Thesis (MEng)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: Most rural African villages enjoy high levels of sunlight, but rolling out solar
power generation technology to tap into this renewable energy resource at remote
rural sites in Africa pose a number of design challenges. To meet these
challenges, a project has been initiated to design, build and test/evaluate a
knock down 3 kW peak electrical stand-alone self-tracking dual-axis concentrating
solar power system.
This study focusses on the mechatronic engineering aspects in the design
and development of a dynamic mechatronic platform and digital electronic
control system for the stand-alone concentrating solar power system. Design
specifications require an accurate automatic positioner and control system for
a motorized parabolic solar reflector with an optical solar harnessing capacity
of 12 kWt at solar noon. It must be suitable for stand-alone rural power generation.
This study presents a conceptual design and engineering prototype
of a balanced cantilever tilt-and-swing dual-axis slew drive actuation means
as mechatronic solar tracking mobility platform for a ∼12 m2 lightweight
parabolic solar concentrator. Digital automation of the concentrated solar
platform is implemented using an industrial Siemens S7-1200 programmable
logic controller (PLC) with digital remote control interfacing, pulse width modulated
direct current driving, and electronic open loop/closed loop solar tracking
control. The design and prototype incorporates off-the-shelf components
to support local manufacturing at reduced cost and generally meets the goal
of delivering a dynamic mechatronic platform for a concentrating solar power
system that is easy to transport, assemble and install at remote rural sites
in Africa. Real-time experiments, conducted in the summer of South Africa,
validated and established the accuracy of the engineering prototype positioning
system. It shows that the as-designed and -built continuous solar tracking
performs to an optical accuracy of better than 1.0◦ on both the azimuth and
elevation tracking axes; and which is also in compliance with the pre-defined
design specifications.
Structural aspects of the prototype parabolic dish are evaluated and optimized
by other researchers while the Stirling and power handling units are under
development in parallel projects. Ultimately, these joint research projects
aim to produce a locally manufactured knock down do-it-yourself concentrated
solar power generation kit, suitable for deployment into Africa. / AFRIKAANSE OPSOMMING: Landelike gebiede in Afrika geniet hoë vlakke van sonskyn, maar die ontwerp
van betroubare sonkrag tegnologie vir die benutting van hierdie hernubare
energie hulpbron by afgeleë gebiede in Afrika bied verskeie uitdagings. Om
hierdie uitdagings te oorkom, is ’n projek van stapel gestuur om ’n afbreekbare
3 kW piek elektriese alleenstaande selfaangedrewe dubbel-as son-konsentreeder
te ontwerp, bou en te toets.
Hierdie studies fokus op die megatroniese ingenieurs-aspekte in die ontwerp
en ontwikkeling van ’n dinamiese megatroniese platform en ’n digitale
elektroniese beheerstelsel vir die alleenstaande gekonsentreerde sonkrag stelsel.
Ontwerp spesifikasies vereis ’n akkurate outomatiese posisionering en beheer
stelsel vir ’n motor aangedrewe paraboliese son reflekteerder met ’n optiesekollekteer-
kapasiteit van 12 kWt by maksimum sonhoogte, en veral geskik wees
vir afgeleë sonkrag opwekking. Hierdie studie lewer ’n konsepsuele ontwerp en
ingenieurs-prototipe van ’n gebalanseerde dubbelas swaai-en-kantel swenkrat
aandrywingsmeganisme as megatroniese sonvolg platform vir ’n ∼12 m2 liggewig
paraboliese son konsentreerder. Digitale outomatisering van die son konsentreerder
platform is geimplementeer op ’n industriële Siemens S7-1200 programmeerbare
logiese beheerder (PLB) met ’n digitale afstandbeheer koppelvlak,
puls-wydte-gemoduleerde gelykstroom aandrywing en elektroniese ooplus
en geslote-lus sonvolg beheer. Die ontwerp en prototipe maak gebruik van
beskikbare komponente om lae-koste plaaslike vervaardiging te ondersteun en
slaag in die algemeen in die doel om ’n dinamiese megatroniese platform vir ’n
gekonsentreerde sonkrag stelsel te lewer wat maklik vervoer, gebou en opgerig
kan word op afgeleë persele in Afrika. Intydse eksperimente is gedurende die
somer uitgevoer om die akkuraatheid van die prototipe posisionering sisteem
te evalueer. Dit toon dat die sisteem die son deurlopend volg met ’n akkuraatheid
beter as 1.0◦ op beide die azimut en elevasie sonvolg asse, wat voldoen
aan die ontwerp spesifikasies.
Strukturele aspekte van die prototipe paraboliese skottel word deur ander
navorsers geëvalueer en verbeter terwyl die Stirling-eenheid en elektriese sisteme
in parallelle projekte ontwikkel word. Die uiteindelike doel met hierdie
groepnavorsing is om ’n plaaslik vervaardigde doen-dit-self sonkrag eenheid te
ontwikkel wat in Afrika ontplooi kan word.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/96137 |
| Date | 12 1900 |
| Creators | Prinsloo, Gerhardus Johannes |
| Contributors | Dobson, R. T., Schreve, K. S., Stellenbosch University. Faculty of Engineering. Department of Mechanical and Mechatronic Engineering. |
| Publisher | Stellenbosch : Stellenbosch University |
| Source Sets | South African National ETD Portal |
| Language | en_ZA |
| Detected Language | Unknown |
| Type | Thesis |
| Format | xviii, 138 p. : ill. |
| Rights | Stellenbosch University |
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