Rockwell Automation Publication 1407-UM002B-EN-P - February 2019
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CGCM-DLR Unit Operation
Chapter
3
Figure 36 - Power System Sign Conventions
Redundancy
The CGCM-DLR unit can be used in a Redundant mode that provides
automatic transfer of control to a second CGCM-DLR unit. In a redundant
configuration, the host Logix programmable controller is primarily responsible
for sensing power system conditions that require a transfer of control. The
CGCM-DLR unit can also initiate a transfer of control in case of certain
CGCM-DLR unit failures.
The CGCM-DLR unit is equipped with two hardware provisions that are
designed to support redundancy, the redundancy communication port and the
redundancy relay output.
Redundancy Communication Port
The redundancy ports of the partner CGCM-DLR units are connected together
with a null modem cable. The redundancy communication channel is used to
exchange tracking information from the primary to the secondary CGCM-DLR
unit to support a bumpless transfer. In addition, the secondary CGCM-DLR
unit can sense a failure in the primary CGCM-DLR unit via this communication
channel to facilitate an automatic transfer of control.
I
II
III
I V
Forward Reactive Power Flow
(export)
watts negative (-)
vars positive (+)
power factor lagging (+)
watts positive (+)
vars positive (+)
power factor lagging (+)
watts negative (-)
vars negative (-)
power factor leading (-)
watts positive (+)
vars negative (-)
power factor leading (-)
Reverse Reactive Power Flow
(import)
Reverse Real Power Flow
(import)
Forward Real Power Flow
(export)