Sampled Values and IEC 61850-9-2 LE: What is it?

The other day I received the following email:

Dear Mr. Karlheinz Schwarz,
I am sorry to disturb you. My name is XXX and I am a researcher from YYY. I would like to ask some questions to you regarding the standard IEC 61850-9-2LE.

1) May I know the status of IEC 61850-9-2LE? Is the standard will be obsolete or remain as it this?

2) Can I get some explanations from you about the differences between IEC 61850-9-2, IEC 61850-9-2LE and IEC 61869-9?

I really appreciate your kindness and time to answer my questions above.
Thank you & best regards,

-------------------------------

I have a very good friend that I asked to answer for me. Her is his answer:

Dear Karlheinz, 

Sure I can do my best for that.

Thanks for this opportunity.

Dear XXX, please see my attempt to answer.

Your questions are our everyday’s questions, and my answers need to be taken with “common sense”, reasonability and not as law, where somebody is right and somebody is wrong.

This is the best I can say.

The IEC 61850-9-2 Light Edition (LE)  is NOT a standard.  It is an UCA profile; a sort of gentlemen agreement (followed by everybody so far), where in principle the dataset carried by the SV Message (Sampled Values message) is fixed to 4 voltages and 4 currents.

The sampling frequency is 80 samples per period (4000 Hz for 50 Hz systems and 4800 Hz for 60 Hz systems).

The length of the SV message is fixed (in terms of bytes)

The quality string has one “extra bit” (the 14th bit, for derived or measured of the analog quantity) compared with a “normal quality string” of IEC 61850 and also IEC 61869 series, of 13 bits.

The time synchronization is 1-PPS

There is formally no support for PTP time synch (typical of “Edition 2” of IEC 61850 standard. LE is “edition 1”)

There is formally no support for “SIMULATION” mechanism (typical od “Edition 2 “ of IEC 61850 standard; LE is “edition 1”)

And many others.

TO MY EXPERIENCE:

It is commonly understood (and you have to make sure it is commonly understood also by the people working in your projects: suppliers, consultants, utility engineers etc) that:

- 9-2 LE supports Simulation mechanisms

- 9-2 LE supports PTP as time synch (be careful that PTP is actually IEC 61850-9-3: 2016 )

Even if formally this is not strictly in line with the UCA specification for “LE”.

So, IEC 61850-9-2LE (written by UCA working group) is a profile of IEC 61850-9-2 (written by the IEC committee TC 57)

And today it is the only “standard” that is implemented and in service for process bus applications.

IEC 61869-9 (and also -6 and also soon the -13) are parts of the IEC 61869 series, written by the IEC committee TC 38 (Instrument Transformer). 

So they have to do with the Merging Units, they are also profiles somehow, and also many other requirements, that you need to fulfill if you want to have a Merging Unit according to IEC standards.

To my opinion, no matter what IEC 61850 says in general, if you do a Merging Unit and follow IEC, you should follow IEC 61869 series.

In principle, the IEC 6185069-9 standards are often associated to:

• “Dynamic” dataset. This means that not only 4 U and 4 I will be transmitted. I can transmit just  one voltage, or 25 currents, or 6 voltages and 3 currents.. This is done from SCL.
• Sampling frequency of 4800 Hz, no matter the power system frequency (50 Hz or 60 Hz).
• PTP time synchronization (for MU)
• 2 samples per SV message (so called ASDU). “LE” has only one sample per message (one ASDU per message)

But it is of course much more than that.

What about protection relays/protection functions?

TC 95 is responsible for protection functions in IEC.

In principle it  is TC 95 / MT 4 (Maintenance Team 4) that takes care of functional standards for protection functions (IEC 60255-121:2014 for distance protection for example). Other maintenance teams take care of protection related standards like EMC etc.

Recently TC 95 has started a new working group (WG 2) that considers IEC 61850 for protection applications. A Technical Report is on its way and parts of that technical report will be implemented in the so called IEC 60255-1xx series, for protection relays.

But this is not ready yet and all of this needs to be considered with extreme care and communication among all the involved parts in a project.

I work as well as consultant for IEC 61850 applications in relay protection. Mainly for TSOs, since many years. Please have a look at this paper, written by many of us active in TC 95 / WG2. I think it will help you to better understand.

https://www.researchgate.net/publication/334050781_Standardisation_Challenges_for_Digital_Inputs_and_Outputs_of_Protection_Functions_in_IEC_60255_series

If you are interested in what TC 95 / WG2 does, you are more than welcome to contact me and I’ll help you in joining “our” activities.

