We have a 28MW gas turbine generator and using MarkVIe control system. (We have a load shedding system)
And there are four breakers. (GTG - 52G - 52L - 52B - 52M - Grid)
1) 52G : Generator circuit breaker (from GTG)
2) 52L : Line circuit breaker (from 52G)
3) 52M : Main circuit breaker (from grid)
4) 52B : Bus tie circuit breaker (from grid and 52L)
The generator has been operated in droop mode, and suddenly the mode changed to isochronous mode.
And load downed to 0MW and then 52G generator breaker tripped. TNKRIPR (Isochronous setpoint preset) was 100% and grid frequency was 100.3%.
I guess generator followed the grid frequency, because generator was operating synchronized with grid.
So, the generator speed did not changed and control system continously load downed. And finally ouput went to 0MW.
Finally I found some resonable reasons. (Maybe 52M or 52B breaker's status relay malfunction. Actually breakers did not opened)
Logically, if 52M or 52B breaker open, generator goes to isochronous mode.
If the generator trip, it cause a lot of electric charges loss.
So we need to figure out making up for logical weak point or hardware sequence.
Is there any good idea ?
Thank you.
(I attatcted logic and sequence drawing)
And there are four breakers. (GTG - 52G - 52L - 52B - 52M - Grid)
1) 52G : Generator circuit breaker (from GTG)
2) 52L : Line circuit breaker (from 52G)
3) 52M : Main circuit breaker (from grid)
4) 52B : Bus tie circuit breaker (from grid and 52L)
The generator has been operated in droop mode, and suddenly the mode changed to isochronous mode.
And load downed to 0MW and then 52G generator breaker tripped. TNKRIPR (Isochronous setpoint preset) was 100% and grid frequency was 100.3%.
I guess generator followed the grid frequency, because generator was operating synchronized with grid.
So, the generator speed did not changed and control system continously load downed. And finally ouput went to 0MW.
Finally I found some resonable reasons. (Maybe 52M or 52B breaker's status relay malfunction. Actually breakers did not opened)
Logically, if 52M or 52B breaker open, generator goes to isochronous mode.
If the generator trip, it cause a lot of electric charges loss.
So we need to figure out making up for logical weak point or hardware sequence.
Is there any good idea ?
Thank you.
(I attatcted logic and sequence drawing)
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