Allen-Bradley 1407-CGCM, User Manual, Page: 93 / 252

Rockwell Automation Publication 1407-UM001H-EN-P - November 2014
CGCM Unit Configuration #HAPTER
An example of how these parameters affect tracking is shown in the Internal
Tracking graph. In this example, a loss of sensing causes a full-scale regulator
output. The internal tracking delay permits FCR mode to begin operation at the
output level prior to the loss of sensing.
&IGURE)NTERNAL4RACKING
Increasing the internal tracking rate makes the tracking function less responsive to
changes in the regulator output by reducing the slope of the tracking function.
Increasing the tracking delay offsets the tracking response to the right in the
figure. In the example above, if the internal tracking delay were reduced, it is likely
that the FCR mode setpoint has started at full regulator output, and recovery to
the desired operation has been delayed.
Redundant Tracking
•
Redundant Tracking Rate - This setting adjusts the rate at which the
tracking function of the redundant CGCM unit matches its regulator
operating point to that of the active CGCM unit. This sets the value of the
RedndtTrackRate tag in the Configuration table, expressed in seconds per
full-scale excursion of the regulator output from zero to the rated
generator field current.
Setpoint / Regulator Output
AVR Setpoint
Regulator
Output
Internal
Tracking
Internal
Tracking Delay
Internal Tracking
Delay
Internal Tracking
Delay
4x Internal
Tracking Delay
FCR
Setpoint
Upset
Mode Switched
to FCR
Rapid Decline to
Tracked Value
Return from Tracked
Value to FCR Setpoint
Time
4)0 Redundant tracking is enabled whenever two CGCM units are configured
in a Redundant mode and both are operational. Redundant tracking
parameters have no effect on a CGCM that is not part of a redundant
pair.