ALSTOM MICROTECH DX21-M2 Digital Excitation Controller
ALSTOM MICROTECH DX21-M2
Automatic Voltage Regulator (AVR) / Digital Excitation Controller
Microprocessor based digital excitation controller intended for excitation systems used with
synchronous generators and motors. The DX21-M2 provides closed-loop voltage regulation,
reactive power management, excitation limiting and integrated operator diagnostics
Product Identification
Manufacturer
Series
Model
Equipment Type
Application
Mounting
Alstom
Microtech
DX21-M2
Digital Excitation Controller / AVR
Generator and synchronous machine excitation
Panel / cabinet installation
Electrical Specifications
Parameter
Value
Voltage sensing input (VT)
Operating frequency
Voltage transformer burden
Compounding CT input
CT burden
100–120 VAC
50 / 60 Hz
1 VA per phase
1 A secondary
1 VA
Measurement accuracy
Excitation current capability
Transient forcing current
Excitation source
BS7625 Class 1
Up to 15 A continuous
Up to 35 A
PMG or external AC excitation sourc
. Control Functions
• Automatic Voltage Regulation (AVR)
• Manual excitation mode support
• Power Factor (PF) control
• Reactive Power (VAr) control
• Voltage raise / lower trim
• Soft build-up and controlled start
• Quadrature droop compensation
• Generator load sharing support
4. Protection & Limiting
• Over Excitation Limiter (OEL)
• Under Excitation Limiter (UEL)
• Volts/Hz (Over fluxing) Protection
• Stator Current Limiting
• Excitation Fault Monitoring
• Trip-to-Manual Transfer Logic
• System alarm and status monitoring
5. Front Panel Interface
Component
Function
LCD Display
Select Pushbutton
Previous Screen
Rotary Selector
Operational values, alarms, parameter menus
Menu selection
Return navigation
Parameter adjustment
LED Indicators
RS232 Port
Key Switch
Power, Trip to Manual, OEL, VAr Limit, SCL, Volts/Hz, PF/VAr
Configuration and diagnostics
Lock / enable settings access