Research On Crosstalk Suppression Drive Of SiC MOSFET And Its Application

The development of power electronics technology gives higher expectations for the miniaturization,lightweight and high efficiency of the converter.High switching frequency and high voltage level are the inevitable trend of the development of power electronic devices.And SiC MOSFET is a typical representative of the third generation wide bandgap semiconductor,its excellent device characteristics bring hope and a fast channel to the development of power converter.In order to adapt to the application of SiC MOSFET converter,the design of drive circuit is the particularly key,and the solution of crosstalk problem is even more urgent.Based on this,the thesis studies the crosstalk suppression drive circuit of SiC MOSFET.The specific research contents are as follows:Firstly,the thesis introduces device characteristics of SiC MOSFET,including its physical structure,static and dynamic characteristics.The characteristics are analyzed combined with its on-off process model,and the mathematical models of equivalent circuits in different stages are established.Considering the influence of parasitic parameters in the switching process,it is extracted and analyzed by simulation software.The principle of bridge arm crosstalk is analyzed,the behavior model is established,and the influencing factors of bridge arm crosstalk voltage are obtained through mathematical derivation.The simulation study of these influencing factors provides a theoretical basis for the design of driving circuit and the selection of device parameters.The design methods of various crosstalk suppression drive circuits are introduced.The model analysis and summary of advantages and disadvantages of traditional,capacitive and push-pull drive circuits are givenThe thesis proposes a new crosstalk suppression drive circuit and analyzes its working principle,then simulates and compares the above four driving circuits.It shows that the new drive circuit has better performance in crosstalk suppression ability,switching speed and switching loss.At the same time,the hardware circuit is designed,including power module,isolation mode,short-circuit protection circuit,Miller clamp,etc.The device parameters are obtained by double pulse test experiment,and the crosstalk suppression ability of the new drive circuit is verified.Combined with bidirectional DC-DC converter,a converter application platform using SiC MOSFET novel crosstalk suppression drive circuit is built,and the effectiveness of the novel drive circuit is verified by experiments.There are 90 fugures,5 tables and 82 references in this dissertation.