Voltage Regulation -- Transformer

[peppa]

Homework Statement

5. A 415V to 11 kV transformer has a rating of 200 kVA. The winding resistance and leakage reactance when referred to the primary are 0.014 Ω and 0.057 Ω respectively.

(a) Determine the % regulation of the transformer at 0.8 power factor lagging.

(b) In designing a particular 415V to 11 kV, 200 kVA transformer, the primary winding resistance is to be 10 mΩ. Find the maximum winding resistance of the secondary winding if the transformer is to have 2% regulation at unity power factor.

Homework Equations

The Attempt at a Solution

Attached

 

[peppa]

I think I'm on the right track with a) but a little lost with part b)

Any help will be much appreciated

 

[berkeman]

Could you please paste your work from the PDF file here into the forum window? That will make it much easier for folks to check your work and comment on it. Thank you.