Analysis of High-Efficiency Operating Modes for Piezoelectric Resonator-Based DC-DC Converters

Demand for power electronics to have smaller volume, lighter weight, and lower cost will eventually require new converter energy storage technologies with fundamentally higher power density and efficiency limits. One promising alternative energy storage mechanism is the piezoelectric resonator (PR), which offers very high power density and efficiency capabilities with emerging materials and significantly improved scaling properties compared to magnetics. PRs have been proposed for power conversion previously, but typically alongside additional magnetics and/or with limited performance. In this paper, we analyze PR-based converter operating modes that best utilize the PR for high efficiency, assuming the PR is the converter’s only energy storage component. In addition, we provide easily-accessible tools for estimating the PR’s charge transfer, energy transfer, and efficiency characteristics, which we verify experimentally in a 200-100 V, 25 W rated prototype. This prototype exhibits peak efficiency >99% as well as high efficiency (≥96%) across a wide range of operating points, illustrating the promise of PR-based converters for high voltage, low power applications.