EE362Homework 3_2010-03-23

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

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
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
Background image of page 1
This is the end of the preview. Sign up to access the rest of the document.

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)....
View Full Document

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.

Ask a homework question - tutors are online