RELATION BETWEEN ROTOR COPPER LOSS, SLIP, AND ROTOR INPUT

We have seen that the electrical power developed in the rotor is converted into mechanical power which is given by the following relation:

Mechanical power developed in the rotor 

The rotor copper losses 

From power flow diagram,

Rotor input = Mechanical power developed + rotor copper losses

From eq. (12.3) and (12.4), we get, 

∴ Rotor copper loss  Mechanical power developed

From eq. (12.4) and (12.5), we get, 

∴ Rotor copper loss = S × Rotor input

Note: All the values are the phase values.