Transformer equivalent circuit open and closed circuit test

[xdeimos]

I see the open and closed circuit test on the transformer section

I don't understand why we doing that(open and closed circuit test)

can anyone explain and give some example?

 

[berkeman]

I see the open and closed circuit test on the transformer section

I don't understand why we doing that(open and closed circuit test)

can anyone explain and give some example?

Could you be more specific please? What kind of transformers? Where have you seen this? Can you post a link? Do you have any ideas yet for why it is done?

 

[Babadag]

Transformer equivalent circuit open and closed circuit tests are some of required Power Transformer Tests [IEC 60076-1Standard]
1)Measurement of voltage ratio and check of phase displacement pen secondary winding test. Since primary EMF in this case is approximately equal to supply voltage and secondary EMF is secondary output voltage the ratio of primary to secondary voltage
it is EMF ratio then directly proportional with number of turns of the windings.
2) Measurement of short-circuit impedance and load loss :short-circuited secondary winding. The primary voltage will rise until the primary current shall not be less than 50 % of rated. The transformer short-circuit impedance will be then Voltage/Current. The resistance has to be
measured separately. As the supply voltage is reduced the no-load losses-magnetic losses-will be negligible. So the active power
measured in short-circuit test will be proportional will the load-loss.