Grainger CEME Seminars

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High-Q Power Magnetics for Resonant Power Conversion and Wireless Power Transfer

Event Type
Grainger CEME
4070 ECEB
Oct 1, 2018   3:00 - 3:50 pm  
Aaron Stein




Advancements in transportation, communication, and energy systems create increased demand for small and efficient power electronics. The largest and least efficient components in a power electronic converter are, often, the magnetic components. Fueled by advances in switch technology and resonant circuit topologies, the increased switching frequency provides strong opportunities for miniaturization of magnetic components, in light of the reduced energy storage requirements. Unfortunately, it is difficult to realize these opportunities due to the high-frequency winding losses.

In this talk, we present a new electromagnetic structure that significantly reduces winding loss in high-frequency resonant magnetics. This new structure uses thin foil layers that are separated by a dielectric material in order to form an integrated LC resonator. The integrated capacitance not only provides a part-count savings, but reduces further winding loss by forcing equal current sharing between many thin conductors. Two applications that may benefit from this technology include resonant inductive wireless power transfer and resonant power conversion. Experimental results of a wireless power transfer coil constructed using this new technology had 6 times less losses compared to similarly-sized coils in the literature. The integration into a wireless power transfer system resulted in a 2 times increase in range with the efficiency maintained above 94 %. Experimental results of a series resonator for resonant power conversion constructed using the new technology had a 1.6 times larger Q than that of a single-layer benchmark.



Aaron L.F. Stein received the M.S. degree and the Ph.D. degree in electrical engineering and computer science from the University of Michigan. In 2016, Aaron published his doctoral thesis entitled “The Design and Effect of Power Electronics on Vibration Based Energy Harvesting Methods”. He currently holds two positions. He is a Post-Doctoral Research Associate at Dartmouth College, and the president of Resonant Link, a startup company formed to commercialize his postdoctoral research. His research interests include electromagnetic component design, wireless power transfer, and energy harvesting.

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