
Rockwell Automation Publication 1407-UM002B-EN-P - February 2019
67
CGCM-DLR Unit Operation
Chapter
3
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Phase rotation (3-phase connection only): If the bus and generator are
opposite in phase rotation, synchronization fails. The CGCM-DLR
unit continually checks phase rotation match when synchronization is
active.
•
Permissive Synchronization
The host controller sets the
PermissiveSyncEn
tag to enable Permissive
Synchronization mode. This mode is the same as Automatic Synchronizing
mode except that the CGCM-DLR unit does not compute error and
correction tags. The CGCM-DLR unit sets the proper close breaker tag
when the synchronizing conditions are met.
•
Check Synchronization
The host controller sets the
CheckSyncEn
tag to enable Check
Synchronization mode. This mode is the same as the Automatic
Synchronization mode except the CGCM-DLR unit does not set a close
breaker tag. This mode is useful for testing the system.
•
Initiate Synchronization
The host Logix controller sets the
InitiateSync
tag to begin the
synchronization process. This tag must remain set during the entire
process. If the initiate synchronization tag is reset, the CGCM-DLR unit
terminates the synchronization process. Similarly, a write of the
Unscheduled Write table terminates an active synchronization process.
The Initiate Synchronization tag enables the operation of the selected
Synchronizing mode. The host controller must select only one of the three
modes before or simultaneously as the Initiate Synchronization tag. If none
are enabled, the CGCM-DLR unit sets the undefined Synchronization
mode error flag. If multiple inputs are enabled, the CGCM-DLR unit sets
the conflict error flag. In either case, synchronization fails and the
CGCM-DLR unit sets the synchronization failure flag.
Synchronizing Error Calculation
When Synchronization is active, the CGCM-DLR unit computes synchronizing
errors as follows.
Voltage Match Error
100
Bus Voltage Generator Voltage
–
Bus Voltage
--------------------------------------------------------------------------------
×
=
Frequency Match Error
Bus Frequency Generator Frequency
–
=
Phase Match Error
Bus Voltage Phase Angle in Degrees
Generator Voltage Phase Angle in Degrees
–
=