Month: June 2025

Application

RET 670 provides fast and selective protection, monitoring and control for two- and three-winding

transformers, autotransformers, generator-transformer units, phase shifting transformers,

special railway transformers and shunt reactors.

The transformer IED is designed to operate correctly over a wide frequency range in order to accommodate power

system frequency variations during disturbances and generator start-up and shut-down.

A very fast differential protection function, with automatic CT ratio matching and vector group compensation,

makes this IED the ideal solution even for the most demanding applications.

RET 670 has very low requirements on the main CTs, no interposing CTs are required.

It is suitable for differential applications with multi-breaker arrangements with up to six restraint CT inputs.

The differential protection function is provided with 2nd harmonic and wave-block restraint features to avoid tripping for magnetizing inrush,

and 5th harmonic restraint to avoid tripping for overexcitation.

• Basic IED functions

– Self supervision with internal event list

– Time synchronization (TIME)

– Parameter setting groups

– Test mode functionality (TEST)

– Change lock function

– IED identifiers

– Rated system frequency

• Hardware

– Power supply module (PSM)

– Binary input module (BIM)

– Binary output module (BOM)

– Binary in/out module (IOM)

– mA input module (MIM)

– Transformer input module, standard compression connection terminals (TRM)

– Optical ethernet module (OEM)

– SPA/LON/IEC module (SLM)

– Line data communication module (LDCM)

– GPS time synchronization module (GSM)

• Accessories

– GPS antenna, including mounting kit

– External interface converter from C37.94 to G703

– High impedance resistor unit

– Test switch module RTXP24

– On/off switch

• Logic

– Tripping logic (PTRC, 94)

– Trip matrix logic

– Configurable logic blocks

– Fixed signal function block

• Monitoring

– Measurements (MMXU)

– Supervision of mA input signals (MVGGIO)

– Event counter (GGIO)

– Event function

– Disturbance report (RBDR)

• Metering

– Pulse counter logic (GGIO)

• Station communication

– IEC61850-8-1 communication

– LON communication protocol

– SPA communication protocol

– IEC 60870-5-103 communication protocol

– Horizontal communication via GOOSE for interlocking

– Single command, 16 signals

– Multiple Command, 80 blocks with 16 signals each

– Ethernet configuration of links

• Remote communication

– Binary signal transfer

• Voltage protection

– Two step undervoltage protection (PUVM, 27)

– Two step overvoltage protection (POVM, 59)

– Two step residual overvoltage protection(POVM , 59N)

– Overexcitation protection (PVPH, 24)

• Frequency protection

– Underfrequency protection (PTUF, 81)

– Overfrequency protection (PTOF, 81)

– Rate-of-change frequency protection (PFRC, 81)

• Multipurpose protection

– General current and voltage protection (GAPC)

• Secondary system supervision

– Current circuit supervision (RDIF)

– Fuse failure supervision (RFUF)

• Control

– Synchrocheck and energizing check (RSYN, 25)

– Apparatus control for single bay, max 8 app.(1CB) incl. Interlocking (APC8)

– Apparatus control for single bay, max 15 app.(2CBs) incl. Interlocking (APC15)

– Apparatus control for up to 6 bays, max 30 app. (6CBs) incl. Interlocking (APC30)

Functions

• Differential protection

– Transformer differential protection, two winding (PDIF, 87T)

– Transformer differential protection, three winding (PDIF, 87T)

– Restricted earth fault protection (PDIF, 87N)

– High impedance differential protection (PDIF, 87X)

• Distance protection

– Distance protection zones (PDIS, 21)

– Phase selection with load encroachment (PDIS, 21)

– Power swing detection (RPSB, 78)

– Automatic switch onto fault logic (PSOF)

• Current protection

– Instantaneous phase overcurrent protection (PIOC, 50)

– Four step phase overcurrent protection (POCM, 51/67)

– Instantaneous residual overcurrent protection (PIOC, 50N)

– Four step residual overcurrent protection (PEFM, 51N/67N)

– Thermal overload protection, two time constants (PTTR, 49)

– Breaker failure protection (RBRF, 50BF)

– Pole discordance protection (RPLD, 52PD)

• Directional overcurrent protection with four steps for each winding

– Each step can be inverse or definite time delayed

– Each step can be directional or non-directional

• Instantaneous high speed earth fault function with low transient overreach

• Directional earth fault protection with four stages for each winding

– Each step can be inverse or definite time delayed

– Each step can be directional or non-directional

– Each step can be blocked on second harmonic component

• Synchrocheck function for single- or multi-breaker arrangements:

– Selectable energizing direction

– Two functions with built-in voltage selection

• Selectable additional software functions such as

breaker failure protection for each breaker, voltage protection, overexcitation protection, control and monitoring

• Tripping from Buchholtz, temperature devices etc. through binary inputs stabilized against capacitive discharges

