Rockwell Automation 1407-CGCM Combination Generator Control Module - Manual (Page 66)

66 Rockwell Automation Publication 1407-UM001G-EN-P - April 2013
Chapter 3 CGCM Unit Operation
Figure 36 - Power System Sign Conventions
Redundancy
The CGCM unit is capable of being used in a Redundant mode that provides
automatic transfer of control to a second CGCM 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 unit also can initiate a transfer of control in case of certain CGCM unit
failures.
The CGCM unit is equipped with two hardware provisions designed to support
redundancy, the redundancy communication port and the redundancy relay
output.
Redundancy Communication Port
The redundancy ports of the partner CGCM units are connected together by
means of a null modem cable. The redundancy communication channel is used to
exchange tracking information from the primary to the secondary CGCM unit
to support a bumpless transfer. In addition, the secondary CGCM unit can sense
a failure in the primary CGCM 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)