Accurate modeling of buck converters with magnetic-core inductors

In this paper, a modeling approach for buck converters with magnetic-core inductors is presented. Due to the high nonlinearity of magnetic materials, the frequency-domain analysis of such circuits is not suitable for an accurate description of their behaviour. Hence, in this work, a time-domain model of buck converters with magnetic-core inductors in a Simulink® environment is proposed. As an example, the presented approach is used to simulate an eight-phase buck converter. The simulation results show that an unexpected system behaviour in terms of current ripple amplitude needs the inductor core hysteretic behavior to be thoroughly taken into account.