SBIR-STTR Award

Power electronics for Grid-tied Battery Energy Storage Systems (BESS) featuring: (a) newly developed monolithically integrated High Voltage SiC MOSFET- Schottky Diodes; (b) Intelligent Gate Drivers that provide in-situ monitoring and restoration capabilities; and (c) novel three level Neutral point clamping topology are proposed. An isolated topology such as dual active bridge followed by an active front end converter and a three-level neutral point clamped topology featuring 3300 Volt rated medium-voltage silicon carbide MOSFETs with integrated Schottky diodes is proposed. An intelligent MV gate driver will minimize the problems of voltage isolation for series connected device topologies. Phase I will perform a comprehensive evaluation of various BESS and grid connected PCS topologies, and quantify SiC MOSFET device stresses and required thermal management, quantify SiC MOSFET lifetime based on standard lifetime and reliability models, and compare losses with Si-IGBT implementation and defining the merits of proposed SiC MOSFET based PCS for ESS.The 400 kW all-SiC power inverters to be developed in this program will significantly improve the performance and decrease the size/weight/footprint of 12.47 kV energy storage grid-tied inverters, FACTS-based devices, and power system switchgear. Industrial applications such as electrostatic precipitators, and oil drilling equipment. This in turn will increase market acceptance of these high-end products and thereby drive skilled-labor jobs creation in the US.

Power electronics for Grid-tied Battery Energy Storage Systems (BESS) featuring: (a) newly developed monolithically integrated High Voltage SiC MOSFET- Schottky Diodes; (b) Intelligent Gate Drivers that provide in-situ monitoring and restoration capabilities; and (c) novel three level Neutral point clamping topology are proposed. An isolated topology such as dual active bridge followed by an active front end converter and a three-level neutral point clamped topology featuring 3300 Volt rated medium-voltage silicon carbide MOSFETs with integrated Schottky diodes is proposed. An intelligent medium-voltage gate driver will minimize the problems of voltage isolation for series connected device topologies. With respect to device development, the Phase I project was able to successfully develop 3300 Volt, 100 Ampere rated silicon carbide MOSFETs with integrated Schottky diodes. On the energy storage system side, the Phase I was able to insert the fabricated silicon carbide MOSFET-diodes into a battery energy storage system inverter switching at 15 kilohertz. A proof-of- concept test was performed at 6000 Volt DC bus and peak load current of 25 Amperes, Specific technical objectives of the Phase II project include: 1. Design and Process Freezing the SiC MOSFET-Diode device technology after improvement few key parameters. Complete device qualification be performing industry-standard, energy storage system specific reliability testing 3. Develop an intelligent gate drive with novel mission-critical detection and restoration features 4. Insertion of finalized MOSFET-diode based power modules into battery energy storage system at NC State and quantifying system efficiency and benchmarking against incumbent Si based technologies. This program will target medium voltage inverter manufacturers like GE, ABB, S&C and Saft America to adopt the device and circuit topologies developed in this program. The higher conversion efficiencies will allow these compact inverters to be deployed at a large scale from residential to industrial usage. The approach is to collaborate with existing inverter manufacturers to incorporate its components into inverters. The competitive advantage is in terms of cost, high temperature, and total power ratings of the devices that form the core of the inverter technology.