# Power factor, active & reactive power basic concept.

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-

Leading power factor- Current leads voltage. Happens with Capacitive load circuit, Lagging power factor- Current lags behind voltage. Happens with Inductive load circuit.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.
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