Another candidate for generator

[Sillyboy]

This is my other candidate for motor conversion to a wind generator. The bearings seems to be out of order.

I measured the resistance.

The meter showed 4.5 ohms (for one coil i assume) between some connection points.

And 9 ohms between some (This would be two coils together i assume).

[hvirtane]

Hi,

you seem to be living in Finland, because your machine has got a Finnish plate. Where?

For the others to understand the specification of the engine: the grid system in Finland is 50 Hz 220 V, for single phase connections. The rest of the specifications seem to be obvious from the plate.

In my opinion the engine is quite small, but by doing a permanent magnet rotor for it, a similar way others have done, it could probably work to get 100 W (for 12 V battery charging purposes, maybe 200 W for 24 V) out of it?

- Hannu

[hvirtane]

I don't understand well issues of motor conversions. There has been recently lots of talk about motor conversions. Please try reading from the stuff others got as responses.

'Flux' wrote recently concerning another discussion:  

Try to find all the good work that Zubbly did on motor conversions, there is a lot of good advice there.

- Hannu

[Sillyboy]

Hi Hannu. I'm living in the West Coast. 30 km north from Vaasa.

[Warrior]

I'd say that's a very nice motor for conversion. You would probably have to reconnect the coils to get decent power out of it at typical battery voltages i.e. 12v, 24v, or 48v.

Zubbly has managed about 1000 watts out of a 2 HP motor such as yours.

Good luck,

[wdyasq]

I will agree with Warrior here. That is a 4 pole motor. You should look for Zubbly's information on motor conversions and also look at Peter Dingman's work.

http://www.zubbly.com/

http://www.anotherpower.com/gallery/dinges

Zubbly's album on another power has a lot of information also.

Ron

[Sillyboy]

Thank you guys for the comments and information sources. You've been very helpful.

I have a question to ask after two days of reading the boards. Why is it better to make a new rotor in motor conversions? Why is it not a good idea to use the old rotor as it is by just drilling holes for mags in it?

[ZooT]

Try drilling a laminated rotor stack sometime....

They're made of thin plates, and they delaminate and bend and do all kinds of strange things.

Drill holes close enough together so as to make the best use of the coils and none of the holes will end up round because the drlll will push the soft laminations into any surrounding holes...

[Flux]

Yes ZooT is absolutely right, machining any form of laminated material is a pain.

There is even more to it than this. You must not put your magnets in drilled holes, the leakage flux will be dreadful and you will waste much of the magnets potential. Those cages that people hold the magnets in are fibreglass or aluminium or some non magnetic material.

You can machine the rotor down to stick the magnets on the top, but you will find that it is not a solid steel core, it has slots with aluminium bars cast in it( connected to those end rings with fans). If you machine to a diameter where it is part steel and part aluminium you will only have a small steel area and you may saturate what is left.

If you choose a diameter that brings you below the cage bars then the end rings will fall off and most likely the whole core will collapse into a series of individual rings.

Some do it, much more trouble than making a new rotor in the end.

Flux

[hvirtane]

My estimation of the available power

was based on the amperage of the motor.

If it is 6,5 A, at 14 V it means 91 W?

I think that at least that much can be

taken out without overheating.

Is this a correct way of thinking?

- Hannu

[Flux]

Yes that would be a continuous rating for 12v, The winding would more suit 24 or 48v so you could manage 2 or 3 times that.

Now bearing in mind that the wind duty cycle is low you can probably overload it by a factor of 3. if it had a design life of 20 years and you are prepared for a shorter life then perhaps overload it by a factor of 4.

That would give a rating of over 1200W at 48v.

Motor conversions are better cooled than air gap machines and they are also likely to be to some extent reactance limited. In some cases they can be almost self protecting if you can live with the noise in a high wind.

Flux

[hvirtane]

Good. I agree that it would be much better to use it with higher voltages. Maybe delta would be quite a lot better than star.

What about another way of doing? Putting magnets in grooves of the rotor?

 

Better or worse use of the expensive material than on the top of the rotor?

- Hannu

[Flux]

Good idea for low flux ceramic magnets. I don't see any virtue with neo where the remnant flux is virtually saturation for steel.

In fact I see several reasons not to do it that way including the old issue of eddy loss in the solid steel pole pieces. The big commercial boys have tried it and rejected it. You may find it used in certain types of motor but there are other reasons for adopting it there to increase saliency torque.

Flux

[Sillyboy]

Thank you again guys. You've been very helpful. Been studying again and a i have a new question for you.

The original rotor has cooling fans on both sides. How important would those be in the generator use? Could i use that space in new rotor for magnets to improve the performance?