What is KVA KVAR And KW?

KVA KVAR And KW are various types of power.

KVA means Kilo volt ampere. VI1000

KVAR means Kilo Volt Ampere Reactive. VISinϕ*1000

KW means Kilo Watt. VICosϕ*1000

where V is in volts

I is in Amps.

Actual Power consumed by loads is called Kilo Watt Power. All the Power given to the load is not utilized as useful power, some power is being wasted. The power which is not consumed is called Reactive power i.e KVAR.

where as apparent power KVA is the vector sum of KW and KVAR.


VI= VICosϕ + VISinϕ (Added vectorially)

Active Power: KW

  • Active Power is produced by Generators in power plants.
  • Active Power is Consumed by resistive part of the loads. A pure resistive load consumes only active power.
  • Example of Active power loads are Incandescent Bulbs, Heaters, Iron Box etc.

Reactive Power: KVAR

Reactive power is two types.

1. Lagging Reactive Power:

  • Produced by Inductive Reactors known as Reactive Transformers.
  • Consumed by Inductive nature of Loads.
  • Example of Lagging Reactive power loads are Induction Motors and Transformers for producing their magnetizing currents.

2. Leading Reactive Power:

  • Produced by Synchronous Capacitors and Capacitor Banks. Application of Capacitor Banks
  • Consumed by Capacitve nature of Loads.
  • Example of Leading Reactive power loads are Electric Motors with Capacitor for starting and running, Long Transmission Lines.

In AC circuits, KW or kilowatt is the unit of power dissipated by resistive elements. It’s called true power. KVAR or kilovolt reactive is the power dissipated by reactive components such as coils and capacitors. It’s called reactive power. KVA or kilovolt ampere measures the apparent power which is the resultant of true and reactive powers.

Their relationship is best described by the power triangle in which the true power (KW) is the adjacent side, reactive power (KVAR) the opposite side and the apparent power (KVA) is the hypotenuse. The angle theta which is taken at the the point where the hypotenuse and the adjacent side meet, represent the phase angle which represent the phase difference between voltage and current. The cosine of theta is the power factor.