Stuck breaker protection 1

[KnicksJets]

Could somebody give a primer on Stuck breaker protection, beyond the basic understanding (i.e. these are used in case a breaker is not tripped when asked to do so; a timer starts when the trip signal is sent and when the timer expires stuck breaker initiates and trips other breakers around that line). Any document or article detailing this would be appreciated.

 

[dpc]

Breaker failure is well covered in J L Blackburn's Protective Relaying book. I'm sure Googling "breaker failure protection" will turn up a lot of leads as well.

 

[DTR2011]

This sounds like you are looking for a form of breaker failure protection.

Here is a good source (Draft) Breaker Failure

 

[KnicksJets]

Appreciate the response. There are plenty of documents on breaker failure protection schemes. I wanted a specific detail on Stuck Breaker protection. But I appreciate the help.

 

[dpc]

In what way is "stuck breaker" protection different from breaker failure?

 

[stevenal]

From the description provided above, there is no difference.

 

[DTR2011]

@Pdshah

According to the IEEE PSRC document (linked above) on Breaker Failure Protection, "Breaker failure protection is designed to operate when the protective relaying scheme initiates circuit breaker trip and that breaker does not correctly interrupt the fault. The breaker failure condition is also known as “stuck breaker”."

As many have said above, stuck breaker protection = breaker failure protection. With that said, what is your question? I am not sure of an IEC equivalent name, other than breaker failure protection is a fairly well understood concept worldwide. If anything, "Stuck Breaker Protection" is a rather inelegant description of breaker failure protection that needs to be removed from our collective vocabulary.

If you are looking for still more references, there is an excellent FAQ on power system protection located HERE

 

[ScottyUK]

'Breaker fail' is a common name over here. 'Stuck breaker' is a new name to me, sounds like something my young 'un would use as slang for breaker fail protection. ;-)

 

[m3ntosan]

ScottyUK,

In the UK, i heard 'stuck breaker' term being used when you really have a stuck breaker, like 'trip circuit 1 and 2 faulty' and you know whatever happens that CB is not going to trip/open, with only options left to open the breaker locally from the trip coil (if it works) or take it out on a bus coupler or bus section and in the end defeat interlocking function to isolate it on busbar disconnector.

If it's critical for the system or demand and you need to keep the stuck breaker in service, you end up leaving the equipment on a dedicated bar with CBF timer set down to zero.

May you grow up to be righteous, may you grow up to be true...

 

[DTR2011]

A stuck (failed) breaker could also be something completely unrelated to the trip circuit(s). Two such examples that come to mind are
mechanical (linkage, poor lubrication / exercise) failure and loss of dielectric (which is often part of the breaker control circuit (low- low SF6 - block trip/close), which can be used to drive an input to the BF scheme / special logic.

 

[m3ntosan]

Agreed, smallgreek!

There are several ways to end up with a stuck breaker, loss of operating mechanism could cause it, if nitrogen and oil for instance.

For a mechanical problem you don't get any alarm and you don't know you have a stuck breaker until you have a breaker fail. For loss of dielectric, you don't really get a stuck breaker, you should get close lockout before trip lockout, so you have an option to take a decision and get it off the system while you can and most of the cases you can top up the breaker while in service.

May you grow up to be righteous, may you grow up to be true...

 

[stevenal]

"Stuck" to me means a mechanical problem. Open coils don't cause a breaker to "stick" as proven by operating the emergency trip. "Breaker failure" (to interrupt current) relaying doesn't care if the breaker is mechanically stuck closed, there is an open trip circuit, or a failure within the interrupter.

 

[LionelHutz]

I too would like to hear what the OP means. Mechanically stuck or an open trip coil or a miswire in the trip coil circuit all have the same end result no matter what you call it. The breaker doesn't open when the protection relay tries to trip it and sometimes you want or need a backup circuit to still provide protection.