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POWER FACTOR


What is the use of power factor in power system?

Power Factor is defined in the fundamentals of electrical engineering as the cosine of the phase angle between the voltage and the current. An inductive circuit is said to have a lagging power factor, and a capacitive circuit is said to have a leading power factor indicate, respectively, whether the current is lagging or leading the applied voltage. (Stevenson Jr.)

Alternatively, power factor can also be determined to the ratio of power. Power factor is the ratio of useful power to the apparent power. Power factor can be likened to the efficiency formula where it is the ratio of the output over the input. The reason why the useful power is usually lesser to that of the apparent power is simply because apparent power (expressed in kVA) has the useful power (kw) and reactive power (kVAR) as its components. If kW and kVAR is sum vectorially, the result would be kVA.


POWER FACTOR = (KILOWATT) / (KILO VOLT-AMPERE)


Because the kVAR is drawn by the consumer's loads, line and transformers must carry more current than they would if only kW were required by the loads. Since losses equal (I)squared(R), the need to provide kVAR to load increases the losses on the distributor's system.(TVPPA nov.1994)

Regarding Power Factor, the common misconception is that by increasing the power factor would result to lowering the kVAR requirement of the system when it should be the other way around. Power factor is said to be dependent to the value of kW and kVAR which exist in the system.


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