Thesis (MScEng)--University of Stellenbosch, 2005. / ENGLISH ABSTRACT: The calibration and field evaluation of an Insulator Pollution Monitoring Relay (IPMR)
were the main aims of this research programme. A repeatable artificial wetting test
method was developed after several modifications were made to the steam system,
test chamber and the test routine.
The IPMR was successfully calibrated with insulators that were artificially polluted
according to the solid layer method. Linear and polynomial relationships were
determined after curve-fitting techniques were performed on the results. The
calibration showed that the IPMR is capable as a device relating the maximum
conductivity during artificial wetting to the ESDD, a severity classification parameter.
The IPMR was successfully used in a salt fog chamber to determine if the device is
capable to evaluate the severity of an instantaneous pollution event.
The IPMR was successfully installed at a natural pollution test site along the Cape
west coast. The conductivity measurements with natural wetting showed good
correlation to flashovers experienced. A rule of thumb, developed to indicate a
possible risk of flashover, was based on observations made on the relationship
between humidity and surface conductivity. The measured IPMR data was
successfully applied to quantify the site severity according to the conductivity
measurement with natural wetting. This calculated severity value could be used in the
assessment of flashover probability of high voltage insulators. / AFRIKAANSE OPSOMMING: Die hoofdoel van die tesis was die kalibrasie en veldtoetse van 'n isolatorbesoedelingsmonitor
(IPMR). 'n Herhaalbare nagebootste benatting-toetsmetode is
ontwikkel na veranderings aan die stoomstelsel, toetsruimte en die toetsproses.
Die IPMR is suksesvol gekalibreer met isolators wat besoedel was met 'n
nagebootste besoedeling volgens die "solid layer method". Liniêre sowel as
kwadratiese verwantskappe is ontwikkel na krommepassings op die resultate
uitgevoer was. Die kalibrasie het gewys dat die IPMR in staat is om die maksimum
geleidingsvermoë wat d.m.v. nagebootste benatting verkry is, met die ESDD, 'n
besoedelingsklassifikasie, kan vergelyk. Die apparaat is ook suksesvol gebruik
tydens soutmistoetse om te bepaal of dit in staat is om 'n skielike
besoedelingsgebeurtenis te kan meet.
Na die afhandeling van laboratorium werk is die apparaat by 'n natuurlike isolator
besoedeling-toetsstasie langs die Kaapse weskus geïnstalleer. Die geleidingsvermoë
metings met natuurlike benatting het goeie korrelasie getoon met isolator
oorvonkings. 'n Skattingsmetode wat ontwikkel is om moontlike oorvonkings te
voorspel, is gebaseer op waarnemings wat gemaak is van die humiditeit sowel as die
oppervlakte geleidingsvermoë. Die IPMR se geleidingsvermoë metings met
natuurlike benatting is aangewend om die besoedelingsgraad van die gebied te
bepaal. Die bepaalde besoedelingsgraad kan verder gebruik word om die
waarskynlikheid van die oorvonking van isolators vas te stel.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/50372 |
| Date | 04 1900 |
| Creators | Schwardt, Wilhelm Heinrich |
| Contributors | Vermeulen, H. J., 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 | 112 p. : ill. |
| Rights | Stellenbosch University |
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