Application - ABB RELION 630 Series Technical Manual

1MRS757256 F
3.16.9
PML630/Compact Load-Shedding Solution
Technical Manual
source like GPS, or local without synchronization. Using a local SNTP server without
synchronization as primary or secondary server in a redundant configuration is not
recommended.
Synchronization via IRIG-B
IRIG-B is a protocol used only for time synchronization. A clock can provide local
time of the year in this format. The "B" in IRIG-B states that 100 bits per second are
transmitted, and the message is sent every second. After IRIG-B there numbers stating
if and how the signal is modulated and the information transmitted.
To receive IRIG-B there are one dedicated connector for the IRIG-B port. IRIG-B 00x
messages can be supplied via the galvanic interface, where x (in 00x) means a number
in the range of 1-7.
If the x in 00x is 4, 5, 6 or 7, the time message from IRIG-B contains information of
the year. If x is 0, 1, 2 or 3, the information contains only the time within the year, and
year information has to come from the tool or LHMI.
The IRIG-B input also takes care of IEEE1344 messages that are sent by IRIG-B
clocks, as IRIG-B previously did not have any year information. IEEE1344 is
compatible with IRIG-B and contains year information and information of the time-
zone.
It is recommended to use IEEE 1344 for supplying time information to the IRIG-B
module. In this case, send also the local time in the messages.
Synchronization via DNP
The DNP3 communication can be the source for the coarse time synchronization,
while the fine time synchronization needs a source with higher accuracy.
See the communication protocol manual for a detailed description of
the DNP3 protocol.

Application

Time synchronization is used to achieve a common time base for the IEDs in a
protection and control system. This makes comparison of events and disturbance data
between all IEDs in the system possible.
Time-tagging of internal events and disturbances are an excellent help when
evaluating faults. Without time synchronization, only the events within the IED can
be compared to one another. With time synchronization, events and disturbances
within the entire station, and even between line ends, can be compared at evaluation.
In the IED, the internal time can be synchronized from a number of sources.
Section 3
Basic functions
105