유도전동기를 동기 발전기로 개조 하는 방법

[윈드로즈]

My 12 year old washing machine finally fell apart, and I
splashed out on a new one. While stripping the old one
for useful bits, I caught sight of the old motor.

A quick check showed it was an induction motor. I'm in
Australia, so our stuff is 240VAC 50Hz. Although it had
no spec plate or even a model number, I estimate it was
about a 1/2hp to 1hp (~375W to 750W)? Seems to have a
4-pole 2-phase type of arrangement. It had a capacitor for
start/run on the second phase and a thermal fuse imbedded
in the windings. I bypassed the fuse to stop it doing anything
silly. This is a close up of the fuse.

The belt pulley was made of aluminium, and I will turn that
down in the lathe to become part of the blade hub later.

The rotor was about 80mm in diameter, and about 30mm
deep. I thought about buying some long narrow bar magnets
and skewing them slightly. But I remembered I had a pack
of 100 13mm x 5mm disk magnets. Although they are small
and fiddly, I got them for about AU$15 and stacking them
should improve the flux output.

This is what the rotor looked like after being machined down
and with the magnets stacked in a 3x2 configuration. I seem
to allow more space between poles than a lot of other conversion
people do, perhaps I'm fussy about cancellation in the waveform.
Here is a series of pics, where you can also see how I used the
roof screws again to stop the laminates from falling apart. Also
the magnets over hang the rotor a bit. I could have made a fresh
rotor but - bah, this is more of a toy for me :)

I keep all my old plastic, metal & glass containers these days.
They come in handy for so many things.

I sliced up an old juice container and wrapped it around the magnets.
Super glue joined it at the overlap. A plastic lid formed the bottom
of the mould, and good old silicone sealed all the gaps. You'll notice
I have not used a cage for the magnets. I want to push the new epoxy
to the limits :)

The rotor sat just nice inside the old juice container base.
Making it both a support and a spill container.

I bought some West System Epoxy this time, as I noticed a
lot of the forum use it. I'm using the 206 slow hardener,
as I'm a firm believer in a better cure for a slow cool/reaction.

This is my patented :-) epoxy mixing tool. As you can see,
it was not engineered on a CAD system.

I use an old 12V drill connected to a 50Ahr battery for mixing
the epoxy. It means you never go flat in the middle of mixing,
or any other workshop job for that matter :-)

Here is the rotor about 30 minutes after being poured with epoxy.
Most of the bubbles have risen to the top, and formed a froth layer.

After curing for a week in our tropical sun, I put the rotor back
into the lathe and cleaned up the epoxy. The silicone and old
plastic container bits were peeled off easily by hand.

Here it is with the sun behind it. You can see the magnets inside the epoxy.

It has two new bearings, and I added some welds to the
mounting ears to make sure they don't break.

I used an old MATV amp to fit some 50Amp 600Volt bridge
rectifiers to. It was a good opportunity to play with the new
milling machine. I had to make a wider base for the bridges
to mount to, so a second MATV heatsink was cut down and
bolted to the main one. A 2-phase design has only to be treated
as if it were a 3-phase in regards to rectification. Its overkill,
but I have plenty of new bridges laying about.

I put the motor back into the lathe and did some tests.
I knew from day one that this would not make much power
due to the 20ohm impedance of each winding. One thing I am
happy with is the waveform. Its an almost perfect sine wave.
The 3hp conversion I did earlier has a slight dip part way
through the wave. I suspect this is caused by a lack of magnets,
as I reduced the magnet count in the final stage of design. I hope
to get some digital waveform images soon.

The rotor can be spun between two fingers to produce 20+
Volts. It feels like a fine stepper motor when it's spun by hand.
I coated the windings with motor winding lacquer for use
in outdoor environments. And the whole outer casing got
a coat of my favourite 97% zinc protective Gal paint.

In conclusion, I'm happy that it performed as I expected it would.
It was a fun test project that produced more information for me
and tested my skills, so that makes it a success. I would call this
a 50-80watt alternator to be conservative. I don't think I could
get much more out of it with the stock windings. Considering that
it began life as a mass produced & average quality domestic motor,
worked for 12 years and then changed roles to produce power is
quite a heart warming thought :)

I'm going to do a set of wood blades based on Hugh's designs
and adjusted for higher RPM at lower (20-30klm/h) wind speeds.
About 800mm radius blades with a TSR of about 10 should do it.

I also recovered the "gearbox" from the washing machine, and
it seems to be about a 4:1 or thereabouts. It's a planetary style
with a sealed aluminium casing filled with oil, and brass/plastic
gears. I'm having kinky thoughts about using it as a speed up
for the motor - maybe get some serious RPM out of it. Curious,
the oil that was in the gearbox was squeaky clean after 12 years.

Spank me! The gearbox even has a friction brake!!
This is going to be fun  :)

I might set this one up at home in a suburban setting on a fold
over tube tower. It will be excellent for testing blades, MPPT
designs, my PICAXE LCD logger and generally gathering info.

If not, I can see it becoming a battery charger at a friends house
that has strong daily winds. He has a garden light system that runs
for a few hours a night. A full day of wind charging should handle
this no problem.

Costs:
Magnets  ~AU$15
Motor - free
Epoxy  ~ AU$5
New Bearings ~ AU$12
Rectifiers ~ AU$12
Heatsink - free
Total ~$44

Making power from junk - priceless :)

sPuDd..

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Washing Machine Induction Motor Conversion. | 17 comments (17 topical, 0 editorial)

Re: 3 phase. (3.00 / 0) (#1)
by Jerry on Sat Dec 30th, 2006 at 10:25:43 PM MST
(User Info) http://www.dplusv.com/Photo-03.html

Hi sPuDd.

Here are some thought for the 3 phase 2 pole you posted about earlyer.

Sorry for plcing it here but thought it might get over looked in that thred. It was geeting prety long?LOL

I've played with some 3 phase 2 pole conversions. If your not looking for much power and just expirimenting this might work as well as a group of small NEOs?

Also you might just concidering leaving the stock wireing in the next small 3 phase motor. Just seperate the ends of all coils. Perelell the coils of each phase, use a fullwave bridge for each phase then perelell the outputs of those 3 bridges.

Even though these magnets are only ceramics they cover allmost 100% of the pole face and because of this have practicaly no cogging. The output is low but on a par with the tinny NEOs.

Best part the ceramics are free. I get them from plumbers. Some of the Garbage disposal motor are PM and have a nice littel bridge rectifier also.

Heres a few pictures.

This last 1 is testing.

[신뽀리]

선풍기도 저런 구조로 되어있는데, 문제는 회전축에 사용할 축과 자석을 어떻게 구하는지...

[바람똘이]

한글로 번역 않될까요???ㅠㅠㅠ

[청랑]

우선 베어링부터 베어링 가게서 구입하시고 다음 축은 가공하심됩니다. 자석은 인터넷에 Nb자석류 찾아보시면 찾을 수 있습니다. 에폭시레진은 FRP취급하는 곳이나 대형 페인트 취급점에서 찾을 수 있습니다. 200 RPM일때 10W 수준이면 실망이군요.

[강원남도]

일반유도 전동기 회전축에 영구자석을 부착하면 발전기가 된다는말씀이네요,,,감사,,꾸~벅,,

[특징]

200rpm에 10w라면 모터의 결선을 바꾸어서 극을 늘리면 어떻게 될까요? 세탁기의 모터는 내가 알기로는 단상모터인데 권선의 결선을 바꾸어서 극수를 올리면 출력도 달라질거 같읍니다.

[동양]

초보에겐 어려워보이네요