A 130 kW, 470 V separately excited de motor has the following rated values (nameplate): 1940rpm (full load), 300 A (full load), 0.0935 N armature resistance. The motor efficiency is 90%. Armature and field windings have separate power supplies. Assume the magnetic circuit isnot saturated and neglect armature reaction. Ignore all mechanical losses in the calculation oftorque. 2. Motor operation variable speed controlCompute, for the following operating conditions, the speed for no load and rated load, theelectromagnetic power and torque, and the speed regulation.(a) rated armature voltage, rated armature current, rated field current.(b) 30% rated voltage, rated armature current, rated field current.(c) rated voltage, rated armature current, 65 % rated field current.Draw the speed-torque characteristics for the 2 operating voltages in (a)-(b).

rpm (full load), 300 A (full load), 0.0935 armature resistance. The motor efficiency is 90 %. Armature and field windings have separate power supplies. Assume the magnetic circuit is not saturated and neglect armature reaction. Ignore all mechanical losses in the calculation of torque.

rpm (full load), 300 A (full load), 0.0935 armature resistance. The motor efficiency is 90 %. Armature and field windings have separate power supplies. Assume the magnetic circuit is not saturated and neglect armature reaction. Ignore all mechanical losses in the calculation of torque.

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...

See similar textbooks

Related questions

Q: Calculate the flux per pole

Q: 12 pole DC shunt generator has an armature resistance of 0.02 2 The armature is lap wound with 620…

A: The solution can be achieved as follows.

Q: determine the total torque developed in 250 V , 4 pole d.c shunt motor with lap winding, accomodated…

A: Given data: The number of pole is: 4 Number of slots is: 60 Flux per pole is: 23 mWb Armature…

Q: A 460V series motor runs at 500 rpm taking a current of 40A. Calculate the speed if the load that…

A: In this question, We need to determine the speed if the load that the motor is taking is reduced to…

Q: : O-poles lap field resistance of 125 2 . The number of conductrors of the armature winding is 500…

A: Since you have asked multiple questions in a single request, we will be answering only the first…

Q: For torque vs. speed, varying the armature voltage with constant field flux will: a. Shift the…

A: By increasing or decreasing the armature voltage, the motor's input power and hence the torque…

Q: An 4 pole, wave-wound DC motor has a 200 V supply. The armature has 1000 conductors and a…

A: An 4 pole, wave-wound DC motor has a 200 V supply. Armature conductor Z=1000 Armuatrur resistance…

Q: A 4 pole, wave wound, dc series motor is driven at 1600 rpm and takes armature current of 60A. The…

Q: 5. An 8-pole lap-wound d.c. motor has a 200 V supply. The armature has 800 conductors and a…

A: a)Given: Since it is a lap wound DC machine the No. of parallel path = no. of poles(i.e P=A) E=200V…

Q: A 4 pole, 220 V d.c. shunt motor, lap wound has 960 conductors. The flux per pole is 20 mWb.…

A: We have a DC shunt motor having, Pole (P) = 4 Voltage (V) = 220 V Lap conductor (Z) = 960 Flux per…

Q: 25. When a no-load test is conducted in an induction motor, what would happen to its circuit? a. the…

A: Given date , Testing of induction motor About No load test and blocked rotor test. We know slip =(…

Q: 3. A 4 pole, 250 dc shunt motor has a lap connected armature with 960 conductors. The flux per pole…

A: The solution can be achieved as follows.

Q: An 8 pole, lap-wound DC motor has a 250 V supply. The armature has 600 conductors and a resistance…

Q: A 250-V shunt motor runs at 1000 rpm, at no-load and takes 8A. The total armature and shunt field…

A: We have an shunt motor which is running we have been asked to find the speed when loaded and taking…

Q: A 230 V dc shunt generator delivers 150A with friction loss of 1200W. The armature shunt field…

Q: A 4 pole, 230 volt, lap wound d.c. motor has 545 conductors. With a speed of 1200 RPM, the flux per…

Q: (e) enciency. Q6 A 460-V series motor runs at 500 r.p.m. Taking a current of 40 A. Calculate the…

Q: 14.a. The reason for using a laminated stator core in a universal motor is to A. limit the eddy…

A: Iron losses of motor contain hysteresis and eddy current loss. Hysteresis loss depends upon core…

Q: A 4-pole, 250-V, d.c. shunt motor has a lap-connected armature with 960 conductors. The flux per…

A: Given:

Q: Q4) A 220 V, d.c. shunt motor has an armature resistance of 0.4 2 and a field resistance of 220 2.…

Q: The no-load speed of a 240 V Dc shunt motor is 800 r/min and the armature current is 2A. Determine…

A: Given,No load armature current=Iao=2ANo load back emf=Ebo=240-Iao×RaEbo=240-2×0.4=239.2Vand, ϕo∝ no…

Q: A 300 V d.c. shunt motor takes a current of 3 A on no-load. The resistances of the armature and…

A: In the question, 300V DC shunt motor Take no load current 3A We know Efficiency = Pnet/Pinput…

Q: Q2- A 6 pole lap connected DC generator has 480 turns ,the resistance of each turn is 0.03 Q, the…

