Power Factor

on . Posted in Electrical Engineering

pie chartPower factor, abbreviated as PF, a dimensionless number, is a measure of how effectively electrical power is being converted into useful work output in a circuit.  It is defined as the ratio of real power to apparent power.  The power factor is a number between 0 and 1, and it is expressed as a decimal or percentage.

The power factor is a parameter in electrical systems because it indicates how effectively electrical power is being converted into useful work.  A power factor of 1 (or 100%) means that all the power is being used for useful work, while a lower power factor indicates that some power is being wasted as reactive power.  Power factor correction is often used to improve power factor and reduce energy wastage in electrical systems.  This may involve the use of power factor correction capacitors or other devices to offset the effects of reactive power and improve the overall efficiency of the system.


Power Factor formula

\( PF  \;=\;   P_t \;/\; P_a \)     (Power Factor)

\( P_t  \;=\; PF  \; P_a   \)

\( P_a  \;=\;   P_t \;/\; PF \)

Symbol English Metric
\( PF \) = power factor  \( dimensionless \)
\( P_t \) = true power \( W \) \(kg-m^2 \;/\; s^3\)
\( P_a \) = apparent power \( W \) \(kg-m^2 \;/\; s^3\)


Motor Power Factor Formulas

\(V\) = Voltage  -  \(I\) = Amps  -  \(P\) = Power

To Find Direct Current Alternating Current
Single Phase Two Phase Four Wire Three Phase
Power Factor - \(\large{\frac{ input\; P }{ V \; I } }\)  - \(\large{\frac{ input\; P }{ 1.732 \; V \; I } }\)


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Tags: Power Electrical Efficiency Motor