Design Considerations of Very Low Profile Coupled Inductors for Flexible Photovoltaic Module

Power converters with flexible PCB integrated magnetic components are highly demanded in future photovoltaic (PV) applications, resulting in a higher power density. In this paper, a 1.5-mm thickness integrated coupled inductor with planar sandwich core structure is under investigation. Several important design issues for the sandwich core structure including self-inductance, leakage inductance, eddy current effect and core loss are analyzed in-depth in this work. Since the non-uniform flux is distributed in the core plates, the parameters calculation and the design considerations are completely different with the traditional magnetic approaches. Accordingly, this paper enables original design considerations as a guideline for sandwiched coupled inductor. In order to reduce the high frequency eddy current effect in sandwich core structure, section III initiates a discussion with adjustable core structures and winding arrangements such as closed core structure, gapped structure and meander winding. The tradeoffs among them are presented.