Siemens SIPROTEC 4 User Manual page 276

Functions
2.19 Flexible Protection Functions
NOTE
i
i
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
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
cates pickup "Flx01 Pickup A", because the undershooting was detected in the first measured-value
channel.
Table 2-22
Parameter OPERRAT. MODE = 1-phase
Parameter MEAS. QUANTITY = Current or Voltage
Parameter
MEAS. METHOD
Fundamental
True RMS
Parameter MEAS. QUANTITY = Current
Parameter CURRENT
Ia
Ib
Ic
In
In sensitive
In2
Parameter MEAS. QUANTITY = Voltage
Parameter VOLTAGE
Va-n
Vb-n
Vc-n
Va-b
Vb-c
Vc-a
Vn
Vx
Parameter MEAS. QUANTITY = P forward or P reverse or Q forward or Q reverse
Parameter POWER
Ia Va-n
Ib Vb-n
Ic Vc-n
276
drops to such degree that voltages V
A
drops to such degree that its threshold value is reached, the device then indi-
AB
Parameter in the Setting Dialog "Measurement Procedure", Mode of Operation 1-phase
Only the fundamental harmonic is evaluated, higher harmonics are suppressed. This is
the standard measurement procedure of the protection functions.
The "True" RMS value is determined, i.e. higher harmonics are evaluated. This procedure
is applied, for example, if an overload protection element must be realized on the basis of
a current measurement, as the higher harmonics contribute to thermal heating.
It is determined which current-measuring channel must be evaluated by the function.
Depending on the device version, either IN (normal-sensitive ground current input), INS
(sensitive ground current input) or IN2 (second ground current connected to the device)
can be selected.
It is determined which voltage-measuring channel must be evaluated 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-toground voltage. The
extent of the setting texts depends on the connection of the voltage transformer (see
address 213VT Connect. 3ph).
Please note the warning after this table.
It is determined which power-measuring channel (current and voltage) must be evaluated
by the function. With phase-tophase voltage connections the parameter is hidden (see
address 213 VT Connect. 3ph).
and V exceed their threshold values, the
AB A
SIPROTEC 4, 7SJ62/64, Manual
C53000-G1140-C207-8, Edition 08.2016