What is reactive power in an electrical system?

Reactive power is defined as the power that oscillates between the source and the load in an electrical system, primarily between inductive and capacitive components. This oscillation does not contribute to the actual work done (or active power) but is essential for maintaining the voltage levels necessary for active power to be transmitted efficiently.

In alternating current (AC) systems, inductors (such as motors and transformers) and capacitors create a phase difference between voltage and current. This phase difference leads to reactive power, measured in volt-amperes reactive (VAR). When the current lags behind the voltage due to inductance, or leads the voltage due to capacitance, this reactive power circulates back and forth, thereby influencing the overall system stability and performance.

Understanding reactive power is crucial for designing electrical systems as it affects the power factor, which is a key indicator of efficiency. However, it’s important to note that despite reactive power’s critical role in the system, it does not equate to power that is consumed or energy converted into work. It is intrinsically associated with the reactive components of the system that temporarily store energy, but that is distinct from the concept of power consumption.

In contrast, total power consumed by devices refers to active power, which