Research On Current Balance Of Internal Paralleled Chips Of The Large Power Press Pack IGBT

In the development of smart grid,security is an important prerequisite for the operation of the power grid.However,the source of electricity is relatively complex,including not only conventional hydropower and thermal power,but also other large scale new energy connecting to the power grid.The diversification of the source of power has brought serious challenges to the security and smooth operation of the power grid.In order to convert these complex sources and uniform “original power” to uniform,smooth and safe “precision power”,the IGBT semiconductor device is needed to play a regulatory role.The greater the power,the wider of the ability to withstand the range of voltage,the stronger to regulate.So the safety performance of power grid will be higher.Under this background,research on the great power press pack IGBT has become an urgent task for the development of power grid.In order to guarantee the reliability of the large power press pack IGBT,the current balance of its internal chip must be taken into account.Due to the reverse recovery characteristics of the diode,current overshoot is easy to happen during the process to open the great power press pack IGBT.If the internal chip current is also not balance,the chip will be burned due to the large current,thus affecting the reliability of the device and the system.Therefore,this paper make a series of research on the current balance of the internal chips of the great power press pack IGBT:1.Analyzing the structure,working principle and basic characteristics of the press pack IGBT.2.Classifying the factors which affect the internal flow of the device into two types,and analyzing the influence of various parameters on the current distribution through theoretical analysis and simulation.Finally,the range of parameters are given when the unbalance degree of the chip current is limited to 10%.3.Proposing four kinds of chip current balance schemes,which are the reduction method,the grid resistance compensation method,the multiple parameter matching adjustment method and the layout optimization.Finally,taking 3300V/1500 A press pack IGBT device for example,the characteristics of the internal chip current distribution are analyzed in detail,and the corresponding improvement scheme is put forward.