Allen-Bradley 1407-CGCM-DLR, User Manual, Page: 105 / 268

Rockwell Automation Publication 1407-UM002B-EN-P - February 2019 105
CGCM-DLR Unit Configuration Chapter 4
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 before the loss of sensing.
Figure 39 - Internal Tracking
An increase in the internal tracking rate makes the tracking function less
responsive to changes in the regulator output by reducing the slope of the
tracking function. An increase in the tracking delay offsets the tracking response
to the right in the figure. In
Figure 39 , 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-DLR unit matches its
regulator operating point to that of the active CGCM-DLR 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
TIP
Redundant tracking is enabled whenever two CGCM-DLR units are
configured in a Redundant mode and both are operational. Redundant
tracking parameters have no effect on a CGCM-DLR that is not part of a
redundant pair.