2026-08-25 Latest Published
By Merwan Hebbache
Naamane Mohdeb
Hocine Bouchekhou
Nabil Ikhlef
Hicham Allag
Abdelghani Kimouche
Progress In Electromagnetics Research C, Vol. 173, 1-8, 2026
Abstract
Electromagnetic harvesters based on magnetic levitation have emerged as particularly attractive systems owing to their contactless suspension, low mechanical damping, and inherently nonlinear stiffness behavior, which are suited to low-frequency ambient excitation. The investigated harvester consists of a levitating magnet suspended between two fixed outer magnets via repulsive magnetic forces, with a pickup coil converting oscillatory motion into electrical energy under base excitation. The primary source of difficulty in this system is the nonlinear magnetic restoring force Fmag and the electromechanical transduction coefficient γ, which must be pre-characterized via semi-analytical or finite element methods before any solution can be attempted. Therefore, the accurate pre-characterization of both Fmag and γ is the essential foundation of the entire modelling process. A Fourier space semi-analytical approach is proposed and developed, transforming a three-dimensional magnetostatic problem into a computationally efficient one-dimensional spectral calculation without remeshing. The semi-analytical predictions were validated against COMSOL finite element simulations, and their strong mutual agreement confirmed the accuracy of the proposed method before embedding it into the motion's coupled nonlinear equations.
