In this paper, direct and simple expressions for
the doubly-fed induction machine (DFIM) characteristics
such as current, power and torque, for different operating
conditions, are obtained. Using these expressions, the
performance of the DFIM machine can be easily obtained
when the magnitude of the rotor voltage, rotor phase
angle and speed are changing. To validate the presented
expressions, the results obtained from them are compared
with previously published results, and the two sets of
results are found to be identical.