ABB Relion 670 Series Applications Manual page 579

1MRK 511 401-UUS F
• IRIG-B
• SPA
• LON
• PPS
• IEEE 1588 (PTP)
For IEDs using PMU functionality, only PTP, GPS or IRIG-B or a combination of both GPS and IRIG-B
is allowed.
For IEDs using IEC/UCA 61850-9-2LE in "mixed mode" a time synchronization from an external
clock is recommended to the IED and all connected merging units. The time synchronization from
the clock to the IED can be PTP, optical PPS or IRIG-B. For IEDs using IEC/UCA 61850-9-2LE from
one single MU as analog data source, the MU and IED still need to be synchronized to each other.
This could be done by letting the MU supply a PPS signal to the IED or by supplying a PPS signal
from the IED to the MU, by using a GTM.
Out of these, LON and SPA contains two types of synchronization messages:
• 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.
23.13.2 Setting guidelines
All the parameters related to time are divided into two categories: System time and
Synchronization.
23.13.2.1 System time
The time is set with years, month, day, hour, minute, second and millisecond.
Bay control REC670
Application manual
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Section 23
Basic IED functions
IP15089-1 v3
M11348-119 v6
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