A cheaper High Voltage SiC Switch?
Researchers at North Carolina State University say that a high voltage and high frequency SiC power switch they have developed could cost much less than similarly rated SiC power switches.
While offering greater efficiency at higher voltages than prevailing silicon IGBTs, wide bandgap semiconductors, such as SiC, are still much more expensive.
The new SiC power switch, however, could cost around half the estimated cost of conventional high voltage SiC solutions, say Alex Huang and Xiaoqing Song, researchers at NC State's FREEDM Systems Center, funded by the US National Science Foundation.
The power switch, called the FREEDM Super-Cascode, combines 12 smaller SiC power devices in series to reach a power rating of 15kV and 40A. It requires only one gate signal to turn it on and off, making it simple to implement and less complicated than IGBT series connection-based solutions. The power switch is also able to operate over a wide range of temperatures and frequencies due to its proficiency in heat dissipation.
"Today, there is no high voltage SiC device commercially available at voltage higher than 1.7 kV," said Huang, Progress Energy Distinguished Professor and the founding director of the FREEDM Systems Center. "The FREEDM Super-Cascode solution paves the way for power switches to be developed in large quantities with breakdown voltages from 2.4 kV to 15 kV."
The FREEDM Super-Cascode switch was presented by Xiaoqing Song, a Phd candidate at the FREEDM Systems Center under Huang's supervision, at the IEEE Energy Conversion Congress & Exposition (ECCE 2016) held in Milwaukee from Sept. 18-22, 2016.
