ABB REG670 Applications Manual page 744

Section 23
Basic IED functions
738
Time-tagging of internal events and disturbances are an excellent help when
evaluating faults. Without time synchronization, only the events within one IED can
be compared with each other. With time synchronization, events and disturbances
within the whole network, can be compared and evaluated.
In the IED, the internal time can be synchronized from the following sources:
• BIN (Binary Minute Pulse)
• DNP
• GPS
• IEC103
• SNTP
• 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.
Generator protection REG670 2.2 IEC and Injection equipment REX060, REX061, REX062
1MRK 502 071-UEN -
Application manual