What are the proper parameters of SEXS excitation model?

edit

There may be warnings even for proper parameters, so the warnings are only an indication.

The limits for warnings are described in Program Application Guide, Vol II, Chapter 26.5. DOCU,CHECK gives the following report:

 Model SEXS Bus 3011 [MINE_G      13.800] Machine "1 " :
 TB = 4.0, outside of range > 5.0 and < 20.0
 K = 200.0, outside of range > 20.0 and <= 100.0
 TA/TB=     0.2500   K=       200.0000   TRANSIENT GAIN=    50.0000
 EMIN = -4.6, not = 0.0

                    C O N S       S T A T E S
                     133-138          50-51

                TA/TB     TB      K       TE     EMIN   EMAX
                0.250   4.000   200.0   0.020   -4.60   6.00

The used exciter has a very short exciter time constant (20 ms), which means that the block is ignored in a 50 Hz system with simulation step 10 ms.

The transient gain is 50 which is high, resulting in a fast response in field voltage.