Mark VI 2nd breaker synchronization

Dear all,

As you know, Auto and Manual synch options are available in MVI. I would like to understand how you guys see the use of each option.
Our procedure doesn’t distinguish the way 52G or 52L are synchronized and so the auto sync is used for both situations.
I understand auto sync is adequate for 52G synchronization since it automatically setpoints machine slip to avoid reverse power (perfect). But for 52L is the same? I must that tell you that I saw this algorithm bringing installation grid frequency 50.1Hz and I don’t see any benefit from using it for 52L. This may be a challenge since synch periods are smaller and for 52L installation has it own synch relay (which of course I can use bypassing MVI).
Since frequency, voltage, and mainly the angle is ok, I think that manual synch may enough for 52L. What is your opinion?

thank you all
 
Re read my latests posts ( reply to your first post on VTUR...)

You should provide SLD and SYNCHRO PROTOCOL /PROCEDURE that you intending to do ...

Selection of second breaker is another thing ....We know nothing about plant synchro configuration...is there Dead bus selection/synchro solution implemented...

My thinking is that you are not sure about what you are inetnding to do so you come here and try to get help...
But without replying to posts and adding needed /asked informations...it will not possible for me at least to support on this case...


So hasta la vista ! Best for all with that case...
 
Children,

Let's all play nice, please.

50.1 Hz for grid frequency? How does one do that? Is that some bit of code that GE provided? Or something that's recommended by someone else (the external synch check relay)?

A SLD (you really should explain the TLAs (Three-Letter Acronyms) you use, ControlsGuy25), also known as a Single Line Diagram (a dumbed-down version of a three-phase diagram showing major pieces of equipment and protection) would be helpful, because you are adding little bits and pieces of information to this discussion all the time. This is a technical forum, and a technical problem. That means that even though you think your English isn't perfect (it's pretty good, actually, maybe better than ControlsGuy25's) you need to lay out the entire problem in your opening (original) post. Doling out new information in dribs and drabs (a little at a time) isn't good for anyone and doesn't get you a quick or concise answer. Is a SLD (Single-Line Diagram) absolutely necessary? No; not with a good explanation.

And, getting back to MY question--how are you (or anyone) going to adjust the grid frequency (we are presuming--because you haven't told us) the turbine-generator is being synchronized to a large ("infinite") grid, so that's going to be difficult to adjust grid frequency (maybe you meant generator frequency???).

We also don't know what kind of turbine the Mark* is controlling, and we don't know the nature of the load on the other side of 52L. We don't know who provided that bit of code you are referring to--but, if it was provided by GE's Belfort "engineering" group you can be sure it's unusual and probably overly and needlessly complicated, but it was probably written with good intentions based on some input from someone during the engineering phase of the original installation or some modification. But, again, if it came from GE Belfort, you need to work with GE Belfort to understand why they have done that. Because, only GE Belfort (thinks) they know why the code they write is better than anything else which might have been working fine for decades.

And you need to remember most of the people you are explaining your situation to here are not generator relay protection engineers. Myself, I'm just an old field engineer (back when they sent engineers to commission multi-million dollar turbine-generators) who liked being in the field and doing engineering, as opposed to sitting in front of HMIs and making crappy displays "better" or fixing displays from the factory instead of making the turbine-generator start and stop without alarms (yes; it is, indeed, possible--though when working on GE Belfort units it's pretty darned hard to do). Most field people didn't last more than 3-5 years before they wanted to get off the road. Me? I'm not like most people--and that's okay, because the world needs all kinds of people and it's a damn good thing we're not all alike.

Give us complete information, and we can probably help you.
 
Sorry if I confuse you all guys. I understand some times splitting the problem in parts would be better to get concise answers. In this thread I was trying to figure out how Ge Mark vi functions are adequate for each situation (52G or 52L) So point by point:
1. When I said 50.1 Hz i meant industrial electrical system frequency (includes a 6B unit) which i intend to synchronize to the “infinite bus” at 50Hz.
2. Nobody adjusted the industrial electrical system. It was 6B Mark VI auto sync algorithm to do so. I see a +0.15hz setpoint at the code.
3. I’m trying to figure out which is the benefit of using mark vi auto sync instead using a manual sync or just the installation sync relay to perform a industrial electrical system sync to a infinite bus.
4. The industrial installation has two methods to interconnect with the “infinite bus”
- manual sync with a 25 sync relay with a -12,12 deg and -1,1hz windows.
- Mark vi(vtur, vpro) plus the above mentioned 25 sync relay.

btw I must tell you that I’ve learn with your wisdom through all this years. I truly respect your support.Thanks
 
Children,

Let's all play nice, please.

