Differential Protection Topology; Setting Notes - Siemens SIPROTEC 7SD610 Manual

2.2.4

Differential Protection Topology

2.2.4.1 Setting Notes

Protection data topology
First of all, define your protection data communication topology: Number the devices consecutively. This num-
bering is a serial device index that serves for your own overview. It starts for each distance differential protection
system (i.e. for each protected object) with 1. For the differential protection system the device with index 1 is
always the absolute time master, i.e. the absolute time management of all devices which belong together
depends on the absolute time management of this device, if synchronization is set to Source or Timing
Master. As a result, the time information of all devices is comparable at all times. The Timing Master-Setting
has only influence on the absolut time (SCADA-Time). This setting has no impact on the differential protection.
The device index thus serves for the unique identification of the devices within a differential protection system
(i.e. for one protected object).
In addition, assign an ID number to each device (device-ID). The device ID is used by the communication
system to identify each individual device. It must be between 1 and 65534 and must be unique within the com-
munication system. The ID number thus identifies the devices in the communication system (according to a
device address) since the exchange of information between several differential protection systems (thus also
for several protected objects) can be executed via the same communication system.
If you work with different physical interfaces and communication links, please make sure that every protection
data interface corresponds to the projected communication link (direct FO or communication network).
For a protected object with two ends (e.g. a line) the addresses 4701 ID OF RELAY 1 and 4702 ID OF
RELAY 2 are set, e.g. for device 1 the device-ID 16 and for device 2 the device-ID 17 (Figure 2-14). The indices
of the devices and the device-IDs do not have to match here, as mentioned above.
Figure 2-14
In address 4710 LOCAL RELAY you indicate the actual local device. One device has index 1, the other index 2.
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).
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.
SIPROTEC, 7SD610, Manual
C53000-G1176-C145-6, Release date 02.2011
Differential protection topology for 2 ends with 2 devices — example
2.2 Protection Data Interfaces and Protection Data Topology
Functions
63