An Assessment of Coupled Inductor Modeling for a Multi-output Flyback Converter

In this paper, simulation results for a five-winding coupled inductor in a multi-output flyback converter are compared with experimental results. The simulations were usually aborted due to numerical convergence problems. This has been overcome by rearranging the elements of the equivalent circuit of the coupled inductor so as to place every inductance in series with a resistance. Discrepancies between the simulation and experiment have been categorized as follows: (i) coupling factors significantly influence the shapes of the secondary current waveforms and steepness of the slope after a switch transition; (ii) the representations of winding and core losses affect only the losses and not the shapes of the waveforms; (iii) the magnetizing inductance determines whether the converter operates in the continuous or discontinuous current mode