Power Transformer 2

[fshah]

How to calculate winding resistance from the known value of the Power transformer's impedance.
impedance is 5.52%, 20MVA, 44/13.8 kV, delta-wye transformer.

 

[davidbeach]

You don't have enough information there. If you have the X/R of the impedance, or if you have the no load and full load loss data you can calculate the resistance. But with just size, impedance, and voltages there is no way of calculating the resistance.

 

[dpc]

Agree with David Beach. A standard transformer test report will almost always include the winding resistances.

If you are just looking for an approximation, the IEEE Red Book has some X/R ratio graphs that give typical values as function of transformer size and type.

 

[prc]

dpc, can you give me the exact clause.I could not locate it in red book.

 

[davidbeach]

Figure 4A-1 through 4A-3, 1993 edition.