In this tutorial, you have learned how to design an inductor and a transformer using SIMPLIS MDM, simulate the resulting model created based on your design, and perform post-processing in MDM to obtain detailed winding and core loss results. You have also begun to learn how to analyze those results to improve your design for the application at hand.

Summary of Key Concepts

Following are the key concepts presented in the tutorial.

The SIMPLIS Magnetics Design Module

  • SIMPLIS MDM is an add-on to SIMPLIS which allows you to create physical models of inductors and transformers.
  • You build a physical model of an inductor or a transformer from standard parts: cores, bobbins, and wires. You can use the parts already present in MDM's database - MagDB - or define your own based on the available core and wire shapes.
  • Electrical models for use in your schematics are extracted from the physical model you created in MDM.
  • You can save different designs you create inside MDM to .gmd files, allowing you to re-use them in different schematics, or to load several different designs into the same schematic.
  • While the electrical models extracted from the MDM physical model contain some resistive loss, just placing a power probe on them does not provide all of the losses that actually occur inside the inductor or transformer. To obtain those, you must perform MDM post-processing.
  • To obtain valid MDM post-processing results, you must properly identify the fundamental frequency and shape of the inductor or transformer waveforms.
  • MDM post-processing results will then give a you break down of the total losses into core and different types of winding losses, the winding losses by turn of each winding, detailed waveforms (including flux density) of the inductor and transformer, the inductor or transformer boxed volume, the core and winding temperature, and inductance or magnetizing inductance as a function of current.
  • These detailed post-processing results can give you significant insight into how to improve the design: either to reduce its size, or the losses, or both; how to avoid saturation, reduce the temperature rise, and so on.

Inductor Model

  • MDM introduces a new Level 2 model for the Multi-Level Lossy PWL Inductor.
  • The Level 2 model is electrically identical to the Level 1 model, but is extracted from the physical MDM model rather than entered by the user.
  • The Level 0 and 1 models can be extracted from the Level 2 model created by MDM.

Transformer Model

  • A new symbol, the Multi-Level Lossy Transformer, has been introduced along with MDM.
  • Levels 0-2 of the Multi-Level Lossy Transformer do not require MDM and can be entered by the user.
  • Level 3 of the Multi-Level Lossy Transformer is a reluctance circuit generated from the MDM physical model. It requires MDM to generate, and must be used for MDM post-processing.
  • Levels 0-2 can be extracted from the Level 3 model created by MDM.
  • There can be significant differences in how you transformer behaves in a circuit depending on the model level you select.

Electrical and Magnetic Co-Simulation and Co-Design

What you have done while going through this tutorial is to perform an electrical and magnetic co-simulation: the schematic was electrically simulated in SIMPLIS, and the inductor or transformer was magnetically simulated in MDM.

While this tutorial has focused only on building the physical models inside MDM and you did not modify the schematics themselves, it is clear this type of co-simulation opens the ability to perform electrical and magnetic co-design of a converter. The electrical requirements of a converter determine the magnetic components needed, and the magnetic components determine a large part of the circuit's electrical behaviour. Using SIMPLIS MDM, you can simultaneously design your circuit and your magnetics, optimizing both along the way.

Final Remarks

Thank you for going through this tutorial. This tutorial currently comprises all of the extant SIMPLIS MDM documentation. In the near future, sections of this tutorial will be expanded and combined with additional information to provide more comprehensive MDM documentation. If you encounter any difficulties while using MDM, or have any questions regarding it, please contact