Power factor calculation and step by step

Power factor

1. Power Factor Fundamentals

2. What we will learn: Most Industrial loads req u ire both Real power and React i v e po w e r t o produce useful work You pay for BOTH types of power Capacitors can supply the REACTIVE the utility do e s n’t n e ed to power thus Capacitors save you money! 2

3. Why Power Factor Corr ec t i o n Sa ves Apply M o ney! PFC’s? » » » » R e d uces P o wer Bills R e d uces I 2 R l o sses in con d uctors R e d uces l o ading o n tra n s f ormers I m proves v o lt a ge d r op PqcA2.ppt 3

4. What is PF ? Introduction: » Mos t p la n t loa d s ar e In d uctiv e a n d requir e a magnetic fiel d to operate: – – – Moto r s T ra n s f o rmers F lorescen t lig h t i n g » » The magnet i c field is neces s ary, but produces no u s eful work T he utilit y mus t sup p l y t h e p owe r t o pro d uc e t h e magneti c field and th e p o wer t o p rod u ce t h e u s efu wor k : Yo u p ay fo r al l o f i t ! » These t w o types of current are the ACTIVE and RE A CT I VE com p one n t s PqcA2.ppt 4 s l th e T he an d the

5. The Basics: The Power Triangle: Yo u pa y fo r fue l fo r th e V E RT I C A L p o r t ion of f l ight, as well a s the f uel for t he H O R I ZO N T A L portion of fli g ht. No n - Wor k ing (Re a ctive) Power W o rking (Active) Power PqcA2.ppt 5 for t he H O R I ZO N T A L

6. The Power Triangle: Simil a rl y, m o t o r s r equ i re RE A CTIV E po w er to set up the magnetic field whil e th e ACT I V E pow e r p r o d u c es the u s e f ul w ork ( s haft h o r sepo w e r) . Total Po w er is the v ector sum of the t w o & r epr e sents w hat y o u p a y for: A c tiv e Powe r (kW) : Produces Use f ul Work Re a c ti ve Po w er ( kVAR) Sets up Ma g netic Fields Total Power (kVA) What y o u Pay For! PqcA2.ppt 6

7. The Power Triangle: • P o we r Fa c t or is the ratio of Active Po w er to T o t al P o we r : P o we r Fa c t or = Active (Rea l ) Po w er Tota l P o wer kW Act i v e P o we r ( k W ) = Reacti v e Power k V A C os i ne ( ) = T o ta l P o w e r (k V A ) Po w er F a ctor is a m e asu r e of effici e ncy ( O utput / I np u t) PqcA2.ppt 7

8. Why do we Install Capacitors? Cap a citors supply, for fre e , the r eacti v e en e rgy r equi r ed inductive loads. by » » Y o u o nl y h av e t o p a y f o r t h e ca pa c i t o r ! S i n c e t h e util i t y d o esn ’ t su p ply it (kVAR), y o u do n ’ t p a y f o r i t ! M M Utilit y Suppli e s Re a c ti ve Cur r ent Cap a ci t or Supplies Re a c ti ve Cur r ent PqcA2.ppt 8

9. Other Benefits: Re l e ase d sys t e m capac i ty: » T he effect of PF on current d rawn is s h own below: kV A R 100 k VAR 75 kVA = 141 P F = 70% kVA = 125 P F = 80% kVA = 100 P F = 10 % De c re a sing s i ze of conductors r equi r ed to ca r ry r a nging t h e sa m e 1 0kW load at P.F. f r om 7 % to 10 % PqcA2.ppt 9 kW 100 kW 1 kW 100

10. Other Benefits: Reduced Power Losses: » As curren t flow s throug h conductors , th e conductors heat. T h is h e ating is power l o ss Power l o ss is proport iona l t o curren t square d ( P Los s = I 2 R) Current is pr o portional to P.F.: » » » C on d ucto r los s ca n accou n t for tota l load a s muc h a s 2-5 % of Capac i tors can reduce l osses lo a d by 1-2% of the total PqcA2.ppt 10 % Loss Reduction = 1 00 x 1- ( Or i ginal P.F. ) 2 (Desire d P.F.) 2

11. Other Benefits: Voltage Improvement: » » W hen capacitors are added, voltage w ill increase Typically only a few percent – N ot a significant economic or system benefit Severe over-correction (P. F .>1) w ill cause a voltage ! rise that can damage ins u lation & in utility surcharges! equipment; or result – U sually a result of large fixed capacitor s a t mains PqcA2.ppt 11 % Voltage R i se = C ap a citor k V AR x XFMR % Z X F M R k V A

12. Summary of Benefits: Reduced Po w e r Cost s : » Since Capacitors supp l y reactive power, you don’ t pa y th e uti l it y fo r it » Y o u ca n calculat e the savings Off-load transformers » Def e r buyi n g a l a rger transformer when adding loads Reduc e v o l t ag e drop at loads » » O nl y i f capacitor s ar e applie d at loads ( m i nima l benefi t a t best) PqcA2.ppt 12 A2

13. What we learned.. Mos t Industria l l o ad s (i . e . motors)ar e Ind u ctiv e and REAC T IVE power draw T he Utility su p p lies this energy therefore you pay for it Powe r Facto r Capacitor s suppl y REAC T I VE the utility doesn’t need to Powe r Facto r Capacitor s sav e m oney ener g y th u s T her e ar e othe r benefit s t o correcting power factor, » » » r e d uce d h eati n g i n ca b les re d uced h eati n g in transform e r(s) f rees up system capacity PqcA2.ppt 13 A2