The History Of The IEC 61850 Modelling

The standardization of IEC 61850 started in 1995 when the IEC TC 57 Working Groups 10, 11, and 12 had been setup. Later all projects have been moved to the Working Group 10 - that is still (very!) active today.
Prior to the new project proposal for IEC 61850 the EPRI UCA project developed core models for many signals and communication services. UCA used a simple table notation for defining "models".
The experts involved have discussed several options how to model the signals. In December 1998 the editors of the core documents (including myself) met in Ann Arbor (MI, USA).


We discussed modelling with ASN.1 or our own notation:



we were not quite happy ... then we discussed trying UML … walked across the street to the University bookshop to purchase some 10 Books about UML Modelling. I purchased several books, too:





… a senior development manager of protection relays was strictly against UML … he said, it will never be used for protection and automation. Some weeks later I met his engineers in their office … and saw that they used UML for developments …

Later I tried OWL with some success:



Experts involved in CIM (Common Information Models) used UML - with the SPARX tool Enterprise Architect (EA). It took several years before UML (and EA) was used to define all models of IEC 61850. Today (end of 2019) almost all models and other definitions are managed with the EA - it is a big success! The latest version comprises the following parts:


There are tools available to export parts of the model from EA as Word documents, html pages, pdf ...

Example of a model:



With the application of the SPARX EA we have a single source of all crucial definitions.

Note: The EA package "IEC61850Domain" is only available for the experts writing, publishing and maintaining the various standard parts.

Some exported documents (the so-called code components) are available for free access:
Click HERE for accessing these documents.

Thanks to the experts that have continuously pushed for using UML and EA. It took several years ... and it was not easy for engineers to use a formal language and tool to get where we are today.

These days the EA is used also for many other tasks: use cases, design state machines like for IEC 61850-90-16 (System management), ... IEC TC 57 has done a good job in using UML for CIM and IEC 61850. But another generation of engineers is needed to understand the full benefit of using UML.

MegaWatt Needs Smarter Megabit/s

What do we need? Huge countries need many MWatt (unit of power) to survive. To get the power whenever we want to use it, we need more “Smart Mbit/s” (“smart” data transfer rate in Mega bit per second). That means: more communicating devices … maybe tens of Millions in some time down the road. What do 1,000 MegaWatt (= 1 GW) and 1,000 Mbit/s (= 1 Gbit/s) have in common? These are huge numbers! And more: We need them both in the near future! The crucial issue is here: One needs the other. Zero GW means Zero Gbit/s and Zero Gbit/s means Zero GW.

Yes, you got it! The two are becoming increasingly interdependent!

There is (mainly) ONE medium to carry power: wires. There are hundreds or even thousands of media to communicate information! Guess you could not count them all. In order to keep the cost for the future power delivery system reasonably low, we could and should think of preventing the proliferation of communication systems. Guess you agree. But: Which solutions are worth to use? No doubt: IEC 61850, IEC 60870-5-104, DNP3, Modbus, … are those that would do a good job!

I would be very happy to have as many communication systems as we have power delivery systems: DC 24V, DC 48V, 3 phase AC 110V/60Hz, 3 phase AC 240V/50 Hz, … and a few more.

Clark Gellings (one of the world’s leading experts on the electricity system, ERPI Palo Alto) talked in a podcast about “The Future of the Power Grid”. He talks about crucial aspects of the future power systems. Key issues (from my point of view) are summarized in the following three points:

Question:
“So what are a few of the things that will have to happen between now and 50 years from now to make your vision of the grid a reality?

Clark Gellings’ answer:
Well, first, we’re going to need communications standards that allow devices to talk to one another, so that we don’t have the problem we have now. For example, in buildings, the electronics that are being used have as many as 28 different communications architectures. And so one building technology that might control some new thermal storage unit you have may not be able to talk to another device in that building.

Number two, the computer system that would control these millions of nodes in any given region of the United States, they don’t exist. I mean, we can control tens of thousands of nodes, and we do now, but we’re going to need to control millions of nodes. So that’s another area of development.

And thirdly, technology. For example, power electronics to fully be able to control, in a very fluid way, the power systems, even to the point of doing things like having the system self-heal, or taking action so as to mitigate from an outage that it sees, even before necessarily the outage has occurred.”

… sounds very expensive!? Not that much … listen to Clark Gellings.

Click HERE to listen to the podcast, find a link to download the mp3, and read the content.

