Study On Performance Of New Generation Multi-cantilever Piezoelectric Power Generator

Vibration-based energy harvesting has received a great attention in the past decade. Research motivation in this field is due to the reduced power requirement of small electronic components, such as the wireless sensors used in structural health monitoring applications. The vibration energy in the environment is everywhere, the ultimate goal is to power such small electronic devices collecting the losses of the vibration energy in the environment and using the vibration energy available in their ambient so the requirement of an external power source or periodic battery replacement can be removed or at least minimized. This promising way of powering small electronic components and remote sensors has attracted researchers from different disciplines of engineering, including mechanical, electrical, and civil as well as researchers from the field of material science.The vibration energy of piezoelectric cantilever beam can be converted to electrical energy by piezoelectric effect. The piezoelectric cantilever beam is a simple structure and convenient processing without poisonous to the environment, and has less constraint. This is a new type of energy conservation and environmental protection structure. This paper puts forward a new type of piezoelectric generator with multilayer cantilever beams, which can improve the power of piezoelectric generator and solve the multi-layer connection and layers vibration problem of inconsistent. The generator is mainly constituted by butterfly multilayer cantilever beams and mass subassembly two parts.The generating performance of piezoelectric bimorph beam included in the generator is primarily studied in this paper, then, theoretical analysis for this structure is carried on according to the theory of mechanics, including its energy conversion process, resonance frequency solution and output.The output voltage model with load on free end, together with the piezoelectric equivalent circuit model with different outside incentive for predicting the generating power are put forward respectively to analyze its output and power.The finite element model with three-layer cantilever beams is established based on ANSYS12.0with static analysis and modal analysis. The results of the simulation show that, the piezoelectric cantilever beams included have a consistent stress and vibration rule and conformed to structure characteristics of the typical cantilever beam. On the basis of this, electromechanical coupling model is established to analyze the nephogram and fluctuation curve of voltage with outside incentive load on the fixed end (base) of each layer of cantilever beam.Physical device with three-layer beams is produced and the experimental setup is also put up to test the stress, natural frequency and output voltage, and to analyse the model and dynamic power generation. It can be found that each layer of multilayer generator has a similar output voltage and resonant frequency to each other and the typical one with same geometric and material parameters.Finally, the piezoelectric generator for modal and the voltage of the generator in vibration mode is measured, to analyse its resonance frequency and measure its power generation voltage. The comparative data will be provided to validation the theoretical model and the finite element model, which verifies the correctness of them.