Capacitors

series capacitors use at long length power transmissin lines for reduce inductive reactance. that is mean it makes shorter line.

Are you referring to high or medium power distribution systems?

isn't distribution already with medium ?

However you turn it, a capacitor is a extra impedance when used in AC power systems. The impedance Z equals:

___1____

ω*C

or 1/ (2*pi*C) . Used it when it suits you, to correct PF or to lose energy.

2 pi*f = omega

Capacitors wired in series causes the net capacitance added to be a smaller capacitance than either capacitor. By wiring up capacitors in parallel you get the sum of the two capacitors. This means that if you had a 1F and a 2F capacitor (ludicrous values, but easy math) you have the choice of adding five different values with these parts to a power distribution system; 3F (both capacitors in parallel), 2F, 1F, 2/3F (both capacitors in series), 0F (no capacitors).

Now capacitors are added in an AC electric power distribution to balance the loading. This means that the current and the voltage stays closer in phase to each other. This will mean as a power user you can have a more efficient use of the electric power given to you. When the smallest capacitance is added to your power grid, as a user you are already close to using all of the power that you are paying for.

To eliminate transmission of DC voltages.

Cheers! DZ

For long transmission lines the line drop due to line inductance may be very high.To reduce the drop series capacitors may be used.They are preferred over shunt capacitors for this since the regulation remains independent of the load without capacitor switching.For mw rated motor circuits also series capacitors are at times used especially to improve the starting voltage.careful design may be done to avoid problems such as shaft resonance etc.Further the series capacitors are generally rated only as per voltage drop which may be 20-50% system voltage.Should series capacitors open then the full system voltage will fall across the terminals.LA/Switches will be required for protection..