ABB RET670 Relion Transformer Protection Relay

Description

The ABB RET670 is an Intelligent Electronic Device (IED) belonging to the Relion protection and control product family. The device provides selective protection, control, and monitoring solutions for two- and three-winding power transformers, autotransformers, generator-transformer units, phase shifting transformers, special railway transformers, and shunt reactors. It features differential protection with automatic CT ratio matching and vector group compensation, allowing operation across a wide frequency range during power system disturbances, generator start-up, and shut-down.

The ABB RET670 accommodates multi-breaker station arrangements with up to six restraint CT inputs without requiring interposing CTs. It integrates main and backup protection functions, including restricted earth fault, distance protection, directional overcurrent, thermal overload, voltage protection, and local/remote apparatus control with station-wide interlocking. Native support for the IEC 61850 protocol ensures interoperable station communication.

Features

• Transformer Differential Protection: Includes percentage bias restraint, 2nd harmonic and waveform restraint for inrush, 5th harmonic restraint for overexcitation, and symmetrical-component-based sensitivity for winding interturn faults.
• Restricted Earth Fault Protection: Offers low-impedance percentage biased REF with directional zero-sequence criteria or high-impedance differential protection for earthed windings.
• Integrated Distance Protection: Full-scheme phase-to-phase and phase-to-earth distance protection with up to five zones, supporting quadrilateral or mho characteristics with load encroachment features.
• Comprehensive Backup Protection: Multi-step directional phase and residual overcurrent, thermal overload (two time constants), over/undervoltage, volts-per-hertz (overexcitation), and rate-of-change frequency functions.
• Control and Interlocking: Apparatus control for up to 6 bays (maximum 30 devices) with synchrocheck, energizing check, and configurable logic blocks.
• Disturbance & Event Recording: Integrated report function capturing up to 40 analog and 96 binary signals with standard COMTRADE format output.
• Communication Flexibility: Modular architecture supporting IEC 61850-8-1, IEC 60870-5-103, DNP3.0 (EIA-485 or Ethernet), LON, and SPA protocols.

Applications

• Two-winding and three-winding power transformers
• Autotransformers and generator-transformer blocks
• Shunt reactors and tertiary connected reactors
• Phase shifting transformers and railway transformers
• Substation multi-breaker, ring-bus, and mesh-corner feeder arrangements

Technical Specifications

Connections/Interfaces

Installation Guidelines

• Mounting Alternatives: Mountable in standard 19-inch rack frames, wall-mounted, or flush-mounted into control panels using cut-outs corresponding to 1/2, 3/4, or 1/1 casing widths.
• Grounding: Ensure the protective earth conductor is connected to the ground lug on the rear panel before powering the unit.
• CT/VT Secondary Wiring: Connect current transformer secondary outputs using ring lug or compression terminals on the TRM module. CT circuits must never be open-circuited under load.
• Optocoupler Inputs: Ensure external DC auxiliary control voltages match the ordered rating of the binary input modules (24/40 V, 48/60 V, 110/125 V, or 220/250 V DC).
• Fiber Optic Connections: Avoid bending optical cables past their specified minimum bend radius when routing to the OEM, SLM, or LDCM modules. Keep optical connectors clean to maintain signal integrity.

Compliance and Certifications

• Electromagnetic Compatibility: IEC 60255-22-1, IEC 60255-22-2 Class IV, IEC 60255-22-3, IEC 60255-22-4 Class A, IEC 60255-22-5, IEC 61000-4-2 Class IV, ANSI/IEEE C37.90.1, ANSI/IEEE C37.90.2
• Insulation & Voltage: IEC 60255-5 (Dielectric test 2.0 kV AC, Impulse voltage test 15 kV)
• Environmental: IEC 60068-2-1, IEC 60068-2-2, IEC 60068-2-30, IEC 60068-2-78
• Mechanical: IEC 60255-21-1 (Vibration), IEC 60255-21-2 (Shock & Bump), IEC 60255-21-3 (Seismic)
• CE Directives: EN 50263 (EMC Immunity and Emission), EN 50178 (Low Voltage Directive)