Topic 8a. Additive manufacturing of high frequency transformers using coherent wire placement

Solid state, high frequency transformers, enabled by high electron mobility transistors, are a power conversion technology poised to be a key enabler of the modern smart grid, as they allow dramatic increase in power density, and greatly increased control over flow of power through the net- work. Despite this promise, however, these devices are currently hampered by the difficulty in cost-effectively and reliably manufacturing high frequency, high power wirewound electromagnetic components. In short, at these high frequen- cies, the device performance becomes very sensitive to conductor placement, and current approaches offer either inadequate control over this placement (e.g., Litz wire techniques), or inadequate copper fill fraction (e.g., printed circuit board techniques). The proposed approach will solve this problem by lever- aging a custom additive manufacturing platform for precision electromagnetic devices, using this technology to build high performance transformers for the future electricity grid. In prior work, this platform has enabled new classes of inductive sensors, electric motors, and other actuators, with significantly im- proved throughput, material properties, and costs compared to competing AM approaches. During Phase I, the proposed work will expand the capabilities of the AM platform to include printing of soft magnetic core materials. This will involve sourcing and evaluating candidate feedstock materials by printing and testing magnetic properties of representative geometries. The second com- ponent of the Phase I work will be using the existing ability to print wirewound structures to print of fully integrated transformer, including both conductive and soft magnetic materials in a single part. These components will be tested and iterated, resulting in a transformer, printed on a printed circuit board, suitable for use in a dual active bridge power converter. Shifting the energy econ- omy away from fossil fuels will require an ambitious grid infrastructure build- out, as three to four times as much electricity must be delivered as is today. Further, to fully utilize the distributed and variable nature of renewable gener- ation and storage assets, as well as to power a rapidly growing electric vehicle fleet, this infrastructure must be smarter, more flexible, and more bidirectional than the current grid. If successfully implemented, the proposed technology offers a scalable pathway for high frequency solid state transformers, enabling the ubiquitous power conversion necessary for a truly smart grid.