Apparent power is the magnitude of complex power, the vector sum of active and reactive power, expressed in VA, kVA or MVA. Equipment heating depends on current whether or not that current does useful work, so transformers, generators and UPS units carry kVA or MVA ratings rather than kW. In the power triangle, S squared equals P squared plus Q squared.
That transformer is 1500 kVA of apparent power, so at 0.8 PF you only get about 1200 kW out of it before it cooks.
Also heard as
- S
Related terms
Active power
The part of electrical power that does real work, averaged over each cycle and measured in watts.
Reactive power
Power that surges back and forth between the source and the fields of inductors and capacitors, doing no net work.
Power factor
Ratio of active power to apparent power, showing how much of the current drawn does useful work.