Reactance Changes with Fault Currents

This is because of the sudden change of armature reaction due to fault current in its initial few cycles.

For more detail, see this Google book:

http://books.google.com/books?id=KaPmsYEuH7cC&pg=PA62 (section 3.2.1, 3.2.2 and 3.2.3, page 62, 63).

- MS

That is a very good book, explains things in english.. I am still confused however:

The book states:

"The terminal voltage can be restored by increasing the rotor excitation current and hence the flux. So the demagnetising effect of the stator current can be compensated by increasing the field excitation current. This demagnetising effect of the stator current is called 'armature reaction' and gives rise to what is known as the synchronous reactance, which is also called a 'derived' reactance as described in sub-section 3.4."

are they talking about the reactance of the stator winding when they mention armature reaction?