Hello Ismail,
I understand that you want to understand the conversion from “p.u.” to “SI” for Winding 2 of the Three Phase Transformer block. It is done using the same concept as in Winding 1.
When converting Resistance from “p.u.” to “SI” on the D1 side (winding 2) of the transformer
Base power = 100 kVA/3 = 33.3e3 VA
Base voltage = 260 V RMS
Base current = 33.3e3 /260 = 128.2 A RMS
Base resistance = 260/128.2 = 2.028 Ω
Base inductance = 2.03/(2π*60) = 0.00539 H
Quantity in SI units = base value*base value in p.u.
R2(Ω) = R2(p.u.) *Base resistance = 2.028*0.001 = 0.002028 Ω
L2(H) = L2(p.u.)*Base inductance = 0.03*0.00539 = 0.000161 H
You can also refer to Example 1: Three-Phase Transformer from the Documentation link below. It shows the conversion for a 25kV/600V 300kVA Transformer.
I hope this helps!