For your understanding, there is a high dialog between TC 95, TC 38 and TC 17 (circuit breakers) for making the use of IEC 61850 more interoperable not only at “data level” but also at “functional level”, at least for protection applications.

For metering or power quality applications, for example, I don’t know what to say.

I hope this helps you.

Karlheinz, your extra comments are always welcome.

My best regards

Andrea Bonetti

Just passed

 Fachtagung Schutz- und Leittechnik 2020 , Berlin, 18-19 February 2020

NEW FORMAT!  Megger Magazine: ELECTRICAL TESTER
White Paper - Testing ROCOF and IEC 60255-181 Standard

Article - IEC 61850 GOOSE interoperability
IEEE 2018- Paper on IEC 61850 substation maintenance
MATPOST 2019 Lyon FR – Paper on IEC 61850 and Automatic Fault Disturbance Analysis

First time in industry! long duration End to End testing without use of any computer!

Mr. Andrea Bonetti MSEE
Senior Application Specialist Relay Protection and IEC 61850
Active member of IEC TC 95 / MT 4 ”Measuring relays and protection equipment” since 2006.
Megger Sweden AB

andrea.bonetti@megger.com
Rinkebyvägen 19, SE-182 36 Danderyd (Stockholm)
Sweden

IEC 61850 Sampled Values and GOOSE Messages Reduce Complexity and Cost

Synaptec Ltd (a spin-out technology company from the University of Strathclyde, UK) developed a distributed electrical sensing technology platform using IEC 61850. The approach allows measured values from up to 50 current transformers to be acquired passively using a single optical fibre core over a distance of up to 50 km. These measured values can then be utilised as part of centralised PAC schemes, or communicated to traditional PAC devices for analysis via IEC 61850-9-2 / 61869-9. By centralising current measurements, this method eliminates the need of having multiple protection relays at each line ends, complex time synchronisation systems at measurement points, and complex telecommunications equipment among the distributed PAC devices.

Click HERE for downloading the 12 page paper (Differential protection of multi-ended transmission circuits using passive distributed current sensors) describing the application and approach to solve a very crucial challenge.

Another paper (Implementation of centralised, numerical busbar protection using distributed photonic current sensors) describes the design and testing of the first centralised busbar protection scheme that makes use of distributed photonic current sensors and IEC 61850. By utilising distributed, passive sensors which are interrogated purely using standard optical fibre, the requirement for active units in the substation yard is completely eliminated. Additionally, the use of copper wiring from CTs to measurement units may be eliminated. The scheme, designed and built for Statnett by Synaptec, will be installed and trialled at Statnett’s Furuset R&D substation near Oslo, Norway. A prototype centralised busbar protection algorithm, validated with the University of Strathclyde, will run on the central merger unit to prove the principle of centralised busbar protection using a single active IED.

Click HERE for downloading the paper.

Click HERE for the Synaptec news (Norwegian TSO Statnett innovates with Synaptec technologies):

With one system able to instrument 50 locations synchronously, 6 busbar feeders will be independently and simultaneously protected by one system, with capacity to spare for novel temperature and vibration monitoring of nearby HV assets, such as transformers.

The development and the applications show that the standard series IEC 61850 has all the "tools" helping to keep the power flowing and the grass green - at all voltage levels.

IEC TC 57 Just Published Amendment 1 of FDIS of IEC 61850-9-2

The following FDIS has been published last week:
57/2112/FDIS

Amendment 1 – Communication networks and systems for power utility automation – Part 9-2: Specific communication service mapping (SCSM) – Sampled values over ISO/IEC 8802-3

The ballot closes: 2019-08-09

Compared to the second edition, this first revision of the second edition:

a) updates the normative references
b) adds a synchronization clause (Clause 9); adds references to IEC 61588:2009 and
IEC/IEEE 61850-9-3 for SV synchronization;
c) modifies physical layer specification in T-Profile;
d) modifies MSVCB components (Table 9 and Table 10);
e) deprecates usage of USVCB;
f) modifies encoding for the transmission of the sampled value buffer (Table 14);
g) adds Table 20;
h) adds Table 21;
i) adds Annex C related to possible backward compatibility issues between revisions of this
standard;
j) provides clarifications and corrections to the second edition of IEC 61850-9-2, based on the
tissues = { 1349, 1272, 1055, 944, 863 }.

