Letters

Don't hesitate. Tell us what you like and what we can do better. Share your thoughts and experiences.

Alex, I just finished reading the article that you and Benton wrote on “to Goose or not to Goose”.
 I hope that people read it slow.  It really tells the whole story.  The functions, and the reasons that they exist. 

When we were conceiving Goose as part of UCA2, we knew we had to make it as good or better in performance and reliability than the existing wired practice and it needed to come at a lower cost too.  While not a day one objective this is what we were aiming for.  The requirements were derived from the protection practice of using a relay's contact output to drive the next device’s opto-isolator input. 
There were lots of naysayers, but we kept thinking that if protection and control engineers drove the requirements, without sacrificing our principals, we’d get it right.  We clearly did.                                

As we discussed what could go wrong, I came up with the repetition mechanism so that “normal traffic” would not overwhelm the 10 MB Hub’s (circa 1995).  No reason to send the “I’m ok” message every 4ms.  The message counter in the GOOSE is available to detect missed messages so that a breaker failure scheme would not be delayed if the initial message were missed. 

We wanted any generator stability critical clearing times to be adhered to. 
From tests we found that more than 20 GOOSE devices on the same LAN segment would start to produce collisions that might delay message receipt.  So, we knew that network design was essential in assuring that the time requirements were going to be met. 

As time went on Hubs were replaced with switches.  While making the design easier, we must never forget that GOOSE needs a suitable network to make sure that the performance and redundancy requirements will be met under the most severe of power system fault conditions.    
You were instrumental in making sure that we came up with something that we could configure in an actual relay.  The experts in the room included folks that could assure us that our thoughts could be put into firmware and interoperate between vendors. 

We called ourselves the “Chicago 7”.  Chicago is the “birthplace of GOOSE”.   Charlie Sufana, John Tengdin and I have given several presentations on the origin of GOOSE and created the original substation scenarios and lab tests to validate that GOOSE would scale. 
We only hoped that test equipment would be developed.  We did not anticipate how the cost to implement would decrease so dramatically. 

A lot has changed in the years since the UCA2 GOOSE specification was published.
The network hardware that was prohibitively expensive is now commonplace.  No more Hubs.  Switches allow the network to be engineered.  Substation hardened components are available.  Programming tools allow the engineer to develop repeatable designs that can be well documented.  Test equipment assures that the devices are configured as engineered and allow analysis of events.  There are lots of standards, guides and magazine articles that can be consulted. 
This article really describes the features and gives excellent examples.  Like a piece of wire, the applications are endless.  This article should answer anybody’s “where do I start” question.  Great work! 

Mark Simon
Retired - ComEd/Exelon

PAC World:  
Thank you, Mark.
I am glad that you like the article and hope that it will help many people to better understand GOOSE and decide to do it.

Talking about the Chicago 7, maybe many people in our industry do not know who they are: Kay Clinard, George Schimmel, Herb Falk, John Tengdin, Mark Simon, Charlie Sufanna, Alex Apostolov.

 

pac world:

Editor in chief: dr. Alexander Apostolov (USA)
Editors: Christoph Brumer (Switzerland), Yana St. Clair (USA)
Design Layout Concept: Marek Knap (Poland)
Graphic Design: Iagoda Lazarova (USA),
Dan-Andrei Serban (Romania)
Web Master: Ognian Samokovliiski (Bulgaria)

Advisory Board:

Christoph Brumer (Switzerland), dr. Damir Novosel (USA), Graeme Topham (South Africa), dr. Iony Patriota (Brazil), Jorge Miguel Ordacgi Filho (Brazil), prof.
Mohindar Sachdev (Canada), prof. Paul Lee (Korea), prof. Peter Crossley (UK), Rannveig Loken (Norway), Rodney Hughes (Australia), prof. Xinzhou Dong (China

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PAC World magazine is published quarterly by PAC World.  All rights reserved.  All published articles express solely the opinion of the authors. Reproduction in whole or in part of any material in this publication is allowed.
Parent company: OMICRON electronics Corp. USA

Power. Flexible. Easergy.
BeijingSifang June 2016