The action of the capacitor?

 Power capacitor consists of series and shunt capacitors, are to improve power system voltage quality and improving the transmission capacity of transmission line, is the power system equipment.
The function of the series capacitor:
Series capacitor is connected in series in the circuit, the role is as follows:
(1) increase at the end of the line voltage. Connected in series in the circuit of the capacitor, the capacitance XC compensation circuit inductance XL, so that the line voltage drop is reduced, thereby improving the end of line (receiving end) voltage, can be at the end of the line voltage can be increased by 10% ~ 20%.
(2) reduce the receiving end voltage fluctuation. When the electric circuit is connected with the change of impact load great (such as electric arc furnace, electric rail, etc.), the series capacitor can eliminate the violent fluctuation of voltage. This is the role of series capacitor compensation on falling in line voltage is the change through the capacitor and the load, and the instantaneous adjustment has properties along with the change of load, can automatically maintain the load side (the receiving end voltage value).
(3) improve the line transmission capacity. The line reactance XC string into the compensation capacitor, reduce line voltage drop and power loss, accordingly improving the transmission capacity of lines.
(4) to improve the system power flow distribution. Capacitor connected in series on certain lines closed on the network, partially changed the line reactance, the current in the specified line, in order to achieve the purpose of economic power distribution.
(5) to improve the stability of the system. Line string into the capacitor, improve the transmission capacity of the lines, which in itself improve the system static stability. When line fault is resection (such as double loop was removed, but a return circuit of single-phase grounding resection of a phase), the system equivalent reactance, sharp, the series capacitor compensation is mandatory, short-term force a change in capacitor in series, parallel quantity, temporary capacitance Xc, the total system equivalent reactance decrease, increase the limit power delivery so as to improve the stability of dynamic system.
(2) the role of parallel capacitor:
Shunt capacitor in parallel system bus, a capacitive load is similar to the system bus, it absorbs the system capacitive reactive power, this is equivalent to a parallel capacitor to the system sends out the inductive reactive power. , shunt capacitor can to provide inductive reactive power, power factor of system operation, improve the voltage level, the receiving end of bus, it reduces the emotional delivery line reactive power, reducing the voltage and power loss, thus improving the transmission capacity of the lines.