Basler DECS-150 User manual

12570 Route 143 •Highland, Illinois 62249-1074 USA
Tel [phone] •Fax [phone]
www.basler.com •[email protected]
Publication
9492600990 Rev H
Sep 2021
DECS-150
Digital Excitation Control System
Instruction Manual

WARNING: California's Proposition 65 requires special warnings for products that
may contain chemicals known to the state of California to cause cancer, birth defects or
other reproductive harm. Please note that by posting this Proposition 65 warning, we are
notifying you that one or more of the Proposition 65 listed chemicals may be present in
products we sell to you. For more information about the specific chemicals found in this
product, please visit https://www.basler.com/Prop65.

Digital Excitation Control System i
DECS-150 Preface
Preface
This instruction manual provides information about the installation and operation of the DECS-150. To
accomplish this, the following information is provided:
•General information
•Functional description
•Installation and connections
•BESTCOMSPlus®software
•Communication and configuration
•Testing and troubleshooting
•Specifications
Conventions Used in this Manual
Important safety and procedural information is emphasized and presented in this manual through
warning, caution, and note boxes. Each type is illustrated and defined as follows.
Warning!
Warning boxes call attention to conditions or actions that may cause
personal injury or death.
Caution
Caution boxes call attention to operating conditions that may lead to
equipment or property damage.
Note
Note boxes emphasize important information pertaining to installation
or operation.

ii Digital Excitation Control System
Preface DECS-150
12570 State Route 143
Highland IL 62249-1074 USA
www.basler.com
[e-mail]
Tel: [phone]
Fax: [phone]
© 2021 by Basler Electric
All rights reserved
First printing: September 2015
Warning!
READ THIS MANUAL. Read this manual before installing, operating, or maintaining
this equipment. Note all warnings, cautions, and notes in this manual as well as on the
product. Keep this manual with the product for reference. Only qualified personnel
should install, operate, or service this system. Failure to follow warning and cautionary
labels may result in personal injury or property damage. Exercise caution at all times.
Caution
Installing previous versions of firmware may result in compatibility issues causing the
inability to operate properly and may not have the enhancements and resolutions to
issues that more recent versions provide. Basler Electric highly recommends using the
latest version of firmware at all times. Using previous versions of firmware is at the
user’s risk and may void the warranty of the unit.
Basler Electric does not assume any responsibility to compliance or noncompliance with national
code, local code, or any other applicable code. This manual serves as reference material that
must be well understood prior to installation, operation, or maintenance.
For terms of service relating to this product and software, see the Commercial Terms of
Products and Services document available at www.basler.com/terms.
This publication contains confidential information of Basler Electric Company, an Illinois
corporation. It is loaned for confidential use, subject to return on request, and with the mutual
understanding that it will not be used in any manner detrimental to the interests of Basler Electric
Company and used strictly for the purpose intended.
It is not the intention of this manual to cover all details and variations in equipment, nor does this
manual provide data for every possible contingency regarding installation or operation. The
availability and design of all features and options are subject to modification without notice. Over
time, improvements and revisions may be made to this publication. Before performing any of the
following procedures, contact Basler Electric for the latest revision of this manual.
The English-language version of this manual serves as the only approved manual version.

Digital Excitation Control System iii
DECS-150 Revision History
Revision History
A historical summary of the changes made to this instruction manual is provided below. Revisions are
listed in reverse chronological order.
Visit http://www.basler.com to download the latest hardware, firmware, and BESTCOMSPlus®revision
histories.
Instruction Manual Revision History
Manual
Revision and Date
Change
H, Sep 2021
•Adjusted all front panel illustrations to show updated LED labeling
•Added clarification about the DECS-150 sensing and responding to
rms voltage
•Corrected explanation of the exciter diode monitor’s ripple
calculation
•Corrected the DECS-150’s breaker shunt trip output rating
•Added grid code and UKCA compliance statements
•Added caution statement about downgrading DECS-150 firmware
•Corrected unit of measure used by the stator current limiter
G, Jan 2021
•Added description of Tracking Comms Loss alarm
•
Added description of Auto Transfer Enable logic block
F, Apr 2020
•Added Figure 17-4, Typical Connections for motor applications
•Added note about time settings in Timekeeping section
•Added register 1230, Field Voltage Meter, in the Modbus
Communication section
•
Minor text edits throughout manual
E, Sep 2019
•Added support for firmware version 2.04.00 and BESTCOMSPlus
version 4.00.00
•Removed Rev Letter from all pages
•Changed sequential numbering to sectional numbering
•Moved Instruction Manual Revision History into Preface
•Removed standalone Revision History section
D, Apr 2019
•Added support for firmware version 2.03.00 and BESTCOMSPlus
version 3.21.00
•
Minor text edits throughout manual
C1, Oct 2018
•Added California Proposition 65 warning on back of cover page
C, Jan 2018
•Added information on external tracking, network load sharing, and
Modbus
•Added description of Underfrequency Limiter Reset Time setting
B, Mar 2017
•Added caution statement about nonvolatile memory
•Added power dissipation and maximum elevation specifications
•Added manual USB driver installation instructions
•Clarified current-sensing requirements for PSS operation
•Corrected description of online OEL operation

iv Digital Excitation Control System
Revision History DECS-150
Manual
Revision and Date
Change
A, Jul 2016
•Added information on the backup battery for the real-time clock
•Updated connections for Programmable Contact Inputs in the
Typical Connections section
•Added Ethernet Setup in the Communications section
•Updated Generator and Bus Voltage Sensing Ranges in the
Specifications section
•Added Ingress Protection Ratings in the Specifications section
•Updated Maritime Recognition specifications
•Minor text edits throughout manual
―, Sep 2015
•Initial release

