Author Topic: Delta or Wye Connecting 3 Phase Motor  (Read 13808 times)

Offline Ivan

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Delta or Wye Connecting 3 Phase Motor
« on: December 26, 2012, 06:16:13 PM »
This is what a delta connection should look like.
For a EV motor you should allways use a delta connection.
Each phase leg would have 4 poles ie series.



::Just for reference::
With a WYE connection you lose about 20% of your torque.

This is what a wye connection should look like.
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Offline arlo1

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Re: Delta or Wye Connecting 3 Phase Motor
« Reply #1 on: February 28, 2013, 09:32:09 AM »
Now from my understanding the WYE vs Delta changes the voltage of the motor.  So WYE meens you need to up the voltage to make use of it...  What if you wind in WYE when you are winding the motor and use MORE In-Hand (parallel) wires and less turns?

I read some data sheets that say WYE wound for the Azure AC24LS with higher voltage raises the continious HP rating.
So maybe WYE is better if you can use enough In-hand wires to help keep the motorvoltage low enough?

Offline Ivan

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Re: Delta or Wye Connecting 3 Phase Motor
« Reply #2 on: February 28, 2013, 01:27:54 PM »
Now from my understanding the WYE vs Delta changes the voltage of the motor.  So WYE meens you need to up the voltage to make use of it...  What if you wind in WYE when you are winding the motor and use MORE In-Hand (parallel) wires and less turns?

I read some data sheets that say WYE wound for the Azure AC24LS with higher voltage raises the continious HP rating.
So maybe WYE is better if you can use enough In-hand wires to help keep the motorvoltage low enough?

We are not dealing with the ac24ls controllers  yes they are higher voltage. No wye is not better for the curtis we have low voltage motors.   With a given motor voltage, delta is more torque.
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Offline Ivan

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Re: Delta or Wye Connecting 3 Phase Motor
« Reply #3 on: April 23, 2013, 04:28:31 PM »
I got a email today and somebody asked me what is the standard numbering for a motor (3 phase) thought it would be a good thing to post.


number 1, 2, 3 would be the start side of each phase.

number 4, 5, 6 would be the finish side of each phase.

so
 A phase 1 start  4 finish
 B phase 2 start  5 finish
 C phase 3 start  6 finish

for a delta connection  2-4  3-5  1-6

Y connection 4-5-6 tye together   leads 1, 2, 3.....

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Offline few2many

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Re: Delta or Wye Connecting 3 Phase Motor
« Reply #4 on: April 23, 2013, 09:04:05 PM »
Arl, you're suggesting winding for an even lower voltage, then connecting in wye? What effect would that have? Less toque, higher rpm? Broader range? You would probably reduce winding length to about, or very roughly, half. Instead of start to finish in Delta, you'd have start-wye/neutral-finish.

 

Offline Ivan

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Re: Delta or Wye Connecting 3 Phase Motor
« Reply #5 on: April 24, 2013, 02:11:08 AM »
Arl, you're suggesting winding for an even lower voltage, then connecting in wye? What effect would that have? Less toque, higher rpm? Broader range? You would probably reduce winding length to about, or very roughly, half. Instead of start to finish in Delta, you'd have start-wye/neutral-finish.

How did you get a suggestion from the last post (wye) connecting.

Yes it would have less torque.

Wye and delta ONLY are used with a dual voltage 220-440 volt
stock motor.  We are not dealing with stock motors..

We are only dealing with one voltage and allways connect in delta.

With a wye connection you would loose 20% of your torque, cause you would have 2 phases in series, allmost doubling your resistance.
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Offline few2many

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Re: Delta or Wye Connecting 3 Phase Motor
« Reply #6 on: April 24, 2013, 11:03:09 AM »
What if you wind in WYE when you are winding the motor and use MORE In-Hand (parallel) wires and less turns?
Somewhere around there.
May not be dealing with stock motors, but same principals. Wye would double resistance, hence my half the winding length.

Offline mizlplix

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Re: Delta or Wye Connecting 3 Phase Motor
« Reply #7 on: April 25, 2013, 12:37:36 AM »
___________________________________________________________________________ ___________________________________________________
EXAMPLE:  (do not hold me to these exact numbers.  They are as close as I remember them to be)

When we wind 12 in hand and two turns per pole/per phase, we use about 56' of wire.

DELTA: When we wind with 24 in hand and one turn per pole/per phase, we use about 42' of wire.  That is about the
lower limit for our controller.


OK, as for WYE being higher in resistance and allowing a shorter wire length, My only comment is this: We could wire in
WYE, but then to shorten the wire length we would have to skip slots to get back to an acceptable resistance, but it would
 also lower our torque.....  Not what we really want for an EV.

The motors with one turn per pole/per phase saturate slower(and need less field
weakening) than the motors with two turns.  I was using 100% of the controllers
Field weakening on the two turn/pole motor and could have used more. So I
would not recommend a winding with more than 72' as it would be outside the
 controller's ability to weaken the field.  (Which would preclude a Wye connected stator).

