New concepts in substation interlocks?

[slavag]

Dear All.
I would like back to attached topic.
thread238-151464.
Today many mnf. provide projects with protocol IEC61850.
What do you think about new concepts in substation interlocks? Somebody have experience with IEC61850?
1. Only HW interlocks.
2. Only SW interlocks.
3. Both of them.

Note: of course not PLC or interlocks in computer.
Base only on Bay Controllers.
Regards.
Slava

 

[asekhar]

I firmly believe that a combination of both SW & HW interlock is the better option. All emergency / critical interlocks should have hardwired backup, while interlocks of lesser criticality can be just SW interlock.

Anand Sekhar

 

[lz5pl]

In our country only combined interlocks are accepted where substation control system provides software interlocks. By the way, it is a bit difficult to provide SW interlock for some manual operated disconnectors.
Now I have a project for 110 kV block Line-Transformer with earthing switches on both ends of the line. I am considering to propose for them interlocking via spare fiber from FO cable used for cable differential protection. I have controlers on both ends which communicate via this fiber using 61850. But I am not sure whether customer will accept it - utilities are a bit conservative.
What is your opinion?

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It may be like this in theory and practice, but in real life it is completely different.
The favourite sentence of my army sergeant

 

[ScottyUK]

We are in the process of having the ABB SCS-100 in the substation we share with our transmission system operator upgraded to an SCS-500. A bay controller upgrade from the RE*-216 bay computer is part of this work. The new solution will use software interlocking to IEC61850 and I am more than a little nervous about it. We have had some problems with hardware interlocking due to relay problems (long story) but we've never had a fail-to-danger result from these problems.

I'm watching this thread with interest.


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If we learn from our mistakes I'm getting a great education!

 

[lz5pl]

I have no experience with REC670 bay controllers, which probably will be upgrade from REx 216 in your case, but I hope they will be reliable enough. I think we have one system installed here, I haven't heard anything wrong.
My last project was 220/110 kV substation - seven 220 kV and sixteen 110 kV bays, double busbar system with third - transfer bus. This is HV switchyard of a power station, so additional non-standard interlockings were required for operation of generator bays. All this was controlled by SICAM PASS control system (Siemens). No any serious problems after clearing of usual initial mistakes and omissions. Design was made by Siemens. We were subcontractors on commissioning of relay protections only there, but also involved in testing of control, signalling, etc., so some changes in configurations were made by our guys too. My impression is that when the system is carefully commissioned you should not expect serious problems.
I remember another project three years ago - one of the first control systems using 61850 protocol, made by AREVA. Their software was not in very good shape at that time and operator's station PC's crashed very soon after energizing. So until AREVA engineers repair the system, substation operated 2 months only from bay controllers without any problems. Good example about advantages of 61850 protocol - it is not PC-dependent. Actually the system operated, because it exist in bay controllers, not in operator's PC. I don't want to say anything bad for AREVA - it was in the first year of 61850. I am sure now it is much better !
So, don't worry, but watch carefully comissioning ;-)

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It may be like this in theory and practice, but in real life it is completely different.
The favourite sentence of my army sergeant

 

[slavag]

Hi Scotty.
I underastand at you as well.
It's not so simple change logic of interlocks , change philocophy of EE, but we must do it. We must change our mind. It's our future, substation w/o HW interlocks, only SW interlocks.
I don't want disscaus about advantages and disadvantages of IEC61850 ( I haven't any experience with this protocol).
But I have 10 years expirience with other protocols and commissioning at about 45 substations with peer to peer ( bay to bay )communication between IED. All SS with HW and SW intelocks in parallel. It's expensive, hard commissioning
and today ( after 10 years) I understand we don't need so much "redundancy". In additional IEC61850 open for us new option of redandancy:
1. ring connection.
2. double ring connection.
3. full monitoring of communication
etc, etc.
What is our problem, we need learn again.

I think, Scotty, your big problem on this moment and not only your, we depend on many communication "tricks".
But, I'm sure, after good courses, Scotty,you, with your background and experience, will understand, what you have and will happy.
No repeater relays, no wiring betweem bays, additional terminals , interconnection diagrams, etc.
So, as Iz5pl, saied, don't worry, but watch carefully comissioning. I would like add, request from vendor test:
1. Operation in several undefined position of elements.
2. Operation in case of problems with Rx and Tx separatly.
3. Loss of power supply of network switches, check recovery tiome of system.
4. Indication of loss of communication on bay controllers.
5. Overriding.
Second, you are not first.
And, we with you.
Iz5pl, O.K. you have now two ES (grounding switch) on both of ends of line. And don't have communication, no problem:
"No communication-no permit to close"' it's rule.
"No clear position of object-no permit to close"
Now, you have HW interlock, you don't know, what is a status of aux. contacts, what happend with control cable.
In case of FO, you have on-line monitoring. In case of SW interlocks, we work with double indication in case of HW interlocks it's only single.

