7-Assignment7

# 7-Assignment7 - ELECTRICAL ENGINEERING DEPARTMENT...

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ELECTRICAL ENGINEERING DEPARTMENT California Polytechnic State University EE 255 Assignment #7 Problem #1 A 208-V, three-phase, 2-pole, 60-Hz Y-connected wound rotor induction motor is rated at 15- hp. Its equivalent circuit components are: R 1 =0.2 Ohms R 2 =0.12 Ohms X m =15.0 Ohms X 1 =0.41 Ohms X 2 =0.41 Ohms P mech =430 W P stray =0 P core =0 Determine the slip at pullout torque and the pullout torque of this motor. Problem #2 A 440-V, three-phase, 2-pole, 50-Hz Y-connected wound rotor induction motor is rated at 75 KW. Its equivalent circuit components are: R 1 =0.075 Ohms R 2 =0.065 Ohms X m =7.2 Ohms X 1 =0.17 Ohms X 2 =0.17 Ohms P mech =2.1 KW P stray =150 W P core =0 Determine the slip at pullout torque, the pullout torque, and the rotor speed at the pullout torque of this motor. Problem #3 If the motor in Problem 2 is to be driven from a 440-V, 60 Hz power supply, what will the pullout torque be? What will the slip be at pullout torque? Problem #4
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## This note was uploaded on 12/19/2011 for the course EE 295 taught by Professor Alishaban during the Fall '11 term at Cal Poly.

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