So, We stick to Delta, as it is within our controller's comfort zone. 

We have also found out that the wire gauge is not really too critical as long as you are large enough.  We have decided
 that 18 Ga. is big enough for our needs while being easy to hand wind with.  Even 15 Ga. is the upper limit and is MUCh
more difficult to manage for no real world difference. (If you are a motor engineer, you probably could argue with me
over this.)  We feel that the another benefit of the smaller 18 Ga. wire is a better slot fill with less wasted space.

As the motor's operating voltage gets higher, the winding style, wire gauge and patterns would gradually go back to an
 off-the-shelf- industrial AC motor.  But that would require an affordable, high voltage controller (which I don't see any
I can get OR afford)

The controllers for those Ford Transit vans would possibly be really cool if you wanted to try and run an off the shelf
motor, but Good luck with the programming.  They are single purpose programmed and there are no available tools
we could beg/borrow/steal to alter them.

Miz





 
1930 Ford Speedster, AC50, full manual powerglide, 6.14gears, 38-130AH CALBs.

Offline few2many

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Re: Delta or Wye Connecting 3 Phase Motor
« Reply #8 on: April 25, 2013, 06:06:08 AM »
So, 30' of wire, wye connected skipping slots for more back iron.  Actually sounds possible, then you made plenty of points against!
Please keep in mind, some of my ideas may be odd, or outside of what you are doing, but it is how I get an understanding of how things work. You can tell me how you did your motor, and I could duplicate it, or explain how you did or figured things out, so I could figure out my own when ready.
One other thing. I noticed you have nice comfortable loops in your winds. Where as, other motors have a tight bend out of one slot, into another. Its my understanding, the wire in the loop doesn't do much to contribute to the mag field, but does contribute to higher resistance. Has this  been a concern at all? Or is it minimal? Just thinking, 1-2" extra in the loop, *2 sides. * then number of loops, could quickly add up to a few feet of wire.

Offline Ivan

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Re: Delta or Wye Connecting 3 Phase Motor
« Reply #9 on: April 25, 2013, 02:31:22 PM »
So, 30' of wire, wye connected skipping slots for more back iron.  Actually sounds possible, then you made plenty of points against!
Please keep in mind, some of my ideas may be odd, or outside of what you are doing, but it is how I get an understanding of how things work. You can tell me how you did your motor, and I could duplicate it, or explain how you did or figured things out, so I could figure out my own when ready.
One other thing. I noticed you have nice comfortable loops in your winds. Where as, other motors have a tight bend out of one slot, into another. Its my understanding, the wire in the loop doesn't do much to contribute to the mag field, but does contribute to higher resistance. Has this  been a concern at all? Or is it minimal? Just thinking, 1-2" extra in the loop, *2 sides. * then number of loops, could quickly add up to a few feet of wire.


NO NO NO  wye connecting  and motors are not wound for wye or delta they are just wound and then connected..

Most motor shops will have the round loops at the coils they are beaten down to make head room, if you need it. don't need the head room don't worry about it.  If anybody noticed I do have a rubber mallet on the bench to beat on the windings..


Ok got a ?  Do you understand all this.  If not let me no.
Miz said he had a hard time with it at first, so did I...
http://ivanbennett.com/forum/index.php?topic=6.msg488#msg488
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Offline few2many

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Re: Delta or Wye Connecting 3 Phase Motor
« Reply #10 on: April 25, 2013, 03:19:34 PM »
The more I learn, the more questions I will have.
If you are winding a motor, you can wind it for whatever you like, delta or wye. Whether it's worth it and will work, is the experiment.. As you've said, there are no rules for an EV motor, just what works.
And thanks, picking up on it bit by bit.

Offline mizlplix

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Re: Delta or Wye Connecting 3 Phase Motor
« Reply #11 on: April 25, 2013, 10:18:56 PM »
What Ivan is trying to convey to you is that when you have a dual voltage motor, it has all leads brought out so you can change the voltage giving you a Delta and a Wye configuration.

On a single voltage motor, there is just the one configuration.  No real delta or wye. 

If you are meaning to wind it with two phases in series (which would increase the necessary voltage), you would have to skip so many slots to get the voltage back down that it may not even start, or would start and have no real torque.

But on a single voltage motor, the terms delta and wye do not really apply.

We were using the term "delta" to mean that we had a start and a finish to each phase like a delta connected motor would normally have.

I hope I did not confuse you more...LOL

Miz
1930 Ford Speedster, AC50, full manual powerglide, 6.14gears, 38-130AH CALBs.

Offline few2many

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Re: Delta or Wye Connecting 3 Phase Motor
« Reply #12 on: April 26, 2013, 06:35:52 AM »
Yeah, I see your point, not enough copper fill for the iron. Not enough windings to get torque.