Question

3ELEC 3600. Problem H8 3-phase Wound Rotor Induction Motor This sheet is page 1. Number all pages. Consider the following induction machine THREE-PHASE INDUCTION MOTOR DATA* Ratings Line Voltage 2400 V; 72.17 A; Horsepower-300 hp stator frequency60 Hz Design W Poles -4; **Equivalent Circuit Values (in stator ohms Rated Freq)** R1 0.30000 R2'- 0.47159 X2'-1.73000; Jm2.5000 kg-m sq Thevenin Equivalent Circuit Values: RT-0.28524; slip, speed for max Torque0.1375; Rotational Loss Torque-TRL 0.18689 x (speed in rad/s) Nm X1 -1.73000 Xm67.740 ET = 1351.1 volts 3 . 41814 ; ZT- 3.43002 1552.5 rpm XT - Page 2 a. Draw the equivalent circuit, with all relevant values thereupon. Assume the motor operates from a 2400 V 3ph 60 Hz source, with the rotor shorted, and is running at 1762 rpm. Evaluate the slip, and the resistor R2'/s b. Solve the circuit of (a) for the stator and rotor currents l and lA'. Compute all powers and torques, pf, and efficiency Page 3 Submit H8bSolution.pdf after this page, highlighting in yellow each value computed. Comment on how closely your values checked with H8bSolution.pdf Page 4 c. Create a new machine (H8X) identical to Machine H8, except that KRL0 Assume machine H8X is supplied from an ideal ASD whose input is a balanced 3ph 2400V 60 Hz source Determine three Thevenin Equivalent circuits, one each for three values of k: k=1.0: k = 0.7, and k 0.3. For each k, determine SMT (MT maximum torque); MT (rpm) and TMAx (Nm) Page 5 (you must use either computer graphics or graph paper) Make a two dimensional plot of Torque (calibrate from zero to 5000 Nm) on the y-axis versus speed (calibrate from zero to 1800 rpm) on the x-axis. The mechanical load on the machine (motor mode) is Make four plots (all on the same graph) Tm (7 points: speeds of 0, 300, 600, 900, 1200, 1500, and 1800 rpm) TDEV @ k 1.0 (2 points @ speeds of COMT , @s ), sketch TDEV for ωΜΤ < OR < @s TDEV @ k-0.7 (2 points @ speeds of сомт , @s ); Sketch TDEV for ωΜΤ < OR < @s TDEV @ k-O.3 (2 points @ speeds of COMT , @s ), sketch TDEV for ωΜΤ < OR < @s Graphically determine the run speed for each "k" setting (prominently mark the three operating points)

Answer 1

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