The international IEC 61850 standard defines a framework for substation communication networks and systems. The standard consists of several parts ranging from the requirements on substation automation systems to the details of a communication protocol. Its main goal is interoperability; the ability for IEDs from one or different manufacturers to exchange information and use the information for their own functions.
This standard has been out since 2005 and used successfully in ABB products. It is updated with a new version, Edition 2, which extends to new application areas in transmission and distribution power systems and also defines a new functionality to Edition 1 functionality. This product supports IEC 61850 versions Edition 1 and Edition 2.1.
IEC 61850 Edition 2 adds new functionality which is not supported by the Edition 1 devices. Therefore it is recommended to always use the same standard version in all devices and not to mix different versions in the same project.
A major difference between the other communication protocols applied in substation automation and IEC 61850 is that the latter is not only a communication protocol, but a whole framework for specifying, engineering and operating substation automation systems. The communication part covers the connection between the IEDs and the substation clients, for example, SCADA and gateways.
The IEC 61850 standard specifies an expandable object-oriented data model and a wide set of protocol services for substation automation (standard parts 7-x). The standard does not specify any protection or control functions, but specifies how the functions expose their information to a communication network.
The standard supports free allocation of functions to devices. With efficient communication facilities, the functions can be located anywhere in the system, that is, an interlocking function can reside in the IED or on the station level. Additionally, the standard is open for different system implementations, that is, different integration levels and allocation of functions to different devices are supported.
The standard defines a system configuration description language (SCL) for substation automation systems. The language facilitates efficient automated integration of devices into systems. Additionally the standard supports a comprehensive and consistent system definition and engineering, which makes not only the devices, but also their tools and systems interoperable (standard part 6).
The standard uses Ethernet and TCP/IP for communication. Since Ethernet and TCP/ IP are widely accepted and used, the application of these technologies provides a broad range of features from mainstream communication (standard parts 8-1, 9-2). The communication profiles in IEC 61850 can be divided into vertical and horizontal. The vertical profile uses MMS over TCP/IP and horizontal communication Layer 2 Ethernet multicast messages. The standard separates the functionality represented by the data model and the related communication services from the communication implementation thus being open for new communication concepts in the future.
- 1
- Abstract communication services interface (ACSI)
- 2
- Stack interface
- 3
- ISO/OSI stack