Interested to Buy Any Domain ? << Click Here >> for more details...
In a Synchronous generator, Can AC voltage be used instead
of DC voltage in field winding of rotor to produce AC power?
- 10 Answers
- 19211 Views
- NTPC, Windia, I also Faced
- E-Mail Answers
Answers were Sorted based on User's Feedback
No.....AC voltage cannt be used in field winding of rotor
of synchronous machines for following reasons....
1)AC produce poles on rotor whose strength is varying
sinusoidally.It is undesirable because the magnetic locking
between two fields in this case are not achieved troughout
the cycle.At current zero of AC there is no locking at
all.So synchronism will be lost.
2)Field winding is designed for DC. It has higher
resistance.According to Lenz law emf is induced in field
winding.so current flowing through through winding will be
very low.Pole strength is very weak.
| Is This Answer Correct ? | 30 Yes | 0 No |
Answer / santosh kawade
No.
In synchronous generator or motor we cannot use ac voltage
for field winding.
Synchronous generator/motor works on magnetic locking
principle hence we have to create constant magnetic poles
on rotors.
In case of generator these magnetic pole create voltage in
stator winding as per the speed of rotar.
And in case of motor these magnetic poles gets lock with
stator rotating magnetic field.
Santosh Kawade
9224 69 3116
| Is This Answer Correct ? | 23 Yes | 3 No |
Answer / rajasekhar
we cant use ac voltage in place of dc for exitation of field
winding because for every cycle the polarity of the field
winding will be changing so there will not be constant poles
on the rotor
| Is This Answer Correct ? | 15 Yes | 1 No |
Answer / shelja singh
no we cant use AC voltage.if we use this then it will no
longer be called synchronous generator ,it will be called
induction generator as there will be two mmf waves and there
interaction will be same as that in an induction generator.
| Is This Answer Correct ? | 5 Yes | 0 No |
Answer / vino kumar
In case of synchronous machines we have to maintain a
constant frequency.to maintain constant frequency the rotor
of syn.machine should be rotate with same speed of stator
rmf.so finally to achieve magnetic locking between stator
rmf and rotor ,the poles on the rotor should not be vary ,it
should be constant .the ac voltage changes the poles for
every half cycle.
so to maintain fixed polarity poles on rotor and to achieve
magnetic locking the rotor should be excited by dc supply only.
| Is This Answer Correct ? | 2 Yes | 0 No |
Answer / nitin nawaghare
IF YOU apply AC source then it will act as a transformer and
work on mutual inductance like transformer. if you rotate
its rotor then it generate the power with higher frequency
(Harmonic.
| Is This Answer Correct ? | 0 Yes | 0 No |
Answer / sujeet kumar
If we supply 3 phase ac and there is relative motion between
stator rotor flux then only emf will be induced.
| Is This Answer Correct ? | 2 Yes | 6 No |
no, if we supply the ac current in rotor side, then non-
uniform ac will generate, which is not good.
| Is This Answer Correct ? | 5 Yes | 11 No |
Answer / pavan
it can be used to generate ac current if the frequency of
the ac voltage supplied to the rotor and the frequency of
the rotation of the motor are different. but i am not sure
if the generated power will have only a single harmonic.
| Is This Answer Correct ? | 6 Yes | 15 No |
Answer / percy
yes ac can used
if it has frequency of 25 hz then synchronous speed will be
half of the actuall i.e. dc is applied
some how we have to rotate field flux at synchronous speed
| Is This Answer Correct ? | 1 Yes | 10 No |
in 220 kv substation,what is the mean of avr voltage reading? means at oltc temp. 36 the avr voltage was 109v.so what the mean of 109v
How Flywheel run in DG set, tell in details
What is spike & surge.
If two Transformers are connected in parallel having impedance of 50KA in both transformers will the impedance increase or decrease after connecting transformers in parallel?
what is the method to calculate the voltage drop for number of meters Example 250volts I/p at one end if the cable length is 50 meters what could be the drop?, after 100 meters how much? needs formulae.
can i use 10 mfd + 6 mfd instead of 15 mfd capacitor in single phase motor as running capacitor
sometime battery charged and then automatically charged when rectifier ON conition, is there any chances please clarify the same.
I am having dual speed motor of cromton greaves make of 3.7 KW -1400 rpm and 5 KW - 900 rpm. Please let me know groups and winding connction for rewinding purpose.
why power factor occur only inductive load not in resistive ?
What are the common sources of energy?
What you have to see in transformer after week, month?
which level of transformer oil has got low dielectric strength ?why?
-
Civil Engineering (5086) - Mechanical Engineering (4456)
- Electrical Engineering (16639)
- Electronics Communications (3918)
- Chemical Engineering (1095)
- Aeronautical Engineering (239)
- Bio Engineering (96)
- Metallurgy (361)
- Industrial Engineering (259)
- Instrumentation (3014)
- Automobile Engineering (332)
- Mechatronics Engineering (97)
- Marine Engineering (124)
- Power Plant Engineering (172)
- Textile Engineering (575)
- Production Engineering (25)
- Satellite Systems Engineering (106)
- Engineering AllOther (1379)
