ABSTRACT
Except in a very few special situations, electrical energy is generated, transmitted, distributed, and
utilized as alternating current (AC). However, alternating current has several distinct disadvantages. One
of these is the necessity of reactive power that needs to be supplied along with active power. Reactive
power can be leading or lagging. While it is the active power that contributes to the energy consumed, or
transmitted, reactive power does not contribute to the energy. Reactive power is an inherent part of the
‘‘total power.’’ Reactive power is either generated or consumed in almost every component of the system,
generation, transmission, and distribution and eventually by the loads. The impedance of a branch of a
circuit in an AC system consists of two components, resistance and reactance. Reactance can be either
inductive or capacitive, which contribute to reactive power in the circuit. Most of the loads are inductive,
and must be supplied with lagging reactive power. It is economical to supply this reactive power closer to
the load in the distribution system.
