RET620 is a dedicated transformer management relay for protection, control, measurement and supervision of both two-winding power and step-up transformers, including power generator-transformer blocks, in utility and industrial power distribution systems.
The transformer management relay has been designed to be the main transformer differential protection, with one multi-slope stabilized (biased) and one instantaneous stage, providing a fast and selective protection for phase-to-phase short circuits, winding interturn-faults and bushing flash-overs. There is also a choice between either low or high-impedance restricted earth-fault (REF) protection.
RET620 is also ideal for voltage regulation. The voltage regulator has been designed for power transformers with a motor-driven on-load tap-changer and offers both manual and automatic tap-changer control.
RET620 fully supports the IEC 61850 standard for communication and interoperability of substation automation devices, including fast GOOSE messaging and now also IEC 61850-9-2 LE process bus and Edition 2, offering substantial benefits in terms of extended interoperability. RET620 further supports both the parallel redundancy protocol (PRP) and the high-availability seamless redundancy (HSR) protocol, together with the DNP3, IEC 60870-5-103 and Modbus® protocols. With the protocol adapter SPA-ZC 302, Profibus DVP1 can also be used.
RET620 is a member of ABB’s Relion product family and part of its 620 protection and control series of relays.
- Withdrawable plug-in unit design for swift installation and testing
- Extensive range of protection and control functionality for two-winding power transformers, including advanced and fast differential protection with high inrush stability
- Support for various neutral earthing options, matching either high-impedance or numerical low-impedance restricted earth-fault principles
- Automatic voltage regulation of power transformers with a motor-driven on-load tap-changer
- IEC 61850 Edition 2 and Edition 1 support, including HSR and PRP, GOOSE messaging and IEC 61850-9-2 LE for less wiring and supervised communication
- IEEE 1588 V2 for high-accuracy time synchronization and maximum benefit of substation-level Ethernet communication
- Large graphical display for showing customizable SLDs, accessible either locally or through a web browser-based HMI