Shunt Reactors

 What is the use of a shunt reactor in a power system?

Shunt reactor is an equipment used for voltage control of the line in the power system. During the operation of a power line the load fluctuates from full load, light load or no-load causing voltage variations that need to be controlled either in steady-state or transient In these conditions is normal that the line voltage varies due to the capacitive current of the line. During very light load or no-load the line voltage increases. The phenomena is called Ferranti effect. The shunt reactor is an inductance connected from line to ground rated to absorb the capacitive current of the line thus reducing the voltage to avoid damages due to over-voltage to the customers.

Another type of reactor is the series reactor. This type of reactor is used to limit the short-circuit current of the system increasing the equivalent impedance of the line and thus reducing the short-circuit current.