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Why S-Parameters are superior for power module optimization

Reading time: 7 minutes
A power module is a high-power switching circuit – used in electric vehicles, renewable energy, photovoltaics, wind, and many more applications – that uses insulated gate bipolar transistors (IGBT) or metal-oxide-semiconductor field-effect transistors as switching elements. This paper discusses the difference in power module simulation using lumped elements and S-Parameters. Using a simple example, it is shown that S-Parameters are the better choice to predict the electrical behavior of a power module. Finally, the paper outlines a verification method suitable for automatic optimization.

Learn more about power module optimization in the following chapters

  • Introduction: Power modules are high-power switching circuits used in electric vehicles, renewable energy, photovoltaics, wind, and many more applications. Compared to a single device in a package, a power module packages more than one IGBT, MOSFET and diode together.

  • Foundation for S-Parameter usage for power modules: Without the work described in this paper, the transformed S-Parameter cannot be simulated in a circuit simulator. The reason for this is that due to the standardization for high-speed applications, all reference pins are not exported, and the pin is assumed to be connected to the reference.

  • Solution to missing reference pins: The solution is demonstrated for the positive supply voltage called net VPP. For the simulation of the S-Parameter and the later used RLCG matrix, HyperLynx Advanced Solvers, such as Fast 3D and the Hybrid solver, are used

  • Full automatic SPICE wrapper transformation: For a direct integration into the Siemens power modules design suite, Xpedition VB.Net is recommended

  • Function test: The function test is done with the whole power module. For this reason, a complete SPICE simulation in Xpedition AMS was configured.

  • S-Parameter compliance check and optimization: It is recommended to use an S-Parameter compliance check before going into the functional simulation.

  • Conclusion: The work described in this paper enables us to provide design methods and a solution to withstand the high demand for new efficient power modules in the future.

  • References

Learn more about the full power module flow from Siemens on our power electronics page.