Setting Guidelines - ABB RELION RET670 Applications Manual

1MRK 504 163-UUS A
24.13.2
24.13.2.1
24.13.2.2
Transformer protection RET670 2.2 ANSI
Application manual
• Coarse time messages are sent every minute and contain complete date and time,
that is year, month, day, hour, minute, second and millisecond.
• Fine time messages are sent every second and comprise only seconds and
milliseconds.
The selection of the time source is done via the corresponding setting.
It is possible to select more than one time source, in which case one is backup for the
other. The time synchronization source with the best calculated time-quality is
automatically selected. For instance, if both GPS and IRIG-B are selected and both
sources have the required accuracy, optical IRIG-B with IEEE1344 will be
automatically selected as the time synchronization source. Or if GPS and SNTP are
selected, when the GPS signal quality is bad, the IED will automatically choose SNTP
as the time-source.
If PTP is activated, the device with the best accuracy within the synchronizing group
will be selected as the source. For more information about PTP, see the Technical
manual.
IEEE 1588 (PTP)
PTP according to IEEE 1588-2008 and specifically its profile IEC/IEEE 61850-9-3 for
power utility automation is a synchronization method that can be used to maintain a
common time within a station. This time can be synchronized to the global time using,
for instance, a GPS receiver. If PTP is enabled on the IEDs and the switches that
connect the station are compatible with IEEE 1588, the station will become
synchronized to one common time with an accuracy of under 1us. Using an IED as a
boundary clock between several networks will keep 1us accuracy on three levels or
when using an HSR, 15 IEDs can be connected in a ring without losing a single
microsecond in accuracy.

Setting guidelines

All the parameters related to time are divided into two categories: System time and
Synchronization.
System time
The time is set with years, month, day, hour, minute, second and millisecond.
Synchronization
The setting parameters for the real-time clock with external time synchronization are
set via local HMI or PCM600. The path for Time Synchronization parameters on local
Section 24
Basic IED functions
IP15089-1 v3
M11348-119 v5
M11348-143 v4
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