ABB RET670 Transformer Protection and Control IED

Hardware Specifications

ABB Relion 670 Series Protection Processing and Communication Features

The ABB RET670 processes transformer current and voltage measurements through dedicated protection algorithms. It performs differential protection calculations for multi-winding transformers and applies harmonic restraint logic to reduce incorrect operation during magnetizing inrush conditions.

Furthermore, the IED supports restricted earth fault (REF) protection through sensitive neutral fault measurement. The relay also executes phase and earth overcurrent protection, voltage protection, frequency protection, and overexcitation protection functions.

The RET670 integrates IEC 61850 communication functions for substation automation systems. Therefore, it supports station bus data exchange, event reporting, disturbance recording transfer, and remote engineering access through configured communication interfaces.

For ABB Relion platforms, the hardware architecture supports deterministic internal communication between protection functions, input/output processing units, and communication interfaces. In addition, firmware compatibility depends on the installed hardware revision and approved engineering configuration.

Transformer Differential Protection and Control Functions

The RET670 provides transformer protection functions including:

• Multi-winding transformer differential protection.
• Restricted earth fault protection for transformer neutral points.
• Thermal overload calculation based on transformer loading conditions.
• Directional and non-directional phase overcurrent protection.
• Earth fault overcurrent protection.
• Overvoltage and undervoltage protection.
• Overfrequency and underfrequency protection.
• Overexcitation protection based on V/Hz measurement.
• On-load tap changer control and voltage regulation functions.
• Disturbance recording with waveform capture and event logging.

Frequently Asked Questions

Q: Does the ABB RET670 support IEC 61850 communication?

A: Yes. The RET670 supports IEC 61850 communication for substation automation applications, including event reporting and station bus communication.

Q: What current transformer inputs does the RET670 accept?

A: The relay supports selectable 1 A or 5 A AC secondary current inputs through configured CT input channels.

Q: Can the RET670 perform transformer differential protection for multi-winding transformers?

A: Yes. The RET670 executes differential protection calculations for multi-winding transformer configurations with harmonic restraint functions.

Field Installation Guidelines

• Install the ABB RET670 in a suitable protection panel with correct mechanical support for the selected rack configuration.
• Connect CT and VT secondary wiring according to the approved protection scheme and engineering drawings.
• Maintain separation between measurement circuits, communication cables, and high-voltage switching conductors to reduce electrical interference.
• Connect communication interfaces using approved shielded cables and apply grounding practices according to IEC 61850 installation requirements.
• Verify auxiliary power polarity and voltage range before energizing the IED.
• Confirm firmware compatibility, parameter settings, protection logic, and communication configuration before placing the relay into service.
• Perform secondary injection testing to verify differential, overcurrent, voltage, and control functions after installation.