Alstom MiCOM P54 Series, Technical Manual

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SCADA Communications P54x/EN SC/La4
MiCOM P543, P544, P545 & P546 (SC) 13-27
SC
5. IEC 61850 ETHERNET INTERFACE
5.1 Introduction
IEC 61850 is the international standard for Ethernet-based communication in substations. It
enables integration of all protection, control, measurement and monitoring functions within a
substation, and additionally provides the means for interlocking and inter-tripping. It
combines the convenience of Ethernet with the security which is essential in substations
today.
The MiCOM protection relays can integrate with the PACiS substation control systems, to
complete ALSTOM Grid Automation's offer of a full IEC 61850 solution for the substation.
The majority of MiCOM Px4x relay types can be supplied with Ethernet, in addition to
traditional serial protocols. Relays which have already been delivered with UCA2.0 on
Ethernet can be easily upgraded to IEC 61850.
5.2 What is IEC 61850?
IEC 61850 is an international standard, comprising 14 parts, which defines a communication
architecture for substations.
The standard defines and offers much more than just a protocol. It provides:

Standardized models for IEDs and other equipment within the substation

Standardized communication services (the methods used to access and exchange data)

Standardized formats for configuration files

Peer-to-peer (e.g. relay to relay) communication
The standard includes mapping of data onto Ethernet. Using Ethernet in the substation
offers many advantages, most significantly including:

High-speed data rates (currently 100 Mbits/s, rather than 10’s of kbits/s or less used by
most serial protocols)

Multiple masters (called “clients”)

Ethernet is an open standard in every-day use
ALSTOM Grid has been involved in the Working Groups which formed the standard, building
on experience gained with UCA2.0, the predecessor of IEC 61850.
5.2.1 Interoperability
A major benefit of IEC 61850 is interoperability. IEC 61850 standardizes the data model of
substation IEDs. This responds to the utilities’ desire of having easier integration for different
vendors’ products, i.e. interoperability. It means that data is accessed in the same manner in
different IEDs from either the same or different IED vendors, even though, for example, the
protection algorithms of different vendors’ relay types remain different.
When a device is described as IEC 61850-compliant, this does not mean that it is
interchangeable, but does mean that it is interoperable. You cannot simply replace one
product with another, however the terminology is pre-defined and anyone with prior
knowledge of IEC 61850 should be able very quickly integrate a new device without the need
for mapping of all of the new data. IEC 61850 will inevitably bring improved substation
communications and interoperability, at a lower cost to the end user.
5.2.2 The data model
To ease understanding, the data model of any IEC 61850 IED can be viewed as a hierarchy
of information. The categories and naming of this information is standardized in the
IEC 61850 specification.