Previous in Forum: 4160V Overhead Service to a Building Next in Forum: Electrical Cable Routing
Anonymous Poster #1

# Transformer

09/23/2017 6:16 AM

How the transformer reactive losses (in kVAr) is been calculated?

Thanks !!

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

### Comments rated to be Good Answers:

These comments received enough positive ratings to make them "good answers".
2
Guru

Join Date: Aug 2010
Location: Resting under the Major Oak
Posts: 4348
#1

### Re: Transformer

09/23/2017 11:25 AM

__________________
The reports of my death are greatly exaggerated.
Good Answer (Score 2)
2
Guru

Join Date: Apr 2010
Location: About 4000 miles from the center of the earth (+/-100 mi)
Posts: 9090
#2

### Re: Transformer

09/23/2017 6:33 PM

Here is an example that might help.

Good Answer (Score 2)
Guru

Join Date: Jul 2005
Location: Stoke-on-Trent, UK
Posts: 4330
#3

### Re: Transformer

09/24/2017 10:13 AM

If I remember right it's KVA*sin(φ) where φ = acos(PF).

__________________
Give masochists a fair crack of the whip
Guru

Join Date: Oct 2012
Location: 100 miles North from the World Center
Posts: 856
#4

### Re: Transformer

09/27/2017 12:44 PM

If we neglect the resistance and consider Z=X then

Q=usc*S^2/Sn*(Vrat/V)^2 where

Q[MVAR] usc=usc%/100 =transformer short-circuit voltage

S actual apparent power [MVA] Sn=rated power[MVA] Vrat =primary rated voltage[kV] V=actual supply voltage [kV]

__________________
Julius
Participant

Join Date: Nov 2017
Posts: 4
#5

### Re: Transformer

11/02/2017 4:27 AM

I usually do not think about it and just use automatic caculator from website to get the result of KVA and KW.

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