Thesis (PhD)--University of Stellenbosch, 2002. / ENGLISH ABSTRACT: The main aim of this research programme was to compare the relative
performance of different insulator materials used in South Africa when subjected
to a severe marine pollution environment. A test programme and procedure, test
facility and instrumentation were established. Some novel instrumentation and
monitoring equipment were developed and built specifically for this research
programme, supported by data analysing software programs. In order to
compare material performance only, all non-material design variables between
the test insulators had to be removed (e.g. creepage distance, connecting length,
inter-shed spacing, profile, etc.). To achieve this some of the test insulators had
to be specially manufactured. Leakage current, electrical discharge activity,
climatic and environmental data was collected successfully over a one-year test
period, starting with new test insulators.
The peak and energy values of the leakage current were identified as the two
main parameters needed to describe the leakage current activity on the test
insulators. A correlation was found between the climatic and environmental data
and the leakage current data, and it was found that the leakage current can be
determined successfully from some of the climatic and environmental parameters
monitored by using multiple regression techniques. Surface conductivity and
energy were found to be the best parameters to show the maximum and
continuous interaction of the insulator material surface with the electrolytic
pollution layer. A natural ageing and pollution test procedure was developed,
which has become a South African standard and is gaining international
acceptance.
A model and hypothesis are proposed to describe the electrical discharge activity
that takes place on the test insulators and explain the difference in leakage
current performance of the various materials.
Keywords: Insulator, Pollution, High Voltage, Leakage current, Material
performance. / AFRIKAANSE OPSOMMING: Die hoofdoel van hierdie navorsingsprogram was om die relatiewe prestasie van
verskillende isolatormateriale wat in Suid-Afrika gebruik word te vergelyk in 'n
swaar besoedelde marine omgewing. 'n Toetsprogram en prosedure, toets
fasiliteit en instrumentasie is gevestig. 'n Paar nuwe instrumente en moniteer
toerusting is ontwikkel en gebou spesifiek vir hierdie navorsingsprogram, gesteun
deur data analise sagteware programme. Ten einde slegs materiaalprestasie te
vergelyk, moes alle nie-materiaal ontwerpsveranderlikes tussen die toetsisolators
verwyder word (bv. kruipafstand, konnekteer lengte, tussen-skerm spasiëring,
profiel, ens.). Om dit reg te kry moes sommige van die toetsisolators spesiaal
vervaardig word. Lekstroom, elektriese ontladingsaktiwiteit, klimaat en
omgewingsdata is suksesvol versameloor 'n een-jaar toetsperiode, beginnende
met nuwe toets isolators.
Die piek en energie waardes van die lekstroom is identifiseer as die twee hoof
parameters wat nodig is om die lekstroomaktiwiteit op die toetsisolators te
beskryf. 'n Korrelasie is gevind tussen die klimaat- en omgewingsdata en die
lekstroom data, en dit is gevind dat die lekstroom data suksesvol bepaal kan
word van sekere van die klimaat- en omgewingsparameters wat gemoniteer is
deur veelvoudige regressie tegnieke te gebruik. Oppervlakskonduktiwiteit en
energie is gevind die beste parameters te wees om die maksimum en kontinue
interaksie van die isolatormateriaaloppervlak met die elektrolitiese
besoedelingslaag aan te toon. 'n Natuurlike veroudering en besoedeling
toetsprosedure is ontwikkel, wat 'n Suid-Afrikaanse standaard geword het en
besig is om internastionale aanvaarding te wen.
'n Model en hipotese word voorgestelom die elektriese ontladingsaktiwiteit wat
op die toetsisolators plaasvind te beskryf en om die verskil in lekstroomprestasie
van die verskeie materiale te verduidelik.
S/eufelwoorde: Isolator, Besoedeling, Hoog Spanning, Leek stroom, Materiaal
prestasie.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/52625 |
| Date | 04 1900 |
| Creators | Vosloo, Wallace L. (Wallace Lockwood) |
| Contributors | Holtzhausen, J. P., 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 | 262 p. : ill. |
| Rights | Stellenbosch University |
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