Power Dense Converter Electronics for Grid Tie Energy Storage Containers

Increased electricity demand amid infrastructure development restrictions continues to foster innovation for distributed generation. Whereas pumped hydro installations are fixed locations, battery, thermal, compressed air, and flywheel storage can be mobile and competitive if they are cost effective, reliable, and safe, and have regulatory approvals and industry acceptance. Improvements to efficiency, power density and flexibility, and reduced capitalization cost are required to enable these competitive energy storage methods to be realized. Statement of How This Problem or Situation Is Being Addressed. Silicon carbide (SiC) MOSFETs offer benefits of increased efficiency, higher power density, and simplified thermal management compared to silicon devices at 12.47 kV AC/MW+ utility class power levels. We aim to use these emerging devices to greatly improve the value proposition of energy storage based distributed generation by increasing power density and eliminating large 60 Hz magnetics and unreliable liquid cooling. Our innovation is an Advanced Power Inverter (API) with (1) high power density electronic designs having high efficiency at utility power levels; (2) a physical geometry with high heat transfer rates, allowing liquid cooling hardware to be replaced with convective cooling; and (3) a bidirectional transformerless architecture, which greatly increases power density, reduces cost, simplifies the design, and improves reliability. What was done in Phase I? The following API technical milestones were achieved during Phase I: obtained and tested 10 kV SiC MOSFETs in the laboratory, demonstrating that these devices have adequate maturity and performance; achieved power density that is 4.3 times greater than existing inverters; eliminated the 60 Hz transformer and liquid cooling hardware; achieved end to end efficiency of 96%; achieved switching frequency of 20 kHz that is three times higher than for high voltage IGBTs. These accomplishments will provide power conversion electronics for grid tied energy storage applications that are smaller, more efficient, and require lower capital than existing systems. What is planned for Phase II? During Phase II we will complete design work, fabricate a full scale API prototype, evaluate performance, and prepare for commercialization transition. The Phase II API prototype will be manufactured as the first unit from a representative production line, showcasing commercial readiness for our initial Phase III customers. Commercial Application and Other Benefits. This API technology will find broad application to distributed electrical power generation equipment. Our team includes stakeholders with access to both terrestrial utility as well as Department of Defense markets, creating expansive revenue potential for this technology. Innovative API features will improve reliability, increase power density that will simplify deployment for urban and shipboard environments, reduce capitalization cost, and enable far greater power levels and revenue. Key Words. Renewable energy, energy storage, Silicon carbide Summary for Members of Congress. Creare will develop an innovative electrical energy storage and power generation technology that will reduce equipment size and cost for terrestrial utilities and Department of Defense shipboard uses.