7)A separately excited dc motor controlled by a 3 phase full wave full controlled converter connected to the armature and field circuits. the ac supply voltage is 208v and the frequency is 60 Hz. If the field current adjusted to If 1 A and the armature resistance Ra = 0.2 0,the field resistance Rf = 250 n and the voltage constant K = 1.2V/A-rad/sec. The load torque TL=120 Nm and The firing angle of the armeture circuit adjusted to be aa=30. Consider armature inductance La is so large that the output current la can be assumed to be continuous and ripple-free. a) Draw the waveforms of the motor at firing angle a=30. b) Determine the developed torque and the motor speed. c) If the load is decreased by 20% calculate the motor speed. d) Determine the firing angle a to return the speed to its previous value as in case (b).

7)A separately excited dc motor controlled by a 3 phase full wave full controlled converter connected to the armature and field circuits. the ac supply voltage is 208v and the frequency is 60 Hz. If the field current adjusted to If 1 A and the armature resistance Ra = 0.2 0,the field resistance Rf = 250 n and the voltage constant K = 1.2V/A-rad/sec. The load torque TL=120 Nm and The firing angle of the armeture circuit adjusted to be aa=30. Consider armature inductance La is so large that the output current la can be assumed to be continuous and ripple-free. a) Draw the waveforms of the motor at firing angle a=30. b) Determine the developed torque and the motor speed. c) If the load is decreased by 20% calculate the motor speed. d) Determine the firing angle a to return the speed to its previous value as in case (b).

Introductory Circuit Analysis (13th Edition)

13th Edition

ISBN:9780133923605

Author:Robert L. Boylestad

Publisher:Robert L. Boylestad

Chapter1: Introduction

Section: Chapter Questions

Problem 1P: Visit your local library (at school or home) and describe the extent to which it provides literature...

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