PhD Thesis Proposal: Phyo Aung Kyaw

Thursday, March 22, 2018, 10:00am

Room 202, Cummings Hall

“Efficient Power-Dense Passive Components for Next-Generation High-Frequency Power Conversion”


Advancements in energy systems and electric vehicles have increased demands for efficient and compact power electronics. High-frequency operation is important for improving the power density and miniaturization of switching power converters because of reduced energy storage requirement and better transient performance. Wide-bandgap semiconductors allows for efficient high-frequency switching, but full realization of their potential in power electronics requires efficient high-power high-frequency passive components. Magnetic components such as inductors and transformers, due to their frequency-dependent losses, are increasingly the main bottleneck in improvement of switching converter power density.

Although incremental improvements in magnetics, and passives in general, are enabling advances in power electronics, possibility for order-of-magnitude improvement merits consideration of the fundamental performance limits and exploration of alternative technologies. Analysis of various energy storage mechanisms indicates the potential of mechanical storage coupled with a piezoelectric transduction mechanism. Optimal designs of piezoelectric and electromagnetic resonant tanks, in some ideal scenarios, are capable of orders-of-magnitude higher power density than passive components in use today. Investigation of various practical limitations to these ideal scenarios can provide insight into possible improvement achievable by various technological development.

This process of assessing the fundamental performance limits, followed by examination of the impact of various practical limitations has resulted in development of high-performance resonant tank prototypes. First, an integrated LC resonator with a winding made of multiple layers of foil conductors demonstrates a 50% improvement in quality factor over a similar resonator with a single-layer winding. Second, an optimally designed integrated LC resonant tank, made of commercial Class I ceramic capacitors, has a sub-mΩ effective series resistance and incurs only 4.56 W loss, resulting in a power capability of 7.42 kW in a small 1.14 cm3 volume. The high performance means that a power converter utilizing these prototype resonators will be limited by the performance of switches and interconnects rather than by the passive component, and investigations of such limitations are topics for future research.

Thesis Committee

For more information, contact Daryl Laware at