Power factor is a measurement of how efficiently an electrical power system is being used. It is the ratio of the real power consumed by a load to the apparent power flowing in a circuit. Reactive power does not perform work but contributes to energy loss. A power factor of 1 is ideal, with only real power being used. The utility charges for total power used based on apparent power, so consumers aim for a power factor close to 1 to reduce costs.

1. 16. Power Factor

2. Electricity
y
Active and Reactive Power
• Active power (kW): real power used
• Reactive power (kVAR): virtual power that
determines load/demand
• Utility pays for total power (kVA)
kVA = √ (KW)2 + (KVAR)2

3. Electricity
Electricity
Electricity
Electricity
Power Factor Correlation
Power Factor Correlation

4. Th (P ) i h
The power factor: cos(φ)
• The average ac power (Pav) is the power
dissipated on the load resistor.
0≤ θ≤1 d d h l
• 0≤cosθ≤1, dependent on the complex
load.
Id l f t θ 1 Z R
• Ideal power factor: cosθ =1, Z=R, pure
resistive load
( )
t
V
t)
(
Z
I
V
I
t
P
2
~
cos
~
~
)
( =
θ
θ
( )
( )
θ
ω
ω
−
=
=
t
I
t
i
t
V
t
v
p
p
cos
)
(
cos
)
(
R
I
Z
I
2
2
~
cos
=
= θ
( )
p
R
I
=

6. Discussion of Problem –
Discussion of Problem
Power Factor
– Power Factor is the percentage difference between
apparent and actual power
apparent and actual power.
ƒThe Electric utility requires at least 95%.
ƒP.S. SA‐8 was 84%.