CR4® - The Engineer's Place for News and Discussion®

 Previous in Forum: Current Calculating Question Next in Forum: Power and Voltage Transmission
Active Contributor

Join Date: Apr 2013
Location: East Africa
Posts: 19

How to Calculate Winding Temperature in Transformer?

04/22/2013 1:47 AM

Hello Everyone. Can someone give me the formula for calculating Winding temperature in a Transformer Layer Wound Type. Thank you in Advance

__________________
"Do not follow where the path may lead. Go instead where there is no path and leave a trail."
Pathfinder Tags: temperature
Interested in this topic? By joining CR4 you can "subscribe" to

Guru

Join Date: Jan 2007
Location: In the bothy, 7 chains down the line from Dodman's Lane level crossing, in the nation formerly known as Great Britain, and now disconnecting ["brexit" - ugh] as Little England and Wales (not too sure about Wales bit, either). Kettle's on.
Posts: 27038
#1

Re: How to Calculate Winding Temperature in Transformer ?

04/22/2013 3:16 AM

Why not just measure it?

__________________
"Did you get my e-mail?" - "The biggest problem in communication is the illusion that it has taken place" - George Bernard Shaw, 1856
Active Contributor

Join Date: Apr 2013
Location: East Africa
Posts: 19
#2

Re: How to Calculate Winding Temperature in Transformer ?

04/22/2013 3:23 AM

Thanx for your reply, But what i need is to calculate it at design stage, i.e before manufacturing the winding and then measure. I want to be able to calculate what will be the expected temperature in the Lv and Hv windings of a Layer type at design stage. The measuring will be done after manufacture.

__________________
"Do not follow where the path may lead. Go instead where there is no path and leave a trail."
Guru

Join Date: Jan 2007
Location: In the bothy, 7 chains down the line from Dodman's Lane level crossing, in the nation formerly known as Great Britain, and now disconnecting ["brexit" - ugh] as Little England and Wales (not too sure about Wales bit, either). Kettle's on.
Posts: 27038
#3

Re: How to Calculate Winding Temperature in Transformer ?

04/22/2013 3:50 AM

It depends upon its ventilation. Check out Perry, "The Chemical Engineer's Handbook" any edition, looking for entries on heat transfer, perhaps?

Is there no previous commissioning data that could be referenced?

__________________
"Did you get my e-mail?" - "The biggest problem in communication is the illusion that it has taken place" - George Bernard Shaw, 1856
Active Contributor

Join Date: Apr 2013
Location: East Africa
Posts: 19
#4

Re: How to Calculate Winding Temperature in Transformer ?

04/22/2013 4:17 AM

Thanx once more .. am working on a Project to design a distribution Transformer .. Everything have done, So am Looking for the formula to calculate it manually, Where i am they have a Program and it just give you the figures without showing you how to calculate it. i need to Present the Project with the formulas showing how i calculated the Temperature. Thanx for the reference book, i will look for it ... but still looking for Help Here though from anyone with the formula.

__________________
"Do not follow where the path may lead. Go instead where there is no path and leave a trail."
Guru

Join Date: Jan 2007
Location: In the bothy, 7 chains down the line from Dodman's Lane level crossing, in the nation formerly known as Great Britain, and now disconnecting ["brexit" - ugh] as Little England and Wales (not too sure about Wales bit, either). Kettle's on.
Posts: 27038
#5

Re: How to Calculate Winding Temperature in Transformer ?

04/22/2013 5:18 AM

From historical commissioning data of other equipment, plot heat dissipation, size of equipment and temperature rise above ambient onto a 3-dimensional surface graphically. When the details of the proposed new equipment begin to come into focus, the surface can be extended to encompass the new equipment and estimate the missing information. Testing then establishes a new data point. Equations can then be developed to help understand the shape of that surface.

The process is iterative.

__________________
"Did you get my e-mail?" - "The biggest problem in communication is the illusion that it has taken place" - George Bernard Shaw, 1856
Guru

Join Date: Oct 2009
Posts: 2030
#6

Re: How to Calculate Winding Temperature in Transformer ?

04/22/2013 5:34 AM

Have you tried J & P Transformer Book?

Active Contributor

Join Date: Apr 2013
Location: East Africa
Posts: 19
#7

Re: How to Calculate Winding Temperature in Transformer ?

04/22/2013 6:04 AM

Thanx ... Not yet tried it.

