ABB Relion RES670, Technical Manual, Page: 773 / 934

SW time
Time
regulator
Time tagging and general synchronization
Time
regulator
Commu-
nication
Events
Synchronization for differential protection
(Echo mode or GPS)
Diff.
commu-
nication
*IEC 61850-9-2
IEC140000113-2-en.vsdx
External
synchronization
sources
Mergin
units*
GPS
IRIG-B
Off
Protection
and control
functions
A/D
converter
HW time
(Setting:
see
Technical
manual)
Off
On
PTP(IEEE 1588)
Slave only
IEC140000113 V2 EN-US
Figure 293: 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.
SyncLostMode is not required to set as Block / BlockonLostUTC when differential
protection is based on ECHO mode.
Fast clock synchronization mode
At start-up and after interruptions in the GPS, PTP or IRIG B time signals, the
deviation between the external time system and the internal differential time system
can be substantial. A new start-up is also required, for example, after maintenance of
the auxiliary voltage system.
When the time difference is < 16 μs, the line differential protection function is blocked
and the time regulator for the hardware clock automatically uses a fast mode to
synchronize the clock systems. Time adjustment is made with an exponential function,
that is, with big time adjustment steps in the beginning, and then smaller steps until a
time deviation between the GPS time and the differential time system of < 16 μs has
1MRK 511 408-UUS A
Section 22
Basic IED functions
Phasor measurement unit RES670 2.2 ANSI 767
Technical manual