KVA and KW are the terms related to electrical systems. Both are units of electrical energy. Electric power is distributed in three types, namely real power, apparent power and reactive power. KW is real power that really works. KVA is apparent power and only a small fraction of it works. In DC, the KVA and KW are the same, while in AC system, the KVA and KW are different from each other. The difference between KVA and KW is due to the phase difference between current and voltage which varies the power factor of the unit, either leading or lagging.

What is KVA?

It is called a kilovolt ampere. KVA is apparent power and only a small fraction of it works. Mathematically, the relationship of KVA to KW is kVA = kW / power factor.

What is KW?

It is called kilowatts. KW is real power that really works. Mathematically, the relationship of KW to KVA is kW = kVA x power factor. The real power of an AC system depends on the power factor which is cos @.

Key differences

1. KW is the real electrical power while KVA is the apparent electrical power.
2. KW is called kilowatts while KVA is called kilovolt amps.
3. KW is the amount of work done by electricity while only a small fraction of KVA works.
4. Electrical appliances that deal with power factor are rated in KW while those that do not deal with power factor are rated in KVA.
5. Transformers are rated in KVA while generators are rated in KW.
6. KVA and KW are the same in DC system while they differ in AC system.
7. The difference between KVA and KW occurs due to the phase difference between voltage and current.
8. The mathematical equation for KVA is kVA = kW / PF, while KW is kW = kVA x PF.