Power Factor

Power Factor can be defined as the ratio between Real Power (Watts) and Apparent Power (VA). In simpler words, it tells how effectively your device utilizes electricity. We already know that the apparent power is the combination of Real power (kW) and Reactive power (kVAR).

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For calculating PF:

power factor triangle
power factor triangle

PF = REAL POWER / APPARENT POWER

PF = REAL POWER / (REAL POWER + REACTIVE POWER)

PF = KW / KVA OR KW / (KW + KVAR)

Power Factor can be simplified by considering the beer analogy which, further, helps understand it better.

Power Triangle:

As Apparent Power is made up of two parts, the resistive power (the in-phase power in watts) and the reactive power (the out-of-phase power in volt-amperes), we can show the vector addition of these two power components in the form of a power triangle.

power triangle
power triangle

Low Power Factor:

Low Power Factor is majorly caused by huge inductive load which causes the reactive power to increase in magnitude, ultimately dropping the power factor. As discussed above, lower power factor doesn’t allow effective usage of electric power. From an industrial point of view, this low power factor is resulted by these causes.

6 causes of low power factor
6 causes of low power factor

Power Factor Calculations:

It is imperative to know that power factor is only calculated for AC circuits and currents for both single phase and three phase. Some of these helpful formulae can help in calculating the power factor of single and three phase circuit.

Power Factor Correction:

Power factor correction can be defined as the method of improving power factor to make it reach unity or nearby unity value, such that the angle between voltage and current reduces.

These three conditions need to be considered when carrying out power factor correction.

power factor correction
power factor correction

Importance of Power Factor Correction: ​

Low Power Factor can cause problems for both consumers and generating utilities, that is why its improvement is vital for both.

​Knowing about power factor is very crucial for any electrical power system as it tells the amount of power wasted (Reactive Power) and consumed (Real Power) by it. Taking corrective measures will result in reduced power losses, increased voltage stability and eventually result in lowering the electric utility bills.

Let us know if you have any queries regarding this topic and do provide us with your feedback in the comments.

About The Author

Abdur Rehman is a professional electrical engineer with more than eight years of experience working with equipment from 208V to 115kV in both the Utility and Industrial & Commercial space. He has a particular focus on Power Systems Protection & Engineering Studies.

Abdur Rehman is the CEO and co-founder of allumiax.com and creator of GeneralPAC by AllumiaX. He has been actively involved in various roles in the IEEE Seattle Section, IEEE PES Seattle, IEEE Region 6, and IEEE MGA.

Leaders in Industrial & Commercial Power Systems Engineering