CAREER: Hybrid Multimode Resonant Switched-Capacitor Converters for Renewable Energy and Point-of-Load Power Delivery

Dartmouth College, Hanover NH

Investigators

Abstract

The field of power electronics is expected to grow in scope and importance in coming decades due to the rising need for renewable energy generation and storage, increasing adoption of electrified transportation, and to broadly reduce energy consumption of end-load applications. This research effort targets circuit, system, and implementation details of new families of power electronics based on resonant and multimode operation of switched-capacitor (SC) families of DC-DC converters. The work holds promise in facilitating greatly increased utilization of high-energy-density passive devices (capacitors and inductors) while leveraging exponential (Moore's Law) semiconductor scaling, and transformational benefits of wide-bandgap transistors. Specific research will address next-generation energy management circuits and architectures for photovoltaic systems, and large-scale battery arrays used in electrified transportation and grid-embedded energy storage. The work will also extend more generally to a variety of applications that demand high power-efficiency in a variety of load conditions, high power-density (small size), low cost, and robust variable regulation capability. Research and teaching are integrated through the training and involvement of Dartmouth graduate and undergraduate students, specific outreach modules that will engage k-12 students and the general public, and teaching activities that integrate research topics and findings in the curriculum. Resonant or hybrid operation of switched-capacitor (SC) DC-DC converters is growing increasingly attractive as the approach benefits from many of the fundamental advantages SC topologies have compared to more traditional magnetics-based topologies (e.g. buck or boost), but it can eliminate many specific limitations or disadvantages of the SC architecture. In particular, we address key knowledge gaps related to achieving highly-efficient variable voltage regulation by using the native switching capability of SC topologies merged with resonating or soft-charging inductors. We will explore the prospects of merged-multiphase interleaving that have the potential to reduce size and cost, while increasing efficiency and power-density. Variable regulation is essential for most point-of-load applications, but also promising as a way to implement distributed granular maximum power point tracking (MPPT) in photovoltaic systems, and online spectroscopic diagnostic capability in large-scale electrochemical storage systems. We will also explore multi-mode operation to extend high efficiency across a wide load range for a range of circuit topologies spanning moderate-low voltage and higher voltage applications using wide-bandgap devices.