Functions
2.2 Protection Data Interfaces and Protection Data Topology
SIPROTEC, 7SD5, Manual
C53000-G1176-C169-5, Release date 02.2011
91
In address
4710
LOCAL RELAY
you indicate the actual local device. Enter the index for each device (according
to the consecutive numbering used). Each index from 1 to the entire number of devices must be used once,
but may not be used twice.
Figure 2-21
Differential protection topology for 4 ends with 4 devices — example
Make sure that the parameters of the differential protection topology for the differential protection system are
conclusive:
• Each device index can only be used once.
• Each device index must be assigned unambiguously to one device ID.
• Each device index must be the index of a local device once.
• The device with index 1 is the source for the absolute time management (timing master).
• The number of configured devices must be identical in all devices.
During startup of the protection system, the above listed conditions are checked. If one of these conditions is
not yet fulfilled, the differential protection does not operate.
The device then issues one of the following error messages
•
„DT inconsistent“
(Device Table contains two or more identical device ident numbers)
•
„DT unequal“
(Different settings of parameters
4701
to
4706
)
•
„Equal IDs“
(Protection system contains devices with identical settings of parameter
4710
)
If the indication
„Par. different“
ON is displayed, the differential protection is blocked as well. In this case
the following parameters, which should have identical settings in the devices, have in fact different settings.
• Address
230
Rated Frequency
• Address
143
TRANSFORMER
in the protected zone
• Address
1104
FullScaleCurr.
• Parameter
1106
OPERATION POWER
primary parameter
1106
is only displayed if parameter
143
is set to
yes
• Address
112
DIFF.PROTECTION
exists
• Address
149
charge I comp.
exists