50.1 Hz for grid frequency? How does one do that? Is that some bit of code that GE provided? Or something that's recommended by someone else (the external synch check relay)?

A SLD (you really should explain the TLAs (Three-Letter Acronyms) you use, ControlsGuy25), also known as a Single Line Diagram (a dumbed-down version of a three-phase diagram showing major pieces of equipment and protection) would be helpful, because you are adding little bits and pieces of information to this discussion all the time. This is a technical forum, and a technical problem. That means that even though you think your English isn't perfect (it's pretty good, actually, maybe better than ControlsGuy25's) you need to lay out the entire problem in your opening (original) post. Doling out new information in dribs and drabs (a little at a time) isn't good for anyone and doesn't get you a quick or concise answer. Is a SLD (Single-Line Diagram) absolutely necessary? No; not with a good explanation.

And, getting back to MY question--how are you (or anyone) going to adjust the grid frequency (we are presuming--because you haven't told us) the turbine-generator is being synchronized to a large ("infinite") grid, so that's going to be difficult to adjust grid frequency (maybe you meant generator frequency???).

We also don't know what kind of turbine the Mark* is controlling, and we don't know the nature of the load on the other side of 52L. We don't know who provided that bit of code you are referring to--but, if it was provided by GE's Belfort "engineering" group you can be sure it's unusual and probably overly and needlessly complicated, but it was probably written with good intentions based on some input from someone during the engineering phase of the original installation or some modification. But, again, if it came from GE Belfort, you need to work with GE Belfort to understand why they have done that. Because, only GE Belfort (thinks) they know why the code they write is better than anything else which might have been working fine for decades.

And you need to remember most of the people you are explaining your situation to here are not generator relay protection engineers. Myself, I'm just an old field engineer (back when they sent engineers to commission multi-million dollar turbine-generators) who liked being in the field and doing engineering, as opposed to sitting in front of HMIs and making crappy displays "better" or fixing displays from the factory instead of making the turbine-generator start and stop without alarms (yes; it is, indeed, possible--though when working on GE Belfort units it's pretty darned hard to do). Most field people didn't last more than 3-5 years before they wanted to get off the road. Me? I'm not like most people--and that's okay, because the world needs all kinds of people and it's a damn good thing we're not all alike.

Give us complete information, and we can probably help you.
Hi All,


Lets play nice!

CSA,
I have never hear that my english was not ok ....I did something like 30 countries worldwide and worked on several projects ...with many people..

So these comments are just not founded on any serious criteria for me ..

Esganfia,

All the best with this case!
 
Sorry if I confuse you all guys. I understand some times splitting the problem in parts would be better to get concise answers. In this thread I was trying to figure out how Ge Mark vi functions are adequate for each situation (52G or 52L) So point by point:
1. When I said 50.1 Hz i meant industrial electrical system frequency (includes a 6B unit) which i intend to synchronize to the “infinite bus” at 50Hz.
2. Nobody adjusted the industrial electrical system. It was 6B Mark VI auto sync algorithm to do so. I see a +0.15hz setpoint at the code.
3. I’m trying to figure out which is the benefit of using mark vi auto sync instead using a manual sync or just the installation sync relay to perform a industrial electrical system sync to a infinite bus.
4. The industrial installation has two methods to interconnect with the “infinite bus”
- manual sync with a 25 sync relay with a -12,12 deg and -1,1hz windows.
- Mark vi(vtur, vpro) plus the above mentioned 25 sync relay.

btw I must tell you that I’ve learn with your wisdom through all this years. I truly respect your support.Thanks
I am trying to sort this out. So please correct me if I have not sorted properly.

GE Frame 6 with MKVI controls.

This machine has two generator breakers. I will call them breaker 1 and breaker 2.
Breaker 1 uses the MKVI auto synch to close.
Breaker 2 uses manual synch controls. I assume Breaker 1 has auto synch disabled during startup which will allow one to close breaker 2 when needed.

Just guessing but this unique configuration is probably there to allow the generator to connect to 2 seperate ring bus in the switchyard for redundancy.

I think you are trying to ask how do I use the MKVI to close either breaker( breaker 1 or breaker 2) with MarkVI auto synch.

Have I sorted properly?
 
I am trying to sort this out. So please correct me if I have not sorted properly.

