Research On Characteristics Of Silicon Carbide Devices And Their Application In Pulse Power Supply

Pulse power supply is an important part of the electromagnetic emission system.The semiconductor device in the pulse power source has a direct impact on the performance of the pulse power supply.At present,there are high power thyristors and power diodes in pulse power supply.However,in the pulse power supply,it often needs to be used in series because the thyristor withstand voltage is not high as we hope to.Its switching speed is slower than that of silicon carbide devices,and the loss is higher.Under high repetition frequency pulse discharge,the junction temperature of thyristors and the power diodes will rise and the performance of two devices will become worse.With the rapid development of silicon carbide materials,the voltage and current levels of silicon carbide devices continue to increase.Silicon carbide devices are suitable for operation in high temperature and high temperature environments.Therefore,the application of two kinds of silicon carbide devices in the pulse power supply is studied in this paper.Firstly,silicon carbide gate-off thyristor,the popular device in pulsed power supply,are studied.According to the design principle and the previous research results,a 4kV forward blocking voltage SiC GTO is designed and compared with Si GTO which has similar structure with SiC GTO.And the two GTOs are studied in a pulse forming network.Then,through the circuit simulation,the static characteristics,dynamic characteristics of the silicon ultra-fast recovery diode and SiC JBS which has same voltage and current with are analyzed.Next,a simple mathematical analysis and simulation of the discharge process of the pulse forming network is performed to analyze the voltage and current environment of the semiconductor device during the pulse discharge process.The surge current in the pulse forming network is estimated by combining the parameter table of the silicon carbide junction barrier Schottky diode and the silicon ultra-fast recovery diode.The surge current of the silicon carbide junction barrier Schottky diode and the silicon ultrafast recovery diode are test in the pulse discharge environment at room temperature and high temperature to decide weather they are suitable for the environment.Finally,it is concluded that silicon carbide power devices have great potential in the field of pulse power supply.With advances in technologies such as silicon carbide materials,device structure optimization,and high-temperature packaging,silicon carbide power devices can exhibit better performance than silicon power devices in the pulse power supply.