Optimization of Parallel Structure of Planar Inductor Winding

Planar magnetic components have the advantages of high operating frequency, high efficiency, and low susceptibility to interference, and are widely used in high-frequency and miniaturized power supply systems. However, due to the limitation of the copper thickness of the PCB winding, multiple parallel connections are required to reduce the current density in high current applications. This paper completes the design of the planar inductor based on the two-stage Buck-Boost integrated LLC converter(BBLLC). Three different parallel structures are proposed, which called direct parallel structure, interleaved parallel structure, and sandwich parallel structure. The loss of three different structures will be analyzed, and the simulation is verified by ANASYS Maxwell software. The purposed structure improves the current sharing ability between layers and reduces the current density, which compares to the unparalleled structure. The AC resistance of the purposed structure is the smallest, which minimizes the copper loss of the inductor and improves the efficiency of the converter.