SiC power converter technology in future

The characteristics of the inverter have been improved but the developing speed of the inverter will soon be saturated if using silicon-devices because of its physical characteristics. New devices which have better characteristics than that of silicon are being developed. Silicon-carbide (SiC) semiconductor is now considered as the most promising material for devices with large capacity and high frequency power converter uses. It has physically bout 10 times the blocking-voltage and 1/100 times of switching time of silicon and it can work at over 600/spl deg/C wafer-temperature. By using this device, a high capacity high frequency and small size power converter will be produced. Many problems need to be considered to realize SiC power converters. This paper proposes a 1 MW small size and high efficiency AC-AC direct frequency changer, which uses SiC devices (SiC diode and SiC switching devices). The construction of the frequency changer and basic design is also discussed. Technical methods to make possible high power 1 MW and high frequency 10 kHz AC to AC frequency changer are described. It has small size, less than 1/50 of today's frequency changers. To realize it, SiC switching devices and some new technologies must be employed. At least 20 years will be necessary to accomplish the project. The size of about 500 W 230 D 180 H, maximum allowable temperature of above 400/spl deg/C, and high efficiency of 99.6% including input and output filters will be obtained.