Design of an efficient energy harvester from ambient vibration

Abstract

The aim of this thesis is to design and construct 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 will design a vibrational 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 will create 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 will design the electro-mechanical energy harvesting system for optimum performance for a range of vibration energy and frequency and study the impact of difference device parameters, such as, size of the mass, stiffness of the spring, number of turns and dia of the coil. A charge controller circuit to store the generated electrical energy will also be designed.