__________________
"Do not follow where the path may lead. Go instead where there is no path and leave a trail."
Anonymous Poster #1
#13

Re: How to Calculate Winding Temperature in Transformer ?

05/09/2013 3:05 AM

The formula is in the reference book....too lazy to look for it???

Anonymous Poster #1
#8

Re: How to Calculate Winding Temperature in Transformer ?

04/22/2013 6:04 AM

At different loads it has different temperatures.....the higher the load the higher the temperature of the transformer

Guru

Join Date: Jan 2007
Location: In the bothy, 7 chains down the line from Dodman's Lane level crossing, in the nation formerly known as Great Britain, and now disconnecting ["brexit" - ugh] as Little England and Wales (not too sure about Wales bit, either). Kettle's on.
Posts: 27038
#9

Re: How to Calculate Winding Temperature in Transformer ?

04/22/2013 6:08 AM

Good point. Let the graph method proposed above become a four-dimensional surface instead.

__________________
"Did you get my e-mail?" - "The biggest problem in communication is the illusion that it has taken place" - George Bernard Shaw, 1856
Guru

Join Date: Oct 2012
Location: 100 miles North from the World Center
Posts: 764
#10

Re: How to Calculate Winding Temperature in Transformer?

04/22/2013 9:21 AM

The J&P Transformer Book is a very interesting book but this does not indicate how to calculate the winding maximum-and average-temperature of a dry power transformer. In chapter 4.5 THERMAL CONSIDERATIONS there are some considerations-not calculations-about oil transformer, mainly.You have to find an Electrical Machine Construction Manual.I have-for instance-"Electrische Maschinen" Rudolf Richter[5 volumes].First it is in German. Second, it is very old-volIII-The Transformer is printed in 1954.See:

http://www.amazon.de/elektrische-maschinen-Rudolf-Richter-B%C3%BCcher/s?ie=UTF8&keywords=Elektrische%20Maschinen&page=1&rh=n%3A186606%2Ck%3AElektrische%20Maschinen%2Cp_lbr_books_authors_browse-bin%3ARudolf%20Richter

If you are IEEE member you may consult this:

or this:

__________________
Julius
3
Guru

Join Date: May 2007
Location: NYC metropolitan area.
Posts: 3045
#11

Re: How to Calculate Winding Temperature in Transformer?

04/22/2013 12:49 PM

Sorry but there is no simple formula for calculating the winding temperature because there are simply too many variables. This is rightfully a mechanical engineering problem related to heat transfer; calculating the amount of heat produced by the current flowing in the windings is the easy part. Here's a short list of info needed:

1. Everything about the winding shape, material, insulation, interconnections, etc.

2. Everything about the winding configuration, number of layers and turns, interturn spacing, intercoil spacing, every dimension regarding the position of each coil relative to each other, the core and the tank.

3. Everything about the core, its type, material, dimensions, how it's clamped, mounted to the tank, etc.

4. Everything about the tank, its materials, dimensions, cooling type, coolers, radiators, fins, fans, etc.

5. Everything about the overall insulation system, type and class, liquid, solid, air, location and dimensions of interwinding cooling channels, whether it is forced, conductive, and/or convective.

6. And that's just the easy stuff....

It is possible to gather all this information and input it into a very sophisticated mechanical engineering heat transfer modeling program; names like Mentor Graphics, Comsol, Catia and others come to mind. None of these are cheap, and I suspect that that's where the numbers you are trying to reverse engineer come from. It's one of the reasons why in the old days before computers, the only way to be sure was to build a prototype, instrument it, test it under varying load conditions, analyze the data, then rip it apart for verification.

If you want a condensed overview of this process, plus the calculations, charts and nomographs that come out of it, check out the Westinghouse Electrical Transmission and Distribution Reference Handbook, Ch 5, Article VII., pages 109-115. There are some formulas there, but they rely on physical constants that can only be developed after rigorous modeling and testing.

__________________
Curious minds want to know, engineering minds get answers....
Power-User

Join Date: Jun 2009
Posts: 222
#12

Re: How to Calculate Winding Temperature in Transformer?

04/22/2013 11:21 PM

http://www.neoptix.com/literature/v1109r1_Art_Recent_dev_in_windings_temp.pdf offers some practical tips that may help alongside IEEE and IEC documents . . . but actua calculations require too much actual information of the design as already stated on this thread

Interested in this topic? By joining CR4 you can "subscribe" to