HW8 - 2 . The torque constant K T =1 N•m/A. (a) If a...

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M E 576 HW #8 1. A DC motor (wound, brush types) consumes a 2 HP under no-load condition to maintain a constant speed of 600 rpm. The motor torque constant K T = 1 kg•m/A, the rotor-shaft moment of inertia J m = 0.1Kg-m 2 , the voltage constant K b = 1 V•s and the armature circuit resistance R a = 10 Ω . (a) Calculate the maximum torque and acceleration attainable from this motor-shaft system. (b) Determine the total damping coefficient of this motor-shaft system. (c) Determine the maximum speed and power available from this motor by using the speed control when the maximum voltage must be limited to 250V. 2. The armature current of a brush type DC motor was found to be 20A when the motor starts rotating with the rotor input voltage of 200V. While running at a speed of 600 rpm, the armature current was measured again and found to be 15A when the armature voltage was maintained at 200V. This motor is going to be used to drive a NC table. The total equivalent moment of inertia of this table is 10 kg-m
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Unformatted text preview: 2 . The torque constant K T =1 N•m/A. (a) If a constant torque is required up to 1,000 rpm, determine the rotor voltage increase needed to increase the speed from 0 to 1,000 rpm. (b) If the speed needs to be further increased from 1,000 rpm to 1,500 rpm using the field control, how much should the stator field flux (or current) be reduced in percentile compared with the flux at 1,000 rpm while maintaining the rotor voltage and current at maximum. (c) If the machining process generates and applies a constant torque of 5 N-m to the table, what is the maximum acceleration attainable from this motor-table when the effect of damping is neglected? 3. A three phase induction motor has one pole pair per phase. The equivalent resistance and leakage inductance in the rotor winding are 10 Ω and 0.06 H, respectively. The motor is supplied with 220 V in each phase at 60Hz. Compute the torque-speed relationship and generate a plot....
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This document was uploaded on 12/28/2011.

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