Real And Reactive Power

KVA,KW,KVAR,KWh,Kvar.....

As an electrical engineer we seen a lot as KW,MW,KVA etc. These are some units related with power and energy. It varies with the nature of the power and energy. Before that we can just see what is reactive and real power.

REACTIVE POWER:

The book definition is ‘it is the power absorbed by the inductor or released by the capacitor’. We know in AC circuit only the inductance and capacitance are present. It may be a line capacitance or winding inductance.It is the imaginary power etc.

          This reactive power is simply circulating power due to the phase shift between the source and the loads. This additional power that appears to be flowing requires the equipment to be rated higher than that for a system operating at unity. Obviously these circulating currents while real..produce no useful work. It is the job of the Electrical Engineer to correct the load reactance as close as possible to unity to increase efficiency and reduce operational costs. That means simply match the capacitance and inductance.

          Start now,
Total power     KVA   =   Kilo Volt Amp(v*I)

Real power      KW    =    Kilo Watt(v*I*cosΦ)
Reactive power KVAR = Kilo Volt Amp Reactance  (v*I*sinΦ)

Total power  KVA=KW+jKVAR
Power * Time= Energy 
Eg:KW*Hour=KWh(unit of electrical energy)

Friends, the field of reactive power is a wide area and researches are now going on, so i am not yet expert. The interesing fact is Reactive power is needed to transport the real power!! So we minimize it what ever we can. We use capacitor banks and other FACTS(Flexible AC Transmission System) devices for minimize it.