IEC 61850-7-4 Edition 2 FDIS open for Ballot

The second edition of IEC 61850-7-4 has been published for final ballot until February 05, 2010:

IEC 61850-7-4 Ed.2:
Communication networks and systems for power utility automation –
Part 7-4: Basic communication structure – Compatible logical node classes and data object classes

The second edition specifies more than 150 Logical Nodes.

The major technical changes with regard to the first edition are as follows:

• corrections and clarifications according to information letter;
• extensions for new logical nodes for the power quality domain;
• extensions for the model for statistical and historical statistical data;
• extensions regarding IEC 61850-90-1 (substation-substation communication);
• extensions for new logical nodes for monitoring functions according to IEC 62271;
• new logical nodes from IEC 61850-7-410 and IEC 61850-7-420 of general interest.

Example of new Logical Nodes in IEC 61850-7-4 Edition 2:

New Logical nodes for functional blocks:

Counter - FCNT
Curve shape - FCSD
Generic filter - FFIL
Control function output limitation - FLIM
PID regulator - FPID
Ramp function - FRMP
Set-point control function - FSPT
Action at over threshold - FXOT
Action at under threshold - FXUT

An example of a PID loop control with an Logical Node FPID representing the attributes (or input and output signals):

Note that IEC 61850 DOES NOT specify the PID loop control algorithm or function. IEC 61850-7-4 Logical Nodes provide the "interface" or the presentation of the signals, the configuration of the object models and the exchange of the values. The Data Object "KP" (Proportional gain) can be set by an ACSI service. Or the Data Object "DAct" (Derivative action) can be read, reported, logged, or GOOSED.

If you are interested to comment on the document, please contact your national committee of the IEC TC 57.