• Built-in data communication modules for station bus IEC 61850-8-1

• Data communication modules for station bus IEC 60870-5-103. LON and SPA

• Integrated disturbance and event recorder for up to 40 analog and 96 binary signals

• Time synchronization over IEC 61850-8-1. LON, SPA, binary input or with optional GPS module

• Analog measurements accuracy up to below 0.5% for power and 0.25% for current and voltage and with site calibration to optimize total accuracy

• Versatile local human-machine interface

• Extensive self-supervision with internal event recorder

• Six independent groups of complete setting parameters with password protection

• Powerful software PC tool for setting, disturbance evaluation and configuration

• Remote end data communication modules for C37.94 and G.703

Features

• A protection, control, and monitoring IED with extensive functional library and configuration

possibilities and expandable hardware design to meet specific user requirements

• For power transformers, autotransformers, shunt reactors, T-protection, generator transformer

blocks, phase shifting transformers and small busbar systems

• For two- and three-winding transformers with up to six stabilized inputs

• For multi- or single-breaker arrangements

• Transformer differential protection with:

– Percentage bias restraint for through faults

– Waveform and Second harmonic restraint for transformer inrush

– Fifth harmonic restraint for overexcitation

– High sensitivity for interturn faults

• Restricted earth fault protection for all direct or low impedance earthed windings

– Extremely fast operation

– High sensitivity

– High and low impedance based

• Full scheme phase-to-phase and phase-to-earth distance protection with up to five zones:

– Load encroachment feature

• Instantaneous high speed short circuit function with low transient overreach

The REF620 is a member of the 620 Protection, Measurement and Control product family within the ABB Relion® product family.

Key benefits

• Protection, control, monitoring and management integrated in a single relay provides a compact and versatile solution for public and industrial power distribution systems
• Wide range of protection and control functions, either with sensors or conventional CTs and PTs
• Functional scalability and wide range of applications allow users to easily customise configuration applications to meet specific requirements
• Pluggable design for quick installation and testing
• Large LCD screen with single-line graphic display, accessible locally or via an easy-to-connect and navigate HMI
• Thoughtful product lifecycle service

Key Features

• Wide range of protection and control functions for incoming or outgoing applications
• Multi-frequency conductive earth protection package with high sensitivity and selectivity
• Advanced and fast short-circuit and earth-fault location functions
• Several optional function packages – for distributed generation, capacitors, basic motor and arc-light protection
• Supports IEC61850 Version 1 and 2, including redundant HSR and PRP, GOOSE and IEC61850-9-2
• Supports Modbus, DNP3, IEC 60870-5-103 communication protocols and different time synchronisation methods, including IEEE 1588 v2 precision time protocols

REF620 as a specialised feeder protection device for the protection, control, measurement and monitoring of public and industrial power distribution systems

REF620 IEC feeder protection and measurement and control device, as a dedicated feeder protection device, is specially designed for the protection, control, measurement and monitoring of public and industrial grids, including radial, ring and mesh grids.

The REF620 provides feeder overcurrent and earth fault protection that can be applied to both ungrounded neutral networks and resistance or impedance neutral grounded networks.

In addition, the REF620 can also be used for ring mesh distribution or radial network protection, utilising the unit’s advanced inter-station communication capabilities.

The REF620 IEC Feeder Protection and Measurement Control Unit is available in single and dual busbar configurations, with one or two circuit breakers and multiple switchgear configurations for each busbar configuration.

The unit supports a large number of manual and motorised disconnect and earth switches. The number of available I/Os can be increased as required by ABB’s RIO600 remote I/O unit.

The REF620 IEC Feeder Protection and Control Unit features support for the IEC61850 communication standard for substations, covering both vertical and horizontal communications.

It includes GOOSE telegrams with switching and analogue signals and constant value adjustment based on IEC 61850-8-1.

The REF620 also supports DNP3, IEC 60870-5-103 and Modbus® protocols.

The REF620 provides an optional Ethernet port for non-delayed redundant Ethernet or a ring self-healing RSTP communication in the event of a communication failure via PRP or HSR protocols.

This solution eliminates the effects of a single point of failure and improves communication reliability. The solution can be applied to Ethernet based IEC 61850, Modbus® and DNP3 protocols.

Relay protection for overhead lines and cable feeders in distribution networks for different application areas

Feeder protection, precisely the protection of overhead lines and cables, is the most commonly used type of protection.

The protection must ensure that the grid continues to supply power. In the event of a fault, it must be prevented from propagating to the normal part of the network.

Relay protection must also minimise damage to cables and other connected equipment from faults and ensure the safety of everyone involved.

ABB offers a wide range of feeder protection. There is a wide range of multifunctional relays for different application areas.

There are some for general feeder protection (overcurrent protection) and backup protection, and some more specialised ones, e.g. for line differential protection.

Main advantages

• Devices can be used for a wide range of applications
• Ranging from simple protection devices as back-up protection to specialised protection devices
• Well-established and modern technology
• Arc detection as an option