IEC 61850 Is Very Crucial For Semantic Models And Interoperability

IEC 61850 provides a huge number of generic and specific semantic models ... Logical Nodes, Data Objects, Common Data Classes, Instance-Information, Topology Information, Information Exchange, Communication, Protocols, ...

Can you please show me an easy to understand example! Here you are!

The following figure shows how (meta) model information is added to a simple voltage measurement (right upper corner). The value is wrapped with a data object model comprising with many attributes like instCVal.mag.i or units ...
The logical device and and logical node instance information is added next. Finally the semantic of the information exchange (report model) is applied to the value - sure, there is a data set involved as well (not shown here).
All this information (general and specific (instance) semantic) could be described in an SCL document (using an XML based SCL schema). Note that some configuration information, e.g., engineering unit (kV), may be contained in the SCL document only. The device needs to process implicitly the voltage in kV. A device may allow to use the SCL document to configure the device to expose the voltage in V ... or mV ... A client (SCADA or ...) may read out the model at runtime (including the engineering unit, if that is implemented as a model attribute) or may just read locally the SCL document and get the engineering unit from the file. Note: the SCL document is the main document for the models and configuration ... keep it safe!! And check the online read model against the SCL file from time to time to compare the two in order to figure out any change!


Further in our example we have a simple bay topology with electrical equipment like generator, switch gears, voltage and current sensors. This topology could be engineered and documented with the SCL (System Configuration Language) - an XML schema for a whole system. The equipment is assigned to specific information models (MMXU.PhV.phsA. ...).
The system engineering could be managed, e.g., with the Helinks STS Tool. An easy to use tool.
The generic Information Model, e.g., MMXU (defined in IEC 61850-7-4) is concatenated with the application designation (MyGenSets/Gen11).


The various levels of semantics of the Message elements are:

1. Model Instance: Hierarchical Identification of the specific Model of Semantics (in SCL) 
2. Message Elements: Service Type, Identification, Value, Quality, and Timestamp (ACSI - Abstract Services)
3. Message Instance: Service Type, Instance of Identification, of Value, of Quality, and of Timestamp (Report)
4. Message semantic (ACSI mapped to MMS)

The modeling approach of IEC 61850 could be applied in most automation domains ... especially when electric power is applied.

Let me know please if there is a similar standard model defined for automation systems that may compete with IEC 61850 and IEC 61400-25. 

How Many and Which Information Models are defined in IEC 61850?

I guess you have heard that IEC 61850 defines a lot of Information Models. Yes, You are right.

The models are managed exclusively by the corresponding working groups with the Enterprise Architect UML Tool (the UML data base is for internal use only). The model version:

UML model of 61850 (wg10built6-wg18built3-wg17built5-jwg25built2-tc17built1-tc38built1.eap)

comprises the following number of Logical Node Classes, Data Objects (Attributes), Enumerations and Abbreviations:



An excerpt from the UML modes looks like this:



The UML Model is the single source data base that is used for the extensions and maintenance of the model, as well as the generation of Word or PDF documents ... The PDF documents are sold by IEC and other organizations.

You may complain that the standards are not for free ... hmm ... BUT look: You can download the various Code Components for free.

Click HERE for the Code Component for IEC_61850-7-4.NSD.2007A2.light.zip (IEC 61850-7-4 2007A2 NSD light, see the IEC 61850-7-4:2010 for full legal notices). The full version has additionally the semantic descriptions of the models.

Example of Enumeration:


Example of excerpt of LN Class MMU:



Click HERE to see the list of all Code Components as per today ... more to come soon.

To my understanding you can model many required information generated and consumed by a huge number of applications in almost all application domains of automation in the electrical system and beyond.

As the above example of MMXU shows, you can use this LN Class wherever you have 3 phase AC system!! In a building heating system for the electrical values of a compressor or a fan or a pump or ... the blue sky is the limit for the applications.

Click HERE to learn about crucial details discussing the LN Class MMXU and how it can be applied ... you may have never expected this comprehensiveness of the MMXU.

Note that the 3 phase system was first (more than 100 years ago) - then we have put a facade in front of the measurement function which exposes the measurements as data objects of the class MMXU. The application has driven the class - not vice versa.

The current edition 2.1 models defined in IEC 61850-7-3 and 7-3 are listed in the contents tables of the preview documents. The following Preview documents (free access) for models of the edition 2.1 consolidated versions are available:

Preview IEC 61850-7-3 Edition 2.1
Preview IEC 61850-7-4 Edition 2.1

Example of 7-4 from the preview:



In case you find any error in the standards, please visit the Tissue Database:
https://iec61850.tissue-db.com/parts.mspx