Author Topic: 2hp 3 phase. Open forum. Rewind for best low speed output  (Read 8854 times)

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topper

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2hp 3 phase. Open forum. Rewind for best low speed output
« on: March 06, 2016, 06:24:36 PM »
So. I have a 2 horse Teco Westinghouse 3 phase motor. 36 slot stator(3" long, 3-3/4' Dia). Windings were shot and I'm bored (unemployed ATM).
I figured I'd play a bit and see what I can do.  It came wired as a 12 wire, 4 pole with 30 turns per slot with a pair of 22AWG.
I'm looking to build it up for a low speed test bed (<200RPM) It'd be nice to have it suitable for a few amps into a 24 volt bank.
 If it were you, What would you do with a bare bones 2HP?? 4 pole, 6 pole, # turns, mags.
Thanks in advance.
I'm flying blind and just learning from others' posts.

 Currently have 84 Neo's 1/4 x 1/4 x 1" and a pail of 22 AWG .
 I do realize I'll probably have to buy some different magnets and spin the rotor down to suit.

Ready, set??   GOOOO!!!!!

topper

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Re: 2hp 3 phase. Open forum. Rewind for best low speed output
« Reply #1 on: March 06, 2016, 06:50:58 PM »
 Rotor is 3 3/4" diameter and 3" long. < might come in handy.

joestue

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Re: 2hp 3 phase. Open forum. Rewind for best low speed output
« Reply #2 on: March 06, 2016, 10:42:09 PM »
if you buy 6 more of those magnets you can make a 30 pole, 18 coil system.
see here: http://www.fieldlines.com/index.php?topic=147695.0

I was able to get 138 watts with a voltage drop of 8.5% at 526 rpm. given 6 times the magnet volume, and at least 50 percent more core area, you should be able to get perhaps half a hp at 500 rpm at about the same voltage drop.

If you don't want to buy 6 more magnets, I would try a 28 pole configuration but its 12% less efficient as far as copper losses,
you can find the wiring options here:
https://www.emetor.com/edit/windings/

I would not turn the rotor down yet, simply machine .25 inch wide slots in the rotor and slip the magnets in the groove. yeah some flux will be lost but its not a big deal, and i don't believe you will have to epoxy the magnets in provided you keep the rpm down.
My wife says I'm not just a different colored rubik's cube, i am a rubik's knot in a cage.

joestue

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Re: 2hp 3 phase. Open forum. Rewind for best low speed output
« Reply #3 on: March 07, 2016, 10:44:43 PM »
edit: you have about 3 times the magnet volume I do.

anyhow, if you drop to less than 28 poles, the next options you have are 12, 10, 8, and 6.

10 poles is a good idea to reduce cogging torque, but doesn't evenly divide the magnets you have.
The coils for 10 poles is the same style as 12 poles, two layer mush winding will work (36 coils, each spanning 3 slots).However, the connections are rather complicated.
My wife says I'm not just a different colored rubik's cube, i am a rubik's knot in a cage.

SparWeb

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Re: 2hp 3 phase. Open forum. Rewind for best low speed output
« Reply #4 on: March 07, 2016, 11:44:34 PM »
36 slots: it probably had 3 coils per pole per phase.  (3 x 3 x 4 = 36)
The simplest way to change number of poles is to go from 4 poles to 12.  Then you use 1 coil per pole per phase.  (1 x 12 x 3 = 36)
The consequences of that change affect your choice of wire gauge and connection of the coils in series and/or parallel later.  It's important to figure out all of these things in advance, and best to make connection diagrams that you can follow when you get the new wire in.

You don't have to do too much fancy stuff to get a good motor conversion, as long as you start out with a quality motor with big bearings and damage-free iron in the stator.

I strongly recommend bonding the magnets to the rotor to keep them in place, even if you try slots and they work. 

New wiring gives you options to improve cogging without having to twist or skew the magnets.  Less skew to the magnets means you can keep the clearance between magnets and stator very tight - and that's good for the flux density.  Just bear in mind that changing the pole count in a motor/generator is a bit like changing the winding count in a transformer:  you can step up and down but the power in is roughly equal to the power out, no matter what ratio you choose.

