Zero sequence winding component

[EngRepair]

What is and how to calculate a zero sequence winding component for 3ph induction motor?
Where to find more on this topic?
Thanks in advance.

 

[electricpete]

Can you clarify what you mean by that terminology?

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(2B)+(2B)' ?

 

[waross]

If English is not your first language, try using
Translation Assistance for Engineers Forum

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[zlatkodo]

I think the question is related to the analysis of unbalanced windings.
As is well known, each harmonic of unbalanced winding has two components in the same time (CW and CCW).
As far I know, sometimes they are called as "positive" and "negative sequence winding component". The terminology we use instead is "winding factor of CW and CCW component ".
For example: "fundamental negative sequence winding component" would be a winding factor of the CCW component for fundamental wave.
Please, see the first table on the link below (highlighted row). In this example is:
- fundamental positive sequence winding component = 0,9359
- fundamental negative sequence winding component = 0,0253
But the question remains what is understood as "zero sequence winding component".

http://winding.wix.com/design#!blank/c7lq

 

[deltawhy]

Here is a video on symmetrical components you may consider watching.

http://www.youtube.com/watch?v=oYj7j5QBlY0

 

[EngRepair]

Thanks for useful explanation and link although it is related to the power supply more then to motor windings.
Yes, I know to calculate the positive and negative sequence winding componenet but have an issue with zero sequence.
Calculating a zero sequence winding component is important for each unbalanced winding in order to determine whether the winding could be connected in delta, not just wye.

 

[electricpete]

My simple view.
You could assign each slot a voltage vector, expressed in complex notation as:
V = exp(i*n* (2*Pi)*pp/N)
where
n = stator slot number, sequentially numbered by physical position from 1 to N
N = number of stator slots
pp = number of pole pairs (pp=1 for 2-pole motor).


Then add up the voltage vectors for all slots of a given phase using a spreadsheet.
Repeat for each phase.
Now you have three vectors, one per phase.
Perform symmetrical components transform on the three vectors.
I can post example spreadsheet of what I have in mind if you're interested.

But I'll bet you already knew that much. Understanding and interpreting the the finer points of the results requires more knowledge than I have.

fwiw, I'd think 3rd harmonic zero-sequence components (present even in balanced winding) may play a large role in evaluating circulating currents in delta configuration also.


=====================================
(2B)+(2B)' ?

 

[electricpete]

fwiw, I'd think 3rd harmonic zero-sequence components (present even in balanced winding) may play a large role in evaluating circulating currents in delta configuration also.

... I should clarify that was referring to delta configuration.

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(2B)+(2B)' ?

 

[zlatkodo]

It is a mathematical problem: how to transform a star with three nonsymmetrical vectors to three symmetrical components. Maybe this helps:
[URL unfurl="true"]http://helios.acomp.usf.edu/~fehr/TE-2006-000213-draft.pdf[/url]