The world’s first truly IEC 61850-based protection relay

In the beginning of the 21st century, ABB started to develop a brand new and innovative product range in line with emerging market requirements. These requirements served as the natural starting point for what was to become the 615 protection and control series of relays. Fast Ethernet technology to enable a web-based user interface and communication-based protection and control solutions, together with introducing the world’s first, truly IEC 61850-based protection relay were among the key factors driving the development. 

One of many reasons for the widespread popularity of the 615 series is its wide application coverage, ranging from feeder and line differential protection, through transformer, motor, generator, capacitor bank, interconnection and voltage protection, to automatic voltage regulation. Another reason is the extensive range of state-of-the-art protection and control functionality, either with sensors or conventional instrument transformers. With integration of protection, control, monitoring and supervision in one relay, the 615 series represents a compact and versatile solution for utility, industrial, and transport and infrastructure applications.

Since 2015, the 615 series offers ABB’s unique and truly innovative solution for reliable and sensitive all-in-one earth-fault protection – the multifrequency admittance protection (MFA). Created in response to the requirements of today’s growing cable networks, this method ensures reliable protection also in compensated networks, irrespective of the type of earth fault. 

With full support for the IEC 61850 standard, communication is supervised – which makes it both fast and secure – and time and space-consuming wiring minimized – which saves money. In fact, 615 was the first relay in the world to introduce both fast GOOSE messaging and process bus with sampled values in the medium-voltage substation. 

The vast experience and world-class, in-depth knowledge that ABB has acquired over the decades have provided a solid foundation for a dynamic approach to continuous and incremental development ever since the launch in 2008. The ability to meet the rapidly changing market requirements with agility and flexibility is key to being able to evolve alongside the power system. The 615 series has managed – and will continue – to do just that.  

Major milestones

Wave 1 Launching the 615 protection and control series 

  • Feeder protection and control REF615
  • Line differential protection and control RED615 – phase-segregated
  • IEC 61850 with fast GOOSE messaging – communication and interoperability of substation automation devices
  • Withdrawable plug-in unit design for swift installation and testing

Wave 2 – Extending the application range and increasing the flexibility

  • Motor protection and control REM615 
  • Transformer protection and control RET615 
  • Voltage protection and control REU615
  • Application configurability support
  • Large graphical display for showing customizable SLDs
  • Sensor inputs to support perfect linearity throughout the whole measurement range and digital switchgear

Wave 3 – Introducing standardized redundant Ethernet solutions

  • High-availability seamless redundancy (HSR) protocol support
  • Parallel redundancy protocol (PRP-1) support

Wave 4 – Taking the IEC 61850 implementation to the next level

  • Capacitor bank protection and control REV615
  • IEC 61850-9-2 LE process bus solution for less wiring and supervised communication
  • IEEE 1588 V2 for high-accuracy time synchronization and maximum benefit of substation-level optical Ethernet communication
  • IEC 61850 Edition 2 with substantial benefits in terms of extended interoperability of substation automation devices
  • Multifrequency admittance protection for all types of earth faults – continuous, transient and intermittent
  • Generator and interconnection protection REG615 for renewable and distributed generation


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