A three-phase, 220-V, 60-Hz, four-pole, wye connected induction motor has a per-phase stator resistance of 0.5 Ω. The following no-load and blocked rotor test data on the motor are given:
• No-load test: line-to-line voltage 220 V, total input power 600 W, of which 200 W is the friction and wind age loss, and line current 3 A
• Blocked-rotor test: line-to-line voltage 35 V, total input power 720 W, and line current 15 A
(a) Calculate the parameters of the equivalent circuit shown in Figure 13.2.5(c).
(b) Compute the output power, output torque, and efficiency if the machine runs as a motor with a slip of 0.05.
(c) Determine the slip at which maximum torque is developed, and obtain the value of the maximum torque.
Note: It may help the student to solve Problems 13.2.15 through 13.2.17 if the background given in the solutions manual as part of the solution to Problem 13.2.15 is provided.
