Q. Answer the following for DC Machines: (i) Explain the armature reaction in DC motor. How the flux is distorted by armature reaction? How the effect of armature reaction could be resolved? (ii) What are compensating windings and what function do they serve? Explain how they work and why they are connected in series with the armature. (iii) Explain why a resistor is needed in series with the armature when starting a DC motor, but is not needed when the motor is operating at its steady-state speed.

Q. Answer the following for DC Machines: (i) Explain the armature reaction in DC motor. How the flux is distorted by armature reaction? How the effect of armature reaction could be resolved? (ii) What are compensating windings and what function do they serve? Explain how they work and why they are connected in series with the armature. (iii) Explain why a resistor is needed in series with the armature when starting a DC motor, but is not needed when the motor is operating at its steady-state speed.

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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Q2) In DC machine, the speed is 800 RPM, the flux per pole is 2 m wb, and it has a Lap winding armature with 6 coils (4 turns conductor per coil) . The DC machine has 2 poles and armature draws lc= 5.5 A. If the winding redesigned as wave winding, find the EA , Tem and Pem and explain what will happen when we change the design from lap to wave winding connection.
A dc shunt generator delivers 50 kw at 250 v, its armature has a 4-pole wave winding with a resistance of 0.01 ohm and its field resistance is 125 ohm. if the number of turns in the armature is 201 and the flux per pole is 0.02 wb, find the voltage generated and the speed of operation. *
A 10 pole lap wound DC armature has a total of 200 conductors each with a current carrying capacity of 10 A. The average induced emf per conductor is 10 V. The power rating of the DC machine is
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Differentiate the two types of armature windings in DC machines: lap winding and wave winding.
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Which of the following is preferred to counter the effect of armature reaction in DC machine? O Use of main pole OUse of interpoles Use of series winding O Shifting of brushes
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The dimensions of the circuit and the number of windings are indicated on the figure. a) Draw the equivalent circuit. b) Find the equivalent reluctance value of the magnetic circuit. c) Find the value of the total magneto-motor force produced by the coils wound on the magnetic core. d) Find the values of total magnetic flux and arm magnetic flux flowing through the magnetic circuit. e) Find the self-inductance value of each winding and the common inductance value between the windings.
Q3. B. what are the features of Lap winding of DC machine?
Which of the following is preferred to counter the effect of armature reaction in DC machine? Use of main pole Use of interpoles Use of series winding Shifting of brushes