A square-wave VSI drive supplies 460 V line-line at a frequency of 60 Hz to an induction motor that develops a rated torque of 50 N-m at 1750 rpm. The motor and the inverter efficiencies can be assumed to be constant at 90 and 95%, respectively, while operating at the rated torque of the motor. If the motor is operated at its rated torque and the rated air gap flux, determine the equivalent resistance R, that can represent the inverter-motor combination in Fig. P14-9 at the motor frequencies of 60, 45, 30, and 15 Hz.
