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9440300990 Rev J
Regulation
DECS-250
The following examples demonstrate the advantages of internal tracking:
•
If the excitation system is operating online with internal tracking enabled, a loss of sensing condition
could trigger a transfer to FCR mode. Autotracking minimizes the impact that a loss of sensing
condition has on the exciter’s ability to maintain the proper excitation level.
•
While performing routine testing of the DECS-250 in backup mode, the internal tracking feature
allows a transfer to an inactive mode that will result in no disturbance to the system.
Two parameters control the behavior of internal tracking. A delay setting
B
determines the time delay
between large system disturbance and the start of setpoint tracking. A traverse rate setting
C
configures
the length of time for the inactive mode setpoints to traverse the full setting range of the active mode
setpoint.
External Setpoint Tracking
For critical applications, a second DECS-250 can provide backup excitation control. The DECS-250 (style
xx2xxxx) allows for excitation redundancy by providing external tracking and transfer provisions between
DECS-250 controllers. The secondary DECS-250 can be configured to track the primary DECS-250
setpoint. Proper redundant excitation system design allows for removal of the failed system.
Note
Periodic testing of the backup system must be performed to ensure
that it is operational and can be placed in service without warning.
Like internal tracking, external setpoint tracking uses enable/disable
D
, delay
E
, and traverse rate
F
settings.
Figure 20. Autotracking Settings
A
Internal Tracking Enabled
: Place a check in the checkbox to enable internal tracking.
B
Internal Tracking Delay
: Adjustable from 0 to 8 seconds in 0.1 second increments.
C
Internal Tracking Traverse Rate
: Adjustable from 1 to 80 seconds in 0.1 second increments.
D
External Tracking Enabled
: Place a check in the checkbox to enable external tracking.
E
External Tracking Delay
: Adjustable from 0 to 8 seconds in 0.1 second increments.
F
External Tracking Traverse Rate
: Adjustable from 1 to 80 seconds in 0.1 second increments.
Setpoint Configure
When the Auto Save setting is enabled, the DECS-250 automatically saves the active setpoint in one-
minute intervals. Otherwise, the setpoint which was last sent to the DECS-250 is retained. Figure 21
illustrates the Setpoint Configure screen.
Figure 21. Setpoint Configure Setting
Содержание DECS-250
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Страница 20: ...4 9440300990 Rev J Introduction DECS 250 ...
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Страница 84: ...68 9440300990 Rev J Limiters DECS 250 ...
Страница 108: ...92 9440300990 Rev J Power System Stabilizer DECS 250 Figure 85 PSS Function Blocks and Software Switches ...
Страница 114: ...98 9440300990 Rev J Power System Stabilizer DECS 250 Figure 96 PSS Parameter Settings ...
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Страница 126: ...110 9440300990 Rev J Mounting DECS 250 Figure 103 Overall and Projection Mounting Dimensions ...
Страница 127: ...9440300990 Rev J 111 DECS 250 Mounting Figure 104 DECS 250 Escutcheon Plate Dimensions ...
Страница 128: ...112 9440300990 Rev J Mounting DECS 250 Figure 105 Panel Cutting and Drilling Dimensions for DECS 250 Panel Mounting ...
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Страница 334: ...318 9440300990 Rev J Analog Expansion Module DECS 250 ...
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