# Power Factor Correction

• posted

Hello,

i'm interested in learning a little bit about PF Correction, by means of using compensation capacitors. More specifically, i want to search for products in this category for OUTDOOR use in distribution networks (not in industries, buildings etc. where capacitor banks are used).

Any suggestions?

And more importanly: i've heard that capacitors used for PF Correction cause harmonics in the network. Is this true? Because it doesn't seem very logical (to me at least). Why would a capacitor be responsible for harmonics?

George Tsakalos

• posted

I don't believe you are capable of power factor correction. When you can show me more skillful use of your shift key to CORRECT your orthography, I might start thinking an effort to help CORRECT power factor will be useful!

Bill

-- Ferme le Bush

• posted

Here is a simplified explanation of what happens. The capacitor resonates with the system's inductance. If that resonance occurs at a harmonic frequency, it greatly amplifies the effect of that harmonic throughout the system. The whole thing can look like a short circuit to the source at the harmonic frequency, causing protectors to trip, etc. The solution is to "detune" it by adding inductance so that the resonant frequency is between harmonics.

Ben Miller

• posted

Bill, you don't usually play the troll. Why this time? Bad day maybe?

• posted

Ben, first of all thanks for the answer, it covers me completely. I thought i was right to suspect that a capacitor can not produce any harmonics (a passive element cannot produce anything right?)

My special interest is in capacitors that are pole-mounted in MV networks. Is there any theory or "algorithm" that states where we should place capacitors to correct the cosö in the span of a MV line?

And by the way, can we use filters instead to filter out anything else than the 60 or 50 Hz signal and stop worrying about any high harmonic currents? You mentioned the inductance in series solution with the capacitors. But, wouldn't that work in the opposite way we're trying to go? Wouldn't that reduce the amount of Var the capacitors are "feeding" the network?

George Tsakalos

• posted

• posted

I get pissed off when someone wants help but is unwilling present the problem reasonably well. I can take a typo or two in stride. But all lower case or all upper cases is discourteous. Even bad grammar from someone where English is not a native language won't get me as upset as someone too lazy to use a shift key.

Bill

-- Ferme le Bush

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