New Merging Unit Development Kit

A new Merging Unit Development Kit based on the NovTech IoT Smart Grid Platform with Intel Cyclone V SoC Core is available for your next project.
Utility companies are adapting their infrastructures to support bidirectional energy flow to handle the emergence of DER (Distributed Energy Resources) via microgrids, photovoltaic panels, and local energy storage. As distributed energy generation increases, new intelligence of sensors, measurement and protection equipment will be required to process data at the edge. Also with the increase in variable DER, it is more challenging for substations to deliver sinusoidal and predictable steady-state voltage and current. Utility companies rely on substation metering of secondary voltage (VT) and current transformer (CT) circuits to detect performance issues and to provide vital information in real time to distributed digital protection nodes.

To satisfy this need, SystemCORP and Intel developed an IEC 61850-9-2LE compliant merging unit solution in form of a demonstrator/development platform.

This development kit consists of 6 parts:

1. NovTech IoT Octopus Smart Grid IoT Platform
2. SystemCORP VT/CT Interface board
3. SystemCORP IEC 61850-9-2LE Sample Value software stack (PIS-11) on ARM Cortex A9 core 1
4. SystemCORP IEC standard 61850 server/client software stack (PIS-10) on ARM Cortex A9 core 2 (optional)
5. Flexibilis embedded FPGA analogue front-end IP core
6. Flexibilis Ethernet PRP/HSR FPGA IP core (optional) 

Click HERE for more information.

NEW HW: IEC 61850-9-2 LE Sampled Value Publisher

The SystemCorp "IEC 61850-9-2 LE Sampled Value Publisher" is a hardware platform for specific sampled value publisher applications for the Smart Grid IoT Platform from Novtech using the Altera (now part of Intel) dual core ARM/FPGA Cyclone V SoC.
This Smart Grid IoT Platform provides eight high precision analogue inputs. The A/D converter is directly controlled by the FPGA producing the sampling rate required for the SV publisher,   which is implemented in one ARM core.
The Sampled Values are published at a rate of 4000 frames per second for a grid frequency of 50Hz and 4800 frames per second for 60 Hz.
An eight channel VT/CT interface module is also available from SystemCORP Embedded technology allowing a direct connection of the Smart Grid IoT Platform to 110 V VTs and 5 A CTs.





Click HERE for downloading a two page description and additional information [pdf, 390 KB].

FITNESS Pilot: Are You Fit For The Future?

Are You Fit For The Future?
IEC 61850 is a crucial component in the FITNESS pilot project:

Presentation of the project: Thursday October 27, 2016 from 1:30 PM to 5:30 PM

Future Intelligent Transmission Network SubStation (FITNESS) is the pilot live multi-vendor digital substation demonstration in GB. The project was successfully awarded under RIIO NIC, Ofgem, in late 2015 and detailed design work began in 2016. Together with our partners GE Grid Solutions, ABB, Synaptec and the University of Manchester we will like to invite to share the objectives of project FITNESS, selection of substation architecture, discussions about change in substation design principles to optical measuring techniques and of course international substation standard IEC 61850. The event will be a part of the international IEC WG10 “Power systems management and associated information exchange” meeting and will provide an excellent opportunity to discuss and interact with international experts:



Source and details (SP Energy Networks)

IEC 61850-9-2 Sampled Values In Use

Quite often people ask me about the application of sampled values according to IEC 61850-9-2 (9-2LE). The sampled values require very solid products (publisher, Ethernet Switches, and subscribers). The recent years have shown that the technology has matured to an extend that applications are already available or underway.

Please find useful links:

Click HERE for the paper:

Test and Evaluation of Non Conventional Instrument
Transformers and Sampled Value Process Bus on Powerlink’s
Transmission Network

Click HERE for a related publication:

Australia Leads With Process Bus

Click HERE for the 9-2LE guideline published by the IEC 61850 community.

More and more 9-2LE compliant IEDs are tested and certified.

There are more than 400 IEDs (Server, clients, publisher) that have been certified by the UCAIug:

Source: UCAIug

What’s about subscriber to sampled values?

Click HERE for various protection IEDs implementing the subscriber role for sampled values, e.g., Alstom Distance Protection Relay P446, …

More to come.

