> Most magnets used in PMAs (permanent magnet alternators) are Neodymium
> (Rare Earth) magnets. Any other magnet just doesn't have the power
> behind it. PMA output has to be externally regulated.
> The other type of alternator uses an electro-magnetic rotor (core) in
> the alternator. Your car alternator works like this, it is less
> efficient due to powering the core, but the output can be regulated
> much easier - simply by shutting down the core.
> Neodymuims are chosen because they are the strongest non-electro
> magnets around and are very small for their magnetic power.
> Im sure I read somewhere that Neodymiums take a few hundred years
> before you start to notice a drop in their magnetic power, unlike
> typical magnets you find that loose 2-3% per year.
> In the field, PMA's using Neodymium magnets (you most probably wont
> find any other type), you should never have to worry about replacing
> them in your lifetime.
> However more inportantly would be the bearings that allow the tubine
> to spin. As it is spinning at reasonably high RPMs for most of its
> life, bearings will be destryed quickly. Possibly needing replacing
> every 5 years or so.. Then again, I don't own one so I don't know the
> life of the bearings..
> Would anyone else like to comment on the life of the bearings in a
> wind turbine?
> I hope this helps!
With electro magnet the rpms can be lower with the right winding.
Ceil fans are a example of that and the bearing life you can expect.
With reduced rpm's..... more inportantly is tip speed below the speed of
sound.
At the same time lubrication makes a differences ,too .
I would never make a flying windmill with PMA magnets.
But that is the state of the art at this time instead of pole mounted
windmills.
Do you know the wind speed your area .....
Like today at 7GMT the ground level wind was Ambato 6mph
Gulapagos 5mph
Iberarruito 15 mph
Iqobambo 15
Latacungo 6
Manta 16
Milago 5
Porttovieto 16
Quito 15
At 200mb (15000 ft) the number (or the single digit groundspeed areas) was
20.
Groundspeed areas with 15 to 16 mph...had 30 to 35 at that higher
atitude.
But then I should be telling you something you already know...if you are
doing your research.
If you were living in Chile (instead) storm pressure front has the wind
blow at 80 mph at 15000 ftabove the surface at7Gmt
You have to go to lower altitudes with a flying windmill at about 115 to
125mph wind.It may well get that later on today .
----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==----
http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+
Newsgroups
----= East and West-Coast Server Farms - Total Privacy via Encryption =----
XML site map
> (Rare Earth) magnets. Any other magnet just doesn't have the power
> behind it. PMA output has to be externally regulated.
> The other type of alternator uses an electro-magnetic rotor (core) in
> the alternator. Your car alternator works like this, it is less
> efficient due to powering the core, but the output can be regulated
> much easier - simply by shutting down the core.
> Neodymuims are chosen because they are the strongest non-electro
> magnets around and are very small for their magnetic power.
> Im sure I read somewhere that Neodymiums take a few hundred years
> before you start to notice a drop in their magnetic power, unlike
> typical magnets you find that loose 2-3% per year.
> In the field, PMA's using Neodymium magnets (you most probably wont
> find any other type), you should never have to worry about replacing
> them in your lifetime.
> However more inportantly would be the bearings that allow the tubine
> to spin. As it is spinning at reasonably high RPMs for most of its
> life, bearings will be destryed quickly. Possibly needing replacing
> every 5 years or so.. Then again, I don't own one so I don't know the
> life of the bearings..
> Would anyone else like to comment on the life of the bearings in a
> wind turbine?
> I hope this helps!