Whatever wire you cut out of the motor, carefully measure the gauge of the wire.  It could be millimeter gauge or american gauge.  And if it's american gauge don't assume the gauge is an even number like house wiring - the motors I've converted have had 21, 18, 17 gauge wire in them, etc.
No one believes the theory except the one who developed it. Everyone believes the experiment except the one who ran it.
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topper

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Re: 2hp 3 phase. Open forum. Rewind for best low speed output
« Reply #5 on: March 08, 2016, 09:03:37 AM »
Thank you both for the replies.
 The original stator was wound as a 4 pole. (-a1, -a1, -a1)  (-b1, -b1, -b1) (-c1, -c1, -c1)  Then 3 slots for phase +a,  +b, 3 for +c etc. I did spec the original wire and it seems to be actual 22AWG , 2 wires parallel @ 30 turns. Rated @ 1740 RPM.  2.67Amps @ 460Volt<which would give me 26+ volts @ 100 RPM in an ideal world.
 I'm still pondering which way to go to accomplish the least cogging with the best low RPM performance. I may stay with a 4 magnet pole design or step up my coils/phase to get better low end voltage.
 I'm still working my rotor circumference and magnet fill to maximize each scenario.
 I currently have 3 of these motors, all with shorted stators, so I have 3 tries to get it workable.  ;D.
 Cheers and thx again.

topper

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Re: 2hp 3 phase. Open forum. Rewind for best low speed output
« Reply #6 on: March 09, 2016, 05:24:33 PM »
 I'm beginning to be a fan of your conversions Spar. Your 3HP looks awesome. Am I spying 1/2" thick mags on that rotor?? I'm quite impressed by your output as well.
The more I think about it, the more I think I should stay with what has been proven to work.
So rather then sticking with my 1/4" magnets and try to squish them together, I'll source some with counter sunk mounting holes.
Anyone care to share their sources?? I am in Canada.

SparWeb

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Re: 2hp 3 phase. Open forum. Rewind for best low speed output
« Reply #7 on: March 10, 2016, 09:52:18 PM »
Thanks.  Every project has room for your own ideas so go ahead and try what you think is right.
Yes I used 1/2" magnets.  I think I got mine from KJ magentics.  I don't recall that shipping was a hassle.  Nowadays, of course, you get the hoser discount when buying from the US.

Wow, you're going to have a fleet when you're done. 
No one believes the theory except the one who developed it. Everyone believes the experiment except the one who ran it.
System spec: 135w BP multicrystalline panels, Xantrex C40, DIY 10ft (3m) diameter wind turbine, Tri-Star TS60, 800AH x 24V AGM Battery, Xantrex SW4024
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topper

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Re: 2hp 3 phase. Open forum. Rewind for best low speed output
« Reply #8 on: March 11, 2016, 02:00:56 PM »
 I may just end up with a pallet of projects. LOL. My next trip to Airdrie I'll have to scoot by and oogle your builds Spar. And just to say, Your web page has helped me in numerous ways. So I thank you again for sharing your learnings.
 
 Mags got ordered yesterday.Stuck with 1/4" thick x 1/2" wide instead of building all new rotor cores. 2 rotors being cut down as we speak. TGIF means they'll do it for beer cash  ;D
Starting on a lenz2 design(VAWT). Hoping for 3ft diameter and 4ft tall. Still calculating. My house sits in a wind tunnel most days so VAWT should work successfully. Being in residential sucks these days. No one wants turbine blades in the traditional sense and clean air is a long way up there.
 Have a good weekend everyone.

SparWeb

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Re: 2hp 3 phase. Open forum. Rewind for best low speed output
« Reply #9 on: March 13, 2016, 11:53:57 PM »
I sense a mismatch in the making.
The start-up cogging of a motor conversion is a big impediment to success in a VAWT, which has very very low torque to start with.
I have read about a number of Ed Lenz VAWT's on axial-flux alternators that do well.  I haven't seen one mated to a motor conversion that was a documented success.
Not saying it can't be done, but....
No one believes the theory except the one who developed it. Everyone believes the experiment except the one who ran it.
System spec: 135w BP multicrystalline panels, Xantrex C40, DIY 10ft (3m) diameter wind turbine, Tri-Star TS60, 800AH x 24V AGM Battery, Xantrex SW4024
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topper

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Re: 2hp 3 phase. Open forum. Rewind for best low speed output
« Reply #10 on: March 15, 2016, 02:14:52 PM »
Funny you should say that. I was thinking the exact same thing. But doing a motor conversion would be a good learning experience...  And It'll keep my hands busy for a while.
 That being said. I have been playing with a few different VAWT vs Axial designs. Starting small 25-50 watt realistically... Maybe....
 Mag rotors can all be of one design (12 or 16 pole) and a new stator is an afternoon of winding and casting. And we will see where it goes from there.
 5 watts is enough to float my bank of AGM's anyway :)
CHEERS!!

