What is the definition of reactive power in electrical systems?

Reactive power is an essential concept in electrical systems, particularly in alternating current (AC) circuits, where it is associated with energy storage in inductive and capacitive components. It represents the power that periodically oscillates between the source and reactive components, such as inductors and capacitors, rather than being consumed or converted into useful work. This oscillation does not perform any active work; instead, it facilitates the functioning of electrical systems by maintaining voltage levels necessary for proper operation.

In AC systems, reactive power is measured in var (volt-amperes reactive). It plays a critical role in voltage regulation and is vital for the efficiency and stability of the power system, as it is necessary for generating magnetic fields in inductors and maintaining electric fields in capacitors. The ability to understand and manage reactive power is crucial for engineers and technicians working with power systems to ensure optimal performance and reliability.

Understanding that reactive power oscillates and is essential for system functionality clarifies why it is fundamentally different from power that flows only in one direction or is measured in watts for active work. Reactive power does not contribute to real power consumption, and thus, power stored in batteries, which represents a different type of energy storage, is also not related to the definition of reactive