6-32. A 460-V, 10 hp, two-pole, Y-connected induction motor has the following parametersTh...

6-32. A 460-V, 10 hp, two-pole, Y-connected induction motor has the following parameters

The rotor is a dual-cage design, with a tightly-coupled, high resistance outer bar and a loosely-coupled, low resistance inner bar (see Figure 6-25c). The parameters of the outer bar are

The resistance is high due to the lower cross sectional area, and the reactance is relatively low due to the tight coupling between the rotor and stator. The parameters of the inner bar are

The resistance is low due to the high cross sectional area, but the reactance is relatively high due to the quite loose coupling between the rotor and stator.

Calculate the torque-speed characteristic for this induction motor, and compare it to the torque-speed characteristic for the single-cage design in Problem 6-21. How do the curves differ? Explain the differences.