ABB REG316 4 Series Operating Instructions Manual page 200

ABB Switzerland Ltd
Typical settings:
XA-Setting
XB-Setting
Phase-angle
Tripping delay timer:
Delay
or separate integrator ("Delay" function):
Trip-Delay
Reset-Delay
E
x - generator synchronous reactance [p.u.]
d
x - transformater short-circuit reactance [p.u.]
T
x
T
x'
d
2
Characteristic of the
underexcitation function
XA set
settings [U / I ]
N N
XB set
Fig. 3.5.14.3 Setting the characteristic of the underexcitation
function according to the steady-state stability
limit curve of the generator/transformer set
All reactances in p.u.
3-162
REG 316*4 1MRB520049-Uen / Rev. F
(delta-connected v.t's)
Step-up
transformer
U
S
x x
d T
Steady-state stability
x
limit curve
0
XB-Setting
x
d
XA-Setting
HEST 905 021 C
according to application
e.g. -2.0
according to application
e.g. -0.13
r
+30°
2 s
6 s
3 s