Anyway, the 28 different communication architectures in the building automation he mentions are not so bad - compared to the factory automation with hundreds of solutions!

why not use the IEC 61158 (solutions)? Because it has too many!

IEC 61850 is about to unify most of them (at least at the near-process level where we find the Millions of signals to be shared between Millions of smart devices). And to provide smarter mechanisms to share information.

I hope we can convert more Mbit/s into “Smart Mbit/s”: using them in a smart way. Using smart communication mechanisms (like IEC 61850) will require less bandwidth and smart power systems will need less MW.

Brief EPRI Report on Standards of DistribuTech 2014

EPRI has published a Brief Report of DistribuTECH 2014.

It seems that a hot topic was “DATA” … data from everywhere of everything! Sure there is a need to share the pool of “Big Data”. I have heard about a SCADA project that receives Terra Bytes of “big Data” from a huge wind power park trough IEC 61400-25. This seems to be “Big Data” and “little information” … good for hardware manufacturers.

The EPRI Brief reports from the DistribuTech 2014:

“This was also another good year for standards. The vendor community has heard loud and clear that standards are a preference of electric utilities and the vendors have done a good job of promoting where they are using standards including DNP3, IEC 61850, IEC 61968/61970 (the CIM), MultiSpeak, and more. One relatively new standard that had a strong presence was OpenADR (Open Automatic Demand Response).”

Click HERE for the complete report.

I hope that they are looking at useful information rather than bunches of Data – that just may tell the receiver: nothing has changed, nothing has changed, nothing has changed, … stop here and make it smarter:

This is one aspect of the philosophy of IEC 61850 – which needs to be understood by more people … it will take some time to understand this.

Use-Cases for Distributed Photovoltaic and Storage Systems

EPRI (Electric Power Research Institute, Palo Alto, USA) has been active in the research and development of the electrical power delivery systems. Just remember the projects UCA 1.0 (Utility Communication Architecture) and UCA 2.0. Both projects have contributed to the IEC TC 57 (Power System Management) and influenced several crucial standard series like the CIM, IEC 60870-6 TASE.2 and IEC 61850.

The work on the “Utility Communication Architecture” is going on in various IEC TC 57 projects and EPRI is still contributing to this process (especially to the definition of IEC 6185-90-7 - Object models for photovoltaic, storage, and other DER inverters). A very interesting EPRI report looks into the “Uses for Distributed Photovoltaic and Storage Systems”. The report lists and discusses briefly the following use-cases:

• Energy Generation
• Local Energy Storage to Compensate for Photovoltaic Intermittency
• Use of Energy Storage for Arbitrage Benefit
• Use of Local Energy Storage to Maximize Photovoltaic Generation Value
• Energy Storage for Customer or Community Backup Power
• Energy Storage to Reduce or Limit Peak Loading on the Utility System
• Energy Storage for Load Following
• Energy Storage to Reduce Customer Peak Demand
• Energy Storage for Local Power Quality Control
• System Stabilization – Transient Watt Modulation with Line Frequency
• System Stabilization - Transient Watt Modulation with Line Voltage
• Var Production for Voltage Regulation
• Var Production for Voltage Stabilization
• Var Production for Power Factor Management
• Var Compensation for Intermittent Generation
• Connect/Disconnect from Grid – Non Islanding
• Connect/Disconnect from Grid – Islanding
• On/Off Control of PV and/or Storage Inverter
• Adjusting Maximum Generation Level
• Metering Energy from Photovoltaic or Storage Device
• State Monitoring
• Event Reporting by Exception
• Event Logging

Click HERE for the 44 page report on use cases.
Click HERE for an overview about IEC 61850-90-7.

In an up-to-date publication of the German VDI nachrichten it is reported about storage possibilities on 2011-10-28 that:

• The capacity of all German pumped-storage hydropower plants would provide power for 1 hour.
• The capacity of 42 million German cars would last for 24 hours.
• The capacity of the German oil and gas storages would last at least for 2 months.
• The storage of “Wind or PV Power” (Converting Electricity to Natural Gas) is also an option.

Click HERE for an R&D report on Converting Electricity to Natural Gas.

Whatever the energy Mix will be – there is a crucial need for information and communication systems supporting the future power delivery system!

The good news is that there is no need to develop standards for information and communication systems from scratch! There are sufficient standards available, implemented and tested so that the power industry can straight use them: IEC 60870-6 TASE.2, CIM, IEC 61850, IEC 61400-25, …