What is the role of capacitors in a power system?

In a power system, capacitors play a critical role in improving the power factor. The power factor is a measure of how effectively electrical power is being used, and it is expressed as a ratio of real power (used to perform work) to apparent power (total power in the circuit). A low power factor indicates that the system is using more apparent power than necessary to deliver useful work, which can lead to increased losses and decreased efficiency.

Capacitors help by providing reactive power to the system, which compensates for the inductive effects of devices like motors and transformers that consume reactive power. By injecting capacitive reactive power, capacitors help to balance the inductive load, therefore improving the overall power factor.

While capacitors can indeed store energy temporarily, their primary role in power systems is not energy storage but rather the enhancement of the power factor and voltage stability. They do not generate power nor directly regulate voltage without influencing power factor, although improvements in power factor can lead to better voltage regulation in some contexts. The main contribution of capacitors in power systems is thus to optimize energy usage and minimize losses by improving the power factor.