Product Core Brief
- Model: RET670
- Brand: ABB
- Series: Relion® 670
- Core Function: Transformer differential protection, monitoring, and control
- Type: Numerical transformer protection relay / Intelligent Electronic Device (IED)
- Key Features: IEC 61850 communication; harmonic restraint; vector group compensation; disturbance recording
- Typical Applications: Power transformers, autotransformers, generator-transformer blocks, shunt reactors
- Condition: New Original (New Surplus) / Tested Used Available
Product Introduction
ABB RET670 belongs to the Relion® 670 protection platform and is widely used in utility substations, industrial HV distribution systems, refinery power systems, and power generation facilities where transformer protection reliability directly affects grid stability. The relay integrates protection, monitoring, measurement, disturbance recording, and control functions into a single IED platform.
One reason RET670 remains common in retrofit projects is its low CT burden requirement and built-in vector group compensation. In practice, this reduces the need for interposing CTs and simplifies transformer replacement projects. The relay supports both single-breaker and multi-breaker arrangements and can handle up to six stabilized CT inputs for advanced transformer differential schemes.
The differential protection algorithm includes second harmonic restraint for transformer inrush current and fifth harmonic restraint for overexcitation conditions, helping prevent nuisance trips during energization events. Advanced disturbance recording and IEC 61850 communication support simplify integration into modern digital substations.
Key Selling Points & Differentiators
- RET670 supports transformer differential protection, restricted earth fault protection, breaker failure logic, overexcitation protection, thermal overload monitoring, and backup overcurrent functions in one platform.
- Automatic CT ratio matching and vector group compensation simplify commissioning and retrofit projects.
- 2nd harmonic restraint and wave-block logic reduce false differential trips during transformer energization.
- 5th harmonic restraint improves stability during transformer overfluxing and overexcitation events.
- IEC 61850, MMS, GOOSE, Modbus, and DNP3 communication support enable integration into modern SCADA and digital substation systems.
- Built-in disturbance and event recorder supports post-fault analysis with COMTRADE recording capability.
- Supports generator-transformer blocks, autotransformers, phase-shifting transformers, and shunt reactor protection applications.
