Unit Aux. Transformer (UAT)
Unit Aux. Transformer (UAT)
(OP)
Dear Folks,
I would like know the benefits, if UAT are connected at the terminals of GTGs (Gas turbine Generators ), instead of STGs (Steam Turbine G) in a combined cycle power plant.
Advanced Thanks...
I would like know the benefits, if UAT are connected at the terminals of GTGs (Gas turbine Generators ), instead of STGs (Steam Turbine G) in a combined cycle power plant.
Advanced Thanks...






RE: Unit Aux. Transformer (UAT)
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If we learn from our mistakes I'm getting a great education!
RE: Unit Aux. Transformer (UAT)
1. one UAT connected at GTG terminals + one UAT connected at STG terminals
(These UATs will feed unit loads as well as station loads)
2. one UAT connected at GTG terminals + One Station transformer
RE: Unit Aux. Transformer (UAT)
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If we learn from our mistakes I'm getting a great education!
RE: Unit Aux. Transformer (UAT)
Thanks for Info. Pl. find the attached conceptual SLD which shows two options. Which option is better?
RE: Unit Aux. Transformer (UAT)
Is there a reason why there is no breaker between STG-2 and T20?
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If it is broken, fix it. If it isn't broken, I'll soon fix that.
RE: Unit Aux. Transformer (UAT)
From my point of view---> option#2 is better.
TurbineGen,
Good Q, but I would see it in another way:
or both steam turbine with GCB, or both w/o.
BTW, I think Kssschsekhar forgot delete GCB for the STG1 after revesion of option#1
Best Regards.
Slava
RE: Unit Aux. Transformer (UAT)
With a 3km line between the transformer and the HV sub I'd very much prefer to see a local GCB to protect the generator.
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If we learn from our mistakes I'm getting a great education!
RE: Unit Aux. Transformer (UAT)
I fully agree with you.
GCB is better from protection/operation/maintanance and synchronization point of view.
Best Regards.
Slava
RE: Unit Aux. Transformer (UAT)
1. Yes, I forgot to delete the GCB for STG#1 in option-2. Good observation
2. With all your discussion, it seems reasonable to provide GCB at STG#2. I would like to think more of it. Thanks for this.
3. As two boilers (coal based) are there in this project apart from HRSG, Steam turbines are not exclusively depending on GT .
As both UATs in Option-1 will be sized for 2x100% plant load, still option-2 is recommended!!!
RE: Unit Aux. Transformer (UAT)
I think if "Steam turbines are not exclusively depending on GT" , possible system w/o SAT. In case of GCB, possible feed plant load from the grid and after synchronazing generator.
In additional you wrote that size of every UAT enough for the whole plant load.
But in all cases a good style add GCB for the second STG.
Best Regards.
Slava