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Forum Index : Windmills : Artical on clogging
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| Clive Newbie  Joined: 29/09/2008 Location: Posts: 8 |
Might be a worthy read. Artical on clogging |
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| Dinges Senior Member  Joined: 04/01/2008 Location: AlbaniaPosts: 510 |
Darn. I was looking forward to a nice read on the fine ancient Dutch art of making, wearing and dancing with clogs, only to find a boring article on windturbines...  .
Seriously, thanks for the link. It's an ok read but also a bit disappointing though, I had expected a little more depth and detail (guess I had too high expectations). They don't really give much practical information, such as determining correct skew angle (hint: it's NOT exactly one slot width, at least not when using discrete magnets as we usually do). No mentioning of other useful decogging measures either (offset method). They also claim cogging is an inherent function of PM generators, which it isn't: axial fluxes are PM generators yet don't cog. Clive, if you aren't familiar with it yet, you may be interested too in this little paper on decogging I wrote about a year ago: http://www.otherpower.com/images/scimages/3538/decogging_tut orial_V1.pdf Interesting are figures 3a and 3b, if one takes into account that in motorconversions we normally use flat magnets. Flat magnets would actually increase cogging then, I suppose, if we extrapolate the situation of 3a and 3b. Too bad they don't explain (beyond 'bread loaf shaped') the correct geometry of the magnets, but then again, for most DIY conversions shaping the pole faces isn't very practical (unless one would install steel pole shaping shoes on top of the magnets). |
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vawtman Senior Member Joined: 14/09/2006 Location: United StatesPosts: 146 |
Hi Peter Just wondering how your 10hp conversion ended up "clogging "wise.How did the offset method work? Did i miss an update? |
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| Dinges Senior Member Joined: 04/01/2008 Location: AlbaniaPosts: 510 |
[double post deleted] |
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| Dinges Senior Member Joined: 04/01/2008 Location: AlbaniaPosts: 510 |
Hello Mark, no, you didn't miss any updates. Other things have priority at the moment, but I'll hopefully be able to have the rotor finished and inserted for a single-turn test run in a few weeks. And then you'll be the first to be informed...  |
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| Dinges Senior Member Joined: 04/01/2008 Location: AlbaniaPosts: 510 |
Did a bit of googling myself for the references in the paper. Interesting. I see a *lot* of similarities between the paper in your link and the one below. The names, however, differ... http://nwpc.vtt.fi/papers/kumar.pdf Clive, please allow me to abuse (hijack?) this thread by adding some more worthwhile references: http://www.google.com/patents?id=s7cRAAAAEBAJ&dq=6784582 http://eprints.ecs.soton.ac.uk/11047/1/Compumag2005(Hun)shor tversion.pdf http://www.motordesignsolutions.com/pdf/ias03_metin.pdf http://www.icrepq.com/icrepq-08/412-tudorache.pdf http://journal.library.iisc.ernet.in/vol200604/paper5/355.pd f http://eprints.whiterose.ac.uk/829/1/wangjb11.pdf http://www.epower-llc.com/pdf/LowNoisePMMotors.pdf http://www.ieindia.org/pdf/87/ej0f1kk.pdf http://www.ee.kth.se/php/modules/publications/reports/2003/I R-EE-EME_2003_029.pdf http://people.clarkson.edu/~pillayp/c12.pdf http://adt.curtin.edu.au/theses/available/adt-WCU20020610.11 1258/unrestricted/05Chapter4-4.7.1.pdf http://opus.kobv.de/tuberlin/volltexte/2006/1338/pdf/widyan_ mohammad.pdf Amazing what a little googling turns up... Mark, if you wonder why you don't read any updates about the 10 hp conversion... it'll be because I'm studying the above...  |
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SparWeb Senior Member Joined: 17/04/2008 Location: CanadaPosts: 196 |
Peter, With a few pretty FEMM diagrams and a Excel chart or two, your tutorial wouldn't look so different! Perhaps you can be the next to present at the American Society of Mechanical Engineers Wind Energy Symposium! 
Dinges, PhD,In,GES, Dean of Tinkering, Backshed U, Holland Campus Don't forget to include Mr Zubbly in your bibliography! Steven T. Fahey |
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| SparWeb Senior Member Joined: 17/04/2008 Location: CanadaPosts: 196 |
Peter, I scanned through the reports, some useful, some are intriguingly creative. I can't help but think that Mr. Widyan and Mohammad really missed the boat by only putting half as many coils into their motor design than they could have. There is a lot of flux in their stator that isn't being linked by a coil. Doubling the number of windings in their stator... And how do they go about putting the wire into that stator? With windings that go from inside to outside, they can't make the coils on the bench and put them in, can they? Still, could this be the seed idea for a halbach-array motor conversion? Any takers? Steven T. Fahey |
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Gizmo Admin Group  Joined: 05/06/2004 Location: AustraliaPosts: 5118 |
Hi Dinges That article by you and those links you found are very good. Do you mind if I link to them from my de-cogging page http://www.thebackshed.com/Windmill/articles/decoggingFP.asp Glenn The best time to plant a tree was twenty years ago, the second best time is right now. JAQ |
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| Dinges Senior Member Joined: 04/01/2008 Location: AlbaniaPosts: 510 |
Hello Gordon, nope, I don't mind linking or even hosting it yourself. Steven, a Ph.D. from the University of Backshed... ? Now there's a thought. If I could somehow convince Oztules to be my promotor... Peter. 'nothing is as practical as a good theory' |
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Bryan1 Guru  Joined: 22/02/2006 Location: AustraliaPosts: 1460 |
Now shouldn't this be the otherway around Dr. Oztules the marooned mad inventor.Phd with Dinges being the sponser
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| Dinges Senior Member Joined: 04/01/2008 Location: AlbaniaPosts: 510 |
Bryan, In the presence of Oztules I'd feel like Igor in the presence of Dr. Frankenstein... With me being only worthy to launch the kite in the thunderstorm (or refill the tank of his chainsaw).
ROFL. |
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GWatPE Senior Member Joined: 01/09/2006 Location: AustraliaPosts: 2127 |
Hi dinges, [Gizmo],Glenn requested permission to link to the articles, not me. Gordon. become more energy aware |
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| vawtman Senior Member Joined: 14/09/2006 Location: United StatesPosts: 146 |
You guys take this way to seriously:)A Backshed degree is where bachelors are made. |
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