Permeability Engineered Soft Magnetics for Power Dense Energy Conversion

Traditional manufacturing of tape wound cores with low effective permeability involves a cutting step to allow for gapping. While this process is well established, it is not without consequence. Gapped tape wound cores suffer reduced performance in terms of overall magnetic, thermal, and electrical properties. By working with a new class of Cobalt-rich metal amorphous nanocomposite alloys, the permeability can be controlled to a pre-determined value prior to winding into the final desired core shape, thus eliminating the gapping step. This new ability to tune the permeability of a core material opens opportunities to develop magnetic cores with reduced volume and improved thermal management, while eliminating the need for labor intensive gapping processes that also introduce variability and complexities such as fringing flux and excess losses. In this work, we present three permeability profiles (constant, ideally graded, and exponentially graded) in toroidal tape wound cores to allow for the greatest variation and control of the flux density. We also demonstrate the potential for manufacturing of large-scale permeability engineered inductors.