PyScaleXFMR - Optimization and Scaling of Medium-Frequency Transformers

Introduction

This repository contains the source code related to the following paper:

• Efficiency / Power Density Analysis of Single-Phase and Three-Phase Transformers Employed in DAB and SRC DC/DC Converters
• Thomas Guillod, Daifei Zhang, Charles R. Sullivan, and Johann W. Kolar
• IEEE ICRERA 2025
• DOI (IEEE copyright)
• Paper (IEEE copyright)

This code implements simple medium-frequency transformer models:

• Shell-type and core-type transformers.
• Single-phase and three-phase transformers.
• Delta and wye / star connected transformers.
• Including the high-frequency core and winding losses.
• Including the impact of non-sinusoidal waveforms.

This code implements several optimization methods:

• Analytical optima for the number of turns and the operating frequency.
• Numerical optima with a differential evolution solver.

This code implements several scaling laws:

• Frequency sensitivity of transformers
• Winding material scaling laws
• Power / volume scaling laws
• DAB / SRC converter comparison.
• Single-phase / three-phase comparison.

Gallery

Repository Description

• Main Files
  • paper.pdf - PDF of the paper (IEEE copyright)
  • requirements.txt - List of the used Python packages.
  • param.py - Contains the transformer and converter parameters.
• Transformer Optimization
  • run_design_single.py - Compute a single transformer design.
  • run_design_analytical.py - Compare transformers using analytical optima.
  • run_design_numerical.py - Compare transformers using numerical optima.
• Scaling Laws
  • run_scaling_freq_sensitivity.py - Transformer frequency sensitivity.
  • run_scaling_power_volume.py - Power rating / power density scaling laws.
  • run_scaling_winding_type.py - Winding material and interleaving scaling laws.
  • run_scaling_transformer_type.py - Transformer type / converter type scaling laws.
• Transformer Utils
  • run_utils_steinmetz.py - Extract the Steinmetz parameters.
  • run_utils_waveform.py - Extract the converter waveforms.
  • run_utils_shape.py - Extract the optimal geometrical aspect ratios.
• Python Packages
  • transformer_scaling - Python package with the transformer models.
  • transformer_utils - Python package with various design tools.
  • transformer_data - JSON files with the generated parameters.
  • transformer_img - PNG and SVG files for the documentation.

Compatibility

• Tested on Linux x86/64.
• Tested with Python 3.12.3.
• Package list in requirements.txt.

Author

• Name: Thomas Guillod
• Affiliation: Dartmouth College
• Email: guillod@otvam.ch
• Website: https://otvam.ch

Credits

PyScaleXFMR was created at Dartmouth College by the research group of Prof. Sullivan:

• Dartmouth College, NH, USA: https://dartmouth.edu
• Dartmouth Engineering: https://engineering.dartmouth.edu

Copyright

(c) 2025 / Thomas Guillod / Dartmouth College

This Source Code Form is subject to the terms of the Mozilla Public License, v. 2.0. If a copy of the MPL was not distributed with this file, You can obtain one at http://mozilla.org/MPL/2.0/.