SiC-SIT intelligent switches for next-generation distribution systems

In recent years, versatile distribution systems for next generation to realize highly efficient and reliable operation are investigated actively. In such distribution systems, high-speed overcurrent protection is one of the important issues. In addition, dynamic routing of power flow to improve system reliability and efficiency is desired. To meet these requirements, several types of semiconductor power switches have been investigated. In this context, intelligent switches using SiC-SIT for 400V DC distribution systems have been investigated. In this paper, based on the analysis of turn-off process, the required features for the intelligent switch are investigated theoretically. Then, gate voltage waveform effective on overvoltage suppression during the interruption process is presented. Furthermore, a feedback control method to realize the optimum turn-off operation regardless of the variation in the device characteristics is discussed.