Basler Electric DECS-200-2L Digital Excitation Control System

Description

The Basler Electric DECS-200-2L is a total digital excitation control system packaged in a single enclosure, designed to control the output voltage, vars, or power factor of synchronous generators by varying DC excitation applied to the exciter field. Operating with 15 Adc continuous rated output across 32 Vdc, 63 Vdc, or 125 Vdc excitation applications, this unit incorporates a pulse-width-modulated (PWM) power stage to deliver regulation stability under non-linear load conditions. The DECS-200-2L style configuration specifies external and internal autotracking functionality paired with a 24/48 Vdc control power supply.

Equipped with a microprocessor-based architecture, the device provides true RMS single- or three-phase sensing for generator voltage, bus voltage, and generator currents. Integrated features include multiple operating modes (Automatic Voltage Regulation, Field Current Regulation, var, and Power Factor modes), soft start voltage buildup, limiters, generator protection functions, sequence of events recording, and oscillography. Local operator interface is provided via a front-panel backlit LCD display, six navigation pushbuttons, status LEDs, and an RS-232 serial port, with an additional RS-485 port supporting Modbus RTU network communication up to 4,000 feet.

Features

• Microprocessor-based digital regulation with 0.25% voltage regulation accuracy
• True RMS single-phase or three-phase sensing for generator voltage and bus voltage
• Multiple operating modes: Automatic Voltage Regulation (AVR), Field Current Regulation (FCR/Manual Mode), var control, and Power Factor (PF) control
• External and internal autotracking for bumpless mode transfers and dual-unit tracking
• Pulse-width-modulated (PWM) power stage delivering up to 15 Adc continuous output
• Configurable Underfrequency compensation or Volts/Hz Ratio Limiter
• Programmable Soft Start voltage buildup with adjustable rate from 1 to 7200 seconds
• Integrated limiter controls including Minimum Excitation Limiter (UEL), On-line/Off-line Maximum Excitation Limiters (OEL), and Stator Current Limiter (SCL)
• Exciter Diode Monitoring (EDM) for open and shorted diode detection on brushless generators
• Eight integrated generator protective functions with adjustable trip thresholds and time delays
• Sequence of Events Recording (SER) storing up to 127 event reports with date and time stamps
• Oscillography data recording capturing up to 8 records and 6 selectable variables
• Front panel LCD with 64x128 pixel graphic display, navigation pushbuttons, and status LEDs
• Dual RS-232 ports and one RS-485 port with Modbus protocol support

Applications

• Synchronous generator excitation voltage regulation
• Utility grid-connected generator var and power factor control
• Dual-redundant backup generator excitation systems
• Industrial power generation facility generator control

Ordering Information

Technical Specifications

Connections/Interfaces

Installation Guidelines

• Control Power Source Isolation: When using dual AC control power sources, install a Control Power Isolation Transformer (Basler P/N BE31449-001) on the AC control power input.
• Inrush Mitigation: When energizing the system from a source already at rated power input voltage level, connect an Inrush Current Reduction Module (ICRM-15) to limit inrush current.
• Redundant System Freewheeling Diode: Install a DECS Freewheeling Diode Module (Basler P/N 9293600101) when implementing dual DECS-200 redundant configurations.
• Panel Mounting: Mount the enclosure using the six 0.281 in (7.1 mm) diameter clearance holes or use the optional Front Panel Mounting Bracket (Basler P/N 9360107100).
• Transformer Requirements: Ensure potential transformers are installed on voltage sensing inputs if the line voltage exceeds 600 Vac.
• Shielding and Grounding: Attach chassis ground to terminal C1 and utilize shielded twisted-pair conductors for low-level analog accessory inputs (+/-10 Vdc or 4-20 mA) and communication channels.

Compliance and Certifications

• UL Recognized per Std. 508 (UL File Number E97035)
• CSA Certified per Std. CAN/CSA-C22.2, Number 14 (CSA File Number LR23131)
• CE Compliant (EMC and LVD directives)
• Certified per DNV Standard 2.4
• GOST-R Certified (Gosstandart of Russia)
• Byelorussian Certified
• IEEE C37.90.1-1989 Surge Withstand Capability (SWC) and Fast Transient
• IEEE 421.3 High Pot