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