why transformer ratings in kva?
Answer Posted / pradyumna chandra panda
Why the motors are rated in KW and transformers are rated in
KVA?
Ans . Motor is a consuming device it consume the power
(wt) so it is rated in KW. But the
Transformer is a static device which transfers
the power (Apparent power) from the
Generating point to the user. Apparent power is
the product of voltage and current
I.e. Increase voltage with decrease current and
decrease voltage with increase
current. Power factor of the load does not
affect apparent power it affect the Active
Power.
Active power is the real power which the transformer
gives. Transformer should not be rated on the base of
Active power (KW) which is variable because the power factor
of the load is not knows before which to be connected across
the transformer.
Reactive power Apparent power (k)
KVA
VI sin Q k
Kw
Q q
Active power VI cos Q
Active power is equal to apparent power at resistivity load
where power factor is unit at cos Q is equal to zero degree.
Active power is decrease power where cos Q (not fi) is
increase
Therefore in simple we can say due to unknown power factor
transformer and generator are rated in KVA.
Hint – we know cos FI is the value of cos Q i.e. apparent
power/ active power
| Is This Answer Correct ? | 3 Yes | 0 No |
Post New Answer View All Answers
Please explain me abt PQ diagaram in the power sector.
In CTs tan delta point should be earthed , what is the reason behind it?
What is a commutator?
Why Ac Systems Are Preferred Over Dc Systems?
What are the common sources of energy?
can anyone explain the star-delta motor control wiring ,which wire go where and how they operate?
What are the advantages of stationary armature and rotating field system?
plz send me HPCL apptitude paper.. maulik_elect@yahoo.co.in
Can the output voltage of a rectifier be greater than the input AC voltage without the use of any voltage multiplier in the circuit??please provide the explanation too..
Explain the operation principle, advantages and disadvantages of the following converters: a) A 12 pulse converter b) A Switch-mode inverter c) A thyristor inverter
Define unilateral circuit?
We have Diesel generator of 200KW. fuel consumption is always same,even connected light load or full load. Is it right?
HOW TO DESIGN THE body EARTH cable(Copper Conductor) size for 60KVA UPS?
draw the restricted earth fault protection circuit install on power transformer and identify its parameters and draw C/C curve of it
we have 15 ampere variyac but we want 30 ampere variyac what we do