Modelling and switching simulation of gate turn-off thyristor using finite element method

摘要

The gate turn-off (GTO) thyristor has the best voltage blocking and current conductingudcapabilities among all known high power semiconductor switching devices. Theudswitching characteristics of a GTO thyristor are influenced by doping profile, materialudproperties, lifetime and mobility of holes and electrons. Recently, most of the researchudon GTO thyristor is strictly experimental and has focused on their physicaludperformances. On the other hand, the internal behaviour of GTO thyristor is not welludunderstood. The best accuracy switching waveforms and the internal behaviour of theuddevice can only be addressed by device simulation. Physical models (Poisson equation,uddrift-diffusion and current-continuity equations) of GTO thyristor are valuable forudstudying the internal behaviour of the device is used in the simulation. These equationsudare numerically solved by using finite element method. This project presents: theudmodelling and switching simulation of GTO thyristor device by developing a deviceudsimulation software. The software is designed by using MATLAB Graphical UserudInterface (GUI) development environment. The device model has been developed basedudon the device structure and operation. The thesis focuses on the study of a comparisonudbetween silicon and silicon carbide GTO thyristor in terms of switching timeudperformances and efficiency at the system level.