EE362Homework 3_2010-03-23

# EE362Homework 3_2010-03-23 - moved to the motor terminals....

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MIDDLE EAST TECHNICAL UNIVERSITY ELECTRICAL AND ELECTRONICS ENGINEERING DEPARTMENT EE 362 Homework 3 23 Mach 2010 Due: 31 March 2010. Please drop your homework in the homework box in the electrical machines lab until 17:00 Q3 A 3-phase, 4-pole, 50 Hz, 400 Volts l-to-l squirrel-cage induction motor is operating at the rated voltage and frequency. The equivalent circuit parameters are given by the motor manufacturer on per-phase-wye basis as follows : r 1 =0.011 ohm x 1 =0.2 ohm r 2 / =0.25 ohm x 2 / =0.2 ohm G c ≈ 0 ohm B m =287 milli mho The input line current on the stator side is measured to be 180 -36.87 Amps rms [ 1 =180 (0.8 – J0.6)] with respect to the applied line-to-neutral stator voltage. a. Draw the induction motor per-phase-wye equivalent circuit: with the shunt branch
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Unformatted text preview: moved to the motor terminals. Use this equivalent circuit throughout the problem. CALCULATE followings : b. The synchronous speed n s in rpm, and s in mech rad/s, c. The RMS values of referred rotor current I 2 / , and exciting current I e , d. The 3-phase values of the air-gap power P g , the stator copper loss P cus , the rotor copper loss P cur , the gross output power P m and the slip s, e. The operating shaft speed r in mech. rad/s and the electromechanical torque (gross) T e in Nm. Calculate the efficiency by assuming that rotational losses are 2335 W at the speed in (e)....
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## This note was uploaded on 01/30/2011 for the course EE 362 taught by Professor Ermis during the Spring '10 term at Middle East Technical University.

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