Instruction manual
–
AQ G3x7 Generator protection IED
128 (211
)
Table 3-58: Setting parameters of the impedance protection function.
Parameter
Setting value, range
and step
Description
Operation
Off, NoCompound,
FWCompound,
BWCompound
Operating mode selection for the function. Default setting is
NoCompound.
Impedance
start only
Activated
Deactivated
Selection if the function issues either “Start” signal alone or
both “Start” and after set time delay “Trip” signal.
Default is
that both signals are generated (=deactivated).
IPh Base
Sens
10…30%
by step of 1 Minimum current setting for phase currents. Default setting is
20.
IRes Base
Sens
10…50%
by step of 1 Minimum current setting for residual current. Default setting
is 10.
IRes bias
5…30%
by step of 1
Slope of the percentage characteristic for earth-fault
detection. Default setting is 10.
PsImpAng
0…90 deg
by step of
1
Positive impedance angle. Default setting is 10.
OfsImpRch
-150.00
…
150.00
Ohm by step of 0.01.
Offset impedance reach. Default setting is 0.00.
PsImpRch
0.10
…
250.00 Ohm by
step of 0.01.
Positive impedance reach. Default setting is 10.00.
Zone1 (Xo-
X1)/3X1
0.00
…
5.00 by step of
0.01.
The zero sequence current compensation factor, calculated
with X values. Default setting is 0.00.
Zone1 (Ro-
R1)/3R1
0.00
…
5.00 by step of
0.01.
The zero sequence current compensation factor, calculated
with R values. Default setting is 0.00.
Time delay
0
…
60000ms by step
of 1.
Operation time delay. Default setting is 500.
3.2.22
P
OLE SLIP
(78)
(O
PTION
)
The pole slipping protection function can be applied mainly for synchronous machines. If a
machine falls out of synchronism, then the voltage vector induced by the machine rotates
slower or with a higher speed as compared to voltage vectors of the network. The result is that
according to the frequency difference of the two vector systems, the cyclical voltage difference
on the current carrying elements of the network are overloaded cyclically. To protect the stator
coils from the harmful effects of the high currents and to protect the network elements, a
disconnection is required.
The pole slipping protection function is designed for this purpose.
3.2.22.1
Principle of operation
The principle of operation is the impedance calculation.
When a machine falls out of synchronism, then the voltage vector induced by the machine
rotates slower or with a higher speed as compared to voltage vectors of the network. The
result is that according to the frequency difference of the two vector systems the cyclical