To improve the calculation accuracy of leakage inductance in separated winding transformers

a leakage inductance analysis method that accounts for both the core and winding radial magnetic fields was proposed. Firstly

the existence of magnetic leakage energy in the iron core was revealed by experiments. The alternating effective magnetic permeability was obtained from the B-H curve; meanwhile

by utilizing typical soft iron

the angle between the main magnetic flux lines of the silicon steel sheet and the normal to the iron core interface was determined

and the radial leakage magnetic energy of the iron core along with its corresponding leakage inductance were calculated. Then

the length-to-diameter ratio was used to express the leakage magnetic energy density curves of the winding shaft and radial directions. By analyzing the upper and lower limits of the magnetic energy definite integral

the two symmetrical virtual end faces of the winding axis were determined

which was used to select and discard the leakage magnetic energy and leakage inductance corresponding to the winding shaft and radial magnetic fields. Finally

the numerical distribution of core leakage inductance and winding leakage inductance was rendered using 4D technology to provide a range of values for modeling control leakage sensation. The leakage inductance measurement under actual working conditions and the LCR bridge measurement both verified that the error of the controlled leakage inductance was less than 4%

and the effectiveness of this modeling method was demonstrated by replacing the inductor in the LC filter with leakage inductance. This research can provide a reference for manipulating the leakage inductance of separated winding transformers and calculating the radial magnetic field of the winding body.