Answer:
Capacitor bank is use to control the power factor of the load, because there is many inductive load in the circuit which is the cause of the lagging P.F, so we use the capacitors to maintain the P.F to the unity, the capacitor have the nature of the leading P.F that's way the resultant P.F of the load's lagging and the capacitor's leading current is near to the unity, and the unity P.F has very good effect on the network.