Generator Quad Axis Subtransient Time Constants

[Rodmcm]

Gentlemen. I am between a supplier and a regulatory authority. The Supplier has provided a formula for the above as Tq" = Tqo" x (Xq"/Xq) using a Japanese Society formula. He says the derivation of Tq" is not mentioned in ANSI or IEEE for cylindrical rotor synch generator (air cooled 45MW)

The regulator says that the formula is Tq"=Tqo" x (Xq"/Xq')
( last item is different) which he says is 'extracted from IEC standards'.

Can anyone help with an authoritive reference for this or verify either formula.

 

[dpc]

I thought IEEE 115 had procedures to measure time constants based on short circuit testing oscillography. Pretty sure this is the case for direct-axis, not sure about quadrature.

David Castor

http://www.cvoes.com

 

[dpc]

I do see in IEEE 115 a reference to IEC 34A Annex A for "unconfirmed" procedures to determine the quadrature reactances and time constants.

It appears the test procedures in IEEE 519 apply only to direct-axis values, as near I can figure out.

David Castor

http://www.cvoes.com