Full Text Available

Note: Clicking the button above will open the full text document at the original institutional repository in a new window.

Development of a novel air-cored permanent magnet linear generator for direct drive ocean wave energy converters

Thesis (PhD)--Stellenbosch University, 2013.

Saved in:
Bibliographic Details
Main Author: Vermaak, Rieghard
Other Authors: Kamper, M. J.
Format: Thesis
Language:en_ZA
Published: Stellenbosch : Stellenbosch University 2013
Subjects:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1867614007595106304
access_status_str Open Access
author Vermaak, Rieghard
author2 Kamper, M. J.
author_browse Kamper, M. J.
Vermaak, Rieghard
author_facet Kamper, M. J.
Vermaak, Rieghard
author_sort Vermaak, Rieghard
collection Thesis
dc_rights_str_mv Stellenbosch University
description Thesis (PhD)--Stellenbosch University, 2013.
format Thesis
id oai:scholar.sun.ac.za:10019.1/80267
institution Stellenbosch University (South Africa)
language en_ZA
last_indexed 2026-06-10T12:45:11.659Z
license_str Other — see source repository
provenance_str_mv Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository
publishDate 2013
publishDateRange 2013
publishDateSort 2013
publisher Stellenbosch : Stellenbosch University
publisherStr Stellenbosch : Stellenbosch University
record_format dspace
source_str SUNScholar — Stellenbosch University Repository
spelling oai:scholar.sun.ac.za:10019.1/80267 Development of a novel air-cored permanent magnet linear generator for direct drive ocean wave energy converters Vermaak, Rieghard Kamper, M. J. Stellenbosch University. Faculty of Engineering. Dept. of Electrical and Electronic Engineering. Linear generators Permanent magnets Wave energy Dissertations -- Electrical engineering Theses -- Electrical engineering Wave energy converters Thesis (PhD)--Stellenbosch University, 2013. ENGLISH ABSTRACT: In hierdie tesis word ’n nuwe lug kern permanent magnet (PM) lineêre generator (LG) vir toepassing tot direk aangedrewe (DA) oseaan golf energie omsetters (GEO) ontwikkel. Die nuwe LG word ontwikkel vanaf die lineêre dubbel-kant topologie in ’n poging om probleme met die huidige longitudinale vloed (LV) yster kern LGs, wat tot dusvêr oorheersend voorkom in eksperimentele DA-GEOs, te oorkom. Die grootste probleem met hierdie LGs is die masiewe aantrekkings kragte tussen hul yster stators en die PM transleerders. ’n Groot hoeveelheid strukturuele staal word benodig om die luggaping te handhaaf, terwyl die las op die laars ook ’n groot probleem is. Die nuwe LG gebruik ’n lug kern stator wat alle aantrekkings kragte tussen die stator en transleerder elimineer en dus die nodige strukturuele material verminder. Die topologie van die transleerder is ook van so ’n aard dat die netto aantrekkings kragte op enige spesifieke PM ideaal nul is; dit verminder die strukturuele materiaal selfs verder. Die transleerder het ook ’n nuwe transversale vloed pad wat die sogenaamde paarwyse vloed koppeling wat in LV-LGs voorkom, en die negatiewe effekte daarvan, verhoed. ’n Aantal nuwe bydraes tot die veld van LGs vir DA-GEO word in hierdie tesis gemaak. ’n Nuwe topologie lug kern PMLG is ontwikkel soos bespreek. Dit sluit in die ontwikkeling van analitiese en eindige element modelle en ’n optimerings prosedure wat vinnig optimale dimensies vir minimum aktiewe massa van die nuwe LG vind. In die ontwerp word dit ook gevind dat die drywingsdigtheid van LGs verbeter kan word deur zero oorvleuling tussen die die stator en transleerder by die slag endte toe te laat. ’n 1 kW prototipe van die nuwe LG word ontwerp en gebou; die uitvoerbaarheid van die konstruksie vir die nuwe topologie op ’n klein skaal word dus gedemonstreer. ’n Unieke toets opstelling word ook ontwerp en is gebasseer op bestaande toerusting in die vorm van ’n wind turbine generator en rug-aan-rug spannings bron omsetters. Met die toets opstelling word ’n enkel frekwensie golf ge-emuleer om die teorie en simulasies te verifieer en word ook ’n voorspellende beheer strategie geimplementeer, wat