Electric Field Analysis And Insulation Design Of Press Pack IGBT

Press Pack IGBT module has the characteristics of large flow capacity,zero welding point,zero lead wire,low thermal resistance,short circuit and so on.It is one of the key components of the converter valve.In many fields such as converter station,electric locomotive,it has a very important role.Press Pack IGBT module and conventional welding IGBT module in the package structure are quite different,the existing pressure-connected IGBT products have two technical solutions of crimp or flexible crimping,the packaging technology of Press Pack IGBT is also completely different from the conventional welded IGBT module.In the Press Pack IGBT's overall preparation process,the sub-module of the pressure test is a crucial step,which related to the assembly of Press Pack IGBT being put into normal operation.However,in the pressure-type IGBT sub-module for pressure test,IGBT sub-module can not reach the rated level of the chip,there has been a concentrated and discharge electric field phenomenon.When the chip is tested individually,the chip can meet the voltage requirement.Therefore,a possibility that the sub-module frame structure causes the electric field concentration problem was considered.The defects of the frame structure will lead to the failure of the crimp type IGBT.In this paper,by analyzing the advantages and disadvantages of sub-module structure of Press Pack IGBT product,the emulation model of sub-module is established by simulation software COMSOL Multiphysics,the electric field simulation is carried out,and the possible problems of existing IGBT sub-modules are summarized.Then,the structure of the submodule is improved,and the validity of the structure is verified by simulation.At the same time,insulation material category and performance of the shell of Press Pack IGBT and the submodule frame insulation are studied at the same time.A structural design of improved scheme was obtained.