Dr. Benjamin Ducharne


Benjamin Ducharne received his MSc and PhD degrees in electrical engineering from Claude Bernard University Lyon 1, Villeurbanne, France, in 2001 and 2003, respectively. In 2004, he joined the Montefiore Institute in Liège, Belgium, as a postdoctoral researcher. In 2005, he was appointed as an Associate Professor at INSA Lyon, France. From 2018 to 2019, he was a Visiting Scholar and mid-term Lecturer at Purdue University, West Lafayette, IN, USA. Since 2020, he has been a full-time researcher at ELyTMaX, Tohoku University, Sendai, Japan. His research focuses on magnetic non-destructive testing, ferromagnetic and ferroelectric materials, hysteresis modeling, fractional operators, and multiphysics coupling.


Presentation: Viscoelastic modeling of magnetic losses using fractional derivative operators

Modern ferromagnetic materials (GO electrical steel, nanocrystalline, amorphous, etc.) have emerged as advanced solutions for improving magnetic performance, offering reduced core losses and high permeability. However, despite their superior properties, magnetic losses remain critical, particularly under high-frequency conditions. Existing simulation methods, including empirical models, time-dependent hysteresis models, and space-discretized approaches, often fail to accurately capture their complex viscoelastic magnetic properties over wide frequency ranges and amplitudes. This study evaluates the use of fractional derivative operators as innovative tools to predict magnetic losses in ferromagnetic cores. Four simulation approaches are analyzed: an analytical expression of the magnetic losses, two time-dependent hysteresis models (using first-order and fractional-order differential equations), and a space-discretized method coupling Maxwell’s equations with a fractional-order material law. The analytical method provides simplicity and reliable results for total losses but cannot capture temporal or spatial distributions. The lumped hysteresis models, particularly the fractional-order variant, offer improved accuracy by accounting for dynamic effects and frequency dependencies. The space-discretized method is the most robust, achieving the highest precision and providing detailed insights into the local distribution and contributions of magnetic losses.