Answer / guest

See the first thing is Power factor is angle between
voltage & current. see most of our load is inductive, & in
inductive load current always lags the supply voltage. In
unity P.f.condition current & voltage always in phase with
each other.
since P=VIcos(angle between V & I )
Now for a constant power as your pf changes i.e. decreases
to keep power demand constant current has to be increase as
your voltage is constant.in this way your current
increases , it causes increase in your copper losses
(I*I*R), voltage drop(I*R). And to keep voltage constant
more reactive power has to be provide.
generally any supply company penalties for more demand of
reactive power.

Answer / neo

The relation between the KW and KVA are

KW = KVA*Cos(phi)...SO as the power factor is getting lower
the actual outptut that we obtain frm a transformer will be
lower than the desired output for a particular value of
vlotage and current in that circuit.That is why in
industries, much importance in given for power factor
improvement.

Answer / hirosh babu

kw=kvacos(phi)... so larger the value of pf, smaller is the
amount of kva required for supplying active power... for
example if we require 8kw power output and pf is0.8 kva req
is 10.. but if pf is 0.5 kva req is 16... also for
transfering a const power if pf is low,... then value of
current will be high , so cu loss increases so does the
size of conductor..

Answer / hirosh babu

All the above answers are right. I just want to add few
points to that.

For transmitting a const power,

lower the power factor, greater will be the current and
hence greater will be losses and larger area of cross
section of conductor will be required.

By maintaining pf at 0.9, our active power will be high as
P= VI cos (pi), larger the pf larger the active power for a
fixed voltage and current.

Answer / badri narayan satpathy

If the power factor is .9 then we get a power loss.
Because power = volatse*current*cos phi(active power)
there for we also paid tha bill including the losses and
the losses is an usefullpower.power factor depend on the
type load like
inductive
capacitive
resitive

why we are using DC violtage for testing of cables....which is used in HV AC applicatons...

1 Answers  

What is principal to reduce earth leakage current with isolation transformer? When isolation transformer is installed in input stage of system, earth leakage current is reduced. the reason is why the leakage current of 2nd stage of isolation transformer does not affect the 1st stage's leakage current. I would like to know the reason. As you know, earth leakage current is a kind of AC. So, How to reduce earth leakage current in case that isolation transformer is used?

2 Answers  

Is there any local or International standards that prohibit the installation of earthing pit in the planters area where the earthing pit is subject to continues soak in water?

1 Answers  

In the case of petrochemical area AC drive & AC motor is used where the speed variation is required. Why they are not Using DC drive & DC motors in such areas?

1 Answers  

Percentage losses in power generation?

0 Answers   Nespak, Trimax,

why ht cable end termination don't have a gland?

0 Answers   Private,

What mean by MLTP

0 Answers   Machino,

Can i get some examples of mechanical devices?

1 Answers  

Battery is a voltage source? give one example of current source and why?

0 Answers   Suzlon,

WHAT HAPPENS IN DIFFERENTIAL PROTECTION IF CT REACHES ITS KNEE VOLTAGE POINT?

4 Answers   Jindal,

why chock were used in old tubelights but are not newest tubelights?

0 Answers  

on what factor insulation resistance depends

2 Answers   Uttam Sugar,