Given that the motor of Problem 16.1.11 has a full-load slip of 0.05, compute the motor speed corresponding to rated torque and a frequency of 30 Hz.
Problem 16.1.11
A 60-Hz, six-pole, wye-connected, three-phase induction motor, with the parameters R1 = R' 2 = 0.025 Ω and Xl1 = X' l2 = 0.125 Ω, is controlled by variable-frequency control with constant V/f ratio. Use the approximate equivalent circuit of Figure 13.2.6, with jXm moved over to the supply terminals. For an operating frequency of 15 Hz, find:
(a) The maximum motoring torque as a ratio of its value at the rated frequency.
(b) The starting torque and rotor current in terms of their values at the rated frequency.
