Two-Degrees-of-Freedom (2DOF) Magnetic Spring-Based Electromagnetic Energy Harvester

This paper aims to study a two-degree-of-freedom (2DOF) magnetic spring-based electromagnetic generator system theoretically and experimentally. The proposed linear generator system contains a nonlinear nonmagnetic shaft (nonmagnetic materials), two floating magnets, and two fixed magnets. All magnets are placed in the system in a repulsive configuration. First, the magnetic properties of the proposed system are studied to provide insight into its role in the system’s nonlinear oscillatory behavior. The magnetic restoring forces are analyzed, and both linear and nonlinear coefficients of the oscillator system are analyzed based on these forces. The mathematical model of the proposed system is presented to study the dynamic behaviors of the oscillator system. The magnetic restoring forces and dynamic behaviors for different oscillator heights are also studied. Finally, the proposed system’s energy generation capacity is examined using electromechanical coupling.