Basler Electric DECS-200-1L Digital Excitation Control System

Description

The Basler Electric DECS-200-1L Digital Excitation Control System provides precision excitation control for synchronous generators by regulating the direct current applied to the generator exciter field. Equipped with a pulse width modulated (PWM) power stage, the system delivers high performance across non-linear load applications and supports output capabilities of 32 Vdc, 63 Vdc, or 125 Vdc at up to 15 Adc. Operating modes include Automatic Voltage Regulation (AVR) with 0.25% accuracy, Field Current Regulation (FCR/Manual mode), Var control, and Power Factor (PF) control.

The controller features true RMS single- or three-phase sensing for generator voltage, bus voltage matching, and generator current. Interface options consist of contact inputs, proportional ±10 Vdc or 4–20 mA inputs, a front-panel RS-232 port (COM0), a side RS-232 port for unit autotracking (COM1), and a side RS-485 port supporting Modbus RTU protocol (COM2). Integrated machine protection capabilities include generator overvoltage/undervoltage, field overvoltage/overcurrent, loss of sensing, loss of field, exciter diode monitoring (EDM), and overexcitation/underexcitation limiting.

Features

• Microprocessor-based digital excitation control with pulse width modulated power stage
• Single or three-phase true RMS sensing for generator and bus voltage
• 0.25% voltage regulation accuracy over the load range
• Four operating modes: Automatic Voltage Regulation (AVR), Field Current Regulation (FCR), Var control, and Power Factor (PF) control
• Internal autotracking between modes for bumpless transfers
• 20 standard preprogrammed stability selections and user customizable PID settings
• Underfrequency compensation or V/Hz ratio limiter with adjustable corner frequency
• Soft start voltage buildup with adjustable time rates
• Reactive droop and reactive differential (cross-current) paralleling compensation
• Integrated Exciter Diode Monitoring (EDM) for detecting open and shorted diodes
• Sequence of Events Recording (SER) storing up to 127 event reports
• Integrated COMTRADE-compliant oscillography logging up to 8 records
• Front panel HMI with backlit LCD display, programming keys, and diagnostic LEDs
• Multiple communication ports: RS-232 front (COM0), RS-232 side (COM1), and RS-485 side (COM2) with Modbus protocol

Applications

• Excitation voltage and current regulation for synchronous generators
• Utility paralleling power generation systems requiring Var or Power Factor control
• Brushless generator exciter field control with diode health monitoring
• Generator protection and overexcitation/underexcitation limiting

Ordering Information

Technical Specifications

Connections/Interfaces

Installation Guidelines

• Grounding: Connect terminal C1 (GND) securely to the system chassis ground to ensure proper grounding and noise immunity.
• Control Power Isolation: If dual control power sources are utilized, install an AC Control Power Isolation Transformer (Basler P/N BE31449-001) on the AC power input.
• Inrush Current Mitigation: When powering from a source already at rated voltage levels, install an Inrush Current Reduction Module (ICRM-15) to limit startup inrush current.
• Dual Unit Configurations: For redundant DECS-200 arrangements, connect units using interconnection cable P/N 9310300032 and install a DECS Freewheeling Diode Module P/N 9293600101.
• Communication Wiring: Maintain RS-485 network cables within a maximum distance of 4,000 feet using recommended shielded twisted-pair cabling.
• Voltage Sensing: Ensure potential transformers are installed if the line voltage exceeding 600 Vac is connected to the sensing terminals.

Compliance and Certifications

• UL Recognized per Standard 508 (File E97035)
• CSA Certified per Standard CAN/CSA-C22.2 No. 14 (File LR23131)
• CE Compliant (EMC and LVD directives)
• DNV Certified per Standard 2.4
• GOST-R Certified
• Byelorussian Certified
• IEEE C37.90.1-1989 (Surge Withstand Capability and Fast Transient)
• IEEE 421.3 (High Pot testing)
• ISO 9001:2000 Registered