Basler Electric DECS-450 Digital Excitation Control System

Overview

The DECS-450 is a microprocessor based, high performance, extremely reliable

excitation controller for positive and positive/negative forcing excitation systems.

It supplies control voltage to an external bridge, which supplies dc energy to the

main or exciter field of a synchronous machine, making it compatible with any

size machine. The DECS-450 comes in many configurations to satisfy specific

requirements and redundancy needs. Basler offers customized and standard

solutions to fit a wide variety of applications.

Features

• Five control modes with autotracking between modes: AVR, FCR, FVR,

var, and PF

• Redundancy options including dual controllers

• 0.10% voltage regulation accuracy

• Paralleling provisions: network load sharing over Ethernet, reactive

droop, line drop, and cross-current compensation

• Integrated generator protection (24. 25. 27. 59. 81O/U, 32R, 40Q), Field

overvoltage, field overcurrent, field overtemperature, and exciter diode

monitoring

• Configurable protection expands the protection package, allowing the

user to customize protection elements for any sensed parameter

• Limiters include overexcitation, underexcitation, stator current, var and

underfrequency or V/Hz

• Auto tuning feature with two PID settings groups (Patent: US

2009/0195224 A1)

• Optional integrated Power System Stabilizer (PSS), IEEE Std. 421.5 type

PSS2A/2B/2C

• BESTlogic™Plus programmable logic is easy to configure and verify

• Integrated autosynchronizer (standard)

• Backward compatible with DECS-400 controllers

-Installation: Same footprint as DECS-400

-Wiring: A transition plate (optional) adapts DECS-450 terminals to

match DECS-400 terminal positions.

-Settings: Automatic PID/gain conversion from DECS-400 to DECS-450

-Logic: Predefined logic scheme to mimic DECS-400 behavior

• Trending, oscillography, and sequence of events recording

• Digital I/O: 14 programmable inputs, 11 programmable outputs, and

1 Form-C output dedicated to watchdog function

• Four analog meter driver outputs

• Expandable I/O via CAN bus communications

-AEM-2020: Adds 8 analog inputs, 8 RTD inputs, 2 thermocouple

inputs, and 4 analog outputs

-CEM-2020: Adds 10 digital inputs and 24 digital outputs

Benefits

• With its high levels of flexibility and reliability, the DECS-450 is

suitable for virtually any synchronous machine.

• Reduce your setup time with Basler’s intuitive BESTCOMSPlus®

software that simplifies complex setup with simple drag-and-drop

programmable logic (BESTlogic™Plus), visual real-time strip chart

capabilities, and cutting edge auto PID selection capabilities.

• The revolutionary auto tuning function automatically establishes

optimum PID and gain settings, taking the guesswork out

of system setup, reducing commissioning time and cost

while maximizing overall system performance (Patent: US

2009/0195224 A1).

• Avoid costly generator damage and improve overall system

stability with an optional integrated PSS that utilizes the “integral

of accelerating power” to safely dampen local mode, inter-area, and

inter-unit power oscillations.