A Study On Low-power Driving Technology For SiC Bipolar Power Semiconductor Devices

In recent years,the development of Si-based power semiconductor devices has made rapid progress.However,its limitation has become one of the bottlenecks of restricting the development of power electronic technology in the future.Nevertheless,SiC power semiconductor devices can make up for the disadvantages of Si-based power semiconductor devices in large voltage magnitude and high power.Hence,SiC power semiconductor devices has aroused wide attention in related fields.This paper aims to design a low-power drive circuit which can make SiC GTO turn on and turn off quickly.The focus of this study is not only the pursuit of higher drive current's rise and fall rate,but also the turn-off of gate driving current during the conduction of SiC GTO so that the power consumption can be greatly reduced.First of all,starting from the development situation of SiC power semiconductor devices,this paper states the excellent characteristics of SiC power semiconductor devices and their applications in the field of power electronics belonging to the modern electric power system.Then,selecting typical bipolar power semiconductor devices SiC BJT and SiC GTO as research objects,this paper introduces their basic structures,working principles and features respectively.Meanwhile,by combining with typical current drive circuit,the idea of low-power drive circuit design is put forward.Next,on the basis of circuit design ideas,the analysis and the selection of basic devices are made in this paper.After analyzing the design of drive circuits that have been studied,this paper puts forward the basic design scheme of low-power drive circuit: Hall Sensor is selected as the main circuit signal collector of SiC GTO,CMOS Inverter's output high-impedance is used to select NMOS as the switching element,and Feedback Loop is employed to control the turn-on and turn-off of drive circuit.Then,based on the basic design scheme of low-power drive circuit,this paper analyzes and tests three different types of control circuits.The first type is based on the PMOS FET control circuit design scheme.At 1.5kHz,the time to turn off the drive current takes up about 35% of the entire turn-on time;the second type is based on a plurality of MOS FET control circuit design scheme.At 1.5kHz,the time to turn off the drive current occupies about 75% of the entire turn-on time;the third type is based on the operational amplifier control circuit design scheme.At 1.5 kHz,the time to turn off the drive current takes up approximately 65% of the entire turn-on time.These three circuit design schemes can reduce the power consumption during the turn-on of the driver circuit to varying degrees.The topology of control circuit based on operational amplifier is the most simplest and theoretically reliable one,and the time required for providing the drive current from 0 to 200 mA is about 20 ns.Therefore,in this paper,the topology of the circuit structure verifies that SiC GTO can be turned on and turned off quickly and the power consumption of the drive circuit can be reduced.