What is Power Factor?| How to improve power factor in AC Circuits?

What is a power factor? | Power Factor Definition

The cosine coefficient of the phase difference between any two AC quantities is called the power factor.

Importance of Power Factor in AC Circuit

Power factor is of great importance in AC circuits.  Because the power of an AC circuit is multiplied by the voltage, current and power factor of that circuit.  If the power factor of the circuit decreases, the current flowing through the load in that circuit increases.

Example:- Suppose a 1000 watt bulb is supplied with 250 Volts.  If the power factor of that circuit is 1 then the current flowing through that circuit will be something like this…

I = Power / (Voltage × Power Factor)

I =1000/ (250×1)

= 4 amperes

But if the power factor of the same 1000 watt load is 0.8 Amperes, then the current of the same circuit

I = Power / (Voltage × Power Factor)

I =1000/ (250×0.8)

= 5 ampere current will flow through that circuit

This proves that, for the same load, if the power factor is reduced, then a large amount of current will flow through that load.  This results in the power customer and the company supplying electricity to those customers.

Loss to Customers due to Low Power Factor

Due to the low power factor, the current proof for the same load increases. due to this reason

Accessories such as wires, switches, holders, fuses, etc. used for wiring installation have to be used with high capacity.  So their size will also be bigger.

In the wiring installation, incandescent lamps, heaters, etc., inspite of having individual power factor of 1, their output also decreases due to lower total power factor. 

Example:- 250 volt × 4 Amp × 1 power factor = 1000 watts so much power is available. If the power factor becomes 0.8, then 800 watts means 200 watts less power will be available.

Apart from this, due to low power factor of that circuit, the current for the same power load also increases.  Because of this, the energy meter of the customers starts running faster.  Even by using less power directly,

customers have to spend money for more power.

Loss to power companies due to low power factor

• Due to reduced power factor of installation of many customers, as a result the current of transmission line increases.
• The I×I×R power loss in the line increases.
• I × R With such a voltage drop, the voltage at the terminals of the line starts getting less.
• Due to the low terminal voltage, the voltage regulation in the generating station has to be adjusted every time.
• Due to the increase in the line current, the generators become overloaded and overheated.
• Due to the increase in the line current, the size of the line conductors also has to be increased.
• Due to the increase in the size of the conductors, the span of the line pole has to be reduced.
• Due to the reduction in the number of line poles, the number of line poles also has to be increased.
• As the number of poles increases, so does the number of other accessories.
• Overall, the cost of transmission and distribution increases.

All this makes the power companies very expensive.

Advantages of High Power Factor |  Why is it important to have more power factor?

Benefits of High Power Factor Why is it important to have more power factor?

Due to the high power factor, the power distribution company and customers get the benefits mentioned below.

• Helps to keep terminal voltage stable.
• Voltage regulation is good.
• There is less power loss in transmission and distribution lines.
• The efficiency of the generating station increases.  Transmission is cheap.
• Conductors and accessories do not get too hot.
• There is no need to use accessories of large capacity.

For this reason the power factor needs to be high.

What are the reasons for low power factor of industrial customers?

What are the reasons for the lack of power factor of industrial customers?

Industrial sector means more and more induction motors are used in large workshops, factories etc.  Apart from this, fluorescent tubes are also used more.  Meaning in such places the inductive load is high, and the resistive load is very less.  Because of this the reactive current (current flowing due to reactance) is high.  For this reason, the power factor gets reduced by creating a greater degree of phase difference between voltage and current in that circuit.

How to improve power factor?| Method of increasing power factor | How to correct power factor?| What should be the power factor?

How to improve power factor? | Method of increasing power factor |  How to fix power factor?| How much should the power factor be?

In view of the loss due to low power factor, it is very important to improve the power factor.  Because the full load power factor of an induction motor ranges from 0.8 to 0.85.  But it is necessary to have more power factor than this.  The companies providing electrical energy have fixed the power factor of 0.9 for the installation of their customers.  Therefore, electricity customers have to keep the power factor of their installation 0.9 or above. Henceu sing synchronous condenser

The power factor can be improved by adding a parallel capacitor to the line.

Capacitors and their ratings used to improve power factor.

Which motor should be fitted with which capacitor to improve the power factor?

Capacitors and their ratings are used to improve power factor.  Which motor should be applied to which motor to improve the power factor?

The installation in which induction motors are used more. The power factor of that circuit is low. If the power factor of the circuit is to be increased to 0.95 then the capacitors mentioned in the table below will have to be used for the motor.