10KW Homemade generator

[have_blue]

</font><font color="blue" class="small">( Saw this at a new Harbor Freight )</font>

Hi Bob,

I've had my eye on that deal myself.

Problem is, it would need nearly a 10:1 pulley ratio to make it work.

You could make a pair of 3:1 double reduction (speedup) set. The first pulley would kick it up to 1620, and the second to 4860 RPM. Now you can back off the 4860 until you get 3600 RPM, and your engine would run at an efficient speed. You would probably need 35-40 PTO hp to run a pair of 3:1 sets. If you only have say 25hp, you would have to go with a 3:1 and a 2:1 and run the PTO a little above 540 to still get 20hp at the PTO. That's pushing a little.

 

[slowrev]

"A 12 pole, generator with the PTO running @600 rpm generator would have a frequency of 60 Hz."

One thought from here is that with the slower turnig generators, wouldn't an engine speed variation have a larger impact on the output frequency ?

 

[TWINKLE_TOES]

Three Phase Motors as Generators

You can buy it new or used from Amazon or borrow mine if you like.

 

[rockinmywaypa]

Thanks Twinkle Toes Looks like just what the doctor ordered. I'll check it out at the library but thanks for offering yours.

 

[EdK]

I'll bite-

Would you mind jotting a few sentences on that topic? It's an intriguing topic. I'll buy the book if your intro grabs me /forums/images/graemlins/smile.gif

 

[have_blue]

</font><font color="blue" class="small">( "A 12 pole, generator with the PTO running @600 rpm generator would have a frequency of 60 Hz."

One thought from here is that with the slower turnig generators, wouldn't an engine speed variation have a larger impact on the output frequency ? )</font>

I suspect that RPM on slower turning generators would have to be more accurate and stable than faster turning generators. The good news is that super-accurate frequency is not real critical for most things you normally need in an emergency. Even TV's and computers are pretty tolerant of frequency variation.

 

[TWINKLE_TOES]

Ed, I dug up this link which will give you an idea how this works. Nigel Smiths book is more technical and provides more detailed information on "why as opposed to "what"

Induction Motors as Generators

 

[TWINKLE_TOES]

slowrev,
<font color="blue"> wouldn't an engine speed variation have a larger impact on the output frequency ?
</font>

Good point, the 600RPM would have a frequency sensitivity of 1Hz/Rpm, the 3600 RPM would have a sensitivity of 0.167 Hz/RPM, one sixth as much.

Have Blue (deep Tan Man) also makes a good point that most things are not terribly sensitive to frequency

 

[Soundguy]

1HZ per 10rpm right?

Soundguy

 

[EdK]

Thanks Twinkle Toes!

That served as a good intro.

Ed