Why transformer rating is in KVA ?




Transformer is a static device which works in mutual induction. It has two windings one is primary and the other one is secondary. It is usually used for step up and step down voltages and its reading is in KVA. Transformer is an ac machine that is:-
1-It transfer electrical energy from one electrical circuit to another without change of its frequency.
2-It has electric circuits that are linked by a common magnetic circuits.
3-It is a static machine and has very high efficiency in the range of 96-99%.

 Transformer rating in KVA
  KVA = Voltage*Current and K stands for kilo
  KW  = Voltage*Current*Cosθ  (Power factor = Cosθ ; which is depend on load)

 *Types of loads :-
 1- Resistive- It has unity power factor whivh is one.
 2- Inductive- It has lagging power factor, where current lags and voltage leads.
 3- Conductive- It has leading power factor, where current leads and voltage lags.

*Losses in transformer :-
 1- Copper loss- It depends on current and it happens due to heat generates in winding.
 2- Core loss - It depends on voltage and it occurs ony in core of transformer where voltage is fix and                        current changes by the demand of load.

* Total loss- (Copper + Core)loss = KVA 
     KVA=K * voltage * current   (where phase angle between Volt ans amp doesn't matter bcoz                                                            Cosθ is not include in that)

    (That's why rating is in KVA bcoz transformer loss depends on voltage and current instead         of Cosθ)
    *machines which consumes power comes in rating of KW and machines which transfer power comes in KVA.

Why transformer rating is in KVA ? Why transformer rating is in KVA ? Reviewed by Yugank Rawat on 1:52 AM Rating: 5

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