Inductive consumers (single phase and three phase induction motors, transformers, chokes, fluorescent lighting ,...) during the work, withdraw from the network in addition to the active power that is converted to useful work (rotation axis motor, light), and reactive power is used to create a magnetic field. Unlike the active power that is''permanently''in consumer spending, reactive power oscillates between sources and consumers.

 

The presence of reactive energy in the system has negative consequences - though not done useful work, reactive power demand on transmission lines. Apparent power system is a vector sum of active and reactive power system.