Transformer Regulation Homework: Hughes Electrical Book

[billyray]

Homework Statement

[/B]

Homework Equations

I have used the Hughes electrical book for the equations to solve the above. I have very little notes from college to help. I have found these equations fit and am confident on it but not 100% can anyone who knows transformers please advise if they think i am right or wrong on the equations. i am finding it hard but have done my best.

The Attempt at a Solution

uploaded

 

[Babadag]

The a part it is correct. Part b 2% of 415 is o.k. but in the regulation equation you have to employ the primary rated current: 200x1000/sqrt(3)/415. When you'll find R subtract 0.01 and this will be the added resistance at primary side[415 V].Then you have to calculate this resistance as if it is at secondary side.

 

[billyray]

how comes I need to divide 200x 1000 by square route of three?

 

[billyray]

Do you mean R as equivalent resistance referred to primary?

 

[billyray]

is this better?

 

[Babadag]

o.k.

 

[billyray]

you mean its correct?

 

[Babadag]

yes.

 

[billyray]

Thanks so much Babadag

I like your cat by the way.

 

[Babadag]

Thank you, billyray. My cat is called Pitsush. She is 10 years old and very intelligent