What happen if 1200KW/1500KVA alternator runs at no load
and high R.P.M.for one minute?
Answers were Sorted based on User's Feedback
Answer / dr.d.m.kothari
This will never happen because AVR and giverning
arrangement.Governor always control speed according to load.
| Is This Answer Correct ? | 9 Yes | 0 No |
If prime mover runs very high speed (without any control)
within a fraction of second rotor damaged and after that
Excitation system damaged.It will goes very dangerous
mode.So Never run Alternator without control.
| Is This Answer Correct ? | 5 Yes | 1 No |
Answer / gurucharan singh
Generator loading & No load running has no effect its
paramaters, means generator run at no load as required.
Second part of question, generator are normally designed to
1.2 to 1.5 times of nominal speed to run for one minute
without any problem. Very generation system has a speed
controller & voltage controller which responce to these
condition within 1 to 2 seconds. I suggest interviwer shall
not confuse to candidate at interview.
| Is This Answer Correct ? | 2 Yes | 0 No |
Answer / k.prakashchandra
There are over speed and over voltage relays to
protect.Governor becomes helpless if there is sudden throw
off of load,then over speed relay of the governor shuts down
the prime mover.With AVR, voltage does not increase.However
generators are designed to withstand runaway speeds for
short periods. Bearings are first to get damaged under
prolonged high speeds.Governors can also be made not to
allow for undesired high speeds with the help of braking
systems, if they are employed.
| Is This Answer Correct ? | 1 Yes | 0 No |
Answer / k.prakashchandra
The above is applicable to hydro-generator
| Is This Answer Correct ? | 1 Yes | 0 No |
Answer / n r@jesh
D.G runs No load condition out put voltage will generated
high so, system protection will damaged
| Is This Answer Correct ? | 0 Yes | 1 No |
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