primary frequency control
primary frequency control
(OP)
Are there any other way of primary frequency control(to support the grid frequency)in a power plant, besides ST governing valve throttling?
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primary frequency control
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RE: primary frequency control
RE: primary frequency control
this has the following effect: if the grid frequency drops below 50Hz the units doing PFR are able to load 5% to temperature control.
if the grid frequency increases above 50Hz... the units will shed load for some time (usually 2 min) and then resume running 5% below baseload.
the algorithm to do this with gt's is proprietory.
HTH
saludos.
a.
RE: primary frequency control
RE: primary frequency control
I think you are asking. "can the boiler power be held constaint and the turbine power to its generator be varied to match grid comsumption?" or in other words "vary the turbine efficency to change load."
If the unit has an extraction process than can be varied, then it could be used to shed or increase turbine power to its generator.
It becomes very interesting question if the extractions are only to feed water heaters and some one more expertise in thermodymatics of the boiler-feedwater cycle will need to jump in.
But my thinking would be that the base load cycle should be at its most efficeint arrangement. Responding to to a frequency increase the cycle efficiency can be lowered by dumping some steam to condensor (then the $ paid for fuel will be going to heat the enviroment) Responding to a frequency decrease, limiting extraction to a heater to get an increase in flow through the turbine to make more MWs would result in a loss of boiler efficiency due to the cooler feed water and the MW inrease would decay away, plus a little more. It would think the temperary MW increase would only be for a few seconds.
It looks like a PFC which does not effect fuel consumption rate, would effect the plant's heat rate ($/MW).
Since one of my primary jobs is the sequencing of CVs to achieve linear load responds (and optimun efficency)I think this question is very interesting.
RE: primary frequency control
While the ST's governor will position the CVs to provide PFC. It also is to limit the turbine overspeed to less than OS trip following a load rejection.
This is one of my concerns with retrofit turbine controls and primary concern with maintenance of OEMs.
RE: primary frequency control
Best wishes,
gtsim
RE: primary frequency control
Cheer up - ilan