Various outgoing feeders are taken out from the substations which are connected to lighting load, resistive load, capacitive load, or inductive load. Some feeders are having agriculture loads that are purely inductive. Due to inductive load, the power factor of the substation become lagging means the current lag behind the voltage.
During heavy load, the voltage level of the substations decreases, the reactive power supplied from the power station increases, and the power factor of the substation decrease. The shunt capacitor bank provides the additional reactive power required by the load, so shunt capacitors improve both the power factor and the voltage level of the substations. The shunt capacitors are operating at a leading power factor and consume the leading Vars by delivering the lagging Vars.
In short Capacitors bank in substations are used to improve the power factor of the substations from lagging to leading and also used for maintaining the voltage level of substations and also used for reactive power compensation in substations.
