HomeworkLib
Question

Q3) A 20 kW compound generator works on full load with terminal voltage of 230 V....

Q3) A 20 kW compound generator works on full load with terminal voltage of 230 V.
The armature, series and shunt field resistances are 0.1, 0.05 and 115 ohm respectively.
Calculate:
a) The generated e.m.f , if connected short shunt.
b) The generated e.m.f, if connected long shunt.
c) If the machine is connect short shunt, the iron and friction losses at rated power equal
to 850 W. calculate the mechanical efficiency, electrical efficiency and commercial
efficiency.

engineering   Electrical-Engineering   
0 0
Add a comment Improve this question Transcribed image text
Next > < Previous
Sort answers by oldest

Homework Answers

Answer #1


0 0
Add a comment
Know the answer?
Add Answer to:
Q3) A 20 kW compound generator works on full load with terminal voltage of 230 V....
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Log In

Sign Up

Not the answer you're looking for? Ask your own homework help question. Our experts will answer your question WITHIN MINUTES for Free.
Similar Homework Help Questions

  • A long-shunt compound generator running at 1000 r.p.m. supplies 22 kW at a terminal voltage of...

    A long-shunt compound generator running at 1000 r.p.m. supplies 22 kW at a terminal voltage of 220 V. The resistance of the armature, shunt field and series field are 0.05 Ω, 110 Ω, and 0.06 Ω respectively. The overall efficiency at the above load is 88 %. Find (i) Cu losses (ii) iron and friction losses and (iii) torque exerted by the prime mover.

  • In a 110 V compound generator, the resistances of the armature, shunt and series windings are...

    In a 110 V compound generator, the resistances of the armature, shunt and series windings are 0.06 ohm, 25 ohm and 0.04 ohm respectively. The load current is 50 A at 120 V. Find the induced e.m.f. and the armature current when the machine is connected as (i) long-shunt and as (ii) short-shunt. How will the ampere-turns of the series field be changed in (i) if a diverter of 0.1 ohm be connected in parallel with the series winding? Allow...

  • QUESTION 1 A) (10 marks) A 10 kW, 250 V DC self-excited shunt generator, with an...

    QUESTION 1 A) (10 marks) A 10 kW, 250 V DC self-excited shunt generator, with an armature resistance of 0.1 ohm, is delivering 80 % of rated power to the mains at rated voltage when being run at 1000 r.p.m. (revolutions per minute). The field circuit resistance is 220 ohms. The brush contact drop is 0.5 V and rotational (mechanical) losses are 750 W Calculate The induced voltage The electromagnetic torque developed The shaft torque The overall efficiency B) (15...

  • A) The input current to a 220 V, short-shunt compound motor at no load is 6 A. The shunt- field c...

    a) The input current to a 220 V, short-shunt compound motor at no load is 6 A. The shunt- field circuit resistance is 220 Ω; the armature resistance is 0.112, and the series-field resistance is 0.1 Ω, what is the stray power loss ? (b) Assume the input rating of the motor in Part (a) to be 66 A at 220 V with a no-load speed of 1000 rpm. If the stray power loss varies as the counter-electromotive force and...

  • Show all working 1. A 4 pole, 220 V, 10 H.P, d.c. shunt motor is rotating...

    Show all working 1. A 4 pole, 220 V, 10 H.P, d.c. shunt motor is rotating at a speed of 320 rpm. Then the developed useful torque is 2. A 4 pole, lap wound d.c. motor drawing an armature current of 20 A has 360 conductors. If the flux per pole is 0.015 Wb then the gross torque developed by the armature of motor is 3. A 220 V, d.c. motor draws an armature current of 20 A. Its armature...

  • A 25 Ω load is connected to the terminals of a 400 V terminal voltage parallel...

    A 25 Ω load is connected to the terminals of a 400 V terminal voltage parallel excited DC generator. The resistance of the field circuit is 200 Ω, the resistance of the armature is 0,4 Ω, the efficiency is 82%, the speed is 1000 r/min. Draw the equivalent circuit of the generator. Calculate the induced emf, the torque and the magnetic losses if the mechanical losses is 200 W.

  • A 250 V, 10 KW, 1200 rpm dc shunt motor has a full load efficiency of...

    A 250 V, 10 KW, 1200 rpm dc shunt motor has a full load efficiency of 80 percent. Its field and armature resistances are 110 ohms and .25 ohm respectively. Calculate the value of the resistance to be inserted in series with the armature and the power lost in the armature circuit to reduce the speed to 80 percent when the load torque is constant regardless of the speed.

  • A 480-V, 50-Hz, Y-connected, 6-pole synchronous generator has a synchronous reactance of 1 Ohm. Its full...

    A 480-V, 50-Hz, Y-connected, 6-pole synchronous generator has a synchronous reactance of 1 Ohm. Its full load armature current is 60 A at 0.8 pf lagging. Under full load conditions, the friction and windage losses are 1.5 kW, and core losses are 1 kW at 50 Hz. Ignore armature copper losses. The field has been adjusted so that the terminal voltage is 480 V at no load. a.What is the speed of rotation of this gen? b.What is the generator...

  • A 8250 w shunt DC motor has a terminal voltage of 300 V. A field resistance...

    A 8250 w shunt DC motor has a terminal voltage of 300 V. A field resistance Rf of 40 Ω, and an armature resistance Ra of 250 mm2. The field winding has 1500 turns. An adjustable resistance Rad is connected in series to the field winding. Rad is set at 20 Ω, but it can vary from 0 to 80 Ω. The magnetization curve is shown in Figure.1 and it is taken at a speed of 1200 rpm. (Armature reaction...

  • A 480 V, 60 Hz, 470 kVA, 0.85 PF lagging, 2-pole, Y-connected synchronous generator has a...

    A 480 V, 60 Hz, 470 kVA, 0.85 PF lagging, 2-pole, Y-connected synchronous generator has a synchronous reactance of XS=0.016 Ω and an armature resistance of RA=0.016 Ω. At rated conditions the core losses are 7 kW. Friction losses and field winding losses are 8 kW. Suppose the machine is connected to an infinite bus (hence the terminal voltage is fixed) and it is running at the rated conditions. a) What is the rotor speed in rpm? b) Calculate the...

ADVERTISEMENT
Free Homework Help App
Download From Google Play
Scan Your Homework
to Get Instant Free Answers
Need Online Homework Help?
Ask a Question
Get Answers For Free
Most questions answered within 3 hours.
ADVERTISEMENT
ADVERTISEMENT