Saturday, June 30, 2012

Using ConfRev to report a change of value

The configuration revision is a very useful information for clients (Reporting) and subscribers (GOOSE and SV). It is highly recommended that a receiving IED marks the received values as invalid in case the receiver expects ConfRev=X but receives a message with a value unequal X.

The service Reporting (or GOOSE) could be used to inform receivers that there is a change in the ConfRev – long before it may receive a message with a different (incremented) value.

By the way, the functionality to “monitor” changes of control block attribute values is called “Service Tracking” and is defined in IEC 61850-7-2 Edition 2.

The Control Block Attribute ConfRev needs to become a member in a data set. This data set may have all ConfRev attributes of all control blocks as members. So, if any change is detected, a message is issued (Report or GOOSE message, or log entry posted).

It is not yet specified in IEC 61850 if the change of a value (of the ConfRev) implemented by a re-configuration of the IED (e.g., change of the data set) can be used as a trigger (dchg) to issue a report or GOOSE message or post a log entry. Because this new value may become online visible after the IED restart (to interpret the new SCL file).

It would require that the Control Block stores the last ConfRev value non-volatile; in order to figure out that the new value (from configuration tool) is larger than the old one. This is true for SV Control Blocks only, see §19.2.1.6: “A restart of the IED shall not reset the value.”

See IEC 61850 Tissue # 861.

2 comments:

Anonymous said...

i'm a researcher/protection engineer, very interested in the IEC61850 and its application, within my university I'm the first one to do researches related to this area. I spent alot of time reading and understanding the standard, ur block and posts were really very useful. I need to transfer from the reading stage to working with the IEC61850 to improve some protection problems but unfortunately i don'y know how to start :(, can u recommend me a simulation or modelling programs that could help me, do I need to build a model for the logical nodes I'll use using an object oriented language for example. I really don't know how to start and there's no previous knowledge about IEC61850 within my college,I'll appreciate ur help so much thanks

Karlheinz Schwarz said...

Here is the road to a fast getting started: Download the DLL evaluation package:
http://blog.iec61850.com/2011/02/updated-c-client-application-for-iec.html

And/or purchase a Beck IPC Development Kit DK61:
http://nettedautomation.com/iec61850li/index.html