Single Point Failure Modes

[Mbrooke]

Am I the only who sees videos like this and thinks that the owners got screwed/duped?

https://www.youtube.com/watch?v=X3TngyqcU6U

If the bus coupler breaker fails, a breaker sticks or the gear software fails the whole facility is left without power.

https://files.engineering.com/getfi...f23-a474-3ae9db67b207&file=Clipboard01234.jpg

 

[cranky108]

You are not the only one.

The most common single point of failure is the battery/ control power.

If they had used different switchgear for the two buses, there would be a tie breaker on each gear. This was a cost saving choice to use a single gear lineup.

Many plants also don't have but one relay per feeder.

On the other hand it is possible to go overboard with too many systems of backup, making a complicated mess.

 

[7anoter4]

Electrical Systems Reliability Theory which was en vogue in 70th of the last century is now "totally flawed" as some one said today.
However, there are still fewer studies like this:

https://www.intechopen.com/books/sy...iability-mathematical-models-and-applications

 

[Mbrooke]

I agree with both of your replies. Its seems like reliability theory no longer holds or is thought about.

 

[jimmy2times]

Not saying it’s perfect but your could look to offshore dynamic positioning vessels to see how / how not to design when operating a closed bus system. More savvy vessel owners will demand verification of things like short circuit testing of main bus, simulated failures etc. each year vessels in service are required to go through failure mode simulations that prove the redundancy concept and the ability of the ship to keep position in the water during the worst case failure

DP3 systems are designed for failures in all parts of design including flooding of compartment the routing of cables, etc etc

https://www.drillingcontractor.org/...bus-dp-systems-for-integrity-robustness-35010

 

[Mbrooke]

@Jimmy: thanks for the links.

A lot of failures seem to come from solutions to other lesser likely to happen failures or problems that just don't exist to begin. Vids like this remind me of the the outcome:

https://www.youtube.com/watch?v=LeFtwtvy4Wc

https://www.youtube.com/watch?v=YEOmaaofgJk

 

[cranky108]

There is the question of what is the cost of fixing the problem.

For power plants, there are so many things that can go wrong, that it is better to have more than one power plant.