Final answer:
Capacitor banks in substations serve to store electrical charge, stabilize current flow, reduce losses, improve voltage regulation, and enhance transmission capacity. They are comparable to a bucket in water systems, filtering out fluctuations in current flow.
Step-by-step explanation:
The purpose of a capacitor bank in a substation is to store electrical charge and provide energy storage or power conditioning within the electrical system. Specifically, capacitor banks are used to balance the impedance of the effective inductance in transmission lines, reduce power loss, improve voltage regulation, and increase transmission capacity. They act much like a bucket in a water system, smoothing out the current flow and providing a steadier supply of power despite fluctuations that can occur in the system. In terms of energy storage, connecting capacitors in parallel is typically desirable for storing a large amount of energy since it increases the total capacitance and storage capacity.