This video from Sam Ben Yaakov provides detailed insight into modelling and simulation of leakage inductance.
Leakage inductances play an important role, some helpful, and some damaging in most switch-mode converter designs. In circuit analysis, modelling and simulations it is assumed that the leakage inductance is on one side of magnetic element.
This presentation shows that the question of which side is the leakage has no significance on the results of the analysis or simulation.
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