Design and Assessment of a Planar Inductor for a 32 kW High Power Density DC-DC Converter

• Published in: IEEE journal of emerging and selected topics in power electronics Vol. 11; no. 3; p. 1
• Main Authors: Herrera-Aparicio, Brenda-Angelica, Araujo-Vargas, Ismael, Cano-Pulido, Kevin, Cui, Han, Granados-Luna, Teresa-Raquel, Lopez-Salgado, Christian-Ivan
• Format: Journal Article
• Language: English
• Published: Piscataway IEEE 01.06.2023; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Copper; Density distribution; Density measurement; Finite element method; Flux density; Geometry; Inductance; Inductors; Magnetic cores; Magnetic flux; Medium Power DC-DC Converter; Numerical prediction; Planar Inductor; Power system measurements; Tapered Coil; Thermal stability; Thermodynamic properties; Uniform Flux Density Distribution; Voltage converters (DC to DC); Windings
• ISSN: 2168-6777; 2168-6785
• DOI: 10.1109/JESTPE.2023.3261322

A uniform-flux inductor design strategy is described in this paper to improve the gravimetric power density of the common inductor of a 32 kW, 350 V dual-interleaved Buck-Boost DC-DC converter. The strategy consists of an unusual, enclosed winding arrangement that virtually distributes the core magnetic flux density outcoming in a more compact inductor. The resultant common inductor weight and volume are reduced by 41 % and 24 % respectively, the power density being increased to 7.9 kW/kg. A COMSOL numerical prediction confirms almost uniform flux density distribution along the magnetic core axes. Estimation of the inductance, power losses and thermal behaviour are also analysed. Construction assessment is described for a 7 μH, 150 kHz, 180 A inductor, which is experimentally verified in a 350 V, 32 kW prototype. The experiments reveal that the built uniform-flux inductor properly operates ensuring both electrical and thermal stability.