ABB Relion 670 Series Applications Manual page 468

Section 18
Station communication
When only one MU is used as analog source it is theoretically possible to do without time-
synchronization. However, this would mean that timestamps for analog and binary data/events
would be uncorrelated. Disturbance recordings will appear incorrect since analog data will be
timestamped by MU and binary events will use internal IED time. For this reason it is
recommended to use time synchronization also when analog data emanate from only one MU.
An external time-source can be used to synchronize both the IED and the MU. It is also possible to
use the MU as clock-master to synchronize the IED from the MU. When using an external clock, it is
possible to set the IED to be synchronized via PPS or IRIG-B. It is also possible to use an internal
GPS-receiver in the IED (if the external clock is using GPS).
Using the MU as time source for synchronization
IEC 61850-9-2LE
Analog data
IEC10000061 V1 EN-US
Figure 218: Setting example when MU is the synchronizing source
Settings in local HMI under Settings/Time/Synchronization/TIMESYNCHGEN/IEC 61850-9-2:
HwSyncSrc : set to PPS since this is what is generated by the MU (ABB MU)
•
AppSynch : set to Synch , since protection functions should be blocked in case of loss of
•
timesynchronization
SyncAccLevel : could be set to 4us since this corresponds to a maximum phase-angle error of
•
0.072 degrees at 50Hz
fineSyncSource could still be set to something different in order to correlate events and data
•
to other IED's in the station
Settings in PST in PCM600 under: Hardware/Analog modules/Merging units/MU01
SyncMode : set to Operation. This means that the IED will be blocked if the MU loose time
•
synchronization. Since the MU is set as Time-master, this is unlikely to happen so the setting
of SyncMode is not important in this case
There are 3 signals that monitors state related to time synchronization:
• TSYNCERR signal on the TIMEERR function block. This signal will go high whenever internal
timeQuality goes above the setting SyncAccLevel ( 4us in this case) and this will block the
462
IED
MU
PPS
Synchronization
IEC10000061-1-en.vsd
1MRK 511 358-UUS A
Application manual