Follow Our FB Page << CircleMedia.in >> for Daily Laughter. We Post Funny, Viral, Comedy Videos, Memes, Vines...


what will happen when excitation of a synchronous machine
is suddenly reduce to zero when it is running at full
load..??

Answers were Sorted based on User's Feedback



what will happen when excitation of a synchronous machine is suddenly reduce to zero when it is ru..

Answer / vidhya

if its a salient pole synchronous generator whose synchronising power is P=E*v/x+v2/2[1/Xq-1/Xd], where Xq and Xd are quadrature axis reactance and direct axis reactance respectively as can be seen the first term is dependent on excitation (E=field emf) this term will be =0 but the 2nd term does not depend on E hence the synchronous generator (salint pole) will keep supply power but this power is reluctance power and thus the synchronous gen will act as reluctance generator.many might think if E=0 how v(terminal voltage ) is not=0.well thats bcoz the output of generator is connected to infinite bus whose terminal voltage is always maintained at V.

Is This Answer Correct ?    15 Yes 1 No

what will happen when excitation of a synchronous machine is suddenly reduce to zero when it is ru..

Answer / rakesh kumar

in case of a synchronous motor once the excitation is cut
off , then the motor starts to run as an induction motor,
this is because a synchronous motor by itself is not self
starting , and is first started as a squirrel cage
induction motor , once the motor attains about 95% of
synchronous speed then the excitation is applied due to
which the the copper bars are effectively removed from the
circuit as they revolve with the sane speed as the rotating
flux , once the excitation is cut off , the relative motion
between flux and the copper bars come into action and the
motor starts operating as a induction motor.

Is This Answer Correct ?    26 Yes 16 No

what will happen when excitation of a synchronous machine is suddenly reduce to zero when it is ru..

Answer / dileep

there ars two types of rotors 1).salient 2).cylendrical.when the excitation is off,the salient motor will continue to run synchronous speed because of reluctance power .if it is a cylendrical rotor it will work as induction motor

Is This Answer Correct ?    12 Yes 4 No

what will happen when excitation of a synchronous machine is suddenly reduce to zero when it is ru..

Answer / b. b. shukla

Practically, in this case, The motor will draw a high current and finally the relay/safety equipment will trip the motor, because -- it will try to run like an induction motor with dampening winding bars acting as rotor conductors. but it will not be sufficient to fulfill the load requirement. therefore the motor will draw high current and its speed will slow down and finally zero. Accordingly the back emf of rotor will reduce, motor current will increase and finally the motor will trip/burn out.

Is This Answer Correct ?    11 Yes 3 No

what will happen when excitation of a synchronous machine is suddenly reduce to zero when it is ru..

Answer / jamshed hussain (from quest)

In synchronous generator the excitation is given to the rotor circuit and magnetic field is produced. If the excitation is reduced to zero then there will be no magnetic field. It means that no excitation, no magnetic field, so there will be no generation.

Is This Answer Correct ?    4 Yes 4 No

what will happen when excitation of a synchronous machine is suddenly reduce to zero when it is ru..

Answer / k.prakashchandra

If the prime mover is not working ,the synch generator will
run as induction motor and if the prime mover is still
driving , it will run as induction generator.It may be
noted that in large generator, field is the rotor

Is This Answer Correct ?    3 Yes 5 No

what will happen when excitation of a synchronous machine is suddenly reduce to zero when it is ru..

Answer / ghanshyam singh

as the motor is in full load therefore it will stops
because the damper windings can not fulfil full load
requirements

Is This Answer Correct ?    2 Yes 5 No

Post New Answer



More Electrical Engineering Interview Questions

in power station what is the electrical circuit length of spacing between power transformer and lightning arrestors,for the voltage system of 230kv,110kv,33kv,22kv,11kv?

1 Answers  


why holding contact is not using in VCB and ACB breakers?

1 Answers   Cethar,


house wiring - series wiring or parallel wiring

4 Answers  


What is the importance of quality factor in resonance?

3 Answers  


what is current actully?significance of current...not rate of change of flow.....

3 Answers  






Give atleast 20 alternating current apparatus and devices.

0 Answers  


what is the difference between H.T Or HV lines...?

1 Answers  


How many types of AC current?

8 Answers  


using in R,Y& B PHASE LTSIDE(415V)ct ratio 4000/5 WITH ENERGYMETR OF 1280 REV./KWH,240V.WHAT WILL BE MF OF METRE.

1 Answers   HCC,


Can we use all 3 cores of a cable to connect DC motor + ve terminal and similarly one more cable for - ve terminal.

2 Answers  


1- What is the Polarization Index number be good for 15KV 3c#500MCM electrical cable? 2- Can I use the IEEE Std 43-2000 to perfom the PI test? Thanks

0 Answers  


if a single phase 3 hp submersible pump of Crompton Greaves is moving in reverse direction and sometimes it moves in rigth direction ,then what may be the cause....

2 Answers   Crompton Greaves,






Categories
  • Civil Engineering Interview Questions Civil Engineering (5075)
  • Mechanical Engineering Interview Questions Mechanical Engineering (4444)
  • Electrical Engineering Interview Questions Electrical Engineering (16600)
  • Electronics Communications Interview Questions Electronics Communications (3915)
  • Chemical Engineering Interview Questions Chemical Engineering (1092)
  • Aeronautical Engineering Interview Questions Aeronautical Engineering (214)
  • Bio Engineering Interview Questions Bio Engineering (96)
  • Metallurgy Interview Questions Metallurgy (361)
  • Industrial Engineering Interview Questions Industrial Engineering (258)
  • Instrumentation Interview Questions Instrumentation (2987)
  • Automobile Engineering Interview Questions Automobile Engineering (332)
  • Mechatronics Engineering Interview Questions Mechatronics Engineering (97)
  • Marine Engineering Interview Questions Marine Engineering (123)
  • Power Plant Engineering Interview Questions Power Plant Engineering (170)
  • Textile Engineering Interview Questions Textile Engineering (575)
  • Production Engineering Interview Questions Production Engineering (0)
  • Satellite Systems Engineering Interview Questions Satellite Systems Engineering (106)
  • Engineering AllOther Interview Questions Engineering AllOther (1377)