Diodes based on Silicon Carbide were formulated then that enabled aircraft alternators to operate at extremely high temperatures, exceeding 300 degrees.
However, these early devices were neither reliable nor cost effective. Not until Scofied's work can we point to Silicon Carbide diodes as marketable devices."
SiC Schottky diodes have a high blocking voltage rating of up to 1200 volts commercially, with a practical potential of up to 3000 volts for ultra-high power density applications.
"Because of their faster switching speed, high temperature capability, and efficiency advantages, SiC Schottky devices can now offer high performance solutions for a wide range of power system applications requiring improved performance and increased power density," stated Scofield.
"Applications include industrial motor drives, power factor correction, energy efficient kitchen appliances, power supplies, and a host of other commercial power applications in addition to the harsh environment Defense weapon system applications," he noted. "With rapidly increasing energy costs, and the push toward hybrid and electric vehicles, SiC will eventually power the traction drive motors in automotive applications.
"This application demands a high temperature capable power technology as the available cooling from radiator loop liquid is in the 90 to 110oC range, which is pushing the limit of Si IGBT traction drive inverter technology from a reliability standpoint," Scofield explained. "Power switch maturation, volume availability, and cost remain issues for this application, but a rapidly improving SiC technology and commercial demand will eliminate these obstacles."
The manufacturing of SiC Schottky Diodes has proven beneficial to both military and commercial applications. The Air Force is developing inverters, converters and motor drives with the new SiC semiconducting technology.
The Air Force More Electric Aircraft, or MEA, concept is dependent upon theses and other emerging SiC power devices.
This concept involves replacing all hydraulic, pneumatic, and mechanical powered systems with electronic functionality to improve the reliability, maintainability, and life cycle cost of aircraft.
Continued use of SiC Schottky Diodes and similar high efficiency power technologies will lead to increased electrical performance, which will help meet the increasing power demands of a boundlessly growing electronic world.