2 Basic Methods of Power Factor Correction with Their Pros and Cons


What Is Power Factor?

  1. The power that is used by electrical machines or equipment is called real power.
  2. A particular site generates power that is usually not directly used; this is called reactive power.

Thecombination of these two is called apparent power.

Power Factor is actually a connection between apparent and real power. Power Factor is a level of electrical productivity in an AC circuit, a specific ratio between the useful power kilowatt (actual power required to work any equipment) and apparent power kVA (a collaboration of reactive power and true power – power produced as useful power but doesn’t contribute with the electric equipment).

What Is Power Factor Correction?

The modern technology of Power Factor Correction equipment enables the user to cut down their utility bill by sustaining the particular level of reactive power usage.

If a site’s PF declines below a pre-specified ratio, then the power supplier adds reactive power rates to the consumer’s bill. Generally speaking, the load on electrical systems is decreased if the Power Factor is of good quality.

Methods of Power Factor Correction

There are a couple of popular techniques or methods of power factor correction for supplies; the active PFC and the passive PFC.

Passive PFC  

This is usually used for small energy supplies of 100W or less.

This correction method makes use of a low pass harmonic filtration system at the AC input with the inductor and capacitor developing a line of the resonance circuit. The parts are quite small while rendering an efficient and inexpensive power factor correction.


  • Affordable
  • Productive
  • Simple construction


  • The minimal range of input voltages
  • Large and heavy size
  • No voltage controls

Active PFC  

The active Power Factor Correction method is recommended for electricity supplies of over 100W.

This particular method supplies a more cost-effective correction, which is lighter weight and less cumbersome. A simple active PFC circuit includes a control circuit that processes the input current and voltage and then sets the transitioning duty cycle and time to make sure that the input current and voltage are in the set cycle.

This gives a programmed correction of the input AC current and voltage, leading to a theoretical PF of over 1.95. In contrast to the passive Power Factor Correction, the active PFC runs on the number of input currents or voltages. On the other hand, it has extra components, that make it more expensive and complex.


  • Attains PF 0.95 or higher
  • Light and small
  • Frequency (47Hz- 63Hz and 87 Vrms -266 Vrms)
  • A wide range of AC input voltage 
  • More adaptable
  • Better control


  • Higher cost
  • Complex
  • High frequencies require more filtering which can affect the lines
  • Components require high current and voltage as compared to the passive PFC


Installing PFC can decrease the power consumption, resulting in reduced charges and electricity bills. As a result of heat reduction, voltage drop reductions and power stabilization, there’ll be an overall betterment in power quality, leading to a long lifespan of your electric equipment. Distribution losses, transformation and circulation can also be reduced, resulting in an improvement in supply efficiency.

Leave a Reply

Your email address will not be published. Required fields are marked *