Topic 9a. High Conversion Cell-Level Battery Power Converter

With the aggressive adoption of renewable energy sources, the demand for reliable, efficient energy storage systems continues to grow in step. By 2030, the Li-ion battery energy storage systems are expected to exceed 2 TWh of energy storage, creating a market opportunity for efficient power conversion systems. With the rapid advancement of wide-bandgap semiconductors, the next generation of power converters can eliminate up to 90% of the power losses experienced by their silicon-based counterparts. In addition to the increased efficiency, the wide-bandgap semiconductors can be pushed to much higher frequencies, greatly shrinking the magnetics of the power converters and increasing the power density. These next-generation power conversion systems will further facilitate the adoption of renewable energy sources by increasing system efficiency and power density to levels not commercially available today. This proposal features a novel cell-level DC-DC converter topology, based on wide-bandgap semiconductors and custom planar magnetics, to drive the miniaturization and electrical performance of the system. This converter features a modular structure and control scheme allowing it to be integrated into systems of different sizes and power levels. The efficiency, power density, and modularity of the converter will demonstrate an increase in performance of next-generation power conversion systems providing economic incentive for commercial adoption. During Phase I, high fidelity models and simulations will be developed to demonstrate the system level benefits. Prototypes of the custom magnetics will be designed, constructed, and tested to verify performance. Finally, a full set of schematics and printed circuit board layouts will be developed allowing the project to rapidly progress to system-level integration in Phase II. This next-generation power converter can be integrated into a full-scale battery storage system of varying power levels. Phase II will demonstrate this capability by implementing a 2-kW single phase off-grid system. Pending a successful Phase I/II effort, this power conversion system will demonstrate its commercial potential for small, efficient battery energy storage systems leveraging the technology to Phase III and beyond.