Q: Question 3/ A 220-volt d.c. shunt motor is running at a speed of 800 r.p.m. and draws 100 A. If the…

Q: A 230 V, d.c. shunt motor runs at 1000 r.p.m. on full load, drawing current of 10 A. The shunt field…

Q: A 4-pole, DC shunt motor has a flux per pole of 0.04 Wb and the armature is lap-wound with 720…

Q: 7. The main purpose of the commutator in a DC Generator is to a. provide smoother output c. convert…

Q: A 12 pole DC shunt generator has an armature resistance of 0.02 2 The armature is lap wound with 620…

A: Given P=12 poles ra=0.02Ω for lap wound , no. of parallel paths are A=P=12 therefore, no. of…

Concept explainers

Speed control of motor

Speed control by DC motor-speed controller is required to realize variable speed drive. Whenever a motor drives a particular load, it is called drive, and variable speed drive refers to a load requiring variable speed. All this is obtained by a DC motor speed controller.

Question

A 130 kW, 470 V separately excited de motor has the following rated values (nameplate): 1940
rpm (full load), 300 A (full load), 0.0935 N armature resistance. The motor efficiency is 90
%. Armature and field windings have separate power supplies. Assume the magnetic circuit is
not saturated and neglect armature reaction. Ignore all mechanical losses in the calculation of
torque.

2. Motor operation variable speed control
Compute, for the following operating conditions, the speed for no load and rated load, the
electromagnetic power and torque, and the speed regulation.
(a) rated armature voltage, rated armature current, rated field current.
(b) 30% rated voltage, rated armature current, rated field current.
(c) rated voltage, rated armature current, 65 % rated field current.
Draw the speed-torque characteristics for the 2 operating voltages in (a)-(b).

Expert Solution

This question has been solved!

Explore an expertly crafted, step-by-step solution for a thorough understanding of key concepts.

SEE SOLUTION Check out a sample Q&A here

Step 1

VIEW

Step 2

VIEW

Step 3

VIEW

Step by step

Solved in 3 steps with 2 images

SEE SOLUTION Check out a sample Q&A here

Knowledge Booster

Learn more about

Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, electrical-engineering and related others by exploring similar questions and additional content below.

Similar questions

A 500 V shunt motor runs at its normal speed of 250 rpm with an armature current of 200 A. The resistance of armature is 0.12 02. Calculate the speed when a resistance is inserted in the field, reducing the flux to 80% of normal value, and the armature current is 100 A.
Fill in the blank: 1- Lap winding is suitable for ----- current, voltage d.c. generators. 2-A 220 V shunt motor develops a torque of 54 N-m at armature current of 10 A. The torque produced when the armature current is 20 A, is N-m. 3- The d.c. series motor should never be switched on at no-load because 4- The equation relating the generated e.m.f., E, terminal voltage, armature current and armature resistance for a d.c. motor is E = ‒‒‒‒‒‒‒‒‒‒‒ 5- A transformer having 1000 primary turns is connected to a 250 V a.c. supply. For a secondary voltage of 400 V, the number of secondary turns should be turns. 6- The equivalent resistance of the primary of a transformer having N2/N1 = 5 and R1 = 0.1 ohm when referred to secondary becomes ohm. 7- The maximum efficiency of a 100 kVA transformer having iron loss of 900 W and F.L. cu loss of 1600 W occurs at - kVA. ‒‒‒‒‒‒ ‒‒‒‒‒‒‒ 8- If Cu loss of a transformer at 7/8 full load is 4900 W, then its full-load Cu loss would be watt.
Q2- A 6 pole lap connected DC generator has 480 turns ,the resistance of each turn is 0.03 Q, the flux per pole is 0.042 Wb and the machine is driven at 1200 rpm. Find E, and terminal voltage at full load armature current of 45 A
A 4 pole d.c. motor takes a 38.6 A armature current. The armature has lap connected 350 conductors. The flux per pole is 15 mWb. Calculate the gross torque developed by the armature of the motor. Also calculate Torque if flux per pole changes to 18 mWb and state difference in torque from 18 mWb to 15 mWb
06) A 12 pole DC shunt generator has an armature resistance of 0.022 The armature is lap wound with 620 conductors, when driven at 750 RPM the machine produces a total armature current of 500 A at a terminal voltage of 100 V. Calculate the total useful flux. If the armature winding is reconnected as wave calculate the terminal voltage.
A 230 V DC Shunt motor runs at 700 r.p.m. and takes armature current of 40 A. Find resistance to be added to the field circult to increase speed to 1200 r.p.m. at an armature current of 60 A. Assume flux proportional to field current. Armature resistance = 0.12 n and field winding resistance is 115h
A full load current of 50 A is generated by a 250 V d.c. shunt motor with a 0.5 ohm armature resistance. When a 1 ohm resistance is connected in series with the armature, what is the ratio of stalling torque to full load torque?
Q2) Determine the back e.m.f at this load of series motor has a series field resistance of (0.301 2) and an armature resistance of (0.1892).It is connected to a (220 V) supply and at a particular load runs at (1500 r.p.m) when drawing (16.2 A) from the supply, if that this cases a three times of flux. Calculate the speed of motor when the load is changed such that the current is increased to (32.23 A).