what is power factor? whether it should be high or low? why?
Answer Posted / rajani
Power factor is the ratio of true power to apparant power
and it is the cosine of angle between voltage and current
P=V I *pf
if pf is poor ex: 0.17 to meet actual power load has to
draw more current(V constant),result in more losses
if pf is good ex: 0.95 to meet actual power load has to
draw less current(V constant),result in less losses
if cosign angle is 80degrees cos 90= 0.17 means pf =0.17
current vector is lagging 80degrees (i>>v) so load draws
more current so losses are high
if angle is 20 degrees cos 20 = 0.93 means pf =0.93 (good
pf) current is lagging only 20degrees, i value is less
so to decrease current drawn of the load we have to
maintain good pf
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