Thesis (MScEng)--University of Stellenbosch, 2005. / ENGLISH ABSTRACT: The main objective of this research project was to develop a methodology which can be
used to assist in developing an insulator pollution severity application map (INSMAP),
more particularly for South Africa. The techniques must be able to assist in determining
pollution severity levels.
At the inception of this project a phase one insulator pollution severity application map
was available; this map was based on an existing corrosion map, climatic maps and dust
gauge measurements. The phase one map was conservative and did not highlight localised
pollution. To confirm and possibly improve on this map, a phase two map was developed,
which was based on feedback from Eskom field personnel via an electronic insulator
pollution questionnaire survey (based on IEC 60815 guidelines).Jhe questionnaire was
incorrectly completed in most cases due to a lack of understanding by field personnel of
environmental pollution and the impact on insulator performance. This resulted in an
unrealistic map with exaggerated contamination levels.
To confirm the findings of the phase one map, a phase three approach was followed, which
was focused on an investigation into pollution measurement techniques and
methodologies. Based on the phase one map, a need was identified to confirm by
measurements the impact of distance-to-coast. Also, the validity of installing a dust gauge
at 3 metres above ground level, while insulators are at a height of 8 to 40 meters, had to be
investigated. Two pollution monitoring programmes were established: a distance-to-coast
and height-above-ground environmental pollution study. Various test methods are
described with a complete testing procedure, descriptive equations and related pollution
severity classifications for insulator pollution (DDG and ESDD) and corrosion (CLIMAT
and metal specimens).
The distance-to-coast test results confirm the phase one map, while the height-aboveground
measurements justify the installation of dust gauges at 3 metres above ground level.
Good correlations were found for the distance-to-coast study between insulator pollution
severity and corrosion rates. From the height-above-ground study, a slight (insignificant) decrease in pollution levels
was found for increase in height for insulator pollution and corrosion tests.
Recommendations are made on setting up a basic pollution monitoring station.
Key words: Insulator pollution, Corrosion, Distance, Height. / AFRIKAANSE OPSOMMING: Die hoofoogmerk van hierdie navorsingprojek was die ontwikkeling van 'n metodiek om
'n isolator besoedelingskaart saam te stel, meer spesifiek vir Suid Afrika. Die tegnieke
moet die besoedelingsvlakke en impak-afstand van elke besoedelingvlak aandui.
'n Fase een isolator besoedelingskaart het reeds bestaan by die aanvang van hierdie projek,
hierdie kaart was gebaseer op 'n bestaande korrosiekaart. Die fase een kaart was baie
konserwatief en het nie lokale besoedeling aangedui nie. Dit was besluit om die fase een
kaart te verbeter en 'n fase twee kaart was ontwikkel wat gebaseer was op 'n elektroniese
isolator-besoedeling vraelys wat deur Eskom se tegniese veldpersoneel voltooi is. Die
vraelys is in baie gevalle verkeerdelik ingevul, as gevolg van 'n gebrek aan die kennis oor
besoedeling en die impak daarvan op isolatorprestasie. Dit het tot 'n onrealistise kaart gelei
met onakurate besoedelingsvlakke.
'n Fase drie ontwikkeling is begin, waar 'n ondersoek gekyk het na metingstegnieke en
metodiek vir besoedelingsmetings. 'n Volledige toetsprosedure, beskrywende vergelykings
en besoedelingklassifikasies is ontwikkel vir die isolator-besoedeling (DDG en ESDD) en
korrosietoetse (CLIMAT en metaal monsters). Toetsstasie seleksiekriterea vir die
geografiese plasing van 'n toetsstasie is vasgestel. Twee toetsprogamme is vasgestel: 'n
afstand-van-see en 'n hoogte-bo-grondvlak besoedelingsstudie.
Die afstand-van-see studie het 'n impak-afstand vir elke besoedelingsvlak vir beide
isolatorbesoedeling en korrosietoetse vasgestel. 'n Goeie korrelasie is vasgestel tussen
isolator-besoedeling en korrosievlakke.
Vir die hoogte-bo-grondvlak studie was gevind dat daar 'n klein (weglaatbare)
vermindering in besoedelingsvlakke met toename in hoogte bo grondvlak vir isolatorbesoedeling-
en korrosievlakke onstaan. 'n Goeie korrelasie bestaan tussen isolatorbesoedeling-
en korrosievlakke.
Aanbevelings word gemaak vir die opstel van 'n basiese besoedelingsmetingstasie.
Sleutelwoorde: Isolator besoedeling, Korrosie, Afstand, Hoogte.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/50475 |
| Date | 04 1900 |
| Creators | Pietersen, Donovan |
| Contributors | Holtzhausen, J. P., Vosloo, W. L., 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 | 185 p. : ill. |
| Rights | Stellenbosch University |
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