Section 3 Common Time Synchronization; Design Of The Time System (Clock Synchronization) - ABB RELION 670 Series Application Manual

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Section 3
3.1
Communication set-up 670/650 series 2.2
Application Guide
Common time synchronization

Design of the time system (clock synchronization)

The time system is based on software and hardware clocks that run independently
from each other (see Figure 8).
External
synchronization
sources
Off
LON
SPA
Min. pulse
GPS
SNTP
DNP
IRIG-B
PPS
Off
GPS
IRIG-B
PPS
IEC08000287 V4 EN-US
Figure 8: Design of the time system (clock synchronization)
All time tagging is performed by the software clock. When, for example, a status
signal is changed in the protection system of a function based on the free running
hardware clock, the event is time tagged by the software clock when it reaches the
event recorder. The hardware clock can thus run independently.
The echo mode of the line differential protection function is based on the hardware
clock. Thus, there is no need to synchronize the hardware clock and the software
clock.
Synchronization of the hardware clock to the software clock is necessary when
GPS or IRIG B 00X with optical fiber, IEEE 1344 is used for differential
Common time synchronization
PTP(IEEE 1588)
Off
On
Time tagging and general synchronization
Slave only
Commu-
Time nication
regulator
(Setting:
see SW time
Technical
manual
Connected when GPS time is used
for differential protection or when
PTP is activated or when PMU
report is used
Synchronization for differential protection
Time
HW time
regulator
(fast or slow)
converter
Section 3
GUID-E2B9E81C-5733-4521-B27F-BF33E05CCFB0 v10
Protection
Events
and control
functions
(Echo mode or GPS)
Diff.
A/D
Merging
commu-
units*
nication
*IEC 61850-9-2
IEC08000287-4-en.vsdx
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