Why, we don't say about "new" BBP, line differntial protection, it's work many years w/o problem and based on FO communication. What is a differnce?

Regards.
Slava.
We'll continue

 

[lz5pl]

Slava, I am fully agree with you. I rely on FO communications and SW interlock for this case. Problem is conservatism in utilities. I will propose this solution, and will see what they will decide. But I am not very optimistic. They don't like to approve control of 110 kV bay via relay protection and insist of separate controller. I mean control from back-up protections, like REF543, or 7SJ64, or MiCOM P139, not from main protection.
But you are right, we should push a bit and after some time the things will change.
I remember i mid-80-s Head of relay protection department in National Electric Company blocked any but electromechanical relay protections, because "Who will maintain them? Who will repair printed circuit boards when faulty ?" Because of that we jumped from electromechanical directly to numerical relays!

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It may be like this in theory and practice, but in real life it is completely different.
The favourite sentence of my army sergeant

 

[slavag]

Hi Iz5pl.
Yes, it's our next step, control via back up protection in HV and EHV.
You are right, conservatism in utilities and in many designer company, this is bigest problem.
We also provide on last year for trafos 161kV/22kV 90MVA IED with protection and control in same box. Any problem( on this moment of course).
Now in all tenders for the industrial, I put control and protection in smae box. From next projects, I start push on customer, used only SW interlocks.
We have reference with BFP and ATS applycation via FO and SW only.
Iz5pl, jump directly from EM relay to numerical, it's very dificult. Today, lot of russian EE in this position.
Good luck.
Regards.
Slava

 

[lz5pl]

I don't think it is so difficult to jump from electromechanical to numerical. At least I cannot remember for myself any "cultural shock" For me is more difficult, if not impossible to start now again with electromechanical !

Seriously speaking, it depends on the people. Young engineers are so flexible, that one of my guys started with generator relays 5 months after coming in the company - first relay - watching me, second - under my supervision, next - I just check test records. I don't think he even considers that as something so much difficult ! Well, I prepared the test routine, but why else I get old on that job



------------------------
It may be like this in theory and practice, but in real life it is completely different.
The favourite sentence of my army sergeant

 

[slavag]

Only one small thing.
Check generator relay with test procedure ( connection points, values of secondary injection) it's one side.
What about primary test and on-load test, what about fix problems?

 

[lz5pl]

This particular case was retrofit of old power station - replacement of complete control and protection systems, where our part include only relay protections. Testing of the generators was not our's. Primary tests and on-load test of relay protections operation is included in procedures, of course.

------------------------
It may be like this in theory and practice, but in real life it is completely different.
The favourite sentence of my army sergeant

 

[slavag]

Scotty, what happend?
What news?
Heh, prefer SW interlocking and FO connection.( after 6 hours of contol cables checking!!!!)
Regards.
Slava

 

[ScottyUK]

Hi Slava,

We share a transmission substation with our TSO but they're carrying out the upgrade on our equipment because of certain legal requirements in the contracts between our companies. The project is progressing at a slow pace due to some operational restrictions which are limiting release of bays for upgrade. I am trying to reserve judgement and maintain a professional neutrality but up until now I wish ABB Baden were doing the upgrade in terms of the appearance of the project. Functionally it seems fine, it just doesn't look like the attention to detail which was obvious in the original build is present in the upgrade. We haven't got enough bays changed over for me to comment on the bay-to-bay interlocking, but the bay internal interlocking seems well thought out. Our circuits don't get started until next year because of generator outage profiles - ask me for my feelings next year when we start commissioning!


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If we learn from our mistakes I'm getting a great education!

 

[slavag]

Scotty Good Luck.
My regards to Baden.
I hope, you are in Du-Parc.
Are you upgrade RE216 to new FW with IEC61850 or upgrade
them to RE670?
Regards.
Slava

 

[ScottyUK]

It's RE670 based. It is a shame to lose the REG216 - it has been outstandingly reliable. Hopefully the '670 will be as good.



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If we learn from our mistakes I'm getting a great education!

 

[slavag]

What Scotty?
Are them upgrade generator protection REG216 to REG670?
or you meant control REC216 to REC670?

 

[ScottyUK]

Hi Slava,

Sorry, I should have been more clear. The REG216 is being replaced with a hybrid system using RE670 and REG561. The 561 is providing bay control and protection, and the 670 is providing interlocking and local MMI. There is currently a separate topology control REC216 which handles interlocking for the substation. I've had limited involvement in the design so far because the generator bay designs have not yet been formally released for review, but that is the basic concept as far as I understand it.


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If we learn from our mistakes I'm getting a great education!