Monday, January 14, 2013

IEC 61850 as Digital Interface for Instrument Transformers

The CDV (Committee Draft for Voting) of IEC 61869-9: Instrument Transformers - Part 9: “Digital interface for instrument transformers” is out for ballot and comments until 2013-03-01.

This document will replace and extend the so-called “9-2LE” that defines the first profile (or subset) of IEC 61850 for voltage and current sensors (Merging Units).

The new standard is based on experience gained since the publication of “9-2LE”. There are a lot of new details in the configuration and description of the information models defined – in order to reduce the number of options.

The IEC 61869-9 standard will (when published):

  • Replace IEC 60044-8 digital solution.
  • Provide a product standard for instrument transformers with a digital interface according
    to 61850; similar to what IEC 62271-3 is doing for switchgear.
  • Be backward compatible with the UCA International Users Group’s Guideline for Digital Interface to Instrument Transformers Using IEC 61850
  • Use IEC 61588-Ed2 for time synchronization, with an option for 1PPS.
  • Be applicable for AC and DC measurements.
  • Be using 100 Mbit/s or 1 Gbit/s Ethernet.
  • Specify 4.800 digital output sample rate with 2 sets of values per message (2.400 messages/s) for general measuring and protective accuracy classes, regardless of the
    power system frequency.
  • Specify 14.400 digital output sample rate with 6 sets of values per message (2.400 messages/s) for quality metering accuracy class, regardless of the power system frequency.
  • Specify 96.000 digital output sample rate with 1 set of values per message (96.000 messages/s) for DC instrument transformer applications [likely to using high speed Ethernet end-to-end].

Proposed conformance classes are (with detailed PICS in the draft):

  • class a: the minimal set of services required to transmit MU data using sampled values;
  • class b: class a capabilities plus the minimal set of services required to support GOOSE
    messages;
  • class c: class b capabilities plus the implementation of the IEC 61850 series’ information
    model self-descriptive capabilities;
  • class d: class c capabilities plus services for file transfer and either one or more of
    unbuffered reporting, buffered reporting, or logging.

4 comments:

Iqbal said...

Dear Mr. Schwarz,

May I know what does the standard mean by "2 sets of values per message" for the 4800 Hz sampling for measurement? Does this means:

1) Single phase value of voltage and current per message?

or

2)2 sets for 3 phase values of voltage and current per message?

Your kind reply is highly appreciated. Thanks in advance.

Karlheinz Schwarz said...

One set means: 3 (4) sampled values of voltage and current at the same time tx communicated in one message.

Two sets mean: same as above but for two (2) consecutive sampling times: tx and tx+1 communicated together in one message.

Chen Fan said...

Dear Mr. Schwarz,
May I know the newest status of this standard(IEC61869-9) as two years past since the CDV.Will it be published in this year of 2015? Thank you.

Best Regards,

Chen Fan

Karlheinz Schwarz said...

Dear Chen Fan,
Thanks for the question.
You can find the status of all projects at the IEC website. For IEC 61869-9:

http://www.iec.ch/dyn/www/f?p=103:23:0::::FSP_ORG_ID:1241

The publication is planned for 2016-01

Best Regards,
Karlheinz Schwarz