WHAT IS POWER FACTOR? HOW MUCH IT REQUIRED?

Hello everyone...

Today we gonna discuss something which is very important in industrial topic. Every Electrical engineer needs to be very conscious about this.



WHAT IS POWER FACTOR? HOW MUCH IT REQUIRED?😅

Now all of you know that every industry required to maintain as possible as 0.99 pf . but most of the engineers are not aware what is the required KVAR to reach or to make 0.99 pf.

so here i am gonna share something which will show how to and what are the requirement.

• What is power factor?

          "In ac circuits power factor is the ration of real power to apparent power"

           "In dc circuits power factor is unity because reactive power absorbed by any inductive circuit is zero. so power factor is unity" 

Now most of the of us are working with already installed plant or industries so we don't know what is KVAR rating we need to maintain our power factor at 0.99. 

from google image

So majority of engineers are demanding more quantity of capacitors for improvement of power factor which is practically not reliable or it cost much to company and then most of capacitors are then not used. because there is no requirement of such quantity of capacitors.

from google image

so it is very important that we need to first calculate what are the requirement and then purchase.

I am sure it will effect on your image with your boss..😀


Calculation of KVAR rating:-

• First of you should know that how much is your Load.
• Then you must know how much P.F comes at time you need to improve.
• How much you want to reach? obviously it 0.99

Note:-
(Now when all the power is reactive power with no real power there then power factor is 0.
when all the power is reactive power with reactive power there then power factor is unity (1).)

Now for ex. lets assume that our

LOAD =150 KW
P.F φ 1      =0.70
ACHIEVE φ 2= 0.99

So for that we have formula

                                               KVAR = P(tanφ 1 - tanφ 2)

          we have        cos φ 1 =0.7
                               cos φ 2= 0.99

so                           φ 1=cos-1(0.7) 
                                      =45.57
                               
                               φ 2=cos-1(0.99) 
                                      =0.10         


so                                         KVAR= 150 (tan (45.57)-tan (0.10))

                                                        =132 KVAR

so we required 132 KVAR to reach our power factor at 0.99.

from google image

(Capacitors are rated in KVAR unit and are available in 1 phase and 3 phase.                             

ex.25kvar 50kvar)

Problems with capacitors in industries :-

• Most of the failure occurred in capacitors are due to temperature high in APFC panel. so proper ventilation is required for it
• Sometimes due to failure of the starters fuse are burned out but we continuously use the capacitors which makes the failures in it.
• Proper inspection is not there until there is no issues or when low power factors we run out to maintain it.
• Loose connections of the capacitor terminal may damage it.

Alert when working with capacitor panel:-

• Always turn of power while working with capacitors and do wear proper gloves and safety shoes. the current is very dangerous.( i am experience with current😝)
• Always give discharge time to capacitor although now days contactor and capacitor itself has this protection but still as mention on capacitor give it the time which requires to be discharge.

I suggest to use Schneider electric, Siemens and abb capacitors

https://www.se.com/in/en/product-range/60419-varpluscan/

https://mall.industry.siemens.com/mall/en/WW/Catalog/Products/10164637

https://new.abb.com/high-voltage/capacitors

-As engineer i must tell you guys do your capacitor panel on automatic system so that you don't get more worry about power factor 

          THANK YOU😊