir die snelle ontwikkeling
van 'n basiese oorgangsimulasie program wat gebruik kan word om die gedrag van
verskillende gekoppelde dinamiese masjienemodelle te bestudeer.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/20432 |
| Date | 03 1900 |
| Creators | Claassens, Andries Johannes |
| Contributors | Vermeulen, H. J., Stellenbosch University. Faculty of Engineering. Dept. of Electrical and Electronic Engineering. |
| Publisher | Stellenbosch : Stellenbosch University |
| Source Sets | South African National ETD Portal |
| Language | en_ZA |
| Detected Language | Unknown |
| Type | Thesis |
| Format | 365 leaves : ill. |
| Rights | Stellenbosch University |
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