Basler DECS-250, Instruction Manual

Page: 17 / 352

9440300990 Rev J 1
DECS-250 Introduction
Introduction
DECS-250 Digital Excitation Control Systems offer precise excitation control and machine protection in a
compact package. DECS-250 adaptability to many applications is assured through configurable contact
inputs and outputs, flexible communication capabilities, and programmable logic implemented with the
provided BESTCOMS
Plus
®
software.
Features and Functions
DECS-250 features and functions include:
•
Precise excitation control for synchronous generator or synchronous motor applications
o
Power factor and var metering values will be opposite in motor mode
•
Five excitation control modes:
o
Automatic Voltage Regulation (AVR)
o
Field Current Regulation (FCR)
o
Field Voltage Regulation (FVR)
o
Power Factor Regulation (PF)
o
Var Regulation (var)
•
Three pre-position setpoints for each excitation control mode
•
Internal tracking between operating mode setpoints and external tracking of a second DECS
excitation setpoint
•
Two PID stability groups with Auto Tune feature
•
Remote setpoint control input accepts analog voltage or current control signal
•
Real-time metering
•
Optional automatic synchronizer
•
Optional integrated power system stabilizer (PSS)
o
Generator or motor control modes, accommodates phase rotation changes between
modes
o
Speed and power sensing or speed-only sensing
o
Two wattmeter or three-wattmeter methods of power measurement
•
Soft start and voltage buildup control
•
Five limiting functions:
o
Overexcitation: summing point and takeover
o
Underexcitation
o
Stator current
o
Reactive power (var)
o
Underfrequency
•
Twenty protection functions:
o
Generator undervoltage (27)
o
Generator overvoltage (59)
o
Loss of sensing (LOS)
o
Overfrequency (81O)
o
Underfrequency (81U)
o
Reverse power (32R)
o
Loss of excitation (40Q)
o
Field overvoltage
o
Field overcurrent
o
Loss of PMG
o
Exciter diode failure
o
Sync-check (25)
o
Eight configurable protection elements
•
IRIG or network time synchronization
•
Sixteen contact sensing inputs
o
Two fixed-function inputs: Start and Stop
o
Fourteen programmable inputs