Thesis (MScEng)--University of Stellenbosch, 2001, / ENGLISH ABSTRACT: A frequency domain Power Line Carrier (PLC) simulation program, with the
ability to simulate signal attenuation including the coupling equipment, was
developed. This simulation program was put to the test against the independent
program of Professor L.M. Wedepohl and against practical field measurements.
The predictions of the two programs were in precise agreement for a wide range of
input parameters. Results from the field tests and predictions also showed close
agreement.
Further investigations, applying the simulation program, explained how ground
conductors and soil resistivity influences PLC signal propagation.
An experiment, which was developed to monitor PLC signal attenuation, was
installed on the PLC system between Koeberg power station and Acacia substation,
both near Cape Town. Data logged continuously over 28 days, indicated
measurable and deterministic PLC signal attenuation variations with typical time
constants of a few hours. Simulations of the PLC system indicated that the signal
amplitude variations were influenced by changes in the height above the ground
plane of the phase conductor.
This significant finding creates the possibility to obtain real time knowledge of the
sag of an Over Head Transmission Line (OHTL) by exploiting an operational PLC
system. The knowledge about real time sag can be used in economical dynamic
ampacity control systems. The practical and financial benefits to the electricity
supply and distribution industry can be significant. / AFRIKAANSE OPSOMMING: 'n Frekwensie gebied "Power Line Carrier" (PLC) simulasie program wat die sein
verswakking en die koppeling verliese kan naboots, is ontwikkel. Die program is
getoets teen die onafhanklike program van Professor L.M. Wedepohl asook
praktiese metings in die veld. Die vooruitskatings van beide programme is presies
die selfde vir 'n wye reeks van parameters. Metings en nabootsings het ook noue
ooreenstemming getoon.
Verdere ondersoek, m. b. v. die program, is gedoen ten einde te verduidelik hoe
grond-geleiers en grond weerstand die PLC sein se voortplanting beïnvloed.
'n Eksperiment om die PLC sein se verswakking mee te monitor is ontwerp. Die
eksperiment was geïnstalleer in die PLC stelsel tussen Koeberg kernkragstasie en
Acacia substasie, naby Kaapstad. Die eksperiment was vir 28 dae geaktiveer en
die data wat die eksperiment opgelewer het toon meetbare PLC sein verswakking
met tyd konstantes van 'n paar uur. Verdere nabootsings het gewys dat die
veranderende verswakking in die PLC seinsterkte toegeskryf kan word aan die
wisseling in hoogte van die fase geleiers bo die grondvlak.
Hierdie bevinding is van besondere belang aangesien dit die moontlikheid
oopmaak om die gemiddelde sak van kraglyne in reële tyd en onder bedryfs
toestande te kan meet. Die informasie van die reële sak van kraglyne kan gebruik
word in effektiewe stroomdrae-vermoë beheer stelsels. Die praktiese en finansiële
voordele wat krag voorsieners en verspreiders hieruit kan put kan aansienlik
wees.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/52410 |
| Date | 12 1900 |
| Creators | De Villiers, Wernich |
| Contributors | Cloete, J. H., Herman, R., 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 | English |
| Type | Thesis |
| Format | 111 p. : ill. |
| Rights | Stellenbosch University |
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