Answer / ranjith

KW=KVA*cos(phi)

In case of dc machines cos(phi) is always 1... but this in
not in case of ac machines, as depending upon the
load(inductive, capacitive) the power factor(cos phi) will
change.

Correct me if am wrong

Answer / asif ur rahaman

First we should understand what is Kw and KVA in a local
language. Kw is the load which we connect/ use. KVA is the
Power generated / supplied to us by DG or Electricity
board. Suppose our DG is of 1000 KVA capacity and if we
have
10 Motors of 100 KW,
10 Lights of 100kw
10 TVs/ Computers load of 100 KW.

When we connect 10 Motors of 100kw to 1000kva dg, only 8
motors will function and dg trips when 9th motor is
connected. This is because induction load has 0.8 pf. This
indicates that 1000 kva dg can give out put of only 800kw.

Now if connect when 10 lights of 100kw connected all the
10 lights will glow. This indicates that 1000kva dg is
giving 1000kw output. Light/ resistive pf is UNITY (1).

Now when 10 of TV/ computers connected to same 1000 kva dg,
more than 10 TV/ computers will function (may be 11 or12).
This indicates 1000kva dg is giving out put of 1200Kw. This
is because capacitive pf is greater than 1.

For all the above, DG is same 1000kva and also loads are
same 1000kw. But all the three types of loads (inductive,
Resistive and Capacitive) doesn't consume power same style
because of different power factors. So where ever Power is
generated (DGs, Inverters, Transformer etc) they give in
KVA. Where ever same Power is utilised /consumed they will
give in KW.

MECHANICAL EXAMPLE:
Suppose Hero honda two wheeler gives miliage of 65 kms per
liter.
If students are riding (more than two persons)then milage
will be 50 kms/liter.(which may be estimated as nductive
load).
If a fat person rides it gives only 60 km/liter which you
can say Resistive load.

But if a thin person rides the same two wheeler may give
more than 65 kms / liter which you can say Capacitive load.

So variation is not with the vehicle but with customer's
load use. So production/generation is always in KVA (idle
condition)and customer load in KW.

Answer / srilu

KW is an average power(I*IR)units are KILLO WATTS. where as
KVA is an apperant power (I*I*Z)units are KILO VOLT AMPERES

Answer / raktim

KW is called active power, where KVA is apparent power.
In AC system we know there is another power called Reactive power (KVAr).
KW= KVA*cos(thita)
where cos(thita) is power factor.
KVA=root of ((kw)^2 +(kvar)^2)

Answer / nitin

KW IS KILOWATT & KVA IS KILO VOLT AMPERE

Answer / vijay sundararaju

In Ac Circuit there are Catagory

1.Active power (P=I*I*R),(P=(E*E)/R),
2.Apparent power (=I*I)*Z,
3,Reactive power=(I*I)*Z.

Answer / r.saravanan.

In power system, there is three power,
1.Real Power (Useful Power) or Active Power called kW -
donated by "P"
2.Imaginary Power (Useless power) or Re-active Power called
kVAR - donated by "Q".
3.Complexe Power ('Vector SUM' of useful & useless power)
or Apparent Power called KVA - donated by "S"
The relation of each other is S^2= P^2 +or- jQ^2
Note : here 'j' is represents imaginary parts and S,P,&Q
are vectors (Not scalar)

So the kW is actual power which is utilized by people
effectively and KVA is the vector sum of actual power +
imaginary power which is not utilized by people but same
think wasted at somewhere by inductive or capacitive loads.

Answer / sudhir patil

KW:-it is total connected load.
KVA :- For given connected load how many power required

KW=KAV*COS{phi}

Answer / ashok mishra

KW=KAV*COS{phi}
kw=vi cos(phi)
kva= VI

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