# Equivalent ciruit parameters of a 1kVA transformer

I would like to conduct some simulations in Matlab/Simulink and I need to know the equivalent circuit parameters of a transformer with power rating around of 1kVA (regardless the primary and secondary voltage)

I did some research and I couldn't find all the parameters that I need. Is there anyone who has the parameters of a transformer similar to mine?

• No way to know if we have parameters for a transformer similar to yours, the construction of the transformer has a huge impact on the equivalent circuit. For example a toroid should have lower leakage inductance than an E-core. The other parameters will vary quite a lot with the turns ratio and target voltage ratings. Just saying you have a 1KVA transformer is not enough information. Nov 11, 2017 at 23:56
• @JohnD I just need to have the parameters in order to have some realistic results. I am not going to design/construct a transformer. So it would be very useful to me to have the parameters (or an estimation of the parameters) that correspond to a real transformer regardless the voltage rating e.t.c. Nov 12, 2017 at 0:16

I found data for a 1.05 kVA transformer for 60 Hz power. The efficiency is 94.7%, the core loss 22.6 W and the copper loss 37.4 W. That should give you something to work with.

The width of the transformer core is given as 2-1/8 inches. The thickness of the stack is not given, but in another table of data, most of the cores are square. The maximum flux density is given as 14.8 kilogauss (1.48 Tesla).

Other information from table:

Lamination: EI 212

Area product (core area x window area): 15.3

Current density: 1550 A/sq. in.

Copper regulation: 3.6%

Iron weight: 14.2 lbs.

Copper weight: 5.18 lbs.

Lamination: 29-Gauge, grain oriented (M6) silicon steel

Exciting VA / Input VA 23.5% for EI 625, 9.1 VA, 12.7% for EI 251, 3551 VA

Operating temperature = 75C (amb) + 75C (rise) = 150C

Information is from Nathan A. Grossner, Transformers for Electronic Circuits, McGraw Hill 1967 wit source listed as Electro-Technol., vol 67, no. 1, p. 61, January 1961, Copyright C-M Technical Publications Corp., 1961

Here are the lamination dimensions from Lamination Specialties Corp.

• Thank you for your answer. Is it possible to have the voltage ratio and the turns ratio of the transformer? Thanks in advance. Nov 12, 2017 at 0:50
• The voltage ratio is not given. The source of the information is a book entitled "Transformers for Electronic Circuits." I expect the information is for transformers to step 120 or 240 volts down to a lower voltage. The losses would not be influenced a lot by the operating voltage.
– user80875
Nov 12, 2017 at 1:40
• Thank you very much for the and information and your time. Nov 12, 2017 at 10:14
• And about 0.1 p.u. magnitizing inductance? Nov 12, 2017 at 11:25