3D Mixed-Mode Simulation of Current Filaments in Multicell IGBT

powerex21.in : 3D Mixed-Mode Simulation of Current Filaments in Multicell IGBT

Requires: VictoryProcess3D / VictoryDevice3D
Minimum Versions: Victory Process 7.30.4.R, Victory Mesh 1.4.6.R, Victory Device 1.14.1.R

When an IGBT is turned on in the presence of a short-circuit in an output circuit for a period of time, it can dissipate power in the form of heat to such an extent that current filaments evolve in a localized area within the IGBT device. The heating effects of current filaments are destructive and thus should not be allowed to arise during a short-circuit operation of an IGBT.

In this example, the 3D mixed-mode short-circuit simulation is performed on an IGBT composed of 8 cells to demonstrate the occurrence of current filaments in multicell IGBT.

The 8-cell IGBT structure is constructed in cell mode of Victory Process by joining 8 duplicates of the IGBT single cell together using the parameter mirror on the export statement. Each IGBT single cell has a width of 1um and features a 1.3 kV trench-gate design with a field-stop layer (n-buffer).

Short-circuit testing is conducted with a test circuit consisting of a vc 600V DC power supply in series with a 10-mohm resistor rs and a 10-nH inductor ls . A vg gate pulse generator in series with a 10-ohm resistor rg generates a 15V pulse in 10 ns with a pulse length of 10 us.

It is assumed that the bottom collector electrode of the IGBT is maintained at an ambient temperature of 300 K via a thermal contact with a thermal resistance of 0.3 cm2.K/W ( thermcontact name=collector ext.temp=300 alpha=1/0.3 ).

As the mixed-mode simulation starts from an initial DC voltage supply of 600V, a Victory Device solution powerex21_1.str for the IGBT device adevice at a collector-to-emitter voltage of 600V is first obtained from the stand-alone Victory Device simulation and then loaded into the mixed-mode part of the input deck with .options loadsolutions for use as an initial guess.

Victory Device utilizes a set of physical models for the non-isothermal ( lat.temp self-heating) simulation including klassen low-field doping-dependent mobility , fldmob lateral electric field-dependent mobility, srh Shockley-Read-Hall recombination, hnsaug temperature and concentration dependence Auger recombination, and selb impact ionization. The pas MPI-based parallel direct solver specified in the Victory Device part of the mixed-mode input deck ( method device=adevice pas ) proves to greatly enhance Victor Device performance in terms of speed and robustness.

The simulation results give the short-circuit waveforms up to destruction of the IGBT at time t=5.24 us as evidenced by a sharp rising of temperature in conjunction with the establishment of current filaments. A 3D electron current density distribution at that device destruction time is captured and saved for visualization in TonyPlot with .save tsave="5.24us".

To load and run this example, select the Load button in DeckBuild > Examples. This will copy the input file and any support files to your current working directory. Select the Run button in DeckBuild to execute the example.