Digital Excitation Control System v
DECS-150 Contents
Contents
Introduction................................................................................................................................................. 1-1
Front Panel................................................................................................................................................. 2-1
Power Input and Outputs ........................................................................................................................... 3-1
Voltage and Current Sensing ..................................................................................................................... 4-1
Regulation .................................................................................................................................................. 5-1
Auxiliary Control ......................................................................................................................................... 6-1
Contact Inputs and Outputs ....................................................................................................................... 7-1
Protection ................................................................................................................................................... 8-1
Limiters....................................................................................................................................................... 9-1
Grid Code ................................................................................................................................................. 10-1
Metering ................................................................................................................................................... 11-1
Reports..................................................................................................................................................... 12-1
Power System Stabilizer .......................................................................................................................... 13-1
Stability Tuning......................................................................................................................................... 14-1
Mounting................................................................................................................................................... 15-1
Terminals and Connectors ....................................................................................................................... 16-1
Typical Connections................................................................................................................................. 17-1
BESTCOMSPlus®Software ..................................................................................................................... 18-1
BESTlogic™Plus ....................................................................................................................................... 19-1
Communication ........................................................................................................................................ 20-1
Configuration ............................................................................................................................................ 21-1
Security .................................................................................................................................................... 22-1
Timekeeping............................................................................................................................................. 23-1
Testing...................................................................................................................................................... 24-1
Modbus Communication .......................................................................................................................... 25-1
Maintenance............................................................................................................................................. 26-1
Troubleshooting ....................................................................................................................................... 27-1
Specifications ........................................................................................................................................... 28-1
BESTCOMSPlus®Settings Loader Tool .................................................................................................. 29-1

vi Digital Excitation Control System
Contents DECS-150

9492600990 1-1
DECS-150 Introduction
1 • Introduction
DECS-150 Digital Excitation Control Systems offer precise excitation control and machine protection in a
compact package. DECS-150 adaptability to many applications is assured through configurable contact
inputs and outputs, flexible communication capabilities, and programmable logic implemented with the
provided BESTCOMSPlus®software.
Applications
The DECS-150 is intended for brushless ac synchronous generator or synchronous motor applications.
The DECS-150 controls the machine output through the application of regulated dc excitation power to
the exciter field. The level of excitation power is based on the monitored voltage and current, and a
regulation setpoint established by the user. The operating mode, generator or motor, is changed on the
Operating Mode settings screen. Power factor and var metering values will be opposite in motor mode.
Excitation power is supplied from the DECS-150 by means of a filtered, switching power module that uses
pulse-width modulation. It is capable of supplying 7 Adc (70°C ambient) continuously and 10 Adc (55°C
ambient) continuously at nominal voltages of 63 or 125 Vdc. With nominal operating voltage applied, it
has a forcing capability of 11 Adc for 10 seconds (70°C ambient) or 14 Adc for 10 seconds (55°C
ambient).
Features and Functions
DECS-150 features and functions include:
•Precise excitation control for synchronous generator or synchronous motor applications
oPower factor and var metering values will be opposite in motor mode
•Four excitation control modes:
oAutomatic Voltage Regulation (AVR)
oField Current Regulation (FCR)
oPower Factor Regulation (PF)
oVar Regulation (var)
•Three pre-position setpoints for each excitation control mode
•Internal tracking between operating mode setpoints and optional 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
•Grid code functions
oConnect and disconnect
oActive power control
oReactive power control
•Optional network load sharing
•Real-time metering
•Optional integrated power system stabilizer (PSS)
oGenerator or motor control modes, accommodates phase rotation changes between modes
oSpeed and power sensing or speed-only sensing
•Soft start and voltage buildup control
•Four limiting functions:
oOverexcitation: summing point and takeover
oUnderexcitation
oStator current
oUnderfrequency
•Seventeen protection functions:
oMachine undervoltage (27)
oMachine overvoltage (59)
oLoss of sensing (LOS)

1-2 9492600990
Introduction DECS-150
oOverfrequency (81O)
oUnderfrequency (81U)
oField overvoltage
oExciter diode failure
oSync-check (25)
oEight configurable protection elements
•Eight programmable contact-sensing inputs
•Three contact outputs
oOne, fixed-function output: Watchdog (SPDT configuration)
oTwo programmable outputs
•Flexible communication
oSerial communication through optional front- or rear-panel USB port
oOptional CAN communication for external setpoint tracking
oOptional Modbus®communication through Modbus TCP
oEthernet communication through an RJ-45 port
•Data logging and sequence of events
•USB powered for programming via BESTCOMSPlus software
Package
A single, compact package contains all excitation control and power components.
The front panel provides local annunciation through light-emitting diodes (LEDs). Remote annunciation
and control is provided through a flexible communication interface, which accommodates Ethernet and
USB.
Optional Features and Capabilities
DECS-150 optional features and capabilities are defined by a style number. The model number and style
number describe options and characteristics in a specific device and appear on a label affixed to the
device.
Style Number
The style number identification chart in Figure 1-1 defines the electrical characteristics and operational
features available in the DECS-150.
Figure 1-1. DECS-150 Style Chart