vir die eerste keer gedemonstreer word vir LGs vir DA-GEOs. Goeie ooreenstemming tussen die gemete en gesimuleerde data bevestig die voorgestelde modellerings en ontwerps metodes. AFRIKAANSE OPSOMMING: In this thesis, a novel air-cored permanent magnet (PM) linear generator (LG) is developed with application to direct drive (DD) wave energy converters (WECs). The novel LG is developed from the linear double-sided topology in an attempt to overcome the problems with current longitudinal flux (LF) iron-cored LGs, which have so far been dominant in experimental DD-WECs. The biggest problem with these LGs is the massive attraction forces between their iron stators and PM translators. A large amount of structural steel is required to maintain the air gap, while the load on the bearings is also a large concern. The novel LG uses an air-cored stator which eliminates any attraction forces between the stator and translator and hence reduces the required structural material. Furthermore, the topology of the translator is such that the net attraction force on any particular PM is ideally zero, which even further reduces the structural material required for the translator. A new transverse circulating flux path is also introduced in the translator which prevents pair-wise flux coupling and its negative effects as observed in LF-LGs. A number of new contributions are made to the field of LGs for DD-WECs in this thesis. A novel topology aircored PMLG is developed as described. This includes the development of analytical and finite element models and an exhaustive optimisation procedure for quickly finding optimal dimensions for minimum active mass of the novel LG. In the design it is also found that the power density of LGs can be improved by allowing zero overlap between the stator and translator at the stroke ends. A 1 kW prototype of the novel LG is designed and built; the feasibility of constructing the novel LG on a small scale is as such demonstrated. A unique test rig is designed based on existing equipment in the form of a wind turbine generator and back-to-back voltage source converters. The test rig allows emulation of a monochromatic wave for verifying the theory and simulations and also allows for implementation of a predictive control strategy, which is for the first time demonstrated for LGs for DD-WECs. Good agreement between measured and simulated data confirms the presented modelling and design methods. Doctoral 2013-02-22T14:24:02Z 2013-03-15T07:43:06Z 2013-02-22T14:24:02Z 2013-03-15T07:43:06Z 2013-03 Thesis http://hdl.handle.net/10019.1/80267 en_ZA Stellenbosch University 168 p. : ill. application/pdf Stellenbosch : Stellenbosch University
spellingShingle Linear generators
Permanent magnets
Wave energy
Dissertations -- Electrical engineering
Theses -- Electrical engineering
Wave energy converters
Vermaak, Rieghard
Development of a novel air-cored permanent magnet linear generator for direct drive ocean wave energy converters
title Development of a novel air-cored permanent magnet linear generator for direct drive ocean wave energy converters
title_full Development of a novel air-cored permanent magnet linear generator for direct drive ocean wave energy converters
title_fullStr Development of a novel air-cored permanent magnet linear generator for direct drive ocean wave energy converters
title_full_unstemmed Development of a novel air-cored permanent magnet linear generator for direct drive ocean wave energy converters
title_short Development of a novel air-cored permanent magnet linear generator for direct drive ocean wave energy converters
title_sort development of a novel air cored permanent magnet linear generator for direct drive ocean wave energy converters
topic Linear generators
Permanent magnets
Wave energy
Dissertations -- Electrical engineering
Theses -- Electrical engineering
Wave energy converters
url http://hdl.handle.net/10019.1/80267
work_keys_str_mv AT vermaakrieghard developmentofanovelaircoredpermanentmagnetlineargeneratorfordirectdriveoceanwaveenergyconverters