| Medium voltage high power conversion equipment directly determines the operation performance of the whole DC distribution system.And power devices,as the core components of power conversion,are developing towards the direction of high voltage,high current and low loss.With the rapid development of wide band gap device technology,it has become a hot spot in academia and industry to carry out the research of medium voltage high power converter technology based on silicon carbide power devices.Therefore,this paper studies the crosstalk phenomenon of SiC MOSFET and the specific application of low voltage SiC MOSFET series technology.SiC MOSFET has superior high-speed switching characteristics.However,stray parameters are introduced into device packaging and design,which results in gate crosstalk voltage in the switching process.At the same time,commercial low-voltage SiC MOSFET faces the limitation of insufficient breakdown voltage in the medium voltage field.In order to solve the above problems,this paper includes the following three aspects.Firstly,by studying the source of crosstalk voltage in half bridge topology,a mathematical model of crosstalk voltage considering the common source inductance is proposed.The rationality and accuracy of the model have been verified by simulation and experiment,so it can guide the design of device driving parameters according to the mathematical model.Secondly,in order to realize the loss evaluation of the converter,a set of loss evaluation tool chain is proposed,which is from the bottom up,from the single tube to the module,then to the system.The tool chain has a wide range of applications and is easy to migrate.There are three levels in the tool chain: the first level is the full-automatic double pulse test platform based on LabVIEW,the second level is the double pulse characteristic parameter extraction tool based on MATLAB,and the third level is the loss evaluation tool based on MathCAD.In the process of engineering application,the tool chain can provide great convenience for the project.Finally,the 10 kV / 200 A half bridge module based on low-voltage SiC MOSFET series and 10 kV / 450 A half bridge module based on low-voltage IGBT series are built.Through the double pulse test,the dynamic parameters and loss characteristics of the two modules are compared.Then two modules are applied to the medium voltage rectifier,and the loss evaluation tool is used to complete the system loss evaluation.Through comparative analysis,the application potential of low voltage SiC MOSFET series technology is verified. |
