**Power factor- **In ac circuit there is some phase difference between the voltage and current. The cosine of this angle phase difference is called Power factor or PF. Popularly defined as **cosφ**.

## Power factor types-

**Value of Power factor**– As power factor is a cos function its possible value ranges from -1 to +1

## Active and reactive component of power factor:

I cosφ is called active or watt full component, I sinφ called reactive or watt less component.Reactive component is very much important for power factor measurement and control. It has a inverse relationship with power factor. The less the reactive component the more is the power factor.

## Active, reactive and apparent power-

- VIcosφ- active power in KW.
- VIsinφ- reactive power in KVAR.
- VI- Apparent power in VA.

**Electrical power** is the geometrical sum of two parts.

• S² = P² + Q², where

S = Apparent Power, kVA

P = Active Power, kW

Q = Reactive Power, kvar

• cos φ = P/S=PF, **power factor **which tells us what is the proportion between the active and the apparent power, how much there is active power in apparent power.

[alva]