Inductive load in a power factor improvement project

Thread Starter


Joined Nov 10, 2014
I am studying about to do a student project about improving power factor which is less than 1 because of inductive loads. How it work I know but what I want to know is that what to use as inductive load. Should I use two terminal components called inductors which are available pretty easily in markets? If yes then please can anyone tell which different standard values of inductors should be used to decrease power factor to different values?? I want to use at least 5 inductive loads. so how to calculate values of inductors on a 220 v mains supply that will give noticeable reduction in power factor. any formula?
my friend suggested me to use a multiple winding transformer as a load so each winding will act as an inductive load. is it possible. if yes. then how i am gonna get the inductive value for the winding? Please please help


Joined Feb 24, 2006
The usual load is an AC motor. A fixed inductor does not have the same properties as a motor. An AC motor provides a variable inductive load that is usually not amenable to PF manipulations with a fixed capacitor. Ignoring startup you might be able to get a solution for running at a constant speed. The problem is that the startup behavior will be affected and probably not in a good way.


Joined Mar 14, 2008
You see to have a misconception about PF. The PF of any pure inductive load is 0. The size of the inductor makes no difference.
The way to change the power factor is to change the value of a resistor in series with the inductor.

It's dangerous to experiment directly with the line voltage so you should use an isolation transformer.

Can you do the experiment at a lower, safer voltage from a transformer secondary?
That would also reduce the size of the inductor you need to prevent saturation of the inductor since the inductor saturation point is proportional to the applied voltage for a given frequency.

A transformer can be used as an inductor but they have a large inductance so the inductive current is small (generally a fraction of an amp).