What is the purpose of a capacitor bank in a substation?

The purpose of a capacitor bank in a substation is primarily for power factor correction and voltage regulation. Capacitor banks help improve the efficiency of the electrical system by correcting the power factor, which measures how effectively the electrical power is being converted into useful work output. A low power factor indicates that not all the power supplied by the utility is being effectively utilized, which can lead to increased energy costs and potential penalties from utility providers.

By adding capacitors to the system, the capacitor bank provides reactive power, which helps to offset the inductive loads from devices such as transformers and motors. This not only improves the overall power factor but also stabilizes the system voltage. When the voltage is regulated, it ensures that electrical devices receive the proper voltage needed for optimal operation, thereby enhancing reliability and performance.

While other options touch on related concepts, such as reducing line losses or preventing overloads, these are indirect benefits of having a well-regulated power factor and voltage level. The primary and direct purpose of a capacitor bank in a substation remains power factor correction and voltage regulation, making it an essential component for maintaining a stable and efficient electrical grid.