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View Full Version : What are the uses of capacitor bank


dinny shinny
Oct 21, 2009, 12:16 PM
How is the voltage profile increased by using capacitor bank..

KISS
Oct 21, 2009, 12:22 PM
It's not. The phase relationship between voltage and current is.

dinny shinny
Oct 21, 2009, 05:54 PM
It's not. The phase relationship between voltage and current is.

Can u explain it in clear...

KISS
Oct 21, 2009, 06:05 PM
Voltage is delivered as say 120 V, 60 Hz, so that never changes, capacitor or no capacitor, the utility will adjust so voltage is constant.

Power is equal to V * I * cos (theta) when the current is sinusoidal and the voltage is sinusoidal. Theta is the phase angle between voltage and current and is 1 for resistive loads.

AC inductor circuits : REACTANCE AND IMPEDANCE -- INDUCTIVE (http://www.allaboutcircuits.com/vol_2/chpt_3/2.html)

Current lags voltage by 90 deg in a pure inductor.

Current leads voltage by 90 deg for a pure capacitor.

By automagicly adding capacitors, you can force the phase angle to be close to zero. Power factor = 1, cos(0deg) = 1

Commercial customers typically get charged a premium when their power factor is low because the utilities transmission lines have to be bigger.