How to Calculate Power Factor Correction

Step-by-Step Guide

1. 1

   Step 1: Calculate impedance.

   (Pretend as if impedance was in the same place as apparent power in the picture above).
   
   So to find impedance you need to use the Pythagorean Theorem c² = √ (a² + b²).
2. 2

   Step 2: Therefore Impedance Total (represented as “Z”) is equal to Real Power squared plus Reactive power squared and then take the square root of the answer.

   ( Z = √(60² + 60²) ).
   
   So if you enter that into your scientific calculator you will receive an answer of
   84.85Ω. ( Z =
   84.85Ω ). , So you now have your hypotenuse which is your impedance.
   
   You also have your adjacent side which is your true power and you have your opposite side which is your reactive power.
   
   So to find the angle you can use any the laws stated earlier.
   
   For example we use the Tangent Law which is the opposite side divided by the adjacent side (Reactive/True).
   
   You should have an equation that looks like this: (60/60 = 1) , The inverse tangent is a button on your calculator.
   
   So you now take the inverse tangent of the equation in the previous step and this will give you your phase angle.
   
   Your equation should look something like this: tan ‾ ¹ (1) = Phase Angle.
   
   So your answer should be 45°. , Your current is in the units of amps also represented as an “A”.
   
   The formula used for calculating current is Voltage divided by Impedance which numerically looks like this: 120V/84.85Ω.
   
   You should now have an answer around
   1.141A. ( 120V/84.84Ω =
   1.141A ). , To calculate apparent power you do not need to use the Pythagorean Theorem because your hypotenuse was considered your impedance.
   
   Remembering that apparent power is in the units of Volt-Amps we can calculate apparent power using the formula:
   Voltage squared divided by your total impedance.
   
   Your equation should look like this: 120V²/84.85Ω.
   
   You should now get an answer of
   169.71VA. ( 120²/84.85 =
   169.71 ) , To calculate true power you must have found current which you did in step number four.
   
   True power which is in the units of a Watt is calculated by multiplying your current squared (1.141²) by the resistance (60Ω) in your circuit.
   
   You should get an answer of
   78.11 watts.
   
   Your equation should look like this:
   1.141² x 60 =
   78.11 , To calculate your power factor you need the following information:
   Watts and Volt-Amps.
   
   You have calculated this information in the previous steps.
   
   Your wattage is equal to
   78.11W and your Volt-Amps are equal to
   169.71VA.
   
   The formula for your power factor, also represented as Pf, is Watts divided by Volt-Amps.
   
   You should have an equation that looks something like this:
   78.11/169.71 = .460 This can also be expressed as a percentage therefore you multiply .460 by 100 giving you a power factor of 46%.
3. 3

   Step 3: Find your phase angle.

4. 4

   Step 4: Take the inverse of the tangent and acquire your Phase Angle.

5. 5

   Step 5: Calculate your total Current (Amps).

6. 6

   Step 6: You must now calculate your apparent power which is represented as “S”.

7. 7

   Step 7: You must now calculate your true power which is represented as “P”.

8. 8

   Step 8: Calculate your Power Factor!

Detailed Guide

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