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 made mobile and may become competitive if they are cost- effective, reliable, and safe, and have regulatory approvals and industry acceptance. Advances in power converter efficiency, power density, and flexibility are required to enable these competitive energy storage methods to be realized. Wide Band Gap semiconductor devices such as Silicon Carbide SiC) MOSFETs offer benefits of increased efficiency, higher power density, and simplified thermal management compared to silicon Si) devices at utility 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 60 Hz magnetics liquid cooling. Our innovation uses 1) power dense electronic designs, which achieve high efficiency at utility power levels; 2) a physical geometry with high heat transfer rates, which permits convective cooling; and 3) a bidirectional transformerless architecture, which further increases power density, reduces cost, simplifies the design, and improves reliability. During Phase I we will demonstrate the feasibility of improving upon an existing energy storage inverter product. We will develop a full-scale, containerized grid tie energy storage system design, having three- phase, 12.47 kVAC, 100 kW, convection cooling, bidirectionality, and greater than twice the power density over existing converters. We will validate the design with subscale power converter prototype demonstrations. We have teamed with a well-known provider of power conversion equipment, and we will work closely with our partner to plan a Phase II demonstration. Based on these results, we will formulate a business case to quantify the markets, investment required, return on investment, and pathway to achieving that return. This technology will find immediate commercial application to distributed electrical power generation equipment. Features include elimination of 60 Hz magnetics and allowance for interface with renewable energy sources, which provide benefits of reduced cost, increased source flexibility, and improved efficiency.