ALSTOM MCGG62N1CB0753F Generator Protection Relay

Overview

The MCGG62N1CB0753F continuously monitors generator stator currents, voltages, and frequency. Its primary protection is the high-impedance or biased differential protection that detects internal phase-to-phase and phase-to-earth faults. Additional functions include overcurrent, overvoltage, undervoltage, overfrequency, underfrequency, reverse power, and loss of excitation. The relay is equipped with multiple setting groups, allowing adaptation to different operating conditions.

Key Features

• Differential Protection (87G): High stability for external faults, high sensitivity for internal faults.

• Backup Overcurrent (50/51/50N/51N): Phase and earth fault protection with definite or inverse time characteristics.

• Voltage Protection (27/59): Undervoltage and overvoltage with definite or inverse time.

• Frequency Protection (81O/U): Overfrequency and underfrequency.

• Reverse Power (32R): Prevents motoring of generator.

• Loss of Excitation (40): Detects field failure.

• Measurement: True RMS currents, voltages, power, energy, power factor.

• Fault Recording: Oscillography for post-fault analysis.

• Communication: Multiple protocols (Modbus, Profibus, IEC 61850).

Technical Specifications

• Nominal Current: 1 A or 5 A (CT inputs).

• Nominal Voltage: 100-240 VAC / 110-250 VDC auxiliary.

• Differential Inputs: 3-phase + neutral current inputs.

• Voltage Inputs: 3-phase + residual voltage.

• Accuracy: ±2% for protection elements, ±0.5% for metering.

• Output Contacts: 8 form-C (expandable).

• Digital Inputs: 8 (expandable).

• Operating Temperature: -25°C to +70°C.

• Enclosure: 19" rack mount or panel mount.

• Certifications: IEC 60255, IEEE C37.90, CE.

Applications

The MCGG62N1CB0753F is used for protecting generators of all sizes, from small industrial generators to large utility turbines. Typical applications include:

• Steam turbine generators.

• Gas turbine generators.

• Hydroelectric generators.

• Diesel generator sets.

• Cogeneration plants.

Configuration and Integration

The relay is configured using ALSTOM's graphical setting software. It supports multiple setting groups that can be changed via digital inputs or communication. The comprehensive event and fault records assist in analyzing system disturbances. With advanced communication capabilities, the relay can be integrated into plant DCS, SCADA, or substation automation systems, providing real-time data and remote control.

In summary, the ALSTOM MCGG62N1CB0753F generator protection relay offers a complete protection solution for synchronous generators, ensuring reliable operation and minimizing damage in case of faults.