In this article, we will review the process of generating S-parameters from a busbar and placing them in a power converter simulation usingHyperSpice in PSIM.
From the extraction of the S parameters, we can obtain a ".s#p" file (where # corresponds to the number of ports) which can be read by the "S-Parameter" block on PSIM, and then resolved with HyperSpice in PSIM.
SimLab | S parameter extraction workflow
SimLab is used for this part of the workflow. The first step is to create a "Parasitic Extraction" solution:
Here, it is important to configure the simulation type on "Extraction of S parameters" and the type of port on "Differential".
The following conditions apply to the definition of frequency:
- The frequency definition can be configured according to your needs. A good rule of thumb for the upper frequency limit is: "A wavelength must be greater than the largest dimension of the geometry." A warning will appear if the selected frequency exceeds this limit.
- This workflow will utilize the model order reduction capabilities of the parasite extraction solver to be able to select a large number of frequency points without impacting the resolution time.
Once the Parasitics Extraction solution is created, the PE Workflow ribbon appears with all the steps and tools required for this workflow. These steps must be followed from left to right, starting with the CAD file import.
The attached Parasolid file ".xmt_txt" is imported with default settings, then a material must be applied:
Next, a quick Tet mesh is created with an element size of 0,5 mm and default parameters (for other CAD models, this may vary):
Next, the ports must be created and assigned. Two ports have been created for this extraction, and the configuration is as follows:
Activate the function "Use the model order reduction" in the solver settings. Ability effects can also be disabled. If they are not used, this will speed up the calculation. Use the default value "Tolerance of the stopping criterion" to obtain better results (1e-07).
The solution can then be resolved and a parameters file ".s#p" will be created. You will find it in the results folder [Right-click on Results > Open Results Folder].
PSIM | Converter simulation with busbar S parameter
About the S Parameter block in PSIM
The ".s#p" file is managed by the "S Parameter" block in PSIM. This block only works with the HyperSpice solver image and is only available in PSIM 2024.
The ports of parameter S are arranged as follows, with the circle indicating the input nodes:
The attached simulation (BoostWSparams.psimsch) is a boost converter with two ideal MOSFET models in parallel. The simulation already includes the S-Parameter block, and the only configuration required is to select the ".s#p" file. (double-click on the S-Parameter block to open the attributes).
Running the simulation at different switching frequencies shows the behavior of the S parameters affecting the current sharing of MOSFETs.
