Design of Coupled Inductor for Two-Phase Synchronous Boost Converters in Automotive Applications

This paper introduces a design for a coupled inductor for a two-phase synchronous boost converter based on silicon carbide (SiC) MOSFETs. The converter operates at a high switching frequency of 300 kHz and is designed for a maximum output power of 32 kW. Despite the very high switching frequency and consequently smaller sizes of passive components, passives remain one of the largest components of the converter, especially inductors. The magnetic coupling of several phases of a converter in the form of coupled inductors allows a further reduction in size and weight of these passive components. Fast switching SiC devices and the high power rating require a sophisticated design, whose process is described in detail. For evaluation in an experimental setup, a prototype is manufactured and the efficiency is compared to the converter operated with uncoupled inductors. The design of the coupled inductor achieves similar efficiency while requiring less material, which improves the power density and decreases costs.