Integrated Inductors for Interleaving Buck and Boost Converters

Inhalt:
This paper explores the integration of inductors in interleaved buck and boost converters, particularly for fuel cell applications. While interleaving enhances efficiency and reduces output ripple, it also introduces challenges such as increased circuit complexity, higher inductor ripple, additional semiconductor requirements, and leakage magnetic flux, which can interfere with nearby components. To address these issues, this study proposes an advanced integration method that significantly reduces volume, minimizes leakage inductance, and mitigates stray magnetic fields to enhance overall converter performance. A detailed analysis of magnetic integration is presented, emphasizing leakage inductance utilization, magnetic flux distribution, core saturation, and manufacturing constraints. Finite Element Method (FEM) simulations are employed to assess integration strategies, ensuring optimal electrical performance and reduced electromagnetic interference (EMI). A case study on an automotive boost converter demonstrates the practical benefits of inductor integration. Experimental results show that integrating coupled inductors with optimized shielding techniques improves total efficiency by 1.3%, translating to a reduction of 325 W in power losses for a 25 kW system. The shielding approach confines the magnetic field within the core, enhancing electromagnetic compatibility (EMC). Integrated inductors offer a viable solution for improving power converter efficiency while reducing size, cost, and stray flux.