Demagnetization time constant

Any one have idea about this test please for Genrator Demagnetization time constant and stator residual voltage after automatic demagnetization please
Amie. . .
There is no parameter "Generator-Demagnetization-Time Constant", nor one called "Stator-Residual-Voltage" ! I believe you are referring to the phenomenon where the DC excitation-generator for the Main-Generator, loses its residual-magnetism Thus, preventing build-up of voltage of the Main-Generator during start-up. This problem mostly occurs when the system is not used for a long time, but can occur for other reasons.

The procedure to correct this problem is called "Flashing" ! Essentially the exciter is:
a) electrically isolated.
b) its field is then momentarily connected to a DC source like a car or truck battery.
c) for a brief time, even several times (hence the term "Flash" because an arc is drawn).

Regards, Phil Corso