Basler DECS-250 User Manual

9440300990 7-1
DECS-250 Regulation
7 • Regulation
The DECS-250 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-250
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-250 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-250 regulates the excitation
level in order to maintain the generator terminal voltage setpoint despite changes in load and operating
conditions. AVR setpoint (or operating point) adjustment is made through:
• Application of contacts at DECS-250 contact inputs configured for raising and lowering the active
setpoint
• Application of an analog control signal at the DECS-250 Auxiliary Control input.
• The BESTCOMSPlus
®
Control Panel screen (available in the BESTCOMSPlus Metering
Explorer)
• A raise or lower command transmitted through the DECS-250 Modbus port
The range of adjustment is defined by Minimum and Maximum 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.
Settings that are related to machine ratings can be set in either actual units of voltage or in per unit
values. When a native unit is edited, BESTCOMSPlus automatically recalculates the per unit value based
on the native unit setting and the rated data parameter (on the System Parameters, Rated Data screen)
associated with it. When a per unit value is edited, BESTCOMSPlus automatically recalculates the native
value based on the per unit setting and the rated data parameter associated with it.
Once all per unit values are assigned, if the rated data parameters are changed, BESTCOMSPlus
automatically recalculates all native unit settings based on the modified rated data parameters.
The AVR setpoint has a native unit of Primary Volts and the rated data associated with it is Machine
Rated Data, Voltage (on the System Parameters, Rated Data screen).
These settings are illustrated in Figure 7-1.
FCR
When operating in FCR (Field Current Regulation) mode, the DECS-250 regulates the level of current it
supplies to the field based on the FCR setpoint. 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-250 contact inputs configured for raising and lowering the active
setpoint
• Application of an analog control signal at the DECS-250 Auxiliary Control input
• The BESTCOMSPlus
®
Control Panel screen (available in the BESTCOMSPlus Metering
Explorer)
• A raise or lower command transmitted through the DECS-250 Modbus port

Basler DECS-250 Specifications

General

Brand	Basler
Model	DECS-250
Category	Control Systems
Language	English