High Power Density SiC Driver Technology Based On GaN Devices

With the widespread application of silicon carbide devices(Si C),the high-frequency and high-voltage working environment and the high power density requirements of power electronic converters,new challenges have been brought to the drive design of Si C devices,which are mainly reflected in: high power density and Miniaturization,higher isolation performance,and fast and accurate protection capabilities.Although resonant drive is an effective way to reduce drive loss at high switching frequencies,it has problems with complex structure and control,and numerous devices.There is still room for improvement in drive efficiency;although desaturation protection circuit(DESAT)is the most Universal power device short-circuit protection circuits,however,there is still a lack of research on DESAT circuit design guidelines and high-speed DESAT short-circuit protection circuits that specifically target the short-circuit characteristics of Si C devices,that is,short short-circuit withstand time,fast current rise speed,and high-speed DESAT short-circuit protection circuits.In response to the above problems,in order to achieve a high power density Si C drive module,this article starts from three aspects: reducing drive loss,realizing fast protection,and increasing the power density of the drive stage,and researches on silicon carbide drive technology based on low-voltage gallium nitride(Ga N)devices.First of all,this paper proposes a new type of Ga N-based hybrid resonant gate driver,which organically combines resonant turn-on and active clamp turn-off,which not only greatly reduces the reverse recovery loss in the resonant drive energy feedback,but also effectively avoids it.Crosstalk issues in high-speed Si C half-bridge devices.Compared with the Si MOSFET-based full-bridge resonant drive,this topology has the advantages of simple control,fast drive speed,low reverse recovery loss and small size,achieving a 29% reduction in loop area and reduced gate driver loss 49.3%.Secondly,in order to ensure that Si C can be turned off safely and reliably in the event of a short-circuit fault,this paper analyzes the basic laws of its short-circuit characteristics,focusing on the short-circuit withstand time of Si C and the insignificant inflection point of the drain-source voltage of the device under short-circuit conditions.,Launched the research on the key parameters of DESAT circuit,and formulated the reference standard for its engineering design.On this basis,this paper further proposes a Ga N-based high-speed,low-transmission delay DESAT short-circuit protection circuit.In the simulation,the driving action delay of the short-circuit protection circuit is only 23.2% of the conventional silicon-based DESAT circuit.The Ga N-based DESAT short-circuit protection circuit cooperates with the proposed new Ga N-based hybrid resonant gate driver to form a high-power-density Si C drive module.