Hi, I need to calculate the voltage regulation of the 3 ph Dzn transformer. I have knowledge of the current going into the primary winding of the transformer (Delta winding) and hence need to calculate the current in the secondary (load current) so that I can use this in the voltage regulation calculations. I am unsure of the current relationships for a Dzn transformer, are they the same as for a Delta - Star transformer (Dyn)? Also, for the voltage regulation, I have P.U. values of Positive Sequence Impedance Resistance and Reactance. Are these the values that I should convert into actual values and then use in the regulation equation, or do I use Zero sequence values as I have them also?