Functions
2.6 Flexible Protection Functions
SIPROTEC, 7RW80, Manual
C53000-G1140-C233-1, Release date 10.2010
85
Note
With regard to the phase-selective pickup messages, a special behavior is observed in the three-phase voltage
protection with phase-to-phase variables, because the phase-selective pickup message "Flx01 Pickup Lx" is
allocated to the respective measured-value channel "Lx".
Single-phase faults:
If, for example, voltage V
A
drops to such degree that voltages V
AB
and V
CA
exceed their threshold values, the
device indicates pickups “Flx01 Pickup A” and “Flx01 Pickup C”, because the undershooting was detected in
the first and third measured-value channel.
Two-phase faults:
If, for example, voltage V
AB
drops to such degree that its threshold value is reached, the device then indicates
pickup "Flx01 Pickup A", because the undershooting was detected in the first measured-value channel.
Table 2-9
Parameter in the Setting Dialog "Measurement Procedure", Mode of Operation 1-phase
Note
If you have selected
Vph-g, VSyn
in
VT Connect. 3ph
, the connected phase-to-ground voltage can be
processed. If you select
VOLTAGE
as measured quantity, this connected voltage is used automatically.
Mode of Oper-
ation
Measured
Quantity
Notes
single-phase
Voltage
Parameter
MEAS. METHOD
Setting Options
Fundamental Harmonic Only the fundamental harmonic is evaluated, higher harmon-
ics are suppressed. This is the standard measurement proce-
dure of the protection functions.
True RMS
The „True“ RMS value is determined, i.e. higher harmonics
are evaluated.
Parameter
VOLTAGE
Setting Selection
Vab
Vbc
Vca
Van
Vbn
Vcn
Vn
Vx
It is determined which voltage-measuring channel is evaluat-
ed by the function. When selecting phase-to-phase voltage,
the threshold value must be set as a phase-to-phase value,
when selecting a phase-to-ground variable as phase-to-
ground voltage. The extent of the setting texts depends on
the connection of the voltage transformer (see address 213
VT Connect. 3ph).
