Basler Electric DECS-250N - Manual (Page 41)

9440500990 Rev D 25
DECS-250N Regulation
Regulation
The DECS-250N precisely regulates the level of supplied excitation power in each of the five available
regulation modes. Stable regulation is enhanced by the automatic tracking of the active-mode setpoint by
the inactive regulation modes. Pre-position setpoints within each regulation mode enable the DECS-250N
to be configured for multiple system and application needs.
BESTCOMSPlus Navigation Path: Settings Explorer, Operating Settings, AVR/FCR/FVR and VAR/PF
HMI Navigation Path: Settings, Operating Settings, AVR/FCR/FVR and VAR/PF
Regulation Modes
The DECS-250N provides five regulation modes: Automatic Voltage Regulation (AVR), Field Current
Regulation (FCR), Field Voltage Regulation (FVR), var, and Power Factor (PF).
AVR
When operating in AVR (Automatic Voltage Regulation) mode, the DECS-250N regulates the excitation
level in order to maintain the generator terminal voltage setpoint
A despite changes in load and operating
conditions. AVR setpoint (or operating point) adjustment is made through:
•
Application of contacts at DECS-250N contact inputs configured for raising and lowering the
active setpoint
•
Application of an analog control signal at the DECS-250N Auxiliary Control input.
•
The BESTCOMSPlus ® Control Panel screen (available in the BESTCOMSPlus Metering Explorer)
•
A raise or lower command transmitted through the DECS-250N Modbus port
The range of adjustment is defined by Minimum B and Maximum C settings that are expressed as a
percentage of the rated generator voltage. The length of time required to adjust the AVR setpoint from
one limit to the other is controlled by a Traverse Rate setting
D . These settings are illustrated in Figure 15.
FCR
When operating in FCR (Field Current Regulation) mode, the DECS-250N regulates the level of current it
supplies to the field based on the FCR setpoint
E . The setting range of the FCR setpoint depends on the
field rated data and other associated settings. FCR setpoint adjustment is made through:
•
Application of contacts at DECS-250N contact inputs configured for raising and lowering the
active setpoint
•
Application of an analog control signal at the Auxiliary Control input
•
The BESTCOMSPlus Control Panel screen (available in the BESTCOMSPlus Metering Explorer)
•
A raise or lower command transmitted through the DECS-250N Modbus port
The range of adjustment is defined by Minimum F and Maximum G settings that are expressed as a
percentage of the rated field current. The length of time required to adjust the FCR setpoint from one limit
to the other is controlled by a Traverse Rate setting
H . These settings are illustrated in Figure 15.
FVR
FVR (Field Voltage Regulation) mode enables generator modeling and validation testing in accordance
with WECC testing requirements. FVR mode can also be used to smooth the transfer from the active
DECS-250N to a secondary DECS.
When operating in FVR mode, the DECS-250N regulates the level of field voltage it supplies to the field
based on the FVR setpoint
I . The setting range of the FVR setpoint depends on the field rated data and
other associated settings. FVR setpoint adjustment is made through:
•
Application of contacts at DECS-250N contact inputs configured for raising and lowering the
active setpoint
•
Application of an analog control signal at the DECS-250N Auxiliary Control input