Explanation of Power Factor and It’s Importance in Easy Way | Understanding the Power Factor

explain power factor and its importance

Today we will explain the power factor and its importance. We all know about the power factor but somehow still have some confusion. The topic is power factor. The topic is not as easy as we thought. But if you dig in deep you will find it easy to explain the power factor and its importance. We won’t discuss the definition but clear some complicated questions. Let’s get started. 

Explain power factor and its importance

What is meant by a device’s power factor is 0.85?

‌‌Power factor 0.85 means we will get 85-kilowatt real power for 100 kVA supply power. Because of the ratio of real power factor and apparent power. If we compare it to orange juice then there are 85% of orange juice ( real power) and 15% foam ( reactive power) and the whole glass is apparent power.

What is leading, lagging, and unity power factor?

When there is more capacitive load than inductive load, that circuit’s power factor is called the leading power factor. In short, when voltage stays behind current it is the leading power factor. 

When the inductive load is greater than the capacitive load then the power factor of the circuit is lagging.

If the inductive load and capacitive load are equal in the AC circuit, and voltage and current stay at the same phase then it is called the unity power factor. Here voltage and current’s angle is cosine 1. This is the resonant form of the circuit. The resonant circuit’s PF value is 1 and this circuit is also called a resistive circuit.

explain power factor and its importance

Difference between power factor 0.77 leading and 0.77 lagging 

Power factor 0.77 leading means we are using more capacitive power. And for lagging means, we are using more inductive loads. Industries have more inductive loads. That’s why the power factor goes for lagging. And this is the reason behind using capacitor bank/ PFI panel for leading. Because the power factor is leading for capacitors.

explain power factor and its importance motor

What are the problems in the system if the power factor is low?

In an AC system power, voltage, and current are related accordingly :

P= V×I×cosθ____________(1)

Here 0 is voltage and current indicators middle angle in phasor domain. Its cosine is a systems power factor. V×I is apparent power or kVA rating which is indicated by S. Generally machines power is measured by kVA rating. 

V×I= S, cosθ = P.F_______(2)

Now, if a System’s power factor is less, you need more kVA rating for the same amount of power. Because equation 1 says:


Machine with more kVA rating is expensive. So the expense will increase.

If you use the same machine ( s is fixed) then active power will decrease due to less power factor. Because

P= S×P.F_________(4)

If the power factor of your house is excessively less you can get a fine. Because low power factor leads to more electric flow in the current line.


Let’s get back to equation 1. Your house gets electricity which always has a fixed voltage. For our region, the value is 220/230 voltage. Our devices are made for this amount of voltage. That’s why V has to be constant. If you hold a fixed amount of power, the electric flow will increase due to less power factor. 

P= V×I×P.F________(5)

And if the current flow is high then it will lead to system loss which means electricity will be wasted. The line has to be thick for high electricity flow. That’s why expenses increase and the electricity office can charge you.

Can the power factor be negative?

Power factor can be negative for the components which store energy from the source. And also can send back the stored energy. For example, indicator and capacitor. So, when reactive components rule the device, the power factor is negative. Some of you can say that the PF of the reactive component can be zero ( cosθ=cos90=0). It’s the highest. It can also be negative by decreasing.

Why we will use a capacitor bank instead of an inductor bank for power factor improvement?

Power factor bank is used for improving power factor. Because the capacitor’s power factor is leading. Voltage lags current in the capacitor.

When the power factor gets into leading it tends to unity. On the other side, the inductor’s power factor stays in lagging condition. If we use an inductor bank we will get the opposite result. The thing is, we are running towards home. We have to move forward not backward.

This is about the explain power factor and its importance. If you have any questions about the explanation power factor and its importance, you can ask in the comment box.

Read More Article:

Why Power Transmission / Distribution Voltage is always 11KV, 33KV, 66KV, and 132KV?