I'm a little confused about the transformer "leakage inductance" for days. Per this text book, it gives a schematic view of fluxes flow in the transformer:
It's apparent that the two leakage flux will create separate inductance on each side. And it give s equivalent circuit:
You see, there are two separate inductance on each side, that is, the primary leakage inductance and the secondary leakage inductance.
And we reflect all the load at secondary to the primary side, then get
All are easy to understand, there are two "leakage inductance", though you can reflect them to the same side, but in physics, there indeed are two "leakage inductanes".
But in the app note from a leakage inductance tester, it says
Leakage inductance is an inductive component present in a transformer that results from the imperfect magnetic linking of one winding to another. Any magnetic flux that does not link the primary winding to the secondary winding acts as inductive impedance in series with the primary, therefore this “leakage inductance” is shown on a schematic diagram as an additional inductance before the primary of an ideal transformer.
And it gives,
Apparently, there is only one "leakage inductance" at one side in the figure above.
- Which one this inductance conrrespond to in the text book above? The primary one only or the primary one add the reflected secondary one?
- When it measure the "leakage inductance", it short the secondary. I wonder if it can short the secondary leakage out as below (Note: The R2 can't be shorted, it should always exist at the left side of the red line). If it can, then the measured leakage inductance from primary side will contain only the primary leakage; if it can NOT, then it will get the primary inductance added with the reflected secondary leakage, right?