Bruce S

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Re: 2hp 3 phase. Open forum. Rewind for best low speed output
« Reply #11 on: March 15, 2016, 04:34:03 PM »
OKAY , now I gotta ask  :o
How is it that only 5 watts will keep your AGMs in float?
Cheers
Bruce S
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joestue

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Re: 2hp 3 phase. Open forum. Rewind for best low speed output
« Reply #12 on: March 15, 2016, 04:55:14 PM »
10 poles will be the lowest cogging, for the highest copper efficiency, (intrinsically due to the LCM of the slot/magnet numbers, higher is better), the connections are complicated but the coils are the same as 12 poles.

I would not go any higher than 12 poles because iron loss at the higher pole counts is pretty high, and its not until you get to 26 poles or higher before the fundamental  winding factor rises back up to acceptable levels.*

14 poles has an LCM of 252, less cogging than 10 poles at 180, but the fundamental winding factor is .55.. which means you get 55% of the voltage (60% of the 10 pole number) 16 has an lcm of 144, and about the same winding factor.

unfortunately you have to take the fundamental winding factor and square it, take the reciprocal of that to find copper losses.


*As far as acceptable winding factor, that depends on how much power you have. it may be appropriate to use 14 poles (the worst option, but least cogging, except for 26 poles) if you only expect to get 50 watts out of it. but if iron loss dominates at 14 poles at the rpm you expect, then 10 poles would be better.
My wife says I'm not just a different colored rubik's cube, i am a rubik's knot in a cage.

topper

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Re: 2hp 3 phase. Open forum. Rewind for best low speed output
« Reply #13 on: March 17, 2016, 03:03:12 PM »
 To answer your Q Bruce. I am speaking of, once they are charged. They typically take 150-200mA in float @ 27.4Volts, so a little over 5 watts not including line losses of course.
8 enersys AGM 12v155f.  4 Banks @ 24 volt.

SparWeb

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Re: 2hp 3 phase. Open forum. Rewind for best low speed output
« Reply #14 on: March 19, 2016, 03:55:28 PM »
Not so far-fetched Bruce.  My set need 30W at float.
I am absolutely certain his AGM's are newer than mine.
No one believes the theory except the one who developed it. Everyone believes the experiment except the one who ran it.
System spec: 135w BP multicrystalline panels, Xantrex C40, DIY 10ft (3m) diameter wind turbine, Tri-Star TS60, 800AH x 24V AGM Battery, Xantrex SW4024
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Bruce S

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Re: 2hp 3 phase. Open forum. Rewind for best low speed output
« Reply #15 on: March 19, 2016, 05:38:24 PM »
SparWeb;
Agreed , I was more curious about how he got there.
 
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topper

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Re: 2hp 3 phase. Open forum. Rewind for best low speed output
« Reply #16 on: March 21, 2016, 12:20:39 AM »
 Thanks for double checking my math Bruce. Errors always cost more then facts.
 I did have a minor error. My bank is made up of 12v170F's. Manufacture date 04/07/10 makes them almost 6 years old. My last 3 sets were used 155's which were cheap. I learned many valuable lessons about AGM's. Overcharging a single battery voltage WILL KILL it quickly. I now have a Victron balancer in place to keep all batteries in sync +/- 100mV @ float.
Cheers all.

topper

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Re: 2hp 3 phase. Open forum. Rewind for best low speed output
« Reply #17 on: April 23, 2016, 12:26:14 AM »
 Well. After much consideration, I opted for an axial flux machine. A 1000# axle shaft from my stash with a 4 on 4" bolt hub, a couple brake rotors from a BMW if I recall and a hand full of magnets and some 22 AWG wire.
 The rotors are 10 1/4" OD with a 6" center dish. Magnets are 1 1/2 X 1/2 X 1/4" which left me 1/2" of space for coils on the inside deck against the rotor dish-centers. I decided to go with 2-16 pole rotors.
 Next I tackled the stator. 12 1/2" Diameter and 1/2" thick. <mistake. Just too thick given a 1/2" of total magnet height. 12 coils @ 200 turns of 1-22AWG in the standard pie shape.  I brought out 12 connections to keep my options open to the fullest.
 NEVER USE ELECTRICAL TAPE TO SECURE YOUR COILS. After casting, I had many choice words for the electrical tape hanging out of this beautiful piece of art work.
 I tried a few different windy ends of things. Lift, drag, and finally built a Lenz 2 design which has been working rather well for a first timer. Blade cage measures 24" Dia x 30" height. Wired in series star I have seen it up to 22 volts so far in turbulent winds. Still a stretch to my 28 volt goal, but still not bad for a first attempt.
  I plan on winding and casting another stator soon. Probably a wave wound 40-50 turns with my max thickness in check. Shooting for less then 3/8" total thickness.
 I hope to post some pics here soon of my triumphs and failures.
 

