Design, analysis and experimental evaluation of a vibration energy generator

Abstract

Generating energy from ambient vibration is a method of harvesting green energy. Harvesting energy in this manner is similar to that of solar and wind energy harvesting. The vibration energy generator discussed in this dissertation illustrates a thorough example of a method to harvest green energy and the required components for the design of a vibration energy generator. Through the investigation of the design, and further analysis and experimental evaluation, the technical behaviour of an electromagnetic vibration energy generator is predicted and determined. The design of a vibration energy harvester is considered in literature - more specifically, the design of an electromagnetic vibration generator. Multitudes of concepts have been published and compared in studies. For the mechanical system in this study, the design of the vibration energy generator is obtained through the use of a subwoofer (loudspeaker). The mechanical system is studied to determine the typical mechanical properties under varying electrical load. The parameters, for this study, were determined by different methods with aid of mathematical models for characterization and verification. The electrical components were simply measured and implemented into mathematical models. The electrical properties together with the mechanical properties are incorporated for analysis of the generator in context of the mechanical and electrical response. The generator design is analysed in the form of mathematical models. Two mathematical models predict the usable electrical power to be harvested at specific load conditions. The usable electrical power is determined from both a mechanical and an electrical perspective. To evaluate the mathematical models, measurements were made to record the usable electrical power from the systems. The measured values under varying electrical loads are compared to the predicted values from the mechanical and electrical models respectively. To arrive at a design for a vibration energy generator it is essential to address certain design considerations proactively for each specific application, as harmonic tuning and optimal electrical load choice have intricate effects on both the mechanical and electrical systems for performance of the system to produce usable power. Furthermore, it is shown that a loudspeaker can be used as a vibration energy generator. However, changes will be required for use as a vibration energy generator.