What is the difference between Damping reactor & harmoincs reactor

[mostafabakry]

Hello Everybody,


I'm asking about the different between using current limiting reactors & harmonics reactor in a new 3.4MVAR & 6.8MVAR capacitor banks installation in a 33KV network for a 25MVA arc furnace

i had been informed from the supplier this reply here below

" Current limiting reactors are used only for switching transients of capacitor banks and they do not have  effect on harmonics.

But harmonic filter reactors are capable to do for both transients and harmonic filtering. It protects capacitors against bad effects(life time, blowing etc..) of harmonics.

If you compare the prices also, harmonic filtering reactors are approximately 30 times more expensive than current limiting reactor!"

can you please help me understanding that & give me your comments about that

 

[living2learn]

is the current limiting reactor you are talking about a neutral to ground reactor to limit the fault current?

 

[Skogsgurra]

Switching capacitors in a capacitor bank means that you switch devices with different voltage and near-zero impedance and that causes very high transient currents to flow.
Those high currents reduce breaker's life considerably, sometimes also cause the contacts to weld. The current limiting reactor reduces current peak, mostly by reducing the di/dt and needn't have a high L value - usually a few uH is enough.

Harmonics filter reactors are used to move the resonant frequency of transformer leakage inductance plus capacitors down below the harmonics frequencies (usually below third harmonic) and they are a lot bigger than the current limiting reactor. That size difference is reflected in the corresponding price difference.

Gunnar Englund

http://www.gke.org

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100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...

 

[pie314]

Filter reactors are basically shunt reactors. They are connected in series with a capacitor to create a low impedance path to ground for certain frequencies. A current limiting reactor is connected in series and therefore cannot shunt any harmonics.