joestue

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Re: 2hp 3 phase. Open forum. Rewind for best low speed output
« Reply #18 on: April 28, 2016, 01:53:14 AM »
if you pull on the electrical tape slowly, it should pull out of the castings you made. may take a few days though.

a wave winding should be more efficient if you can squash 2 or 3 layers together.
My wife says I'm not just a different colored rubik's cube, i am a rubik's knot in a cage.

topper

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Re: 2hp 3 phase. Open forum. Rewind for best low speed output
« Reply #19 on: April 30, 2016, 12:07:29 PM »
 I have stopped to assess my situation. It appears I have more turbulence then I had first thought, which makes any lift wing (lenz2) design non applicable. I'm still toying with a few designs and sizing up my coil/magnet configuration.
 I may have to scrap the entire thing and start over. At this point in time, I am leaning towards 40 beefier magnets and more turns per coil, which should get my voltage up at lower RPM.
 But for starters, Altering my current set up to a single 32 magnet rotor with 24 coils (8 per phase) rather then my current 6 and up my windings to 300 turns rather then my current 200. Hopefully that will get me into usable voltage range at the rotation speeds I am seeing normally. (30-200RPM).
We will see. As I said, I am still playing around. with ideas. One change at a time.
 


SparWeb

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Re: 2hp 3 phase. Open forum. Rewind for best low speed output
« Reply #20 on: May 01, 2016, 01:22:50 AM »
Don't be discouraged!
My first axial flux PMG wasn't very good either.

While I haven't built a Lenz turbine myself, it seems to be resilient in poor wind sites (judging by comments from others).  If you have a really turbulent site, do you really think another type of turbine blade will work better?  HAWT's and VAWT's both suffer, and I don't personally believe one suffers more than another.  If the turbulence is really so bad that one type of wind turbine won't do well, then don't bother with any type of WT and put up some solar panels.  And now you know they won't blow away!
No one believes the theory except the one who developed it. Everyone believes the experiment except the one who ran it.
System spec: 135w BP multicrystalline panels, Xantrex C40, DIY 10ft (3m) diameter wind turbine, Tri-Star TS60, 800AH x 24V AGM Battery, Xantrex SW4024
www.sparweb.ca

topper

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Re: 2hp 3 phase. Open forum. Rewind for best low speed output
« Reply #21 on: May 01, 2016, 09:58:48 PM »
 I'm really not discouraged. Quite the opposite actually. It is nice to see it turning consistently, even if it is a slow rotation generating NOTHING. LOL.
I do have some work to do to get this axial flux machine generating a consistent 200mA @ 28Volts.
 She seems to run @ 4-8 volts (loaded) most of the time @ roughly 40-60 RPM. And twice today I saw it hit 14+ volts for a moment or two.
So as soon as my "Honey Do" list is finished I'll be starting over on my magnet rotors and cast a higher density stator. My numbers seem to be better with a 28 magnet/21 coil @ 250 turns 3 phase. I wanted to go 32 magnet but don't have the room for the coils.
That being said, I'll continue building on it, Optimize my wing design and hopefully see an ammeter move in the right direction.
I'm feeling like my 5 watt goal is just within reach.
 Never give up. Never surrender. And I have nothing but time till this oil patch fires back up.
Thanks all.
 

SparWeb

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Re: 2hp 3 phase. Open forum. Rewind for best low speed output
« Reply #22 on: May 03, 2016, 10:31:02 PM »
Today, the oil patch is getting fired up...
in the wrong way...
No one believes the theory except the one who developed it. Everyone believes the experiment except the one who ran it.
System spec: 135w BP multicrystalline panels, Xantrex C40, DIY 10ft (3m) diameter wind turbine, Tri-Star TS60, 800AH x 24V AGM Battery, Xantrex SW4024
www.sparweb.ca

topper

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Re: 2hp 3 phase. Open forum. Rewind for best low speed output
« Reply #23 on: May 04, 2016, 12:13:59 PM »
 Prayers with all the 80,000 evacuees of Ft. Mack. TG I'm in SE Saskatchewan. Fire threat is "Extreme", but no smoke here.  We seriously need a 3" rain or more over a couple days.