Energy Harvesting From Train-reduced Vibration With Considering The Inertia Effect

ABSTRACT:Ambient energy harvesting technology gets high attention around the world in recent years, especially energy harvesting from train-reduced vibration which has become a new research direction. With the development of domestic economy, railway construction is very quickly and a lot of ambient energy is in railway system. In fact, the deformation and vibration of railway track caused by moving train can generate much mechanical deformation energy and vibration energy. By using energy harvesting technology, the mechanical deformation energy and vibration energy can be converted into electrical energy which can be provided for the detecting and monitoring system and all kinds of equipment along the railway.Based on the background, energy harvesting from the deformation and vibration of railway track is studied in this work. A kind of piezoelectric energy harvester which can convert mechanical energy into electrical energy is provided based on the piezoelectric effect theory. This work focuses on building analytical model and analyzing factors which affect the output characteristics of energy harvester. There are five chapters in this work and the main works are as follows:In chapter one, the background and significance of the research and related research at home and abroad are introduced. In chapter two, the theory and method related into energy harvesting from train-reduced vibration are introduced. In chapter three, analytical model is built and the track structure and train vehicle load are respectively simplified to elastic point support multi-span Timoshenko beam model and moving mass. The transfer matrix method, modal superposition method and Newmark method are used to study the dynamic behavior of beam with considering the inertia effect. Also the influence of moving mass, velocity and inertia force on dynamic behavior is studied. In chapter four, the dynamic behavior of beam is as the input of energy harvester and the energy storage system is simplified to a resistance, then theoretical solution can be obtained. Based on the solution, influence of parameters of train, such as moving mass, velocity and inertia force are studied in detail. In chapter five, energy storage process with the most commonly used energy harvesting circuit is studied. Obtaining analytical solution is difficult because of the high nonlinearity of circuit. Therefore the Simulink simulation is used to simulate the whole process of energy harvesting from train-reduced vibration and charging the battery. Also the influence of moving mass, velocity, inertia force, energy harvesting circuit and energy storage element on the charging efficiency is studied in detail.The study in this work can provide reference for the research on experimental research in the future and design of piezoelectric energy harvester applicable to track structure.