P.U Current and Transformers

[eng787]

In Kaplan's problem 19:

power system has generator and load connected through 3 transformers in between them I.E ( G-T1-T2-T3-LOAD SEQUENCE). Load current value in P.U is given and solution say since generator, transformers and load are all in series, P.U current is same throughout the system

but In problem 21 they are divinding P.U current in load with sqrt(3) because of windings connected in Delta.

Can somebody explain this P.U Current concept? are they change per delta-Y config IN TRANSFORMERS.

 

[cocky]

In Kaplan's problem 19:
power system has generator and load connected through 3 transformers in between them I.E ( G-T1-T2-T3-LOAD SEQUENCE). Load current value in P.U is given and solution say since generator, transformers and load are all in series, P.U current is same throughout the system

but In problem 21 they are divinding P.U current in load with sqrt(3) because of windings connected in Delta.

Can somebody explain this P.U Current concept? are they change per delta-Y config IN TRANSFORMERS.

Its very hard to comprehend the problem from the description provided. Can you post the exact problem?