NERC asks unusual questions

[cranky108]

How would anyone answer this question from NERC? "Were there alarms in place to notify of a relay misoperation?"
I would be laughing if they weren't serious.

Are there any manufacturers who's relays provide misoperation alarms?

 

[dpc]

Maybe they were referring to a relay failure alarm?

Also, it depends a little on your definition of "misoperation" and knowing NERC, they probably have their own definition. If a relay was supposed to operate but did not, it could conceivably initiate a breaker failure and this would probably be alarmed.

 

[cranky108]

The relay in question is a breaker failure relay.

 

[tlrols]

Does your breaker failure relay post a target or relay status change when it detects a breaker failure? This question is somewhat rhetorical since that is it's purpose, correct? Knowing NERC they are probably asking you if that breaker failure relay function is sent back as an alarm log in your SCADA system. I would think that it would be, and if not you certainly noticed that you cleared a bus section, right?

Be VERY careful in thinking that NERC or FERC staff are not informed. They speak a slightly different language perhaps, but they are competent (and they deserve appropriate respect). We usually try to educate ourselves and them so that we can communicate better as a first step.

 

[cranky108]

Paint on a canvis does not art make. And as I found out, I was not given the whole text, just the questions.

It still stands that if you ask a question wrong, you may get a wrong answer (Which is a debate we are having, what was the intended question).

Can't NERC hire power system engineers.

 

[oldfieldguy]

"Were there alarms in place to notify of a relay misoperation?"

Yeah... They light up on the same panel as the fault anticipator.

old field guy

 

[m3ntosan]

Maybe if you still have old distance protection in the system, that will trip on VT blown fuse, VT supervision might be considered to give a hint on the maloperation

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

 

[cranky108]

I think the term is "unmonitored". That fits most electromechinical relays.

Loss of VT circuit is only good from the VT to the monitor. Dosen't do anything for a loose termation on the relay.
Sort of like the trip circuit monitor.

 

[m3ntosan]

@cranky108

In the UK the electromechanical distance relays will trip the circuit for a blown fuse, instead of locking up. In some other European countries there's a different approach and the protection will lock up for blown VT fuse, hence relying on the protection ‘to know’ if it's a genuine fault or not. In the UK, having a stiff system they decided to trip regardless, for the same reason they don't lock up the protection for power system swings, deemed unlikely to happen.

So, if you have a circuit trip and distance protection operated at one end only, also VT supervision alarm up (blown fuse), you can work out it was a malop


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

 

[cranky108]

All of our distance relays have fault detectors, that require a minimum amount of current in order to trip. IE no fault, no trip.
However our electromechinical panels do have potential lights, and are supose to be checked every month.

 

[tlrols]

Last I knew NERC HAS hired Power Engineers, but perhaps not the most nuanced in the way of relay speak it seems You can ask them what the heck they meant by the way. I do like the comment about the fault anticipator, lol. Where do you buy those at? It might be helpful if you could post the final story on this...

 

[m3ntosan]

@cranky108

In India, they thought that you need a fault to operate a distance protection as well and it ended up in tears

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

 

[DTR2011]

fault anticipator = ratio of current maintenance budget to the maintenance budget of 30 years ago.