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