Design of an efficient energy harvester from ambient vibration

Abstract

The aim of this thesis was to design and an efficient energy harvester from ambient vibrations. An energy harvester is merely a device that will convert ambient energy into some usable electrical energy. In this work we designed a vibration energy harvester using electromagnetic transduction mechanism. The system consists of a fixed (movable) magnet and a movable (fixed) coil attached to a spring. When under vibration, relative motion between the fixed magnet and a moving coil or between the moving magnet and a fixed coil created a time varying flux linkage to the coil, thus inducing an electro-magnetic force. The electrical energy thus extracted from these vibrations need to be stored, using a battery charger circuit, and later on this may be used to drive electronic gadgets, self-powered micro-systems and wireless sensor network. In this work we designed the electro-mechanical energy harvesting system for optimum performance for a range of vibration energy and frequency, starting from 300-350Hz and studied the impact of difference device parameters, such as, size of the mass (510mg), stiffness of the spring, number of turns and dia of the coil. A charge controller circuit to store the generated electrical energy can be designed for implementation.