Rockwell Automation 1407-CGCM Combination Generator Control Module - Manual (Page 92)

92 Rockwell Automation Publication 1407-UM001G-EN-P - April 2013
Chapter 4 CGCM Unit Configuration
Internal Tracking
• Enable internal tracking - This checkbox sets the Boolean tag
Internal_Tracking_En in the Configuration data table. When the value
of this tag is 1, internal tracking between voltage regulating modes is
enabled and the Traverse Rates are enabled. If the tag value is 0, both the
Traverse Rates and tracking between regulation modes is disable.
• Internal Tracking Rate - This setting changes the rate at which the internal
tracking function matches the non-active excitation control modes to the
active excitation control mode. This sets the value of the
InternalTrackRate
tag in the Configuration table, expressed in seconds.
• Internal Tracking Delay - This setting adjusts the delay in the internal
tracking function. This sets the value of the InternalTrackDelay tag in the
Configuration table, expressed in seconds. Its purpose is to reduce the
likelihood that the short-term response of the active regulating mode to an
upset is transferred to a new mode of operation when the mode is
switched. If the internal tracking delay is too short, the transient response
to an upset is transferred to the new operating mode. Conversely, if the
tracking delay is set too long, there is a risk of an old operating point being
transferred to the new operating mode, resulting in an undesirable bump.
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.
Figure 39 - Internal Tracking
<
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