A Method for accurate measurement of heliostat mirror orientation
| dc.contributor.advisor | Treurnicht, J. | en_ZA |
| dc.contributor.advisor | Engelbrecht, H. A. | en_ZA |
| dc.contributor.author | Swart, Benjamin Dawid | en_ZA |
| dc.contributor.other | Stellenbosch University. Faculty of Engineering. Dept. of Electrical and Electronic Engineering. | en_ZA |
| dc.date.accessioned | 2017-02-21T08:40:29Z | |
| dc.date.accessioned | 2017-03-29T12:00:50Z | |
| dc.date.available | 2017-02-21T08:40:29Z | |
| dc.date.available | 2017-03-29T12:00:50Z | |
| dc.date.issued | 2017-03 | |
| dc.description | Thesis (MEng)--Stellenbosch University, 2017. | en_ZA |
| dc.description.abstract | ENGLISH ABSTRACT: Heliostat tracking is a critical component of the solar field of concentrating solar power central receiver systems and can be the source of significant losses in power and profit when it lacks the necessary accuracy. The current industry norm seems to be open-loop tracking using an error model for a tracking error of one milliradian, with error model parameters requiring periodic recalibration. In this thesis a method is developed which is able to determine the orientation of all heliostats in the field simultaneously, providing near real-time feedback to the control system, removing the need for recalibration while maintaining an accurate tracking accuracy. The method works by determining the positions of three or more distinct points on the heliostat mirror surface. These points form a plane which is then used to calculate the heliostat normal vector. The performance of the method is analysed and quantified using simulations, and experiments are used to validate the theoretical models. Quantification of the system performance is used to determine the initial feasibility of the method. Results indicate that for the error sources included in the model it is theoretically possible to achieve a tracking error in the order of one milliradian or less. Furthermore, experimental results are found to differ by only 5% from theoretical results. This is promising and merits further investigation into the method as a possible solution to the current heliostat tracking problem. | en_ZA |
| dc.description.abstract | AFRIKAANSE OPSOMMING: Heliostaat volging (die vermo e om die son te volg) is 'n kritiese komponent van die sonveld in gekonsentreerde son-energie sentrale ontvangerstelsels. Indien die nodige akkuraatheid ontbreek, kan dit aansienlike energie{ en winsverliese tot gevolg h^e. Die huidige industry standaard is o enskynlik opelus-volging met 'n foutmodel wat 'n volgfout van een milliradiaal tot gevolg het, met foutmodel parameters wat periodiese herkalibrasie noodsaak. In hierdie tesis word 'n metode ontwikkel wat die ori entasie van al die heliostate in 'n veld tegelykertyd kan bepaal. Dit voorsien byna-intydse terugvoer aan die beheerstelsel wat herkalibrasie onnodig maak terwyl volging steeds akkuraat kan plaasvind. Die metode werk deur die posisies van drie of meer unieke punte op die heliostaatspie el se oppervlak te bepaal. Hierdie punte vorm 'n vlak wat gebruik kan word om die heliostaat se ori entasie te bereken. Die doeltreffendheid van die metode word geanaliseer en gekwantifiseer deur middel van simulasies en eksperimente word uitgevoer om die teoretiese modelle te bevestig. Die resultate wys dat vir die foutbronne wat in die model ingesluit is dit teoreties moontlik is om 'n volgfout in die orde van een milliradiaal of minder te behaal. Daar is ook bevind dat eksperimentele resultate met minder as 5% van teoretiese resultate verskil. Dit is belowend en verdien verdere ondersoek na hierdie metode as moontlike oplossing vir die huidige probleem met heliostaat volging. | af_ZA |
| dc.format.extent | 128 pages : illustrations, maps | en_ZA |
| dc.identifier.uri | http://hdl.handle.net/10019.1/101038 | |
| dc.language.iso | en_ZA | en_ZA |
| dc.publisher | Stellenbosch : Stellenbosch University | en_ZA |
| dc.rights.holder | Stellenbosch University | en_ZA |
| dc.subject | Heliostat | en_ZA |
| dc.subject | UCTD | en_ZA |
| dc.subject | Solar-powered aircraft | en_ZA |
| dc.subject | Heliostat -- Mirrors -- Measurement | en_ZA |
| dc.title | A Method for accurate measurement of heliostat mirror orientation | en_ZA |
| dc.type | Thesis | en_ZA |