95 or 110kV?
95 or 110kV?
(OP)
A typical hydro power plant consist of some block generator-stepup transformer . Generator are 13,8kV and transformer are 13,8kV-delta/138 or 230 or 525kV star grounded.
Neutral Generator are grounded by high impedance (resistor or singlephase transformer with resistor at secondary.)
Auxiliary transformers are 13,8kV-delta/460V-star grounded.
All 13,8kV equipments, (not generator) are 15kV class.
Question:
What BIL to choose: 95kV or 110kV ?.
note:IEC adopts 95kV.
.
Neutral Generator are grounded by high impedance (resistor or singlephase transformer with resistor at secondary.)
Auxiliary transformers are 13,8kV-delta/460V-star grounded.
All 13,8kV equipments, (not generator) are 15kV class.
Question:
What BIL to choose: 95kV or 110kV ?.
note:IEC adopts 95kV.
.






RE: 95 or 110kV?
RE: 95 or 110kV?
RE: 95 or 110kV?
and
95kV for for transformer with class I : including winding <= 72,5kV.
So we could use 110kV for 13,8kV-stepup transformer and
95 kV for auxliary transformers, CT , PT,switching equipment.
I dont know about bus duct.
RE: 95 or 110kV?
I didn't get a reference standard to suggest you exactly what voltage class to use, but ABB'S T&D reference book made a mention of the fact that 95 kV is used for distribution class and 110 kV for Power class.
RE: 95 or 110kV?
Generation system has rated voltage of 13,8kV. So equipaments are:
By ANSI you chose 15kV class - BIL 95 or 110kV.
By IEC you chose 17,5kV class - BIL 75 or 95kV because in Europe there is rated voltage 15kV for generation.
Manufacture chosen equipments of 17,5kV-95kV.
I prefer 15kV-110kV but I do not know how to justify!