Ground-Fault Detection With Cos Φ/Sin Φ Measurement - Siemens SICAM Manual

NOTE
i
i
The undetermined area for the device MLFB 6MD2321-1AA00-1AA0 is 10° and the respective angles
change accordingly.
The undetermined area for the device MLFB 6MD2322-1AA00-1AA0 is 20° and the respective angles
change accordingly.
For more information about ground-fault direction of solidly grounded system, see
Fault Parameter > Ground-Fault Detection > Neutral-point Treatment menu.
4.1.20 Ground-Fault Detection with Cos φ/Sin φ Measurement
The ground-fault detection with cos φ/sin φ measurement method is used to detect the ground fault based on
the active part of the current (resonant system) or reactive part of the current (isolated system). The ground-
fault detection with cos φ/sin φ measurement method is enabled when the I
the resistive part of the ground current) parameter is configured to the values as in
the device detects the ground fault based on the vector method.
The ground-fault detection with cos φ/sin φ measurement method is only applicable for resonant-grounded
systems and isolated-grounded systems.
If the ground current ((I
the time delay tI
If I is set to 0 (vector method), irrespective of the selected ground-type connection, the total ground current
dir
is compared with the set current I
For resonant-ground connections, if I
method), the active part of the ground current is compared with I
I > for ground-fault detection.
N
For isolated-ground connections, if I
method), the reactive part of the ground current is compared with I
and I > for ground-fault detection.
N
For more information about I
Detection menu.
The following logic diagram illustrates the ground-fault detection with cos φ/sin φ measurement method.
[lo_sfcm-grndfltdet-cossine, 2, en_US]
Figure 4-14
The following table displays the I
method status:
SICAM, Feeder Condition Monitor, Manual
E50417-H8940-C580-A4, Edition 03.2019
>) and the resistive current exceed the set threshold (I
N
> is greater than the set threshold, the device indicates a fault.
N
> for fault detection.
N
is not 0 (ground-fault detection with cos φ/sin φ measurement
dir
is not 0 (ground-fault detection with cos φ/sin φ measurement
dir
parameters, see
dir
Logic Diagram for Ground-Fault Detection with Cos φ/Sin φ Measurement Method
range and the ground-fault detection with cos φ/sin φ measurement
dir
in addition to the total ground current and
dir
in addition to the total ground current
dir
Table A-3 and refer to the Fault Parameters > Ground-Fault
Device Functions
4.1 Description
Table A-3 and refer to the
(user-settable parameter for
dir
Table 4-9. If I is set to 0,
dir
> and I respectively) and if
N dir
45