3
''
N
energisation
d T network
V
I
X X Z
=
+ +
ANSIEQUATION2398 V1 EN-US (Equation 231)
Where
V
N
is the rated voltage of the generator
X
d
’’ is the subtransient reactance for the generator (Ω)
X
T
is the reactance of the step-up transformer (Ω)
Z
network
is the short circuit source impedance of the connected network recalculated to the generator
voltage level (
Ω)
The setting can be chosen:
I to be less than I
energisation
> ⋅0 8.
EQUATION2283 V2 EN-US (Equation 232)
tOC: Time delay for trip in case of high current detection due to accidental energizing
of the generator
. The default value 0.03s is recommended.
27_pick_up: Voltage level, given in % of VBase, for activation (arming) of the
accidental energizing protection function. This voltage shall be lower than the lowest
operation voltage. The default value 50% is recommended.
tArm: Time delay of voltage under the level Arm< for activation. The time delay shall
be longer than the longest fault time at short circuits or phase-ground faults in the
network. The default value 5s is recommended.
59_Drop_out: Voltage level, given in % of VBase, for deactivation (dearming) of the
accidental energizing protection function. This voltage shall be higher than the
27_pick_up level. This setting level shall also be lower than the lowest operation
voltage. The default value 80% is recommended.
tDisarm: Time delay of voltage over the level 59_Drop_out for deactivation. The time
delay shall be longer than tOC. The default value 0.5s is recommended.
1MRK 502 071-UUS A Section 9
Current protection
Generator protection REG670 2.2 ANSI and Injection equipment REX060, REX061, REX062 425
Application manual
To Next Page
Loading...
