Reactors

Do you know any document that can help me in the dimensioning/calculation of High Voltage Reators:

Neutral Grounding Reactors
Shunt Reactors
Current Limiting Reactors


Thanks
Miguel

 

[scottf]

Are you trying to calculate what ratings of reactors you need, or are you trying to design the actual reactor?

 

[mikeangel]

Hi scottf

i've to calculate the ratings of a current limit reactor to reduce the short circuit curren. My custumer give only information about the system voltage (kV)and the Short-circuit power of source (kA) and i've tell him the reactor main characteristics, before i buy the equipment.

thanks
Miguel

 

[slavag]

Miguel.
You need do something with your customer... .
I don't have so much information about reactor calculation.
Please see attached, maybe its help you.
Regards.
Slava.
BTW. for damping ferroresonance, I can recommend you some new device instead resistor, if you want.

 

[majesus]

Excellen PDF, what's the source?

 

[magoo2]

Probably ABB. Resiblock transformers are an ABB product.

 

[slavag]

Magoo2, you are right.
It's ABB Switchgear Manual.
I don't know exactly, but I think possible order it via ABB site.
Regards.
Slava

 

[majesus]

Great, quick google search finds that you can download it here:

http://rs178.rapidshare.com/files/90331371/abb_manual_10e.pdf

 

[burnt2x]

This is what I did when computing for the current limiting reactor used to link two buses with the additional bus having a lower short circuit rating:
1. Start off with the kA of the higher SC rated bus
2. Get the kA rating of the additional bus
3. Calculate the difference of the two kA's.
4. The inductive reactance you need to limit the short circuit amps will be computed using Ohm's Law X =kV/kA (per phase values)

I have verified my calculations with an existing bus tie and found the values in the range, though not as conservative.

 

[mikeangel]

Thank you very much.

You've been very helpful to me.

PS:
thanks for the links to ABB Switchgear Manual.


Regards
Miguel

 

[QBplanner]

Hi Mike:

Size high voltage shunt reactor and Neutral reactor is not simple and can not be explained all here.

Neutral reactor is normally sized by either system planner and/or EMTP people. There is a E.W.Kimbarks paper 1964.
"Suppression of Ground-Fault Arcs on Single-Pole-Switched EHV lines by Shunt Reactors"

Pay attention that that paper offers 100% compensation method which,in reality,you may not require. I don't quite remember that IEC has a old standard, as long as the current follow through Neutral is leaa than 10 A (Or 15A)It shall be ok.

Higher voltage shunt reactor is decided by system planner from system point of view with the verification of EMTP study. A typical compensation level is from 40% to 80% of line charging. Beyond 80% will most likely get into resonance region. However, it is more complicated to size a higher voltage reactor then simply using the percentage of line charging.

It needs a good understanding of the system you studied and over voltage issues (Switching surge and temporary power frequency over voltage and staeady state power freqnecy over voltage)as well as the experience.

Lmiting reactor is low voltage reactor and I did not size it before. can not offer helps.

 

[mikeangel]

Thanks for your sugestions QBplanner.