ABB REM545 Machine Terminal REM545BG225AAA A

The ABB REM545 machine terminal is a numerical protection relay specifically designed for the protection, control, and monitoring of generator-transformer units in power plants and industrial facilities. As a member of ABB’s renowned REM 500 series, the REM545 integrates multifunctional protection with advanced communication capabilities, ensuring reliable and selective fault clearance while maximizing equipment availability.

Key Protection Functions

The REM545 terminal provides comprehensive protection for generators and step-up transformers. Core protection functions include high-impedance or biased differential protection (87G/87T), stator earth fault protection (95% and 100%), overexcitation (V/Hz), overcurrent (50/51), negative sequence overcurrent (46), and directional power (32). The device also offers overvoltage (59), undervoltage (27), frequency elements (81O/U), and thermal overload protection. All protection stages are independently adjustable and can be enabled or disabled to suit specific application requirements.

Control and Monitoring

Beyond protection, the REM545BG225AAA A acts as a local control unit with a clear human-machine interface. It features a programmable logic matrix for user-defined interlocking and automation sequences. The integrated disturbance recorder captures fault waveforms with high resolution, enabling post‑fault analysis. Measured values (currents, voltages, power, frequency) are displayed locally and transmitted via communication links. The unit also includes circuit breaker monitoring and control functions, such as trip circuit supervision and auto‑reclosing for transformer applications when applicable.

Communication and Integration

Designed for modern substation automation, the REM545 supports multiple communication protocols. Standard versions include two rear communication ports for protocols like IEC 61850, IEC 60870‑5‑103, Modbus RTU, and DNP3.0. This ensures seamless integration with ABB’s MicroSCADA or any third‑party SCADA system. The terminal also supports time synchronization via IRIG‑B or SNTP, enabling precise event time‑stamping.

Technical Highlights

• Measuring inputs: 4 current inputs (1 A or 5 A) and 4 voltage inputs (100–230 V AC).

• Binary I/O: Up to 12 binary inputs and 8 output relays, expandable via external I/O units.

• Power supply: Wide-range auxiliary supply (80–265 V DC or 100–240 V AC).

• Enclosure: 19-inch rack mount or flush mount case, IP54 front panel.

• Self‑supervision: Continuous internal hardware and software monitoring with watchdog output.

Application Example

Typical applications include generator protection in combined cycle power plants, industrial co‑generation, and hydroelectric stations. The REM545BG225AAA A variant is equipped with a specific I/O configuration (including additional binary inputs and outputs) suitable for complex interlocking schemes. Its robust design and compliance with international standards (IEC 60255, IEEE) guarantee dependable operation in harsh electrical environments.

With its powerful protection algorithms and flexible communication, the ABB REM545 machine terminal helps utilities and industries improve power generation reliability and reduce downtime. The device is also future‑proof, as firmware upgrades can be easily performed via the front communication port.