When electrical energy transmission methods were used, it was noted that if the voltage is sent by, for example, 100 kV, it reaches the arrival point with a higher value than that sent, it may reach a value of 110 kV or more, and the percentage of increase in voltage changes depending on the length of the line, the value of the transmitted voltage and several other factors.

And this increase in the value of the voltage is not a random increase, but to understand it simply, let’s remember together what is the idea of the work of the Capacitor , it is two conductors with two different voltages and between them is an insulator, and the Capacitor charges and discharges with each cycle of electric current and as we know that the earth is a conductor with zero voltage and the transmission line has a voltage of a value and the air is a dielectric between the earth and the line and therefore we have a capacitor along the line that charges and discharges and this discharge is the one that It increases in voltage and that is why the voltage increases when reaching higher than the voltage when transmitting.

But the value of the voltage designed at the electrical equipment and the maximum value allowed to increase it must be taken into account in a way that does not affect the efficiency of the electrical network.

So it is not correct to design the network, for example, at a voltage of 400 kV and send the voltage at a value of 400 kV, but the voltage reaches a value of 450 kV. Therefore, we need to compensate for the value of the un-required increase in voltage.

Therefore, we need to reverse the value that is added by the formation of capacitance along the line. The theory of the action of the reactor impedance is the opposite of the theory of the work of the capacitor, where the impedance consists of a coil that can be connected in series or in parallel, and in this case it must be connected in parallel with the Shunt reactor line, so if we add the reactor with a value that reduces the voltage equivalent to the value that the capacitor increases along the line, we can maintain the voltage between the transmitter and the receiver.

Where the Reactor can be connected in more than one way, for example, it can be connected with the busbar directly through the circuit braker, and in the event that the line is very long and an increase in voltage may occur with a high value, for example, if the transmitted voltage is 400 and will reach a value of 450 kV, for example, this value must be equalized before connecting the line from the other side with the network, so Reactor must be added to the line directly before connecting with the network.