| Pulsed power technology can achieve high power pulse output in a very short time,and is now widely used in defense and industrial fields such as radar,nuclear energy,and flue gas purification.As the hub of energy conversion in pulsed power systems,the performance of pulsed power switch is closely related to system output quality and robustness.Insulated Gate Trigger Thyristor（IGTT）have the advantages of easy drive,high withstand voltage and high di/dt,and are promising switching devices in the field of pulse power technology.However,in practical applications,IGTT is often affected by high dV/dt,resulting in false triggering of the device.In thesis,a physical model of dV/dt resistance of IGTT devices is established,and the influencing factors of dV/dt resistance of IGTT devices are explored by simulation,and then the dV/dt resistance model of IGTT devices is verified through actual tests,which provides technical support for the subsequent improvement of dV/dt resistance of IGTT devices and the robustness of pulse power systems based on IGTT devices.The main contents of this thesis are summarized below:1.The resistance model of IGTT device dV/dt was established.According to the difference of parasitic capacitance of displacement current when dV/dt changes,the physical models of dV/dt resistance under three conditions:internal dV/dt false trigger,external dV/dt false trigger,and subthreshold current false trigger of IGTT devices are established.2.The influence of different parameters on the dV/dt resistance of the device was explored.According to the modeling results,the influencing factors of dV/dt resistance of the device were analyzed,and the specific analysis was carried out in combination with simulation.Firstly,the effects of key parameters such as doping concentration in P-well region,resistance RGC between gate and cathode,cell thickness and cell width on dV/dt resistance were studied.Secondly,the relationship between dV/dt resistance and initial voltage is explored through theoretical analysis and simulation,and with the increase of the initial voltage before dV/dt,the dV/dt resistance of IGTT devices first increases and then decreases,and it is found that as the depletion region is widened,the current formed by hole injection will superimpose the displacement current on the dV/dt resistance of the device.Finally,the relationship between the reverse conductive structure and the dV/dt resistance of the device is analyzed,and when the initial voltage is 0 V,the reverse conduction structure will not affect the dV/dt resistance of the device.At an initial voltage of 1000V,the reverse conductive structure enhances the dV/dt resistance of the device.3.The physical model of dV/dt resistance of the device was verified through actual testing.A device dV/dt resistance test platform was built,and the dV/dt resistance of RGCdevices with different P-well region doping concentrations,cell thickness,cell width and gate and cathode resistance were quantitatively tested,and the actual test results were consistent with the model analysis results.In addition,the dV/dt resistance of IGTT devices with reverse conductive structure was tested,and the actual test results were slightly differed from the qualitative analysis. |
