69 kV Cap Bank

[jeebusmn]

What limits you on how big of a cap bank you can install at a 69 kV switchyard? I have 18 MVARS already at a switchyard and an 6 additional would help resolve a problem but I am being told that 24 MVARS is quite a bit on a 69 kV system.

 

[rbulsara]

No enough information. 24 MVAR is "quite a bit" relative to what? What is the MVA and MW of the system?

Rafiq Bulsara

http://www.srengineersct.com

 

[Bronzeado]

jeebusmn,

We have used capacitor banks of 21Mvar, 69kV, with series reactor to reduce inrush current.
One of the criteria of sizing capacitor bank is to keep the steady state voltage variation below 3% when switching them.

Best regards,

H. Bronzeado

 

[Marmite]

Check that your switchgear is type tested for, and has an assigned rating for back to back capacitor switching.
Regards
Marmite

 

[jeebusmn]

We don't have room at the switchyard so this isn't a possible solution anymore.

Our system peak is around 1450 MW.

I assume this 3% rule of thumb is only for banks that switch in and out frequently? I beleive that most of our cap banks our switched in or out maybe 2 or 3 times a year.

 

[rbulsara]

Not having room is hardly an electrical engineering problem.

Rafiq Bulsara

http://www.srengineersct.com

 

[davidbeach]

Not having room is hardly an electrical engineering problem.

Oh, but it is though. Just as cost is a constraint, so is available space. If it can't be built because of a lack of space, then it was a bad design that didn't consider all the project requirements.

 

[rbulsara]

david:

Yes. Bad design..lack of creativity..all could be possible. I was just relating to the original question. The actual "problem" and "solution" is still elusive from the posting. 24 MVAR is peanuts compared to 1450 MW.

Rafiq Bulsara

http://www.srengineersct.com