Towards Modelling and Design of Magnetostrictive Electric Generators

Journal article, 2005

During the last decades the interest in research and development of smart actuators, sensors and power generators that used giant magnetostrictive materials is continually growing. Both academia and industry are actively looking for bread utilization of this technology for different applications (active vibration and noise control, structural health monitoring, self-powered electronic equipments and systems, MEMS, robotics, biomedical engineering, etc.). The proposed paper is in the field of applications of novel highly magnetostrictive materials for power harvesting, namely vibration-to-electric energy conversion. The term “power harvesting” is used for process of acquiring the energy surrounding a system and converting it into usable electrical energy. The problem of modelling and design of magnetostrictive electric generators (MEG) are considered. The fundamental basic for design of MEG is a Villari effect. That is, by applying a mechanical stress to a magnetostrictive material, the magnetization along the direction of the applied stress of the material varies due to the magnetostrictive effect. The flux variation obtained in the material induces an emf in a coil surrounding the material. The brief review on research and development of power generators using smart materials is given. Original MEG and the respective test rig which were built for study fundamentals of transduction processes of mechanical energy of vibrating structures into electrical energy are presented. Terfenol – D rod with 50 mm in length and 15 mm in diameter is used as an active material in MEG design. Test rig’s measurement data have confirmed the expected performance of the MEG. These data are used for validation of the mathematical model of MEG that was developed and implemented in Matlab/Simulink environment.