Aging Infrastructure drives Use of IEC 61850

The aging infrastructure in the electric power delivery system drives the application of IEC 61850 conformant products. One example is the the application of optical sensors in Mexico: “ … the last decade, over two hundred failures of conventional instrument transformers occurred in the Mexican Transmission Electric System. … Since 2004, four projects were developed about optical current transformers (OCT´s) to identify its advantages and shortcoming … demonstrating that it is now a reality a protection scheme using optical instrument transformers and Digital relays interconnected using a network according to IEC 61850-9-2.”

The project was also presented at the DistribuTECH 2013 last week in San Diego:

Lessons learned from first multivendor 400 kV transmission line protection scheme using optical CTs and IEC 61850-9-2 process bus protection relays

by James Ariza - Megger
Carlos Melendez - CFE
Nicolas Juarez – CFE
Rodolfo Colon – IIE

The presentation concludes:
The first multivendor 400 kV transmission line protection scheme using an
IEC 61850-9-2 digital network for optical CT´s and digital protection has
been successfully installed and is in operation since May 2011.
Correct operation and interoperability have been demonstrated during the
commissioning tests as well as real fault on the line.

A paper on the same project was presented at Cigre 2012 it could be downloaded [pdf, 586 KB]

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.

Two new Papers on IEC 61850 Sampled Value Exchange Models

Several well known experts from Australia (David M.E. Ingram, Pascal Schaub, Richard R. Taylor, and Duncan Campbell) have spent some time on analyzing the applicability of IEC 61850 Sampled Value exchange methods and IEEE 1588 time synchronization for high voltage substations. Read what they have figured out:

The first paper focuses on “Performance analysis of IEC 61850 sampled value process bus networks”:

Process bus networks are the next stage in the evolution of substation design, bringing digital technology to the high voltage switchyard. Benefits of process buses include facilitating the use of Non-Conventional Instrument Transformers, improved disturbance recording and phasor measurement and the removal of costly, and potentially hazardous, copper cabling from substation switchyards and control rooms. This paper examines the role a process bus plays in an IEC 61850 based Substation Automation System.

More details and download link.

The second paper is on: “Performance analysis of PTP components for IEC 61850 process bus applications”

New substation automation applications, such as sampled value process buses and synchrophasors, require sampling accuracy of 1 µs or better. The Precision Time Protocol (PTP), IEEE Std 1588, achieves this level of performance and integrates well into Ethernet based substation networks. This paper takes a systematic approach to the performance evaluation of commercially available PTP devices (grandmaster, slave, transparent and boundary clocks) from a variety of manufacturers.

More details and download link.

Updated IEC 61850 analyzer for WireShark (V2.6)

An updated analyzer for WireShark (V2.6) is available. It supports IEC 61850 (8-1, SCL import for GOOSE, 9-2, and 90-5), MMS and ICCP-TASE.2. Older versions show some problems that do not really exist. Some people are using the Wireshark as THE reference implementation of IEC 61850! The reference is the standard – but the tool is very helpful!

Download the exe file to install the new Wireshark version for IEC 61850.

The skunkworks version 2.6 analyzes all of the data. An additional utility that must be run to extract the dataset definitions into ETR files. The directory that the ETR files are located in can be set in the protocol preferences tab.

Thanks to Herb Falk for continuously updating the analyzer!

New Parts in IEC 61850 Tissue Database

The following new parts have been added to the tissue database:

Click HERE for Part 4 (2011; Edition 2)
Click HERE for Part 7-1 (2011; Edition 2)
Click HERE for Part 9-2 (2011; Edition 2)

Wireshark Analyzer to encode MMS, GOOSE, and SAV Messages

In July 2011 I reported about a problem analyzing MMS messages with Wireshark.

A comment to that post suggests the following successful solution … configure the analyzer as follows:

Set in PRES protocol preferences new user context item:

Context Id: 3
Syntax Name OID: 1.0.9506.2.1

Select Edit and Preferences at the bottom:

Select Protocols … and PRES:

Edit PRES and select New and enter the values from above::

Thanks for the recommendation!

Have a great week.

Market Trend: IEC 61850-9-2 Sampled Values accepted

Omicron has published a paper on the benefits and acceptance of the IEC 61850-9-2 sampled values:

English (Page 47-49)

Deutsch (Page 43-45)

By Dr Fred Steinhauser:
Technology of the future: Sampled Values provide many benefits for the power systems of tomorrow

Abstracts: “IEC 61850 defines several kinds of communication mechanisms. The Client/Server communication for SCADA and the GOOSE protocol for peer-to-peer status messaging have been widely adopted in a quite short time. Now, after years of experience with these new protocols, also the application of Sampled Values has become a common topic.”