GE Frame 6 with MKVI controls.
Correct
This machine has two generator breakers. I will call them breaker 1 and breaker 2.
Just One Breaker: 52G . 52L is the industrial electrical system main breaker (interconnection the infinite bus)
Breaker 1 uses the MKVI auto synch to close.
Yes. Thats it.
Breaker 2 uses manual synch controls. I assume Breaker 1 has auto synch disabled during startup which will allow one to close breaker 2 when needed.
Breaker 2 can be sync manually (dedicated 25 relay) or by using MVI auto sync (which also as the 25 relay in series). Breaker 2 is sync after Breaker 1 in different time frames.

Just guessing but this unique configuration is probably there to allow the generator to connect to 2 seperate ring bus in the switchyard for redundancy.

I think you are trying to ask how do I use the MKVI to close either breaker( breaker 1 or breaker 2) with MarkVI auto synch.

Have I sorted properly?
Answers in bold.
The point in this thread i would like to clarify is: Why using MVI auto sync algorithm which is pushing frequency (reference bus plus 0.15Hz) and voltage (reference bus plus 1.5%) to synchronise and electrical installation (~20-30MW island)?
I don't see no technical point of view by using a auto sync to synchronise other breakers than 52G. A 25 relay must be enough.
Many thanks for your questions.
 
esganfia,

You're correct--there is no technical reason to use automatic synchronizing at all--even for the generator breaker (52G). Manual synchronization would work just fine. And, most grid operators/regulators will not permit a single automatic relay to perform synchronization--that's why there are usually two synchronizing relays in series for automatic synchronizing, and a single synch check relay for manual synchronizing (which requires the human operating the breaker close switch AND the synch check relay to both be closed at the same time--so two means of checking for proper synchronization).

We can't see the configuration and application code running in the Mark VI at your site. +/- 0.15 Hz seems very excessive. HOWEVER, you say that the scheme has worked in the past. SO, WHAT HAS CHANGED???? Isn't THAT the question???? If it worked, then what has changed?
 
I would like to expand on CSA's comment regarding the need to 2 relays: a synch and a synch check.

Even during manual synch, two relays are in play. But sometimes even that is not enough.

I have witnessed the damage to gen breakers after a out of phase synch. This is why arc chute style breakers are being replaced by the vacuum bottle style.

Something as simple as not maintaining a breaker can cause destruction. I recently witnessed the destruction of a Generator Step Up Transformer. Extreme weather conditions i.e. very cold, Loss of strip heaters in the breaker enclosure, and lack of breaker maintainence caused the breaker timing to increase.

A GSU is not something one can just purchase on the internet. They are very expensive and have long lead times.

I don't see no technical point of view by using a auto sync to synchronise other breakers than 52G. A 25 relay must be enough.

My point is the synch process is not something that is to be taken lightly.
 
I would like to expand on CSA's comment regarding the need to 2 relays: a synch and a synch check.

Even during manual synch, two relays are in play. But sometimes even that is not enough.

I have witnessed the damage to gen breakers after a out of phase synch. This is why arc chute style breakers are being replaced by the vacuum bottle style.

Something as simple as not maintaining a breaker can cause destruction. I recently witnessed the destruction of a Generator Step Up Transformer. Extreme weather conditions i.e. very cold, Loss of strip heaters in the breaker enclosure, and lack of breaker maintainence caused the breaker timing to increase.

A GSU is not something one can just purchase on the internet. They are very expensive and have long lead times.

I don't see no technical point of view by using a auto sync to synchronise other breakers than 52G. A 25 relay must be enough.

My point is the synch process is not something that is to be taken lightly.
I totally agree. I think this image is self explanatory. And that's why i'm struggle to understand if i'm missing some point about MVI ASYNC pros/cons for 2nd breaker sync. Of course MVI has breaker closure compensation and straight windows, but i don't need an algo that shorts sync windows (by accelerating +0,15Hz and setting+1,5% voltage). Thanks
SAMPLE.jpg
 
esganfia,

Your drawing is merely a sample drawing. The MarkV and MarkVI do A LOT more than your drawing.
Each breaker closure is timed in cycles. If the breaker does not perform within specs the MarkVI will alert you of problems.
 
I wrote and submitted my assessment of the drawing above. I would be very surprised if the entire 52L breaker close circuit only contained those elements.

BUT, that interposing relay could be the issue. Even if the Mark VI is trying to close 52L, if the synch scope is rotating faster than 4 or 5 or 6 or more rotations in 10 seconds the breaker close signal may never actually be long enough to pick allow the interposing relay's coil to be energized long enough to actually close the contact. It might be a solid-state relay (I hope not!), but the Mark is probably doing it's job but that interposing relay could be stopping the signal from getting to the 52L breaker close coil.
 
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