Siemens SIPROTEC 4, User Manual

Page: 212 / 734

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Figure 2-93 Determination of the ground fault location basing on directional indicators in the meshed
system
Setting Notes
General Settings
During configuration of the protection functions (Section 2.1.1 Functional Scope , under address 131
Sens.
Gnd Fault
it was determined with which parameters the ground fault detection is functioning.
If address
Sens. Gnd Fault
=
Definite Time
is selected, then the settings for the definite-time
elements are available here.
If address
Sens. Gnd Fault
=
Log. inverse A
is set, a logarithmic inverse time characteristic is avail-
able.
If address
Sens. Gnd Fault
=
Log. Inverse B
is set, a logarithmic inverse time characteristic with knee
point is active.
If
Sens. Gnd Fault
=
User Defined PU
is selected, a user-specified characteristic can be used for the
overcurrent protection elements 50Ns-1 or 51Ns.
If
Sens. Gnd Fault
=
TOC IEC
or
Sens. Gnd Fault
=
TOC ANSI
is selected, you can use an inverse
time characteristic either according to the IEC- or the ANSI-standard.
The superimposed high-current element 50Ns-1 is available in all these cases.
If this function is not required, then
Disabled
is set.
The logarithmic inverse time characteristics, the characteristics according to IEC or ANSI standards and user
characteristics are only available if under address 130 the standard measurement method
cos φ / sin φ
is
set.
The characteristic for determining the direction is set at address 130
S.Gnd.F.Dir.Ch
. It is optional to select
either the standard measurement method
cos φ / sin φ
or the
V0/I0 φ mea.
with one sector charac-
teristic.
At address 3101
Sens. Gnd Fault
, the function
ON
or
OFF
can be set to either
ON with GF log
or
Alarm Only
. If settings
ON
and
ON with GF log
are applied, tripping is also possible, otherwise a fault log
is created. A ground fault log is created for
ON with GF log
and
Alarm Only
. Setting
ON with GF log
is only available if characteristic
V0/I0 φ mea.
has been selected at address 130
S.Gnd.F.Dir.Ch
.
The parameters 3111
T-DELAY Pickup
and 3130
PU CRITERIA
are only visible if the standard measure-
ment method
cos φ / sin φ
has been selected when setting the direction characteristic. The ground fault
is detected and reported when the displacement voltage was sustained a certain time
T-DELAY Pickup
).
Address 3130
PU CRITERIA
specifies whether ground fault detection is enabled only for pickups of V
N
and
Ι
NS
(
Vgnd AND INs
) or as soon as one of the two has picked up (
Vgnd OR INs
).
The pickup can be stabilized for ground fault protection with definite time curve by a settable dropout time
delay (address 3121
50Ns T DROP-OUT
). This facility is used in power systems with intermittent faults. Used
together with electro-mechanical relays, it allows different dropout responses to be adjusted and time grading
of digital and electro-magnetic relays to be implemented. The setting depends on the dropout time delay of
2.13.4
Functions
2.13 Ground Fault Protection 64, 67N(s), 50N(s), 51N(s)
212 SIPROTEC 4, 7SJ62/64, Manual
C53000-G1140-C207-8, Edition 08.2016