Progress in IEC 61850 standardization

The FDIS IEC 61850-9-2 Ed.2:
Communication networks and systems for power utility automation -
Part 9-2: Specific communication service mapping (SCSM) -
Sampled values over ISO/IEC 8802-3

has been accepted as International Standard.

The CDV IEC 61850-10 Ed.2 (57/1162/CDV):
Communication networks and systems for power utility automation -
Part 10: Conformance testing

has been published for comments an ballot by 2012-01-06.

The following has been changed and extended:
- Update of Server device conformance test procedures
- New Client system conformance test procedures
- New Sampled values device conformance test procedures
- New Engineering Tool related conformance test procedures
- New GOOSE performance test procedures

The first Commercial IEC 61850-9-2 Installation by ABB

ABB is implementing the first commercial installation of IEC 61850-9-2 LE process-bus technology (exchanging sampled values), according to a publication from early 2011.

ABB: “Powerlink (Brisbane, Australia) awarded the contract for upgrading the first iPASS substation to ABB. This project represents the world’s first commercial implementation of a process bus according to IEC 61850-9-2 LE. Its implementation is now well under way.”

Click HERE for the complete 5 page ABB publication.
Click HERE for further information provided by Powerlink.

Dissertation on IEC 61850-9-2 Merging Unit

Marcin Adam Gurbiel received her Dr.-Ing. (PhD) with the Dissertation on “Definition and Testing of a Digital Interface of a Power Substation”. Her findings are quite interesting. She writes in the summary: “… it is possible to apply the common information exchange protocol based on IEC 61850 to the process level of the substation automation system by implementing a digital interface or so called “Merging Unit”.

ISSN 16-12-2526
ISBN 978-3-940961-54-9

Click HERE for some interesting results of her work.

IEC 61850-9-2 FDIS of Edition 2 open for Ballot

The IEC 61850-9-2 Edition: Communication networks and systems for power utility automation – Part 9-2: Specific communication service mapping (SCSM) – Sampled values over ISO/IEC 8802-3

is open for FDIS ballot until 2011-07-29.

Changes comprise:

• Addition of an optional Link redundancy layer
  Link Redundancy:
  Parallel redundancy protocol and high availability seamless ring
  IEC 62439-3, Amendment 1
• Redefinition of “reserved” fields in link layer
• USVCB and MSVCB components
• Encoding for the transmission of the sampled value buffer

Podcast from Black and Veatch on IEC 61850 in the U.S.

A podcast provided by Black & Veatch reports how IEC 61850 is expected to be accepted in the U.S. power industry. It is also reported how American Electric Power uses the GE BRICK solution for the interface between the control room and the switch yard.

There is no doubt about the trend towards IEC 61850 in North America!

The GE Brick solution is based on IEC 61850 concepts. Many benefits provided by IEC 61850 are offered by the Bricks – except one crucial issue that is not supported: The Brick solution is NOT interoperable with fully IEC 61850 compliant IEDs like protection and control devices or merging units according to IEC 61850-9-2.

An IED with an IEC 61850 interface can NOT communicate with the Brick! So, the Brick is a vendor specific solution using mainly fiber optic cables and Ethernet and message formats from IEC 61850 to replace copper wires to the switch yard. The idea of an open international standard for multi-vendor systems is supported by fully IEC 61850 compliant merging units and other IEDs (as publisher) and other IEDs (as subscribers).

Click HERE for listening the podcast [some 14 minutes].
Click HERE for more information on the concept.

IEC 61850 in Australia - Some up-to-date Information

The Australiasien Power Technologies Magazine "Transmission & Distribution" published a couple for brief papers on IEC 61850 in the latest issue (05/2010). The following papers are contained:

• What Is IEC 6185O?
• Collaborative Engineering within Electrical Utilities
• Relay Application with IEC 61850 GOOSE Messages
• Scalable IEC 61850 Software Stack (Need Evaluation Software?)
• IEC 61850-9-2LE Process Bus Interface (more information)
• Digital Instrument Transformers with 9-2LE Interface

Please CLICK here to read the magazine.