Merging Unit and Monitoring IED with IEC 61850 Server and I/Os

The Merging Unit MU320 offered by Reason combines the Sampled Value exchange with “conventional” Inputs and Outputs using GOOSE and Client/Server communication. This device seems to be a very convenient way to combine both worlds: real-time and general SCADA applications:

• 9-2LE compliant
• Up to 16 analog inputs, 12 binary inputs and 16 outputs
• Support for Protection and Measurement (metering) profiles simultaneously
• MMS monitoring and control
• Binary inputs and outputs via GOOSE messages
• Synchronization via Ethernet using PTP (IEEE1588)
• Parameter setting using standard data model and SCL language

Click HERE for a more detailed description.

Video with brief Introduction to IEC 61850 and IEC 61400-25

IEC 61850 and IEC 61400-25 comprise some 25 documents. Part IEC 61850-7-1 contains some basic modeling concepts that may help to get a few ideas what IEC 61850 is about. I guess that just a few people have read that part. In my training courses with almost 3.000 attendees I have gained a lot of experience on how to explain the basic concepts. In 2011 I have conducted more than 30 training sessions (from one to 12 days). Today I am starting a new service to the industry: providing videos that explain basics with animated up-to-date slides.

The first video is a brief presentation of the key concepts of IEC 61850 (one slide): modeling methods, models, configuration language, communication, and mappings. The demonstration shows how these concepts are used to compose a system. Of course, this slide is just showing the basics of a “small system”. This slide is part of the introduction of my commercial training curses.

Please click on the start button to see the video – in order to see it in the full screen, click again on the video and select the full screen button.

I hope you will enjoy this video!
Your feedback to Karlheinz Schwarz would be appreciated.

Reporting and GOOSE compared

IEC 61850 and IEC 61400-25 offers various possibilities for exchanging data values in real-time or near real-time. Whatever your definition of real-time is, here are some hints on the options and some hints on how to use them:

List of possibilities to exchange data values:

Comparison of Reporting and GOOSE / Sampled measured values (SMV):

Note that all message contents are encoded ASN.1 BER – with the exception of the data values in SMV and optionally in GOOSE Edition 2 where the data values are fixed encoded (for optimization!).

The timeliness of GOOSE and SMV depends on the definition of the standard (e.g., using special messages directly on data link) AND on the IMPLEMENTATION! The bottleneck is usually in the end-nodes and not in the communication.

Draft Technical Report - IEC 61850 for Synchrophasor

Draft IEC 61850-90-5 TR Ed. 1 – Use of IEC 61850 to transmit synchrophasor information according to IEEE C37.118 has been published as draft Technical Report (57/1086/DC). Comments by 2010-10-01.

This technical report describes how to use IEC 61850 to transmit synchrophasor information according to IEEE C37.118. Later, once the report is approved and published, results will be integrated as amendments in the relevant parts of the IEC 61850 standard.
This document contains a first draft of that report. As a significant part, it includes new mappings of the IEC 61850 GOOSE and sampled value services that can be used for a wide area communication.

Two new control blocks are defined for IP networks:
• The sending of stream information (e.g. Sampled Values)
• The sending of event driven information (e.g. GOOSE)

Two possibilities are drafted:

The streams for SMV and GOOSE will be transmitted over a transport profile that utilizes IPv4 or IPv6, and TCP as well as UDP.

Once these models are extended in the ACSI (IEC 61850-7-2) they may also be used for Reporting over UDP.

What are the benefits of IEC 61850?

If you ask different people you get various answers. Guess most experts agree that crucial benefits are: use of TCP/IP, Ethernet, Client/Server, and Layer 2 Publisher/Subscriber (GOOSE and Sampled Values), get rid of copper wires. What else? Information Models, System Configuration Language (SCL), retrieving the self-description of Information Models from IEDs, and ...

Another crucial benefit of IEC 61850 and IEC 61400-25 (IEC 61850 extensions for Wind Power Plants - defined in IEC TC 88) is that it is a GLOBALLY accepted STANDARD. Hmm, a standard is a standard! - So, what is special here?

If you implement client/server, GOOSE, and SV it is defined WHICH protocol you have to choose for each of the three: MMS, TCP/IP, ... for client/server, "GOOSE" for GOOSE, and "SV" for SV ... You don't have to choose between 40 or 50 solutions! See the international field bus standard IEC 61158: click HERE for a list of the 50+ field-bus-standards in a single standard.

You should ask (from time to time) this question: What would the situation in the domain of power utility protection, control and automation be WITHOUT IEC 61850? We would have a lot of very different vendor specific solutions, regional standards, utility standards, ... and may be a situation like in the field-bus domain!

"A technical standard is an established norm or requirement. It is usually a formal document that establishes UNIFORM engineering or technical criteria, methods, processes and practices." (according to Wikipedia). This is what IEC 61850 provides: UNIFORM definitions to a high degree. The field-bus standard has TOO MANY NON-UNIFORM definitions.

It's a big benefit that we have prevented really an intoxicating proliferation of protocols and other definitions. We have even prevented two standards for utility communication: In 1998 IEC TC 57 and IEEE agreed to merge UCA 2.0 and IEC 61850 into ONE standard - a great decision! From a global viewpoint we have one situation where we have two standards: IEC 610870-5-101/104 and DNP3 ... this is definitely better than having 10 or more under one number ;-) 

IEC 61850-9-2 LE - Process Bus Support by ABB and others

The IEC 61850-9-2 LE (Lite Edition) is key for the first implementations of the IEC 61850 Process Bus. The 9-2 LE edition defines two specific profiles for the exchange of sampled values:

• 80 samples per nominal period for protection applications; one set of samples is sent immediately in one SMV message.
• 256 samples per nominal period for metering applications; eight sets of samples are sent in one SMV message.

Click HERE to download the IEC 61850-9-2 LE (Users Guide) from the UCA International Usersgroup.

ABB stated that "Based on the new technologies ..., the substation footprint can be reduced by more than 50 percent, while at the same time increasing its availability and reliability."

Click HERE for a report from ABB on first experiences with the IEC 61850 Process Bus.

It could be expected that sampled values and GOOSE messages on a process bus will be used in larger scales in about two to four years.

Click HERE for some information of the process bus pilot under way at RWE (Germany - the second biggest German utility). SCC/NettedAutomation is involved with HesoTech (Germany) in the transformer monitoring system based on IEC 61850.

Click HERE for a Paper on the pilot project (in German).