Interleaved buck chopper with coupled inductors

This example, available in SIMBA, shows a parallel interleaved buck chopper with coupled inductors. It has two switching cells and coupled inductors with two windings.

Phase-shift of switching cells

The control signals of the two switching cells are phase-shifted of 180° as in classical interleaved buck choppers with separate inductors.

Coupled inductors and mutual coefficients

In order to minimize the maximum common flux and to get a double apparent switching frequency - which can lead to a downsizing of the magnetic circuit - the coupling between the two inductors should be such as shown in figure below:

Thus, with the classical convention of coupled inductors (which is used in Simba), a negative mutual coefficient must be considered to get this coupling and inductor currents.