Thesis (MEng)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: Efficient and reliable energy generation capability is vital to any
country's economic growth. Many strategic, tactical and operational
decisions take place along the energy supply chain. Shortcomings in
South Africa's electricity production industry have led to the development
of an energy
ow simulator. The energy
ow simulator is
claimed to incorporate all significant factors involved in the energy
ow process from primary energy to end-use consumption. The energy
ow simulator thus provides a decision support system for electric
utility planners.
The original aim of this study was to develop a global optimisation
model and integrate it into the existing energy
ow simulator. After
gaining an understanding of the architecture of the energy
ow simulator
and scrutinising a large number of variables, it was concluded that
global optimisation was infeasible. The energy
ow simulator is made
up of four modules and is operated on a module-by-module basis, with
inputs and outputs
owing between modules. One of the modules,
namely the primary energy module, lends itself well to optimisation.
The primary energy module simulates coal stockpile levels through
Monte Carlo simulation. Classic inventory management policies were
adapted to fit the structure of the primary energy module, which is
treated as a black box. The coal stockpile management policies that
are introduced provide a prescriptive means to deal with the stochastic
nature of the coal stockpiles.
As the planning horizon continuously changes and the entire energy
ow
simulator has to be re-run, an efficient algorithm is required to optimise
stockpile management policies. Optimisation is achieved through
the rapidly converging cross-entropy method. By integrating the simulation and optimisation model, a prescriptive capability is added
to the primary energy module. Furthermore, this study shows that
coal stockpile management policies can be improved. An integrated
solution is developed by nesting the primary energy module within the
optimisation model. Scalability is incorporated into the optimisation
model through a coding approach that automatically adjusts to an everchanging
planning horizon as well as the commission and decommission
of power stations.
As this study is the first of several research projects to come, it paves
the way for future research on the energy
ow simulator by proposing
future areas of investigation. / AFRIKAANSE OPSOMMING: Effektiewe en betroubare energie-opwekkingsvermoë is van kardinale belang
in enige land se ekonomiese groei. Baie strategiese, taktiese en operasionele
besluite word deurgaans in die energie-verskaffingsketting geneem.
Tekortkominge in Suid-Afrika se elektrisiteitsopwekkingsindustrie
het tot die ontwikkeling van 'n energie-vloei-simuleerder gelei. Die
energie-vloei-simuleerder vervat na bewering al die belangrike faktore
wat op die energie-vloei-proses betrekking het van primêre energieverbruik
tot eindgebruik. Die energie-vloei-simuleerder verskaf dus 'n
ondersteuningstelsel aan elektrisiteitsdiensbeplanners vir die neem van
besluite.
Die oorspronklike doel van hierdie studie was om 'n globale optimeringsmodel
te ontwikkel en te integreer in die bestaande energie-vloeisimuleerder.
Na 'n begrip aangaande die argitektuur van die energievloei-
simuleerder gevorm is en 'n groot aantal veranderlikes ondersoek
is, is die slotsom bereik dat globale optimering nie lewensvatbaar is
nie. Die energie-vloei-simuleerder bestaan uit vier eenhede en werk op
'n eenheid-tot-eenheid basis met insette en uitsette wat tussen eenhede
vloei. Een van die eenhede, naamlik die primêre energiemodel, leen
dit goed tot optimering. Die primêre energiemodel boots steenkoolreserwevlakke
deur Monte Carlo-simulering na. Tradisionele voorraadbestuursbeleide
is aangepas om die primêre energiemodel se struktuur
wat as 'n swartboks hanteer word, te pas. Die steenkoolreserwebestuursbeleide
wat ingestel is, verskaf 'n voorgeskrewe middel om met
die stogastiese aard van die steenkoolreserwes te werk.
Aangesien die beplanningshorison deurgaans verander en die hele
energie-vloei-simulering weer met die energie-vloei-simuleerder uitgevoer
moet word, word 'n effektiewe algoritme benodig om die re-serwebestuursbeleide te optimeer. Optimering word bereik deur die
vinnige konvergerende kruis-entropie-metode. 'n Geïntegreerde oplossing
is ontwikkel deur die primêre energiemodel en die optimering
funksie saam te voeg. Skalering word ingesluit in die optimeringsmodel
deur 'n koderingsbenadering wat outomaties aanpas tot 'n
altyd-veranderende beplanningshorison asook die ingebruikneem en
uitgebruikstel van kragstasies.
Aangesien hierdie studie die eerste van verskeie navorsingsprojekte
is, baan dit die weg vir toekomstige navorsing oor die energie-vloeisimuleerder
deur ondersoekareas vir die toekoms voor te stel.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/96956 |
| Date | 03 1900 |
| Creators | Hatton, Marc |
| Contributors | Bekker, James, Stellenbosch University. Faculty of Engineering. Dept of Industrial Engineering. |
| Publisher | Stellenbosch : Stellenbosch University |
| Source Sets | South African National ETD Portal |
| Language | en_ZA |
| Detected Language | Unknown |
| Type | Thesis |
| Format | 170 pages : illustrations |
| Rights | Stellenbosch University |
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