No-load losses for distribution transformers?

Ldscp said:

Trying to get approximate numbers for core/iron/parasitic losses in large (50-500 kVA) distribution transformers that might serve one light-industrial building or complex, taking 13,800V to 480V 3-phase.The application is very low duty-cycle, so unloaded losses will dominate.

Have spent quite a bit of time browsing the Web; most postings either talk about standards or promote advanced tech that may not be in service yet.

Is there a general guideline our group might use?

Thanks very much for all advice.

 

Mike

Dear Mr. Mike ;

As I don't use these special Voltages, I can give you an idea about that I used for some special applications where the Voltages are ” 13.2 KV  &  420 V ” and the manufacter is ” Zucchini – Italy “.

– 100kVA : Po : 380W,     Pt(+70°C) : 1800W

– 160kVA : Po : 480W,     Pt(+70°C) : 2550W

– 250kVA : Po : 750W,     Pt(+70°C) : 3120W

– 315kVA : Po : 1050W,     Pt(+70°C) : 4050W

– 400kVA : Po : 1320W,     Pt(+70°C) : 5000W

– 500kVA : Po : 1630W,     Pt(+70°C) : 5960W

Where :

     – Po : the Losses without load

     – Pt(+70°C) : the losses with ful load at ” +70°C “

Regards.

Dear Mr Ghali,

Apart fom those mentioned above,

What about the losses of transformer with rating above 500kVA, i.e with the following ranges

750kVA-2000kVA

Regards.

Spir Georges GHALI said:

Ally Kanyondo said:

Dear Mr Ghali,

Apart fom those mentioned above,

What about the losses of transformer with rating above 500kVA, i.e with the following ranges

750kVA-2000kVA

 

 Dear Mr Ghali

 

For the above range, take the working voltage as 11kV and 33kV(distribution levels  in my country)

 

Regards.

 

---

Dera Mr. Ally ;

 

Please define the Working Voltages, are the same as above or different ?

 

Regards.

Spir Georges GHALI said:

Dear Mr. Ally ;

 

Please find below the relative information:

For ” 11 kV ” :

– 630kVA : Po : 1790W,     Pt(+70°C) : 6940W

– 800kVA : Po : 2470W,     Pt(+70°C) : 8370W

– 1000kVA : Po : 2940W,     Pt(+70°C) : 9800W

– 1250kVA : Po : 3520W,     Pt(+70°C) : 11800W

– 1600kVA : Po : 3890W,     Pt(+70°C) : 14400W

– 2000kVA : Po : 4830W,     Pt(+70°C) : 17100W

– 2500kVA : Po : 5990W,     Pt(+70°C) : 20700W

– 3200kVA : Po : 4600W,     Pt(+70°C) : 23400W

 

For ” 33 kV ” :

– 630kVA   : Po : 2100W,     Pt(+70°C) : 6750W

– 800kVA   : Po : 2580W,     Pt(+70°C) : 8370W

– 1000kVA : Po : 2800W,     Pt(+70°C) : 9280W

– 1250kVA : Po : 3000W,     Pt(+70°C) : 12350W

– 1600kVA : Po : 3600W,     Pt(+70°C) : 14600W

– 2000kVA : Po : 4600W,     Pt(+70°C) : 16200W

– 2500kVA : Po : 5780W,     Pt(+70°C) : 19800W

– 3200kVA : Po : 6620W,     Pt(+70°C) : 22500W

 

Where :

     – Po : the Losses without load

     – Pt(+70°C) : the losses with ful load at ” +70°C “

 

Noting that values are for ” Zucchini – Italy ” transformers, and there's some differences between manufactures.

 

Regards.]

 

Dear Mr. Ghali

 

Thank you very mch for your clarification.

 

Regards.

kusha02 said:

I think this site will help you ,
 

http://www.siemens.hu/htm/ajanlataink/trf/download/geafolproduct_english.pdf

 

I see Ghail help you but one more isnt anything :) 

Dear Mr. Kusha02

Thanks for your completement

Regards.

it’s really a tough blow for me

i am on 8th semester in university, majoring electrical eng. this far i have been checking all the topics from people journals and some papers but still didnt understand where i should begin this research from, so i try to seek help from you guys if you got some way out for my problems… please share…

tq…

-hanif

university of srwijaya

Good answers!