what is the disadvantage of leading power factor...why can't
we use it (pf=0) for a long period of time?

Answer Posted / guest

actually We cannot use the pf=0 , at least it should be some value. i mean to say,0.x to 1,
0.1 0.3 0.5 0.7 0.9 1 0.9 0.7 0.5 0.3 0.1
Lagging-> Unity <-Leading

Actually there are three power generated in an electrical system.
1. Active, real or true power which are expressed in kw = sqrt(3)*v*I*cosØ
2. Apparent power expressed in kva = sqrt(3)*v*I
3. Reactive Power expressed in kvar = sqrt(3)*v*I*sinØ
If cosØ(power Factor)=0.99 or -0.99, the sinØ will be same=0.14
If cosØ=-0.8 or 0.8, the sinØ will be same=0.6
If cosØ=-0.5 or 0.5, the sinØ will be same=0.86
According to the above values it is clear that if we go for lagging or leading pf the reactive power generated will be equal.
Kva= kw+kvar,
If use lagging or leading pf the real power (kw)we can use is same. So we must go for nearest value to unity pf to make Kva=kw(this condition satisfies only if Kvar=0 and pf=1) Finally more real power usage.
Then one of my friend told govt is advicing them to use leading power factor , its only because apart from the bulk consumers the domestic users wont use pf correction. In order to compensate we are said to use leading pf.

Is This Answer Correct ?    1 Yes 0 No



Post New Answer       View All Answers


Please Help Members By Posting Answers For Below Questions

why are distributed windings generally used in alternators?

2299


how to select battery for 15 KVA UPS with formula

2097


some basic standard questions on transformer.

1331


explain all the classes with example

1501


What is the implications when 600 hp motor is started when the unit is running with Transformer of capacity 1500 KVA and DG set of 1000kva

1743






What is Scheme Test of High Voltage Switchgear. Which tests it includes.

1901


Block diagram of Power line communication?

1884


i have interview in Pepsi company what type of question will ask please send the question and answeer

2988


can anyone explain the star-delta motor control wiring ,which wire go where and how they operate?

956


What is the pro & con of having 11kv & 33kv incoming, and what is the adv & disadv. of converting from 11kv to 33kv.

2398


how to calculate vfd o/p voltage by frequency

1723


What is DC series motor?

724


why do we put a transformer on soak before loading it

659


what is mind in cable

1575


please send me RRB electrical engineer previous year questions for Sr. Section Engineer

1490